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SOILS, AGRICULTURE, AND THE FUTURE OF FOOD
SUMBERDAYA LAHAN DAN KEMANUSIAAN Sumber: Diunduh dari: 21/12/2012 LAHAN PERTANIAN Agriculture can be defined as the systematic and controlled use of living organisms and the environment to improve the human condition. 'Agricultural land' is the land base upon which agriculture is practiced. Typically occurring on farms, agricultural activities are undertaken upon agricultural land to produce agricultural products. Although agricultural land is primarily required for the production of food for human and animal consumption, agricultural activities also include the growing of plants for fibre and fuels (including wood), and for other organically derived products (pharmaceuticals, etc).
PRODUKTIVITAS LAHAN Sumber: Diunduh dari: Productivity-Index-LPI ……………….. 25/12/2012 LAND PRODUCTIVITY INDEX ( LPI) LPI is based on general characteristics of the soil profile, texture of the surfacesoil, soil of the land, climate and other physical factors affecting use of land. It is a parametric approach of assessing the potential of land. In this approach a numerical value,which in principal, ranges between 100 ( for non- constraint situation) and 0.0 (for asevere constraint situation)is assigned to each characteristics. The Value given to eachland quality (characteristics) A,B,C,X and Y are multiplied, and the final product isreconverted into land productivity class with fixed index values. Land Productivity Index ( LPI) = A*B*C*X*Y Where factors are decimal equivalent of percentage rating. A = General characteristics of soil profile B = Texture of the surface soil C = Slope of the land X = Miscellaneous factors; reaction of surface soil, fertility, erosion Y = Average annual rainfall
SUSTAINABLE LAND o o EROSI: DICEGAH PEMUPUKAN PENGOLAHAN TANAH: MINIMUM/TANPA SISTEM POLA TANAM: DIVERSIFIKASI, SISA PANEN KEMBALI PEMBAKARAN SISA: DILARANG ORGANIK SINTETIK BERIMBANG
SUMBERDAYA ALAM 1.Pertanian– Food products, Coca, Drugs 2.Minerals – Diamonds, oil, Copper, Sand/Gravels etc. 3.Forests – Timber, Herbs, Animals, Parks etc 4.Water resources – Hydropower, Drinking and irrigation water, Lakes etc. 5.Wisata Alam Sumber: Natural Resources and Human Security. Er. Sunil Kumar Pokhrel Kennesaw State University USA Lahan sawah di musim kemarau ditanami ubijalar dengan hasil sekitar 40 ton umbi per ha. Foto Smno Agst 2012
1.Over the Land 2.Agricultural – main products, cash products, Livestock, Herbs, Timber 3.Under the Land 4.Minerals, oil, Underground water, Stone 5.On the surface 6.Irrigation, Hydropower, River, Sand, river gravel, Snow mountain, National parks and animals Sumber: Natural Resources and Human Security. Er. Sunil Kumar Pokhrel Kennesaw State University USA SUMBERDAYA ALAM Sumber: diunduh dari: ……………… 23/12/2012 Irrigation is the artificial application of water to the land or soil. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall. Additionally, irrigation also has a few other uses in crop production, which include protecting plants against frost, suppressing weed growing in grain fields and helping in preventing soil consolidation. In contrast, agriculture that relies only on direct rainfall is referred to as rain-fed or dryland farming. Irrigation systems are also used for dust suppression, disposal of sewage, and in mining. Irrigation is often studied together with drainage, which is the natural or artificial removal of surface and sub-surface water from a given area.
1.Perubahan Kebijakan 2.Konsep UNDP tentang Human Security 3.Ketahanan Ekonomi - Assured basic income 4.Ketahanan Pangan - Physical and economic access to food as well as adequate purchasing power 5.Ketahanan Kesehatan - Minimum protection from diseases and unhealthy lifestyles. Sumber: diunduh dari: HUMAN SECURITY Sumber: Natural Resources and Human Security. Er. Sunil Kumar Pokhrel Kennesaw State University USA Food security is commonly defined as sustained access for all individuals to an adequate and safe supply of food for an active, healthy and productive life.
1.Ketahanan Lingkungan Hidup - Clean water, Air pollution, Global warming, Greenhouse gases, etc. 2.Ketahanan Personal - Protect from physical violence, Domestic abuse, Crime. 3.Ketahanan Masyarakat - Protect from loss of traditional relationships, ethnic and cultural value. 4.Ketahanan Politik - Human rights, Freedom of speech, etc Sumber: diunduh dari: 23/12/2012http://ag.arizona.edu/~lmilich/envsec.html HUMAN SECURITY Sumber: Natural Resources and Human Security. Er. Sunil Kumar Pokhrel Kennesaw State University USA KETAHANAN LINGKUNGAN HIDUP There are three hierarchical levels at which the food insecurity paradigm can be considered to be acting so as to generate environmental insecurity, which then generates additional food insecurity. At the top is the state; the midlevel is the village or community; and at the bottom are households, the level at which the actors usually have greatest influence on the environment.
Siapa pemilik sumberdaya alam Bagaimana distribusi hasil sumberdaya alam Who is responsible for security of Natural resource centers, Transmission lines and Transportation Need for new security force other than national army to protect? Sumber: diunduh dari: 23/12/2012http://www.ifad.org/newsletter/pf/3.htm MINAT ttg KETAHANAN Sumber: Natural Resources and Human Security. Er. Sunil Kumar Pokhrel Kennesaw State University USA Special feature on land tenure: securing land for the future Land is vital for farmers and the communities in which they live. Not only does it provide them with economic means to create their livelihood, but it is their most important social and cultural asset. A farmer without land has nothing. A farmer with land has a respected place in the community and society at large. However, owning land or having secure access to it are not always readily achieved. This is particularly true in many poor countries, where legal and cultural restrictions on land rights present a strong obstacle for rural people, particularly the poorest and most vulnerable among them. In many cases, women are not even entitled to land.
MINAT ttg KETAHANAN Natural resource potential can be utilized? Need Security (protection) Need Investment Need Market Need technology Need Manpower – Upward Migration Upward Migration creates a new sets of conflict Sumber: diunduh dari: …..23/12/2012 Sumber: Natural Resources and Human Security. Er. Sunil Kumar Pokhrel Kennesaw State University USA The Relationships among Sustainable Development, Sustainable Land Management, Sustainable Agriculture, and Sustainable Soil Management. (Redrawn from Dumanski 1997)
PERTANIAN SAAT INI We have converted 38% of Earth’s surface for agriculture, the practice of cultivating soil, producing crops, and raising livestock for human use and consumption. Croplands (for growing plant crops) and rangelands (for grazing animal livestock) depend on healthy soil. Diunduh dari: …… 20/12/2012 Kelas Kapabilitas Pertanian Class 1 Class 1 land is capable of producing the very widest range of crops. Soil and climate conditions are optimum, resulting in easy management. Class 2 Class 2 land is capable of producing a wide range of crops. Minor restrictions of soil or climate may reduce capability but pose no major difficulties in management. Class 3 Class 3 land is capable of producing a fairly wide range of crops under good management practices. Soil and/or climate limitations are somewhat restrictive. Class 4 Class 4 land is capable of a restricted range of crops. Soil and climate conditions require special management considerations. Class 5 Class 5 land is capable of production of cultivated perennial forage crops and specially adapted crops. Soil and/or climate conditions severely limit capability. Class 6 Class 6 land is important in its natural state as grazing land. These lands cannot be cultivated due to soil and/or climate limitations. Class 7 Class 7 land has no capability for soil bound agriculture.
Croplands Help maintain water flow and soil infiltration Provide partial erosion protection Can build soil organic matter Store atmospheric carbon Provide wildlife habitat for some species Ecological ServicesEconomic Services Food crops Fiber crops Crop genetic resources Jobs KAPITAL ALAM Lahan Pertanian Jasa EKologi Jasa Ekonomi Help maintain water flow and soil infiltration Provide partial erosion protection Can build soil organic matter Store atmospheric carbon Provide wildlife habitat for some species Food crops Fiber crops Crop genetic resources Jobs Diunduh dari: …… 20/12/2012
KUALITAS LAHAN PERTANIAN
LAHAN = SUMBERDAYA EKONOMI Diunduh dari Sumber: production-3941.html /11/2012. Land is the economic resource encompassing natural resources found within a nation economy. This resource includes timber, land, fisheries, farms and other similar natural resources. Land is usually a limited resource for many economies. Although some natural resources, such as timber, food and animals, are renewable, the physical land is usually a fixed resource. Nations must carefully use their land resource by creating a mix of natural and industrial uses. Gross Margin: The simplest economic measure is the gross margin, which is the cash flow out less the cash flow in, on a per unit area (normalized or standardized) or aggregate (per-field or per-farm) basis, in one accounting period (usually a year). The gross margin can be expressed in terms of the return to labor or the return to land. Return to labor: the farm family’s labor is not included as an expense, and the gross margin must be sufficient to allow the farm family an adequate income. This makes most sense if the gross margin is non- normalized, i.e., the actual amount received for the whole farm. Return to land: the farm family’s labor is included in the expenses, as if the labor had been contracted. If the ‘wage’ is at a reasonable level, the gross margin only has to be positive for the land use to be feasible. This makes most sense if the gross margin is normalized, i.e., the amount received per unit land area.
LAHAN ….. Diunduh dari Sumber: 3/11/2012. Land, In economics, the resource that encompasses the natural resources used in production. In classical economics, the three factors of production are land, labour, and capital. Land was considered to be the “original and inexhaustible gift of nature.” In modern economics, it is broadly defined to include all that nature provides, including minerals, forest products, and water and land resources. While many of these are renewable resources, no one considers them “inexhaustible.” The payment to land is called rent. Automated Land Evaluation System ‘ALES’. How ALES links land characteristics with economic values Starting from the physical inventory of the characteristics of a land area, how do we arrive at an economic value of a land use if implemented on that land area? By means of severity levels of Land Qualities, which can either limit yield (and thus reduce income) or increase costs. Land Qualities, and their diagnostic Land Characteristics, can be divided into two type for this analysis: 1.Location-independent (in-situ) and 2.Location dependent. E.g. (1) soil and climate qualities and characteristics, (2) distance, Adjacency.
LAND QUALITY INDICATOR (LQI) Diunduh dari Sumber: colombia/FAO/AGLL/pdfdocs/landqual.pdf /11/2012. Some generic indicators of land units that must be monitored, especially for: 1.Condition of land resources, both positive and negative; 2.Areas arising from different land uses; 3.Rates of adaptation and adoption of recommended/suggested practices; 4.Farm management practices; 5.Yields and other outputs resulting from project interventions or other development; 6.Rural development issues such as land tenure, population density; 7.Sumberdaya air; 8.Perikanan dan akuakultur; 9.Pengelolaan hutan; 10.Ketersediaan hara dalam tanah.
The holistic concept of Land (FAO,1976; FAO, 1995) : Diunduh dari Sumber: colombia/FAO/AGLL/pdfdocs/landqual.pdf /11/2012. "Land is a delineable area of the earth's terrestrial surface, encompassing all attributes of the biosphere immediately above or below this surface, including those of the near-surface climate, the soil and terrain forms, the surface hydrology (including shallow lakes, rivers, marshes and swamps), the near-surface sedimentary layers and associated groundwater reserve, the plant and animal populations, the human settlement pattern and physical results of past and present human activity (terracing, water storage or drainage structures, roads, buildings, etc.).“ FUNGSI LAHAN: 1.Fungsi Produksi 2.Fungsi Lingkungan Biotik 3.Climate-regulative function 4.Hydrologic function 5.Storage function 6.Waste and pollution control function 7.Living space function 8.Archive or heritage function 9.Fungsi ruang penghubung.
KERANGKA-KERJA EVALUASI LAHAN DARI FAO 1976 Diunduh dari Sumber: colombia/FAO/AGLL/pdfdocs/landqual.pdf /11/2012. LAND QUALITIES RELATED TO PRODUCTIVITY FROM CROPS OR OTHER PLANT GROWTH 1.Crop yields (a resultant of many qualities listed below). 2.Moisture availability. 3.Nutrient availability. 4.Oxygen availability in the root zone. 5.Adequacy of foothold for roots. 6.Conditions for germination. 7.Workability of the land (ease of cultivation). 8.Salinity or sodicity. 9.Soil toxicity. 10.Resistance to soil erosion. 11.Pests and diseases related to the land. 12.Flooding hazard (including frequency, periods of inundation). 13.Temperature regime. 14.Radiation energy and photoperiod. 15.Climatic hazards affecting plant growth (including wind, hail, frost). 16.Kelembaban udara yang mempengaruhi pertumbuhan tanaman. 17.Periode kering untuk panen tanaman.
Diunduh dari Sumber: colombia/FAO/AGLL/pdfdocs/landqual.pdf /11/2012. KUALITAS LAHAN UNTUIK PRODUKTIVITAS TERNAK DOMESTIK 1.Produktivitas lahan berumput. 2.Climatic hardships affecting animals. 3.Endemic pests and diseases. 4.Nutritive value of grazing land. 5.Toxicity of grazing land. 6.Resistance to degradation of vegetation. 7.Resistance to soil erosion under grazing conditions. 8.Ketersediaan air bersih untuk minum. FRAMEWORK FOR LAND EVALUATION OF 1976
Diunduh dari Sumber: colombia/FAO/AGLL/pdfdocs/landqual.pdf /11/2012. KUALITAS LAHAN UNTUK PRODUKTIVITAS HUTAN 1.The qualities listed may refer to natural forests, forestry plantations, or both. 2.Mean annual increments of timber species 3.Types and quantities of indigenous timber species. 4.Site factors affecting establishment of young trees. 5.Hama dan Penyakit. 6.Bahaya Kebakaran. FRAMEWORK FOR LAND EVALUATION OF 1976
LAND QUALITIES RELATED TO MANAGEMENT AND INPUTS 1.The qualities listed may refer to arable use, animal production or forestry. 2.Terrain factors affecting mechanization (trafficability). 3.Terrain factors affecting construction and maintenance of access-roads (accessibility). 4.Size of potential management units (e.g. forest blocks, farms, fields). 5.Location in relation to markets and to supplies of inputs. FRAMEWORK FOR LAND EVALUATION OF 1976 Diunduh dari Sumber: colombia/FAO/AGLL/pdfdocs/landqual.pdf /11/ FAO A framework for land evaluation. Soils Bulletin 32, FAO, Rome. 72 p. Also, Publication 22, (R. Brinkman and A. Young (eds.), ILRI, Wageningen, The Netherlands. 2.FAO Planning for sustainable use of land resources: towards a new approach, W.G. Sombroek and D. Sims. Land and Water Bulletin 2, FAO, Rome.
ATMOSPHERIC QUALITIES 1.Atmospheric moisture supply: rainfall, length of growing season, evaporation, dew formation. 2.Atmospheric energy for photosynthesis: temperature, daylength, sunshine conditions. 3.Atmospheric conditions for crop ripening, harvesting and land preparation: occurrence of dry spells. Land qualities related to vertical components of a natural land unit Diunduh dari Sumber: colombia/FAO/AGLL/pdfdocs/landqual.pdf /11/2012. LAND COVER QUALITIES 1.Value of the standing vegetation as "crop", such as timber. 2.Value of the standing vegetation as germ plasm: biodiversity value. 3.Value of the standing vegetation as protection against degradation of soils and catchment. 4.Value of the standing vegetation as regulator of local and regional climatic conditions. 5.Regeneration capacity of the vegetation after complete removal. 6.Value of the standing vegetation as shelter for crops and cattle against adverse atmospheric influences. 7.Hindrance of vegetation at introduction of crops and pastures: the land "development" costs. 8.Incidence of above-ground pests and vectors of diseases: health risks of humans and animals.
Land qualities related to vertical components of a natural land unit Diunduh dari Sumber: colombia/FAO/AGLL/pdfdocs/landqual.pdf /11/2012. LAND SURFACE AND TERRAIN QUALITIES 1.Surface receptivity as seedbed: the tilth condition. 2.Surface treatability: the bearing capacity for cattle, machinery, etc. 3.Surface limitations for the use of implements (stoniness, stickiness, etc.): the arability. 4.Spatial regularity of soil and terrain pattern, determining size and shape of fields with a capacity for uniform management. 5.Surface liability to deformation: the occurrence or hazard of wind and water erosion. 6.Accessibility of the land: the degree of remoteness from means of transport. 7.The presence of open freshwater bodies for use by humans, animals or fisheries. 8.Surface water storage capacity of the terrain: the presence or potential of ponds, on-farm reservoirs, bunds, etc. 9.Surface propensity to yield run-off water, for local water harvesting or downstream water supply. 10.Accumulation position of the land: degree of fertility renewal or crop damaging by overflow or overblow.
Land qualities related to vertical components of a natural land unit Diunduh dari Sumber: colombia/FAO/AGLL/pdfdocs/landqual.pdf /11/2012. KUALITAS TANAH 1.PHYSICAL SOIL FERTILITY: the net moisture storage capacity in the rootable zone. 2.PHYSICAL SOIL TOXICITY: the presence or hazard of waterlogging in the rootable zone (i.e. the absence of oxygen). 3.CHEMICAL SOIL FERTILITY: the availability of plant nutrients. 4.Chemical soil toxicity: salinity or salinization hazard; excess of exchangeable sodium. 5.Biological soil fertility: the N-fixation capacity of the soil biomass; and its capacity for soil organic matter turnover. 6.Biological soil toxicity: the presence or hazard of soil- borne pests and diseases. 7.Substratum (and soil profile) as source of construction materials. 8.Substratum (and soil profile) as source of minerals. 9.Biological soil toxicity: the presence or hazard of soil- borne pests and diseases.
SUBSTRATUM OR UNDERGROUND QUALITIES 1.Groundwater level and quality in relation to (irrigated) land use. 2.Substratum potential for water storage (local use) and conductance (downstream use). 3.Presence of unconfined freshwater aquifers. 4.Substratum (and soil profile) suitability for foundation works (buildings, roads, canals, etc.) Land qualities related to vertical components of a natural land unit Diunduh dari Sumber: colombia/FAO/AGLL/pdfdocs/landqual.pdf /11/2012.
Ketahanan suatu Lahan : The capacity of the land to recover quickly to former levels of productivity - or to resume the trend to increased productivity - after an adverse influence such as drought, floods, or human abandonment or mismanagement. KETAHANAN LAHAN Diunduh dari Sumber: colombia/FAO/AGLL/pdfdocs/landqual.pdf /11/2012. Some concepts of resilience of land and its productivity, comparing the situation in someindustrialized countries (A) with that of most developing countries (B). (Sombroek, 1993)
1.Decline in quality of soils as rooting environments; 2.Erosion and loss of topsoil by wind and water; 3.Loss of vegetation cover, including woody perennials; 4.Acidification, soil fertility decline and plant nutrient depletion; 5.Salinity and salinization, particularly in irrigated systems. MAJOR ISSUES OF LAND MANAGEMENT…. Diunduh dari Sumber: colombia/FAO/AGLL/pdfdocs/landqual.pdf /11/2012.
KUALITAS LAHAN PERTANIAN Diunduh dari: … … 24/12/2012 Deep Percolation Deep percolation is when water moves down through the soil profile below the root zone and cannot be utilized by plants.
KUALITAS LAHAN PERTANIAN Diunduh dari: …… 24/12/2012 Good soil structure Soil structure affects water and air movement through soil, soil temperature as well as how easily soil can be cultivated. When the structure is good water infiltration into the soil is fast and soil granules are durable (spherical in shape). Good soil absorbs enough water for plants’ growth but extra water moves quickly away in large pores. In dry conditions capillary water movement from deeper layers to root zone is important. Characteristics for well structured soil are also high biological activity, good root growth and high enough bearing capacity. Indicators of damaged soil structure are e.g. compacted layers, surface crusting, poor root growth, or plow pans.
KUALITAS LAHAN PERTANIAN Diunduh dari: … … 24/12/2012 DEEP SOIL Deep soil testing is described as taking soil samples down to depths of 36 inches or more. This usually involves three samples: 0-8”, 8-24, and 24-36”. The 0-8 and 36” profile sample must be done to receive cost share assistance. Pounds of Nitrogen from each sample are determined and from that an estimate can be made on Nitrogen available in the root zone. Sampling needs vary but one test per 40 acres is a good rule to follow. Based on cropping history and the next year’s crop choice, a recommendation is given on fertilizer application.
TANAH: SUATU SISTEM Parent material, such as bedrock, is weathered to begin process of soil formation. Parent material = material geologis dasar di suatu lokasi Bedrock = masa batuan padat yang kontinyu penyusun kerak bumi Weathering = proses yang menghancurkan batuan Diunduh dari: 21/12/2012 Diunduh dari: …… 20/12/2012 Typical layers found in a soil profile. (Source: Physical Geography.net) Most soils have a distinct profile or sequence of horizontal layers. Generally, these horizons result from the processes of chemical weathering, eluviation, illuviation, and organic decomposition. Up to five layers can be present in a typical soil: O, A, B, C, and R horizons weathering
"Karakterisik lahan" merupakan atribut lahan yang dapat diukur atau diestimasi. Misalnya: Kemiringan, Curah hujan, Tekstur tanah, Kapasitas air tersedia, Biomasa vegetasi, dll.
Struktur tanah Resembles cookie crumbs and is usually less than 0.5 cm in diameter. Commonly found in surface horizons where roots have been growing. s/fig3-30_large.jpg
STRUKTUR KUBUS: Blocky Structure Irregular blocks that are usually cm in diameter. Can be subangular or angular blocky. s.nsf/Images/gl167_profile/$File/gl167_profi le.jpg
Struktur Prismatik Vertical columns of soil that might be a number of cm long. Usually found in lower horizons. gif images/fig3-27_large.jpg
Struktur Pipih Thin, flat plates of soil that lie horizontally. Usually found in compacted soil. aty.gif _03.jpg
DEGRADASI TANAH DI DUNIA Europe’s land is most degraded because of its long history of intensive agriculture. But Asia’s and Africa’s soils are fast becoming degraded. Diunduh dari: …… 20/12/2012
KOMPONEN TANAH Soil is a complex mixture of organic and inorganic components and living organisms. Diunduh dari: …… 20/12/2012
HUMUS Dark, crumbly mass of undifferentiated material made up of complex organic compounds Soils with high humus content hold moisture better and are more productive for plant life. Diunduh dari: …… 21/12/2012 Components of soil organic matter and their functions Soil organic matter consists of a variety of components. These include, in varying proportions and many intermediate stages, an active organic fraction including microorganisms (10-40 percent), and resistant or stable organic matter (40-60 percent), also referred to as humus. Diunduh dari: …… 20/12/2012
PROFIL TANAH Consists of layers called horizons. Simplest: A = topsoil B = subsoil C = parent material But most have O, A, E, B, C, and R Diunduh dari: …… 20/12/2012
SOIL PROFILE O Horizon: Organic or litter layer A Horizon: Topsoil. Mostly inorganic minerals with some organic material and humus mixed in. Crucial for plant growth E Horizon: Eluviation horizon; loss of minerals by leaching, a process whereby solid materials are dissolved and transported away B Horizon: Subsoil. Zone of accumulation or deposition of leached minerals and organic acids from above C Horizon: Slightly altered parent material R Horizon: Bedrock Diunduh dari: EssentialCh06Lecture.ppt …… 20/12/2012 Diunduh dari: 1060a.gif/ /AG1060a.gif …… 21/12/2012
DESKRIPSI TANAH Soil can be characterized by color and several other traits: Texture (percentage sand, silt, clay) Structure; Porosity Cation exchange capacity ; pH Parent Material Infiltration rate Nutrient concentrations Best for plant growth is loam, an even mix of sand, silt and clay. Diunduh dari: …… 21/12/2012 Diunduh dari: r.edu/.../BW_EssentialCh0 6Lecture.ppt …… 20/12/2012
EROSION & DEPOSITION Erosion = removal of material from one place and its transport elsewhere by wind or water Deposition = arrival of eroded material at a new location These processes are natural, and can build up fertile soil. But where artificially sped up, they are a big problem for farming. Diunduh dari: …… 20/12/2012
Sand dunes around Moses Lake are all that are left of the wind erosion in that area. The smaller particles, silt and clay were blown eastward toward the Palouse. The deposition of the silt and clay particles led to the formation of the Palouse Hills. The Palouse Hills are a wind/water erosional surface. Diunduh dari: …… 20/12/2012 EROSION & DEPOSITION Diunduh dari: 21/12/2012 Four types of soil erosion on an exposed slope.
Diunduh dari: …… 21/12/2012 EROSI TANAH
TIPE EROSI TANAH Diunduh dari: …… 21/12/2012 Raindrop impact is the major cause of soil particle detachment, which can result in the particles moving down slope in flowing water (as sheet erosion) during a rainfall event. Flowing water can also detach soil particles if the velocity is high enough, usually where water starts to concentrate (rill and gully erosion ). If the velocity is reduced sufficiently, particles will settle out. The velocity at which settling begins is dependent on particle size and density, as is the time required for the particles to settle out. Large, dense particles, such as grains of sand, settle first. Fine clays settle out slowly and only in relatively still water.
Over 19 billion ha (47 billion acres) suffer from erosion or other soil degradation. Mississippi River…to thin to plow to thick to drink (Sam Clemens) Diunduh dari: …… 20/12/2012 EROSI TANAH: MASALAH GLOBAL Terasering pada lahan kentang di lereng G. Arjuno, untuk mengendalikan erosi tanah. Foto Jasa Tirta 2009
Diunduh dari: …… 21/12/2012 KONSERVASI TANAH Soil conservation is the best way to make sure that we have the land we need to live on. Erosion is the biggest enemy of soil and land conservation. Protecting / conserving soil with grass, plants or mulch is needed. Always make sure that the soil on your property stays right where it should be!
Several farming strategies to prevent soil degradation: Crop rotation; Contour farming Intercropping; Terracing Shelterbelts; Conservation tillage Diunduh dari: agroforestry/html/15_effects_of_trees.htm?n=80 …… 21/12/2012 MENCEGAH DEGRADASI TANAH Diunduh dari: …… 20/12/2012
Alternating the crop planted (e.g., between corn and soybeans) can restore nutrients to soil and fight pests and disease. Diunduh dari: nzdl.org …… 21/12/2012 ROTASI TANAMAN DESIGNING THE CROP ROTATION PATTERN: 1.Based on knowledge from past years or from rainfall data, determine the onset and the end of the rainy season. 2.Choose short-maturing varieties of both rice and legume crop to accomodate a three-crop sequence or to avoid water stress. 3.Estimate the planting and harvesting dates of each crop in the cropping sequence. 4.If, based on the rainfall occurrence and drainage system, only a two-crop sequence is possible, there is a flexibility to choose a longer duration crop variety which has other desired characteristics..
Planting along contour lines of slopes helps reduce erosion on hillsides. Diunduh dari: …… 21/12/2012 PERTANIAN KONTUR The management practices such as contouring, strip planting, cover cropping, alley cropping,reduced tillage, terracing and leaving some crop residue on the land help to eliminate or minimize the loss of soil from water and wind erosion
Diunduh dari: …… 21/12/2012 ALLEY CROPPING The Concept of Alley Cropping on Sloping Lands Fast-growing, deep-rooted legume trees such as leucaena ( Leucaena leucocephala) have been planted in double or single rows in Indonesia and the Philippines by small-scale farmers on sloping lands to control erosion (Lungren and Nair 1985). Food crops are then planted in the alleys between the trees. Periodic pruning is needed to prevent shading of the food crops by the tree canopy. Once established, the trees facilitate terrace formation within the alley
Cutting stairsteps or terraces is the only way to farm extremely steep hillsides without causing massive erosion. Bench terraces are a soil and water conservation measure used on sloping land with relatively deep soils to retain water and control erosion. They are normally constructed by cutting and filling to produce a series of level steps or benches. This allows water to infiltrate slowly into the soil. Bench terraces are reinforced by retaining banks of soil or stone on the forward edges. This practice is typical for rice-based cropping systems. In China, a modification of bench terraces includes an interval slope planted with perennials and grasses between individual terraces. This system is suitable where soil erosion is critical, rainfall is low and labor and farm manure are not typically available. Shrubs or herbs can also be grown on the edges of the terraces. Diunduh dari: …… 21/12/2012 TARASSERING
No-till and reduced-tillage farming leaves old crop residue on the ground instead of plowing it into soil. This covers the soil, keeping it in place. Here, corn grows up out of a “cover crop.” Diunduh dari: …… 21/12/2012 PENGOLAHAN TANAH KONSERVASI
Conservation tillage is not a panacea for all crops everywhere. It often requires more chemical herbicides (because weeds are not plowed under). It often requires more fertilizer (because other plants compete with crops for nutrients). But legume cover crops can keep weeds at bay while nourishing soil, and green manures can be used as organic fertilizers. Diunduh dari: much-more-than-plant-nutrition …… 21/12/2012 PENGOLAHAN TANAH KONSERVASI The increased soil stratification and size and activity of soil organism populations under conservation tillage compared to conventional tillage lead to increased nutrient retention. Figure credit: Ed Zaborski, University of Illinois. Adapted from House and Parmelee (1985).
Reduces erosion Saves fuel Cuts costs Holds more soil water Reduces soil compaction Allows several crops per season Does not reduce crop yields Reduces CO 2 release from soil Can increase herbicide use for some crops Leaves stalks that can harbor crop pests and fungal diseases and increase pesticide use Requires investment in expensive equipment Disadvantages Advantages Trade-Offs Conservation Tillage Diunduh dari: …… 20/12/2012
IRRIGATION The artificial provision of water to support agriculture 70% of all freshwater used by humans is used for irrigation. Irrigation has boosted productivity in many places … but too much can cause problems. Diunduh dari: …… 21/12/2012 Fungsi Irigasi 1.memasok kebutuhan air tanaman 2.menjamin ketersediaan air apabila terjadi betatan 3.menurunkan suhu tanah 4.mengurangi kerusakan akibat frost 5.melunakkan lapis keras pada saat pengolahan tanah
Diunduh dari: abadi/69/ …… 21/12/2012 SAWAH IRIGASI Bojonegoro tetapkan sawah irigasi jadi sawah abadi Pemerintah Kabupaten Bojonegoro, Jawa Timur, menetapkan sawah irigasi teknis yang memperoleh air irigasi kontinyu sebagai sawah abadi yang dilarang dimanfaatkan sebagai kawasan industri dan permukiman. Kepala Dinas Pertanian Bojonegoro Subekti, Rabu mengatakan, pihaknya sudah menentukan sawah abadi yang menjadi sentra penghasil tanaman pangan, berdasarkan Peraturan Pemerintah (PP) No. 1 Tahun 2011 tentang Penetapan dan Alih Fungsi Lahan Pertanian Berkelanjutan.
IMPROVED IRRIGATION In conventional irrigation, only 40% of the water reaches plants. Efficient drip irrigation targeted to plants conserves water, saves money, and reduces problems like salinization. Diunduh dari: …… 20/12/2012
Reduce irrigation Switch to salt- tolerant crops (such as barley, cotton, sugar beet) Prevention Flushing soil (expensive and wastes water) Not growing crops for 2-5 years Installing under- ground drainage systems (expensive) Cleanup SALINISASI TANAH Diunduh dari: …… 20/12/2012
Supply nutrients to crops Inorganic fertilizers = mined or synthetically manufactured mineral supplements Organic fertilizers = animal manure, crop residues, compost, etc. Diunduh dari: …… 21/12/2012 PUPUK & PEMUPUKAN Pemberian pupuk berimbang dalam kajian ini bukan berarti memberikan pupuk N, P dan K dalam jumlah seimbang untuk tanaman padi. Yang dimaksud pemupukan berimbang dalam kajian ini adalah pemberian pupuk N, P dan K disesuaikan dengan target hasil gabah yang ingin dicapai, sumbangan hara N, P dan K berasal dari tanah serta kekurangan hara untuk mencapai target hasil tersebut dengan penambahan pupuk anorganik dalam bentuk pupuk urea, SP-36 dan KCl. Berdasar teori dikatakan bahwa hasil gabah ditentukan oleh faktor tanah, tanaman dan lingkungan.
GLOBAL FERTILIZER USAGES Fertilizer use has risen dramatically in the past 50 years. Diunduh dari: …… 20/12/2012
Trade-Offs Inorganic Commercial Fertilizers Advantages Disadvantages Do not add humus to soil Reduce organic matter in soil Reduce ability of soil to hold water Lower oxygen content of soil Require large amounts of energy to produce, transport, and apply Release the greenhouse gas nitrous oxide (N 2 O) Runoff can overfertilize nearby lakes and kill fish Easy to transport Easy to store Easy to apply Inexpensive to produce Help feed one of every three people in the world Without commercial inorganic fertilizers, world food output could drop by 40% Diunduh dari: …… 20/12/2012
Overgrazing When livestock eat too much plant cover on rangelands, impeding plant regrowth The contrast between ungrazed and overgrazed land on either side of a fenceline can be striking. Diunduh dari: …… 20/12/2012
OVERGRAZING Overgrazing can set in motion a series of positive feedback loops. Diunduh dari: …… 20/12/2012
World agricultural production has risen faster than human population. Diunduh dari: …… 20/12/2012 PRODUKSI PANGAN DUNIA
However, the world still has 800 million hungry people, largely due to inadequate distribution. And considering soil degradation, can we count on food production continuing to rise? Global food security is a goal of scientists and policymakers worldwide. Diunduh dari: …… 21/12/2012 KETAHANAN PANGAN DUNIA Pada 2012, produksi padi jatim diperkirakan 11,69 juta ton Kepala Badaan Pusat Statistik (BPS) Jatim Irlan Indrocahyo SE MSi di kantornya Jl Kendangsari Industri, Surabaya,Selasa (3/7) mengatakan, kenaikan produksi padi terjadi karena naiknya luas panen padi seluas 32,81 ribu hektare atau 1,70 persen dan produktivitasnya juga mengalami kenaikan 4,78 kuintal/hektare atau 8,71 persen.
GIZI = NUTRITION Undernourishment = too few calories (especially developing world) Overnutrition = too many calories (especially developed world) Malnutrition = lack of nutritional requirements (causes numerous diseases, esp. in developing world) Diunduh dari: …… 20/12/2012
An intensification of industrialization of agriculture, which has produced large yield increases since 1950 Increased yield per unit of land farmed Begun in U.S. and other developed nations; exported to developing nations like India and those in Africa are more productive for plant life. Diunduh dari: lumbung-padi-jawa-barat/ …… 21/12/2012 REVOLUSI HIJAU Tingginya produksi padi Indramayu ini disebabkan oleh luasnya lahan sawah yang ada. Dari luas wilayah Indramayu yang mencapai 204 ribu ha, 114 ribu ha (55%) di antaranya adalah lahan sawah. Dengan luas sebesar itu, Indramayu menempati urutan pertama di Jawa Barat.
Intensified agriculture meant monocultures, vast spreads of a single crop. This is economically efficient, but increases risk of catastrophic failure (“all eggs in one basket”). Diunduh dari: …… 20/12/2012 SISTEM MONOKULTUR The Costs of Modern Agriculture The process of agricultural modernisation has had an important influence on farm productivity and improved living standards for many farmers. However, farmers need access to: modern seeds, water, labour, capital or credit, fertilisers and pesticides. Many poorer farming households simply cannot adopt the whole package. If one element is missing, the seed delivery system fails or the fertiliser arrives late, or there is insufficient irrigation water, then yields may not be much better that those for traditional varieties. Even if farmers want to use external resources, very often delivery systems are unable to supply them on time. Diunduh dari: 23/12/2012
Monocultures also have reduced crop diversity. 90% of all human food now comes from only 15 crop species and 8 livestock species. Diunduh dari: …… 20/12/2012 DIVERSITAS TANAMAN Pengaturan Jarak Tanam Ubikayu dan Kacang Tanah untuk Meningkatkan Indeks Pertanaman di Lahan Kering Masam Penelitian di Banjarnegara dilakukan dengan menanam ubikayu dengan jarak tanam baris ganda (60 cm x 70 cm) x 2 m dan (60 cm x 70 cm) x 2,6 m. Kacang tanah ditanam diantara baris ganda ubikayu. Pada saat tanam kacang tanah MH II, ubikayu sudah berumur tiga bulan. Pada sistem tanam baris ganda (60 cm x 70 cm) x 2 m dan (60 cm x 70 cm) x 2,6 m populasi ubikayu masing-masing sekitar 105% dan 86% dibandingkan cara petani (monokultur) dengan jarak tanam 120 cm x 80 cm. Populasi kacang tanah pada kedua pola tersebut sekitar 70% dari populasi monokultur.
Biodiversity Loss Loss and degradation of habitat from clearing grasslands and forests and draining wetland Fish kills from pesticide runoff Killing of wild predators to protect livestock Loss of genetic diversity from replacing thousands of wild crop strains with a few monoculture strains Soil Erosion Loss of fertility Salinization Waterlogging Desertification Diunduh dari: …… 20/12/2012
Air Pollution Greenhouse gas emissions from fossil Fuel issue Other air pollutants from fossil fuel use Pollution from pesticide sprays Water Water waste Aquifer depletion Increased runoff and flooding from land cleared to grow crops Sediment pollution from erosion Fish kills from pesticide runoff Surface and groundwater pollution from pesticides and fertilizers Overfertilization of lakes and slow-moving rivers from runoff of nitrates and phosphates from fertilizers, livestock wastes, and food processing wastes Diunduh dari: …… 20/12/2012
Techniques to increase crop output per unit area of cultivated land (since world was running out of arable land) Special crop breeds (drought-tolerant, salt-tolerant, etc.) are a key component. It enabled food production to keep pace with population. Diunduh dari: menjadi.html …… 21/12/2012 REVOLUSI HIJAU HKTI sulap Tanah Tandus Samosir menjadi Ladang Jagung Unggulan HKTI patut bangga. Pasalnya, petani jagung di wilayah tersebut biasanya hanya mampu menghasilkan 4 ton setiap hectare (ha). Namun dengan bibit percontohan dari HKTI mampu menghasilkan 8 ton per ha atau dua kali lipat pipil jagung.
Intensification of agriculture causes environmental harm: Pollution from synthetic fertilizers Pollution from synthetic pesticides Water depleted for irrigation Fossil fuels used for heavy equipment However, without the green revolution, much more land would have been converted for agriculture, destroying forests, wetlands, and other ecosystems. Diunduh dari: 1…… 23/12/2012 REVOLUSI HIJAU: DAMPAK LINGKUNGANNYA Diunduh dari: …… 20/12/2012 "Sustainable Agricultural Development" defined by FAO in 1990 was translated into several basic criteria to measure the sustainability of present agriculture and future trends. These criteria can be listed as follows: 1.Meeting the food needs of present and future generations in terms of quantity and quality and the demand for other agricultural products. 2.Providing enough jobs, securing income and creating human living and working conditions for all those engaged in agricultural production. 3.Maintaining, and where possible enhancing, the productive capacity of the natural resources base as a whole and the regenerative capacity of renewable resources, without impairing the function of basic natural cycles and ecological balance, destroying the socio-cultural identity of rural communities or contaminating the environment. 4.Making the agricultural sector more resilient against adverse natural and socio-economic factors and other risks, and strengthening the self-confidence of rural populations.
Diunduh dari: …… 23/12/2012 REVOLUSI HIJAU: DAMPAK LINGKUNGANNYA Ecological Costs Many ecological problems have increased dramatically in recent years. These include: 1.Contamination of water by pesticides, nitrates, soil and livestock wastes, causing harm to wildlife, disruptions of ecosystems and possible health problems in drinking water; 2.Contamination of food and fodder by residues of pesticides, nitrates and antibiotics; 3.Damage to farm and natural resources by pesticides, causing harm to farmworkers and public, disruption of ecosystems and harm to wildlife; 4.Contamination of the atmosphere by ammonia, nitrous oxide, methane and the products of burning, which play a role in ozone depletion, global warming and atmospheric pollution; 5.Overuse of natural resources, causing depletion of groundwater, and loss of wild foods and habitats, and of their capacity to absorb wastes, causing waterlogging and increased salinity; 6.The tendency in agriculture to standardise and specialise by focusing on modern varieties, causing displacement of traditional varieties and breeds; 7.New health hazards for workers in the agrochemical and food-processing industries.
2,000 1,500 1, Grain production (millions of tons) Total World Grain Production Year Diunduh dari: …… 20/12/2012 Social Costs Agricultural modernisation has also helped to transform many rural communities, both in the South and the North. The process has had many social impacts. These include the loss of jobs, the further disadvantaging of women economically if they do not have access to the use and benefits of the new technology, the increasing specialisation of livelihoods, the growing gap between the well-off and the poor, and the cooption of village institutions by the state. Source: Pretty, J. (1998) Regenerating Agriculture, Earthscan, London, p. 4. Agricultural modernisation
PRODUKSI PANGAN DUNIA In 1983, the amount of grain produced per capita leveled off and began to decline. Diunduh dari: …… 20/12/2012
MANAJEMEN HAMA Terms pest and weed have no scientific or objective definitions. Any organism that does something we humans don’t like gets called a pest or a weed. The organisms are simply trying to survive and reproduce… and a monoculture is an irresistible smorgasbord of food for them. Diunduh dari: …… 23/12/2012 B-IPM Biologically based Integrated Pest Management (B-IPM) integrates, or combines, different management tools to provide better leafy spurge control than any single tool could produce. The foundation for this B-IPM approach is biological control: Biocontrol agents like the host-specific leafy spurge flea beetle are integrated with other tools -- such as multi- species grazing programs, herbicides, reseeding, tillage, burning and clipping -- to produce effective, affordable and ecologically sustainable leafy spurge control. B-IPM offers the flexibility landowners and land managers need to devise different management strategies for different situations.
B-IPM Diunduh dari: …… 23/12/2012 Disadvantages of biological control: Like other management tools, biological control is not a perfect solution to the leafy spurge problem. The biggest drawback is that biological control is not a "quick fix." In most cases, biocontrol agents will take several years to successfully establish a population and begin making a significant contribution to leafy spurge management. In addition, no one biocontrol agent works in every situation. An agent that works well in one soil type, for example, may not work at all in another soil type. In the long run, more than one type of biocontrol agent may have to be used to achieve uniform control across a variety of different situations and land types.
B-IPM Diunduh dari: …… 23/12/2012 Control tools a)Herbicides are the most commonly used control tool, and are the preferred tool for containing and preventing the spread of infestations. Disadvantage: Herbicides are expensive -- the cost of treatment can exceed the value of the land and/or the economic return from the land. In addition, herbicides are not target specific and are subject to environmental restrictions. b)Cultural and mechanical controls such as reseeding, clipping and burning can be used to give desirable grasses and plants a competitive advantage while reducing leafy spurge’s dominance. c)Multi-species grazing can provide leafy spurge control while increasing ranch profitability by diversifying cattle grazing operations with sheep or goats. d)Biological control is another tool that can be used to manage leafy spurge and offers some advantages when compared to "traditional" management tools. 1.Biological control is economically sustainable. Leafy spurge biocontrol agents can usually be obtained or collected for free, and do not require a large investment of money or time to use or maintain. Other tools require a greater investment of resources. 2.Biological control is ecologically sustainable. Once established, leafy spurge biocontrol agents are self-sustaining -- they’ll always be there, working in the background to control leafy spurge. 3.In addition, biocontrol agents are not known to cause any adverse ecological consequences.
B-IPM Diunduh dari: …… 23/12/2012 Biologically based Integrated Pest Management The best approach to controlling leafy spurge is Biologically based Integrated Pest Management. It’s effective and affordable, and can be used anywhere. B-IPM integrates, or combines, different management tools to provide more effective leafy spurge control than could be achieved by using any single tool. This integration offers the flexibility ranchers, landowners and land managers need to tailor management programs that fit their specific needs. Biologically based Integrated Pest Management combines ecologically sound strategies with other tools to provide better control and more flexibility than can be achieved using any single tool alone. It is by far the best approach. The results speak for itself. The dramatic change is the result of a cost-effective, integrated approach using grazing and biological control.
PESTISIDA KIMIAWI Synthetic poisons that target organisms judged to be pests Diunduh dari: …… 20/12/2012
Pesticide use is still rising sharply across the world, although growth has slowed in the U.S. 1 billion kg (2 billion lbs.) of pesticides are applied each year in the U.S. Diunduh dari: …… 20/12/2012 PENGGUNAAN PESTISIDA
Pesticides gradually become less effective, because pests evolve resistance to them. Those few pests that survive pesticide applications because they happen to be genetically immune will be the ones that reproduce and pass on their genes to the next generation. This is evolution by natural selection, and it threatens our very food supply. Diunduh dari: …… 20/12/2012 RESISTENSI HAMA THD PESTISIDA Effects of pesticide selection Repeated use of the same class of pesticides to control a pest can cause undesirable changes in the gene pool of a pest leading to another form of artificial selection, pesticide resistance. When a pesticide is first used, a small proportion of the pest population may survive exposure to the material due to their distinct genetic makeup. These individuals pass along the genes for resistance to the next generation. Subsequent uses of the pesticide increase the proportion of less-susceptible individuals in the population. Through this process of selection, the population gradually develops resistance to the pesticide. Diunduh dari: 23/12/2012
3.All pests except a few with innate resistanc e are killed 4.Survivors breed and produce pesticide-resistant population Diunduh dari: …… 20/12/2012 RESISTENSI HAMA THD PESTISIDA
5.Pesticide applied again 6.Has little effect. More-toxic chemicals must be developed. Diunduh dari: …… 20/12/2012 RESISTENSI HAMA THD PESTISIDA
Diunduh dari: 23/12/2012 RESISTENSI HAMA THD PESTISIDA How pesticide resistance develops Some plant pathogens have also become resistant to pesticides. Among fruit producers in North America, apple growers perhaps have faced the most significant problems with pesticide resistance. Examples include streptomycin resistance in the fire blight bacterium and benomyl resistance in the apple scab pathogen. Although the precise genetic and ecological factors differ among pests that have become resistant, in all cases resistance is driven by one process -- selection. PERKEMBANGAN RESISTENSI PESTISIDA
Synthetic chemicals can pollute and be health hazards. Biological control (biocontrol) avoids this. Biocontol entails battling pests and weeds with other organisms that are natural enemies of those pests and weeds. (“The enemy of my enemy is my friend.”) Diunduh dari: …… 22/12/2012 PENGENDALIAN HAYATI Diunduh dari: …… 20/12/2012 Pengendalian hayati adalah suatu teknik pengendalian hama atau organisme pengganggu tanaman dengan memanfaatkan musuh alami dari OPT tersebut. Pendekatan dalam pengendalian hayati 1.Konservasi : menjaga atau melindungi populasi musuh alami yang terdapat di lapangan. 2.Augmentasi : melakukan pembiakan masal musuh alami di laboratorium jika jumlah populasi musuh alami di lapangan sangat sedikit. 3.Introduksi : mendatangkan musuh alami dari suatu daerah ke daerah lain yang populasinya masih sedikit.
Biocontrol has had success stories. Bacillus thuringiensis (Bt) = soil bacterium that kills many insects. In many cases, seemingly safe and effective. Cactus moth, Cactoblastis cactorum (above), was used to wipe out invasive prickly pear cactus in Australia. Diunduh dari: …… 20/12/2012 PENGENDALIAN HAYATI
Most biocontrol agents are introduced from elsewhere. Some may turn invasive and become pests themselves! Cactus moths brought to the Caribbean jumped to Florida, are eating native cacti, and spreading. Wasps and flies brought to Hawaii to control crop pests are parasitizing native caterpillars in wilderness areas. Diunduh dari: 22/12/2012 RISIKO PENGENDALIAN HAYATI Diunduh dari: …… 20/12/2012 The relativity of potential risk to nontarget plant species based on phylogeny, biogeography, and ecology. The testing procedure should seek to measure the maximum level of risk posed by an agent’s introduction. Actual measured risk may in fact be much lower than potential risk, but the latter provides a useful framework for selecting test plants.
INTEGRATED PEST MANAGEMENT (IPM) Combines biocontrol, chemical, and other methods May involve: Biocontrol Pesticides Close population monitoring Habitat modification Crop rotation Transgenic crops Alternative tillage Mechanical pest removal Diunduh dari: …… 20/12/2012 Diunduh dari: 23/12/2012
Manipulating and engineering genetic material in the lab may represent the best hope for increasing agricultural production further without destroying more natural lands. But many people remain uneasy about genetically engineering crop plants and other organisms. Diunduh dari: …… 20/12/2012 MODIFIKASI GENETIK PANGAN Genetically modified foods (GM foods, or biotech foods) are foods derived from genetically modified organisms (GMOs), specifically, genetically modified crops. GMOs have had specific changes introduced into their DNA by genetic engineering techniques. These techniques are much more precise than mutagenesis (mutation breeding) where an organism is exposed to radiation or chemicals to create a non-specific but stable change. Other techniques by which humans modify food organisms include selective breeding; plant breeding, and animal breeding, and somaclonal variation. Diunduh dari: 22/12/2012
Genetic engineering (GE) = directly manipulating an organism’s genetic material in the lab by adding, deleting, or changing segments of its DNA Genetically modified (GM) organisms = genetically engineered using recombinant DNA technology Recombinant DNA = DNA patched together from DNA of multiple organisms (e.g., adding disease-resistance genes from one plant to the genes of another) Diunduh dari: …… 20/12/2012 REKAYASA GENETIK MENGGUNAKAN DNA - REKOMBINAN Diunduh dari: …… 22/12/2012 What is transgenic food? Transgenic food are those directly made from or processed from the species (animals, plants and microorganisms, etc.) which can produce substances possessing highly effective expressions, such as polypeptide and protein, after one or several types of exogenous genes are transferred into it through the means of genetic engineering. The first category----transgenic plant food product There are various kinds of transgenic plant foods, such as high protein wheat used to bake breads. To reverse the situation that wheat in the current market contains low rate of protein, protein genes possessing highly effective expressions are transferred into wheat, so that bread made from the wheat can be of more nutritious value.
Genes moved between organisms are transgenes, and the organisms are transgenic. These efforts are one type of biotechnology, the material application of biological science to create products derived from organisms. Diunduh dari: …… 20/12/2012 TRANSGENE & BIOTEKNOLOGI Transgenosis technology is a kind of modern technology in molecular biology, which is used to transfer genes from one species into another so as to reconstruct the genetic materials of the receiving species for the improvement of its properties, quality of nutrition in line with the need of human beings. The transgenic species as immediate food and food processed from transgenic species are called transgenic food. Diunduh dari: 22/12/2012
They are similar: We have been altering crop genes (by artificial selection) for thousands of years. There is no fundamental difference: both approaches modify organisms genetically. They are different: GE can mix genes of very different species. GE is in vitro lab work, not with whole organisms. GE uses novel gene combinations that didn’t come together on their own. Diunduh dari: …… 20/12/2012 REKAYASA GENETIK vs. PEMULIAAN TRADISIONAL
Some GM foods Golden rice: Enriched with vitamin A. But too much hype? Bt crops: Widely used on U.S. crops. But ecological concerns? Ice-minus strawberries: Frost-resistant bacteria sprayed on. Images alarmed public. FlavrSavr tomato: Better taste? But pulled from market. Diunduh dari: …… 20/12/2012
Some GM foods Bt sunflowers: Insect resistant. But could hybridize with wild relatives to create “superweeds”? Terminator seeds: Plants kill their own seeds. Farmers forced to buy seeds each year. Roundup-Ready crops: Resistant to Monsanto’s herbicide. But encourages more herbicide use? StarLink corn: Bt corn variety. Genes spread to non-GM corn; pulled from market. Diunduh dari: …… 20/12/2012
Although many early GM crops ran into bad publicity or other problems, biotechnology is already transforming the U.S. food supply. Two-thirds of U.S. soybeans, corn, and cotton are now genetically modified strains. Diunduh dari: 22/12/2012 PREVALENSI PANGAN TRANSGENIK Health concerns and potential food hazards Health risks associated with genetically modified foods are concerned with toxins, allergens, or genetic hazards. The mechanisms of food hazards fall into three main categories (Conner et al., 1999): 1.Inserted genes and their expression products 2.Secondary and pleiotropic effects of gene expression 3.Insertional mutagenesis resulting from gene integration Diunduh dari: …… 20/12/2012 For example, bean plants that were genetically modified to increase cysteine and methionine content were discarded after the discovery that the expressed protein of the transgene was highly allergenic. (Butler et al., 1999)
1.Are there health risks for people? 2.Can transgenes escape into wild plants, pollute ecosystems, harm organisms? 3.Can pests evolve resistance to GM crops just as they can to pesticides? 4.Can transgenes jump from crops to weeds and make them into “superweeds”? 5.Can transgenes get into traditional native crop races and ruin their integrity? ORGANISME TRANSGENIK Diunduh dari: …… 20/12/2012 Diunduh dari: 22/12/2012 The potential risks accompanied by disease resistant plants deal mostly with viral resistance. It is possible that viral resistance can lead to the formation of new viruses, and therefore new diseases. It has been reported that naturally occurring viruses can recombine with viral fragments that are introduced to create transgenic plants, forming new viruses. Additionally, there can be many variations of this newly formed virus. (Steinbrecher, 1996)
These questions are not fully answered yet. In the meantime… Should we not worry, because so many U.S. crops are already GM and little drastic harm is apparent? Or should we adopt the precautionary principle, the idea that one should take no new action until its ramifications are understood? Diunduh dari: …… 20/12/2012 ORGANISME TRANSGENIK
Should scientists and corporations be “tinkering with” our food supply? Are biotech corporations testing their products adequately, and is outside oversight adequate? Should large multinational corporations exercise power over global agriculture and small farmers? Diunduh dari: …… 20/12/2012 PRODUK-PRODUK TRANSGENIK Diunduh dari: …… 20/12/2012 RISKS AND CONTROVERSY With all this new technology comes question and fear. What are the risks of "tampering with Mother Nature"? What effects will this have on the environment? Are there health concerns consumers should be aware of? Is recombinant technology really beneficial? The following section will address some major concerns about the risks involved with genetically modified foods and recombinant technology, touching up environmental risks as well as health risks.
Projected Disadvantages Need less fertilizer Need less water More resistant to insects, plant disease, frost, and drought Faster growth Can grow in slightly salty soils Less spoilage Better flavor Less use of conventional pesticides Tolerate higher levels of pesticide use Higher yields Projected Advantages Trade-Offs Genetically Modified Food and Crops Irreversible and unpredictable genetic and ecological effects Harmful toxins in food From possible plant cell Mutations New allergens in food Lower nutrition Increased evolution of Pesticide-resistant Insects and plant disease Creation of herbicide- Resistant weeds Harm beneficial insects Lower genetic diversity Diunduh dari: …… 20/12/2012
Viewpoints: Genetically modified foods Indra Vasil Ignacio Chapela “We should expect fundamental alterations in ecosystems with the release of transgenic crops… We are experiencing a global experiment without controls.” “Biotech crops are already helping to conserve valuable natural resources, reduce the use of harmful agro- chemicals, produce more nutritious foods, and promote economic development.” Diunduh dari: …… 20/12/2012
Native cultivars of crops are important to preserve, in case we need their genes to overcome future pests or pathogens. Diversity of cultivars has been rapidly disappearing from all crops throughout the world. Diunduh dari: …… 22/12/2012 MELESTARIKAN KEANEKA-RAGAMAN TANAMAN Crop diversity is the variance in genetic and phenotypic characteristics of plants used in agriculture. Crops may vary in seed size, branching pattern, in height, flower color, fruiting time, or flavor. They may also vary in less obvious characteristics such as their response to heat, cold or drought, or their ability to resist specific diseases and pests. It is possible to discover variation in almost every conceivable trait, including nutritional qualities, preparation and cooking techniques, and of course how a crop tastes. And if a trait cannot be found in the crop itself, it can often be found in a wild relative of the crop; a plant that has similar species that have not been farmed or used in agriculture, but exist in the wild. Diunduh dari: …… 20/12/2012
Seed banks preserve seeds, crop varieties Seed banks are living museums of crop diversity, saving collections of seeds and growing them into plants every few years to renew the collection. Careful hand pollination helps ensure plants of one type do not interbreed with plants of another. Diunduh dari: …… 20/12/2012
Animal agriculture: Livestock and poultry Consumption of meat has risen faster than population over the past several decades. Diunduh dari: …… 20/12/2012
Increased meat consumption has led to animals being raised in feedlots (factory farms), huge pens that deliver energy-rich food to animals housed at extremely high densities. Diunduh dari: …… 20/12/2012 PERTANIAN-TERNAK DAMPAK LINGKUNGANNYA
Immense amount of waste produced, polluting air and water nearby Intense usage of chemicals (antibiotics, steroids, hormones), some of which persist in environment However, if all these animals were grazing on rangeland, how much more natural land would be converted for agriculture? Diunduh dari: updates/newsletters/milking-the-weather/june/seasonal-preparation ……..…… 22/12/2012 PERTANIAN-TERNAK DAMPAK LINGKUNGANNYA Diunduh dari: …… 20/12/2012
Energy is lost at each trophic level. When we eat meat from a cow fed on grain, most of the grain’s energy has already been spent on the cow’s metabolism. Eating meat is therefore very energy inefficient. Diunduh dari: …..…… 22/12/2012 PILIHAN PANGAN = PILIHAN ENERGI Diunduh dari: …… 20/12/2012 The FOOD PYRAMID is a nutrition guide that is shaped like a pyramid. It is separated in parts, with each segment depicting the suggested intake of a particular food group.
The raising of aquatic organisms for food in controlled environments Provides 1/3 of world’s fish for consumption 220 species being farmed The fastest growing type of food production Diunduh dari: …… 22/12/2012 AQUACULTURE Diunduh dari: …… 20/12/2012 Aquaculture The cultivation of aquatic organisms. Some of the most common organisms that are cultivated are salmon, trout, oysters, and clams.
1.Provides reliable protein source for people, increases food security 2.Can be small-scale, local, and sustainable 3.Reduces fishing pressure on wild stocks, and eliminates bycatch 4.Uses fewer fossil fuels than fishing 5.Can be very energy efficient Diunduh dari: …… 20/12/2012 MANFAAT AKUAKULUR Budidaya Ikan Lele di Gemolong Sragen Lele merupakan jenis ikan yang digemari masyarakat, dengan rasa yang lezat, daging empuk, duri teratur dan dapat disajikan dalam berbagai macam menu masakan. PT. NATURAL NUSANTARA dengan prinsip K-3 (Kuantitas, Kualitas dan Kesehatan) membantu petani lele dengan paket produk dan teknologi. Diunduh dari: sragen.html …… 20/12/2012
DAMPAK LINGKUNGAN AKIBAT AKUAKULTUR 1.Density of animals leads to disease, antibiotic use, risks to food security. 2.It can generate large amounts of waste. 3.Often animals are fed grain, which is not energy efficient. 4.Sometimes animals are fed fish meal from wild-caught fish. 5.Farmed animals may escape into the wild and interbreed with, compete with, or spread disease to wild animals. Diunduh dari: …… 22/12/2012 Diunduh dari: …… 20/12/2012 Aquaculture is the fastest growing food production sector in the World with annual growth in excess of 10 percent over the last two decades. Much of this development has occurred in Asia, which also has the greatest variety of cultured species and systems. Asia is also perceived as the ‘home’ of aquaculture, as aquaculture has a long history in several areas of the region and knowledge of traditional systems is most widespread.
Transgenic salmon (top) can compete with or spread disease to wild salmon (bottom) when they escape from fish farms. Diunduh dari: …… 20/12/2012 DAMPAK LINGKUNGAN AKUAKULTUR
Highly efficient High yield in small volume of water Increased yields through cross- breeding and genetic engineering Can reduce over- harvesting of conventional fisheries Little use of fuel Profit not tied to price of oil High profits Advantages Large inputs of land, feed, And water needed Produces large and concentrated outputs of waste Destroys mangrove forests Increased grain production needed to feed some species Fish can be killed by pesticide runoff from nearby cropland Dense populations vulnerable to disease Tanks too contaminated to use after about 5 years Disadvantages Trade-Offs Aquaculture Diunduh dari: …… 20/12/2012
Reduce use of fishmeal as a feed to reduce depletion of other fish Improve pollution management of aquaculture wastes Reduce escape of aquaculture species into the wild Restrict location of fish farms to reduce loss of mangrove forests and other threatened areas Farm some aquaculture species (such as salmon and cobia) in deeply submerged cages to protect them from wave action and predators and allow dilution of wastes into the ocean Set up a system for certifying sustainable forms of aquaculture Solutions More Sustainable Aquaculture Diunduh dari: …… 20/12/2012
Agriculture that can practiced the same way far into the future Does not deplete soils faster than they form Does not reduce healthy soil, clean water, and genetic diversity essential for long-term crop and livestock production Low-input agriculture = small amounts of pesticides, fertilizers, water, growth hormones, fossil fuel energy, etc. Organic agriculture = no synthetic chemicals used. Instead, biocontrol, composting, etc. Diunduh dari: …… 23/12/2012 PERTANIAN BERKELANJUTAN Diunduh dari: …… 20/12/2012 Components of a Sustainable Soil Management System
PERTANIAN ORGANIK Small percent of market, but is growing fast 1% of U.S. market, but growing 20%/yr 3–5% of European market, but growing 30%/yr Organic produce: Advantages for consumers: healthier; environmentally better Disadvantages for consumers: less uniform and appealing-looking; more expensive Diunduh dari: …… 23/12/2012 Diunduh dari: …… 20/12/2012 Principles in Organic Farming
PERTANIAN ORGANIK PRINSIP KESEHATAN Organic Agriculture should sustain and enhance the health of soil, plant, animal, human and planet as one and indivisible. This principle points out that the health of individuals and communities cannot be separated from the health of ecosystems - healthy soils produce healthy crops that foster the health of animals and people. Health is the wholeness and integrity of living systems. It is not simply the absence of illness, but the maintenance of physical, mental, social and ecological well-being. Immunity, resilience and regeneration are key characteristics of health. The role of organic agriculture, whether in farming, processing, distribution, or consumption, is to sustain and enhance the health of ecosystems and organisms from the smallest in the soil to human beings. In particular, organic agriculture is intended to produce high quality, nutritious food that contributes to preventive health care and well-being. In view of this it should avoid the use of fertilizers, pesticides, animal drugs and food additives that may have adverse health effects. Diunduh dari: …… 23/12/2012
PERTANIAN ORGANIK PRINSIP EKOLOGI Organic Agriculture should be based on living ecological systems and cycles, work with them, emulate them and help sustain them. This principle roots organic agriculture within living ecological systems. It states that production is to be based on ecological processes, and recycling. Nourishment and well-being are achieved through the ecology of the specific production environment. For example, in the case of crops this is the living soil; for animals it is the farm ecosystem; for fish and marine organisms, the aquatic environment. Organic farming, pastoral and wild harvest systems should fit the cycles and ecological balances in nature. These cycles are universal but their operation is site-specific. Organic management must be adapted to local conditions, ecology, culture and scale. Inputs should be reduced by reuse, recycling and efficient management of materials and energy in order to maintain and improve environmental quality and conserve resources. Organic agriculture should attain ecological balance through the design of farming systems, establishment of habitats and maintenance of genetic and agricultural diversity. Those who produce, process, trade, or consume organic products should protect and benefit the common environment including landscapes, climate, habitats, biodiversity, air and water. Diunduh dari: …… 23/12/2012
PERTANIAN ORGANIK PRINSIP KEADILAN Organic Agriculture should build on relationships that ensure fairness with regard to the common environment and life opportunities. Fairness is characterized by equity, respect, justice and stewardship of the shared world, both among people and in their relations to other living beings. This principle emphasizes that those involved in organic agriculture should conduct human relationships in a manner that ensures fairness at all levels and to all parties - farmers, workers, processors, distributors, traders and consumers. Organic agriculture should provide everyone involved with a good quality of life, and contribute to food sovereignty and reduction of poverty. It aims to produce a sufficient supply of good quality food and other products. This principle insists that animals should be provided with the conditions and opportunities of life that accord with their physiology, natural behavior and well-being. Natural and environmental resources that are used for production and consumption should be managed in a way that is socially and ecologically just and should be held in trust for future generations. Fairness requires systems of production, distribution and trade that are open and equitable and account for real environmental and social costs. Diunduh dari: …… 23/12/2012
PERTANIAN ORGANIK PRINCIPLE OF CARE Organic Agriculture should be managed in a precautionary and responsible manner to protect the health and well-being of current and future generations and the environment. Organic agriculture is a living and dynamic system that responds to internal and external demands and conditions. Practitioners of organic agriculture can enhance efficiency and increase productivity, but this should not be at the risk of jeopardizing health and well-being. Consequently, new technologies need to be assessed and existing methods reviewed. Given the incomplete understanding of ecosystems and agriculture, care must be taken. This principle states that precaution and responsibility are the key concerns in management, development and technology choices in organic agriculture. Science is necessary to ensure that organic agriculture is healthy, safe and ecologically sound. However, scientific knowledge alone is not sufficient. Practical experience, accumulated wisdom and traditional and indigenous knowledge offer valid solutions, tested by time. Organic agriculture should prevent significant risks by adopting appropriate technologies and rejecting unpredictable ones, such as genetic engineering. Decisions should reflect the values and needs of all who might be affected, through transparent and participatory processes. Diunduh dari: …… 23/12/2012
1.Chemical pesticides pollute, and kill pollinators, and pests evolve resistance. 2.GM crops show promise for social and environmental benefits, but questions linger about their impacts. 3.Much of the world’s crop diversity has vanished. 4.Feedlot agriculture and aquaculture pose benefits and harm for the environment and human health. Diunduh dari: …… 23/12/2012 TANTANGAN PERTANIAN MASA DEPAN Diunduh dari: …… 20/12/2012 Pesticide Action Network (PAN) is a global network working to eliminate the human and environmental harm caused by pesticides and to promote biodiversity based ecological agriculture. We are dedicated to protect the safety and health of people, and the environment from pesticide use and genetic engineering.
1.Organic farming remains a small portion of agriculture. 2.Human population continues to grow, requiring more food production. 3.Soil erosion is a problem worldwide. 4.Salinization, waterlogging, and other soil degradation problems are leading to desertification. 5.Grazing and logging, as well as cropland agriculture, contribute to soil degradation. Diunduh dari: …… 23/12/2012 TANTANGAN PERTANIAN MASA DEPAN Diunduh dari: …… 20/12/2012 SUSTAINABLE CROP MANAGEMENT One of the most significant challenges facing Mankind is the adequate provision of food from sustainable and profitable production systems within a context of high energy costs.
1.Biocontrol and IPM offer alternatives to pesticides. 2.Further research and experience with GM crops may eventually resolve questions about impacts, and allow us to maximize benefits while minimizing harm. 3.More funding for seed banks can rebuild crop diversity. 4.Ways are being developed to make feedlot agriculture and aquaculture safer and cleaner. Diunduh dari: …… 20/12/2012 TANTANGAN PERTANIAN MASA DEPAN
1.Organic farming is popular and growing fast. 2.Green revolution advances have kept up with food demand so far. Improved distribution and slowed population growth would help further. 3.Farming strategies like no-till farming, contour farming, terracing, etc., help control erosion. 4.Government laws, and government extension agents working with farmers, have helped improve farming practices and control soil degradation. 5.Better grazing and logging practices exist that have far less impact on soils. Diunduh dari: …… 23/12/2012 SOLUSI PERTANIAN MASA DEPAN Diunduh dari: …… 20/12/2012 An Assets-Based Model for Sustainability Agricultural systems at all levels rely for their success on the value of services flowing from the total stock of assets that they control. Five types of capital, natural, social, human, physical and financial, are now being addressed in the literature : 1.Natural capital 2.Social capital 3.Human capital 4.Physical capital 5.Financial capital.
Diunduh dari: …… 23/12/2012 AN ASSETS-BASED MODEL FOR SUSTAINABILITY 1.Natural capital produces nature’s goods and services, and comprises food (both farmed and harvested or caught from the wild), wood and fibre; water supply and regulation; treatment, assimilation and decomposition of wastes; nutrient cycling and fixation; soil formation; biological control of pests; climate regulation; wildlife habitats; storm protection and flood control; carbon sequestration; pollination; and recreation and leisure. 2.Social capital yields a flow of mutually beneficial collective action, contributing to the cohesiveness of people in their societies. The social assets comprising social capital include norms, values and attitudes that predispose people to cooperate; relations of trust, reciprocity and obligations; and common rules and sanctions mutually-agreed or handed-down. These are connected and structured in networks and groups. 3.Human capital is the total capability residing in individuals, based on their stock of knowledge skills, health and nutrition. It is enhanced by their access to services that provide these, such as schools, medical services, and adult training. People’s productivity is increased by their capacity to interact with productive technologies and with other people. Leadership and organisational skills are particularly important in making other resources more valuable. 4.Physical capital is the store of human-made material resources, and comprises buildings (housing, factories), market infrastructure, irrigation works, roads and bridges, tools and tractors, communications, and energy and transportation systems, that make labour more productive. 5.Financial capital is accumulated claims on goods and services, built up through financial systems that gather savings and issue credit, such as pensions, remittances, welfare payments, grants and subsidies.
Diunduh dari: …… 23/12/2012 AN ASSETS-BASED MODEL FOR SUSTAINABILITY The basic premise is that sustainable systems, whether farms, firms, communities, or economies, accumulate stocks of these five assets, thereby increasing the per capita endowments of all forms of capital over time. But unsustainable systems deplete or run down these various forms, spending assets as if they were income, and so leaving less for future generations.
Diunduh dari: …… 23/12/2012 AN ASSETS-BASED MODEL FOR SUSTAINABILITY The assets-based model shows how farms and rural livelihoods take inputs of various types, including renewable assets, and transform these to produce food and other desirable outputs. These can be processed for home consumption, transformed through value-added processes for sale, or sold directly as raw product. The inputs are shown as: 1.Renewable natural capital – soil, water, air, biodiversity etc; 2.Social and participatory processes – including both locally embedded and externally-induced social capital, and partnerships and linkages between external organisations; 3.New technologies, knowledge and skills – both regenerative (eg legumes, natural enemies) and non-renewable (eg hybrid seeds, machinery); 4.Non-renewable or fossil-fuel derived inputs (eg fertilizers, pesticides, antibiotics); 5.Finance – credit, remittances, income from sales and grants. Availability and access to these five inputs is shaped by a wide range of contextual factors (on the far left). These include unchanging ones (at least over the short-term), such as climate, agro-ecology, soils, culture; and dynamic economic, social, political and legal factors shaped by external institutions and policies. These contextual factors are an important entry point for shaping and influencing agricultural systems (such as national policies, markets, trade).
Diunduh dari: …… 23/12/2012 AN ASSETS-BASED MODEL FOR SUSTAINABILITY The Modernisation of Agriculture The process of agricultural modernisation during the 20 th century has produced three distinct types of agriculture: industrialised, `Green Revolution’, and all that remains - the pre-modern, `traditional’ or `unimproved'. The first two types have been able to respond to modern technological packages, producing highly productive systems of agriculture.
Diunduh dari: …… 23/12/2012 AN ASSETS-BASED MODEL FOR SUSTAINABILITY Sustainable Agriculture A more sustainable farming seeks to make the best use of nature’s goods and services whilst not damaging the environment. It does this by integrating natural processes such as nutrient cycling, nitrogen fixation, soil regeneration and natural enemies of pests into food production processes. It also minimises the use of non- renewable inputs (pesticides and fertilizers) that damage the environment or harm the health of farmers and consumers. It makes better use of the knowledge and skills of farmers, so improving their self-reliance. And it seeks to make productive use of social capital - people’s capacities to work together to solve common management problems, such as pest, watershed, irrigation, forest and credit management
High-yield polyculture Organic fertilizers Biological pest control Integrated pest management Irrigation efficiency Perennial crops Crop rotation Use of more water- efficient crops Soil conservation Subsidies for more sustainable farming and fishing Increase Soil erosion Soil salinization Aquifer depletion Overgrazing Overfishing Loss of biodiversity Loss of prime cropland Food waste Subsidies for unsustainable farming and fishing Population growth Poverty Decrease Sustainable Agriculture Diunduh dari: …… 20/12/2012
Pangan minim limbah Mengurangi konsumsi daging Feed pets balanced grain foods instead of meat Use organic farming to grow some of your food Membeli bahan pangan organik Komposting limbah makanan Apa yang dapat dilakukan ? Sustainable Agriculture Diunduh dari: …… 20/12/2012
DEGRADASI LAHAN PERTANIAN
Diunduh dari: 24/12/2012 DEGRADASI LAHAN Degradasi lahan merupakan proses menurunnya kualitas dan kuantitas suatu lahan yang meliputi aspek fisika tanah, kimia tanah, biologi tanah, pada suatu bidang lahan tertentu. Dalam praktek budidaya pertanian sendiri sering akan menimbulkan dampak pada degradasi lahan. Dua faktor penting dalam usaha pertanian yang potensial menimbulkan dampak pada sumberdaya lahan, yaitu tanaman dan manusia (sosio kultural) yang menjalankan pertanian. Faktor AKTIVITAS manusia dapat memberikan dampak positip atau negatip pada suatu lahan, tergantung pada aktivitas pengelolaan pertanian yang dilakukan. Apabila dalam menjalankan pertaniannya benar maka akan berdampak positip, namun apabila cara menjalankan pertaniannya salah maka akan berdampak negatif. Kegiatan budidaya pertanian yang menimbulkan dampak antara lain meliputi kegiatan pengolahan tanah, penggunaan sarana produksi yang tidak ramah lingkungan (pupuk dan insektisida) serta sistem budidaya termasuk pola tanam yang mereka gunakan. Tiga faktor penyebab degradasi tanah akibat campur tangan manusia secara langsung, yaitu : pertanian intensif, pembukaan tambang, deforestasi. Faktor-faktor tersebut di Indonesia pada umumnya terjadi secara simultan, berikut adalah pembahasan dari ketiga degradasi pada tiga bidang.
DEGRADASI LAHAN DEGRADASI LAHAN PERTANIAN Aktivitas budidaya pertanian dapat menyebabkan dampak negatif pada sumberdaya lahan. Erosi dan pencemaran tanah terjadi akibat budi daya pertanian yang melampaui daya dukung tanah. Penggunaan bahan-bahan agrokimia yang berlebihan dapat mencemari lingkungan dan mengganggu kelestarian kualitas tanah. Cara-cara budi daya pertanian yang tidak mengindahkan kaidahkaidah konservasi lahan menyebabkan kualitas lahan menurun sejalan dengan hilangnya lapisan tanah subur akibat erosi dan pencucian hara. Kegiatan pembangunan yang berpotensi menimbulkan dampak terhadap degradasi lahan antara lain kegiatan deforesterisasi, industri, pertambangan, perumahan, dan kegiatan pertanian sendiri. Apabila kegiatan tersebut tidak dikelola dengan baik, maka akan mengakibatkan terjadinya degradasi lahan pertanian yang mengancam keberlanjutan uasaha tani dan ketahanan pangan. Oleh karenanya, dalam kegiatan pembangunan hendaknya harus dipikirkan keberlanjutannya dimasa mendatang (sustainabilitas). Praktek budidaya pertanian sering mengakibatkan degradasi lahan. Kegiatan budidaya pertanian yang menimbulkan dampak negatif antara lain meliputi kegiatan pengolahan tanah, penggunaan sarana produksi yang tidak ramah lingkungan (pupuk dan pestisida), serta sistem budidaya termasuk pola tanam yang tidak tepat. Diunduh dari: 24/12/2012
Diunduh dari: 24/12/2012 DEGRADASI LAHAN Barrow (1991) merinci faktor-faktor utama penyebab degradasi lahan : 1) Bahaya alami 2) Perubahan jumlah populasi manusia 3) Marjinalisasi tanah 4) Kemiskinan 5) Status kepemilikan tanah 6) Ketidakstabilan politik dan masalah administrasi 7) Kondisi sosial ekonomi 8) Masalah kesehatan 9) Praktek pertanian yang tidak tepat, dan 10) Aktifitas pertambangan dan industri. Degradasi lahan ada tiga aspek, yaitu : aspek fisik. kimia dan biologi. 1.Degradasi fisik terdiri dari pemadatan, pengerakan, ketidakseimbangan air, terhalangnya aerasi, aliran permukaan, dan erosi. 2.Degradasi kimiawi terdiri dari asidifikasi, pengurasan unsur hara, pencucian, ketidakseimbangan unsur hara dan keracunan, salinisasi, dan alkalinisasi. 3.Degradasi biologis meliputi penurunan karbon organik tanah, penurunan keanekaragaman hayati tanah, dan penurunan karbon biomas.
Diunduh dari: 24/12/2012 DEGRADASI LAHAN TYPES OF SOIL DEGRADATION Soil degradation is any type of problem that removes soil in an area or makes high-quality soil become poor. Careless agricultural practices, pollution and deforestation cause lots of soil degradation in the world. Several types of soil degradation exist and are a threat to natural forests and planted crops. Read more: Types of Soil Degradation | eHow.com of Soil Degradation | eHow.com SOIL EROSION Erosion occurs when the topsoil that many plants need to grow gets blown or washed away. While some erosion is natural, the humans often remove plants that cover soil and, therefore, speed up erosion. Since topsoil takes so long to build back up through natural processes, erosion damage is almost irreversible. NUTRIENT LOSS Nutrient loss often occurs in conjunction with salinization. The nutrient loss occurs through a variety of mechanisms, including leaching, erosion, runoff, crop uptake and denitrification. The crops uptake too many soil nutrients that farmers do not always replace. Deforestation and careless agricultural processes lead to soil degradation in the form of nutrient loss. After soil becomes nutrient-poor, crops and naturally occurring plants have a hard time growing in the area.
Diunduh dari: 24/12/2012 DEGRADASI LAHAN SOIL DEGRADATION When plants (trees & shrubs) are cleared from a site, soil is exposed to sunlight and the eroding effects of wind and water. Soil aeration is increased and the rate of weathering increases. Apart from erosion, the proportion of organic matter in the soil gradually decreases, through the action of microbes in the soil which use it as a source of energy ‑ unless the new land use provides some replacement. TYPES OF SOIL DEGRADATION A number of major soil related problems occur in Australia these include: 1.Kehilangan kesuburan tanah 2.Erosi Tanah 3.Salinitas 4.Pemadatan Tanah 5.Pengasaman Tanah 6.Pencemaran tanah oleh bahan kimia berbahaya.
Diunduh dari: ……… 24/12/2012 HILANGNYA KESUBURAN TANAH KESUBURAN TANAH Land use, human nutrition and the carbon cycle form an intricate set of relationships. Healthy plants use carbon dioxide, give off oxygen and increase soil organic matter (OM), thereby enhancing soil fertility. Practices that increase organic matter can increase soil fertility while decreasing greenhouse gas emissions.
Diunduh dari: /ch05.html ……… 24/12/2012 HILANGNYA KESUBURAN TANAH BASIC PLANT NUTRIENT CYCLE The basic nutrient cycle usually describes the outstanding role of soil organic matter. Cycling of many plant nutrients, especially N, P, S, and micronutrients, are similar to the Carbon Cycle. Plant residues, grain green manure, farmyard manure and other substances are returned to the soil. This organic matter pool of carbon compounds serve as food for bacteria, fungi, and other decomposers. As organic matter is decomposed to simpler compounds, plant nutrients are released in available forms for root uptake and the cycle begins again. Plant- available macronutrients such as N, P, K, Ca, Mg, S and micronutrients are also released when soil minerals dissolve.
Diunduh dari: ……… 24/12/2012 HILANGNYA KESUBURAN TANAH POTENTIAL FOR N LOSSES Greater losses occur when soils enter the spring season with recharged subsoil moisture, when more N is in the nitrate form, and when soils are warm. Deciding if losses are substantial enough to warrant supplemental N application must therefore take into consideration the following factors: (1) amount of nitrate present, which is affected by time of N application, form of N applied, rate applied, and use of a nitrification inhibitor; (2) when and the length of time soils are saturated; (3) subsoil recharge, leaching rate, and drainage--water amount moved through the soil; and (4) loss of crop yield potential from water damage.
Diunduh dari: ……… 24/12/2012 HILANGNYA KESUBURAN TANAH Integrated plant nutrient components in the Nepalese farming system An integrated nutrient model developed quite some time ago as shown below was a successful programme but it has not been popularized or has not been well adopted by large number of farmers. There should be a follow up study to see the impact on soil fertility management and to look on how best we can promote to wider areas.
/ch05.html HILANGNYA KESUBURAN TANAH KEHILANGAN HARA DARI TANAH There are several losses from soil nutrient pools caused by either unfavorable soil conditions or improper use of fertilizers. The main characteristics of these losses are the following: Losses will result in a decrease in the amounts of plant available soil nutrients Nutrient losses occur by: 1.Releases from the soil - leaving the soil-plant system 2.Transformation of soil nutrients into non-available forms (i.e. precipitation, chemical reactions resulting insoluble forms etc.) = „internal losses” PELEPASAN HARA DARI TANAH 1.Crop removal by yields 2.Erosion losses – nutrients in soil particles removed from soil by water 3.Runoff – loss of dissolved nutrients moving across the soil profile 4.Leaching– moving dissolved nutrient forms downward into the groundwater 5.Gaseous losses to the atmosphere by volatilization and denitrification. Under various cropping systems, both internal and external losses of nutrients from soils may be rather diverse. „INTERNAL LOSSES” 1.Transformation of soil nutrients into non-available forms (i.e. precipitation, chemical reactions resulting insoluble forms etc.) 2.Transformation into insoluble forms – typical for P Strong fixation in interlayer sites of clay minerals – ammonium and K+ ions 3.These forms do not leave the soil = therefore referred as „internal losses”
Diunduh dari: ……… 24/12/2012 HILANGNYA KESUBURAN TANAH What happens if we lose soil fertility, we will eventually cease to exist as soil is alive and we require soil for almost all of the food that we grow today around the world. The healthy soil contains: 1.It has sufficient concentrations of nitrogen, phosphorous, and potash (potassium) to support plant life. 2.It also has sufficient levels of the trace minerals needed for plant nutrition, including boron, chlorine, cobalt, copper, iron, manganese, magnesium, molybdenum, sulfur, and zinc.
Diunduh dari: 24/12/2012 EROSI TANAH Soil erosion is a natural process characterized by the transport or displacement of particles (sediment) that are detached by rainfall, flowing water, or wind. Soil erosion can be caused by the improper use of lands for cultivation or grazing and by deforestation. The types of soil erosion associated with agricultural activities are : 1.Splash erosion, which occurs when rain hits exposed soils. 2.Sheet and rill erosion, which mainly moves soil particles from the surface or plough layer of the soil. Surface sediments typically contain higher pollution potential due to richer nutrient content, the presence of chemicals from past fertilizer and pesticide applications, and natural biological activities. 3.Rill and gully erosion, severe erosion in which trenches are cut to a depth greater than 1 foot. Generally, trenches too deep to be crossed by farm equipment are considered gullies (USEPA, 1994). 4.Stream and channel erosion, which occurs due to increased rates and volumes of runoff from agricultural land uses flowing through a stream or channel.
Diunduh dari: actors.html……… 24/12/2012 EROSI TANAH Effect on soil erosion Slope angle and length affects runoff generated when rain falls to the surface. Examine the diagram below showing the relationship between hill slope position, runoff, and erosion. The amount of water on a particular hill slope segment is dependent on what falls from precipitation and what runs into it from an upslope hill slope segment. The hill slope has been divided into several segments and the amount of precipitation falling on each segment is the same. As water runs down slope, the water that has accumulated in segment A runs off adding to what falls into segment B by precipitation. The water in B runs into C, and C into D, and so on. The amount of water increases in the down slope direction as water is contributed of water from upslope segments. The velocity of the water increases as well as it moves towards the base of the slope. As a result, the amount and velocity of water, and hence rate of erosion increases as you near the base of the slope.
Diunduh dari: 24/12/2012 EROSI TANAH PENGENDALIAN EROSI Soil erosion occurs naturally when rain falls. Runoff flows to the lowest point of the landscape. The velocity depends on the characteristics of the soils, the slope of the land and the vegetative cover. Erosion can be a serious environmental problem when the land is disturbed by development, agriculture, or forestry. Surfaces like roads, roofs, driveways and hard-packed soils will not absorb water, and the runoff increases. Expanses of pavement like parking lots reduce the chances for ground water recharge. Exposed soils are lost and the land becomes less productive. Fertilizers and pesticides that may have been applied wash away, too, causing water quality problems for people living downstream.
Diunduh dari: ……… 24/12/2012 EROSI TANAH EROSION EFFECTS ON SOIL WATER STORAGE, PLANT WATER UPTAKE, AND CORN GROWTH B. J. Andraski and B. Lowery SSSAJ Vol. 56 No. 6, p Levels of past erosion were based on depth to red clay (2Bt horizon): slight, 0.95 m; moderate, 0.74 m; and severe, 0.45 m. The total quantity of plant-extractable water that could be stored in the upper 1 m of slightly eroded soil (181 mm) was 7% more than that for moderately eroded soil (169 mm) and 14% more than that for severely eroded soil (159 mm). For all erosion levels, water retained in the 0.5- to 1.0-m soil depth was utilized by corn. Erosion level had no negative effect on early-season plant growth. As plant- extractable water decreased to <55 to 60% of total, evapotranspiration (ET) and vegetative-growth rates decreased as erosion level increased. The greatest differences in ET rates among erosion levels were observed during a 35-d period in the drought year of 1988 when rates averaged 3.7 mm d −1 for slight erosion, 2.6 mm d −1 for moderate erosion, and 2.2 mm d −1 for severe erosion. For the 3 yr in which plant water stress was observed, maximum plant heights for the slight erosion level averaged 7% more than those for moderate erosion and 13% more than those for severe erosion. Although the soil's capacity to store and supply water decreased as erosion increased, the observed effects of erosion level on grain and stover yields, grain- yield components, and harvest populations typically were not significant.
Diunduh dari: https://www.soils.org/publications/sssaj/abstracts/76/5/1789……… 24/12/2012 EROSI TANAH. CROPPING AND TILLAGE SYSTEMS EFFECTS ON SOIL EROSION UNDER CLIMATE CHANGE IN OKLAHOMA X.-C.(John) Zhang SSSAJ Vol. 76 No. 5, p Soil erosion under future climate change is very likely to increase because of increases in occurrence of heavy storms. The objective of this study is to quantify the effects of common cropping and tillage systems on soil erosion and surface runoff during 2010 to 2039 in central Oklahoma. A combination of 18 cropping and tillage systems is evaluated using the Water Erosion Prediction Project (WEPP) model for 12 climate change scenarios projected by four global climate models (GCMs) under three emissions scenarios. Tillage systems include conventional, reduced, delayedno tillage. Cropping systems include continuous monocultures of winter wheat, soybean, sorghumcotton and double crops of wheat and soybeans. Compared with the present climate, overall t tests show that the future mean precipitation will decrease by some 6% (>98.5% probability), daily precipitation variance increase by 12% (>99%), and mean temperature increase by 1.36°C (>99%). Despite the projected precipitation declines, the overall averaged runoff and soil loss will increase by 19.5 and 43.5% because of increased occurrence of large storms. Soil erosion is positively related to the degree of tillage disturbances in all cropping systems. Compared with the conventional till, reduced, delayedno tillage substantially reduce soil erosion, showing that adoption of conservation tillage will be effective in controlling soil erosion in the next 30 yr. Cropping systems decrease runoff and soil loss from continuous cotton to soybean to sorghum to wheat in all tillage systems under climate change, indicating a preference of winter wheat for controlling runoff and soil loss in the region.
Diunduh dari: https://www.agronomy.org/publications/sssaj/abstracts/56/3/SS ……… 24/12/2012 DEGRADASI LAHAN. SOIL EROSION EFFECTS ON CORN YIELDS ASSESSED BY POTENTIAL YIELD INDEX MODEL E. M. Craft, R. M. Cruse and G. A. Miller SSSAJ Vol. 56 No. 3, p Soil erosion alters crop production via alteration of the soil chemical and physical environment. The objectives of this study were to: (i) develop a Potential Yield Index (PYI) model to index soil productivity based on simulated root growth, soil properties, and potential nutrient and water uptake of corn (Zea mays L.) through a growing season, (ii) utilize the PYI to estimate erosion effects on soil productivity by simulating the removal of 15 and 30 cm of soil, and (iii) simulate the impact of fertilizer additions to the eroded soil on the PYI. The PYI model independently estimates P, K, and water (W) uptake by corn. From these estimates, three separate yield indexes (PYI P, PYI K, and PYI W ) are calculated. The lowest yield index is identified as the PYI for a given soil. The predicted PYIs for 45 soils in Iowa compared well to the yr average corn yield (R 2 = 0.83) and corn suitability rating (R 2 = 0.73) for each soil. Changes in the PYI were predicted for 15 and 30 cm of simulated erosion. After 15-cm soil loss, the PYI for all soils decreased, with all but three soils remaining within 15% of the uneroded PYI. The PYI decreased further after 30-cm soil loss, with only 12 soils remaining within 15% of the uneroded PYI. Fertilizer additions to the plow layer of the eroded soils were then simulated. The PYI returned to within 5% of the uneroded PYI for 38 soils with 15-cm soil loss and for 27 soils with 30-cm soil loss. The PYI indicated that the soil factor that most limited plant yield changed with the soil, amount of soil loss, and plow-layer soil fertility status.
Diunduh dari: ……… 25/12/2012 EROSI TANAH PERKIRAAN TINGKAT EROSI TANAH DI SUB DAS BESAI, LAMPUNG BARAT Asep Mulyono Jurnal Riset Geologi dan Pertambangan, Vol 19, No 1 (2009) Tingkat erosi tanah di sub DAS Besai telah diperkirakan sebagai dasar kuantitatif dalam merekomendasikan upaya mempertahankan, memulihkan, meningkatkan kesuburan dan fungsi tanah sebagai pengatur tata air. Perkiraan tingkat erosi tanah dilakukan dengan metoda RUSLE yang dilakukan secara spasial dengan menggunakan perangkat lunak Sistem informasi geografis (SIG). Erosivitas, erodibilitas, kemiringan lereng, panjang lereng, sistem penanaman dan faktor konservasi merupakan 6 parameter data yang dimasukan dalam pendekatan RUSLE. Tingkat konversi lahan, khususnya hutan lindung menjadi lahan pertanian dan perkebunan, sangat pesat terjadi di Sub DAS Besai. Sub DAS Besai yang terletak di wilayah Kecamatan Sumber Jaya, Kabupaten Lampung Barat merupakan salah satu bagian hulu DAS Tulang Bawang Lampung. Selama rentang waktu 30 tahun (1970 – 2000) telah terjadi penurunan tutupan lahan hutan sebesar 48 %. Perubahan terjadi sebagai akibat tingginya aktivitas masyarakat dalam usaha tani kopi monokultur dan tanaman semusim. Hasil studi menunjukkan 23.62% wilayah penelitian dikategorikan dalam tingkat erosi tanah yang normal, tingkat ringan seluas 42.98%, tingkat moderat seluas 14.57%, tingkat berat seluas 15.38% dan sangat berat seluas 3.45%. Seluas 45% wilayah dengan tutupan lahan perkebunan kopi mengalami tingkat erosi dalam kategori ringan sampai sangat berat pada semua rentang kelerengan dan jenis tanah. Perkebunan kopi sistem monokultur mengakibatkan lapisan tanah sangat mudah tergerus oleh adanya aliran permukaan dikarenakan tidak adanya tutupan tanah di bawah kanopi tanaman kopi tersebut.
Diunduh dari: staff.uny.ac.id/..../artikel_sediment%20yield_sainte... ……… 25/12/2012 EROSI TANAH EVALUASI SEDIMENT YIELD DI DAERAH ALIRAN SUNGAI CISANGGARUNG BAGIAN HULU DALAM MEMPERKIRAKAN SISA UMUR WADUK DARMA Muhammad Nursa’ban. Hasil Penelitian Dosen muda tahun 2006, Dosen Jurusan Pendidikan Geografi UNY. Hasil penelitian menunjukan bahwa tingkat erosi tanah permukaan yaitu ,74 ton/tahun, atau rata-rata 573,795 ton/ha/tahun, erosi total ,43 ton/tahun atau 717,244 ton/ha/tahun dan erosi tanah yang diperbolehkan yaitu 686,033 ton/tahun atau sekitar 12,473 ton/ha/tahun. Data-data tersebut menunjukkan bahwa tingkat erosi permukaan maupun erosi total berlangsung cukup tinggi dibandingkan dengan besar erosi yang diperbolehkan. Sediment Yield tahunan di Waduk Darma yaitu ,419 ton/tahun atau ,660 m3. Waduk Darma tidak dapat berfungsi lagi yaitu pada saat mencapai umur ± 84,25 tahun. Tahun 2006 Waduk Darma telah beroperasi selama 36 tahun sehingga sisa umur Waduk Darma sampai terpenuhinya tampungan mati oleh sedimen yaitu ± 48,25 tahun atau tampungan mati akan terisi penuh yaitu pada tahun ± 2054.
Diunduh dari: ……… 25/12/2012 EROSI TANAH PREDIKSI BEBAN NUTRIEN DAN SEDIMEN DAS SUMPUR DANAU SINGKARAK MENGGUNAKAN MODEL AGNPS Tuahta Tarigan dan Iwan Ridwansyah. LIMNOTEK, 2005, Vol, XII, No, 2, p AGNPS merupakan sebuah program model untuk mensimulasikan kualitas air dan sedimen dari suatu catchment yang didominasi lahan pertanian. Model ini dikombinasikan dengan perangkat program GIS untuk memperkirakan kemungkinan penambahan fospor ke DAS Sumpur, Paket Program GIS (ArcView 3.1, 3D Analyst, Spatial Analyst) digunakan untuk mempersiapkan input data model dan proses penempatan dari hasil simulasi. Perkiraan dari loading nutrient dari Sungai Sumpur yang masuk ke Danau Singkarak memperlihatkan nilai ton tahun-1 sedimen, 52,5 ton tahun-1 Total N dan 37,5 ton tahun-1 Total P dan 195 ton tahun-1 COD.
Diunduh dari: ……… 25/12/2012 EROSI TANAH MODIFIKASI FAKTOR C-USLE DALAM MODEL ANSWERS UNTUK MEMPREDIKSI EROSI DI DAERAH TROPIKA BASAH (STUDI KASUS: DAS NOPU HULU, SULAWESI TENGAH) Y. Hidayat, N. Sinukaban, H. Pawitan, dan K. Murtilaksono Jurnal Tanah dan Iklim. Vol.26 No.4 Th Penelitian dilakukan untuk : a) mendefinisikan nilai faktor pengelolaan tanaman sebagai parameter input model ANSWERS, b) membangun model ANSWERS dalam PCRaster untuk mensimulasikan perubahan penggunaan lahan dan penerapan teknik konservasi tanah dan air, dan c) mengkaji dampak konversi hutan terhadap aliran permukaan, erosi dan kehilangan hara. Aliran permukaan dan erosi harian diukur pada lahan hutan primer, hutan sekunder, lahan terbuka, jagung, kakao muda, kakao sedang, kakao dewasa, dan tumpang sari antara kakao muda dengan jagung, pisang dan ketela pohon. Pada outlet daerah aliran sungai debit aliran ditentukan melalui pengukuran tinggi muka air dan kecepatan aliran, sedangkan volume sedimen diukur melalui pengambilan sampel sedimen. Penggunaan faktor pengelolaan tanaman parsial pada model ANSWERS dan ANSWERS-PCRaster memberikan hasil prediksi erosi lebih baik dibandingkan dengan menggunakan faktor pengelolaan tanaman USLE (faktor C-USLE), khususnya pada curah hujan tinggi. Penghutanan kembali lahan berlereng curam (> 45%) yang diikuti oleh penerapan teras gulud pada lahan pertanian merupakan tindakan pengelolaan terbaik dalam mengendalikan aliran permukaan dan erosi untuk menjamin pertanian berkelanjutan dan keberlanjutan fungsi daerah aliran sungai. Konversi hutan ke lahan pertanian telah meningkatkan aliran permukaan, erosi dan kehilangan hara.
Diunduh dari: jatim.litbang.deptan.go.id/.../index.php?... ……… 25/12/2012 EROSI TANAH. DEGRADASI TANAH DI LAHAN KERING WILAYAH BARITO KALIMANTAN TENGAH M. A. Firmansyah, R.Y. Galingging dan Suparman (Balai Pengkajian Teknologi Pertanian Kalimantan Tengah) A. Krismawati (Balai Pengkajian Teknologi Pertanian Jawa Timur) Degradasi tanah di Indonesia umumnya terjadi di lahan kering yang dipicu oleh erosi tanah dan salah kelola tanah. Tujuan tulisan ini untuk menunjukkan besarnya erosi yang terjadi pada berbagai sistem usahatani eksisting antara lain: padi gogo, jagung, kacang tanah, ubi kayu, dan karet rakyat. Lokasi penelitian dilaksanakan di Lagan (kemiringan 6%) di Kabupaten Barito Timur dan Jingah (kemiringan 16%) di Kabupaten Barito Utara. Hasil analisis menunjukkan bahwa Jingah mengalami erosi lebih besar dibandingkan Lagan, hal ini disebabkan oleh tingginya faktor erosivitas hujan, kemiringan lereng, dan teknik konservasi tanah yang buruk. Erosi potensial di Jingah mencapai t/ha/th sedangkan di Lagan mencapai 431 t/ha/th. Kondisi tersebut menyebabkan kedua lokasi tergolong memiliki Indeks Bahaya Erosi (IBE) ekstrem, dengan nilai 47,4 untuk Jingah dan 11,2 untuk Lagan. Erosi aktual pada sistem usahatani di Jingah tertinggi pada karet rakyat mencapai 954 t/ha/th (91 mm/th), begitu juga di Lagan mencapai 183 t/ha/th (14 mm/th). Erosi aktual terendah pada sistem usahatani kacang tanah, di Jingah mencapai 505 t/ha/t (48 mm/th) dan di Lagan mencapai 97 t/ha/th (8 mm/th). Erosi yang terjadi dikedua lokasi jauh melampaui Eosi yang piperbolehkan (EDP) yang hanya mencapai 3 mm/th. Erosi yang terjadi berdampak terhadap kehilangan produktivitas cukup besar di Jingah yaitu 21% pada karet rakyat, dan terendah sebesar 2% di Lagan untuk padi gogo dan kacang tanah. Guna mencegah erosi yang besar, maka dikedua lokasi perlu dilakukan perbaikan terutama pada pengelolaan teknik konservasi tanah.
Diunduh dari: balittanah.litbang.deptan.go.id/.../sutonocitarum08... ……… 25/12/2012 EROSI TANAH EROSI PADA BERBAGAI PENGGUNAAN LAHAN DI DAS CITARUM S. Sutono, S. H. Tala’ohu, O. Sopandi, dan F. Agus Balai Penelitian Tanah, Bogor Prosiding Seminar Nasional Multifungsi dan Konversi Lahan Pertanian Lahan sawah mempunyai banyak fungsi, termasuk diantaranya fungsi produksi, dan lingkungan. Penelitian bertujuan untuk menduga besarnya erosi pada lahan pertanian di daerah aliran sungai Citarum serta menduga besarnya biaya pengganti (replacement cost method/RCM) pengamanan erosi jika luas lahan sawah berkurang. Pendugaan erosi menggunakan metode universal soil loss equation (USLE). Hasil penelitian menunjukkan bahwa erosi pada lahan sawah lebih rendah dibandingkan dengan tegalan, kebun campuran, kebun teh, kebun karet, dan hampir sama dengan tingkat erosi hutan. Erosi paling tinggi terjadi pada lahan tegalan. Lahan sawah erosinya berkisar antara 0,33 t/ha/tahun dan 1,45 t/ha/tahun. Seluruh replacement cost untuk Citarum pada tahun 2000 sebesar Rp. 18,6 milyar. Jumlah ini adalah perkiraan investasi yang harus dikorbankan untuk penanganan sedimen apabila sawah yang ada sekarang di Citarum mengalami konversi.
Diunduh dari: balittanah.litbang.deptan.go.id/.../kundarto17.pdf ……… 25/12/2012 EROSI TANAH NERACA AIR, EROSI TANAH DAN TRANSPOR LATERAL HARA NPK PADA SISTEM PERSAWAHAN DI SUB DAS KALI BABON, SEMARANG Muhamad Kundarto 1, F. Agus 2, Azwar Maas 3, dan B. H. Sunarminto 3 Jurusan Ilmu Tanah UPN “Veteran” Yogyakarta, 2 Balai Penelitian Tanah Bogor, 3 Jurusan Tanah UGM Yogyakarta Prosiding Seminar Nasional Air, Erosi Tanah Konversi Lahan Pertanian Penelitian ini bertujuan untuk mengetahui neraca air, erosi tanah, dan transpor lateral hara NPK pada sistem persawahan. Penelitian dilaksanakan selama dua musim tanam dari Oktober 2001 sampai Juni 2002 di sub daerah aliran sungai Kali Babon, Semarang. Hasil penelitian pada musim ke dua menunjukkan total input air sebesar 4031,81 mm yang berasal dari air irigasi 3530,41 mm dan air hujan 501,40 mm. Total output air sebesar 3035,13 mm terdiri atas air drainase 153,22 mm, infiltrasi/perkolasi 94,74 mm, evapotranspirasi 85,87 mm, dan genangan 2701,30 mm. Selisih antara input dan output air sejumlah 996,68 mm diduga merupakan total air yang menyusup secara lateral melalui pematang (seepage dan lubang tikus/ketam) dan air yang tersimpan pada lapisan olah. Total tanah yang tererosi dari daerah atas (upland) dan masuk ke sawah pada musim sebesar 864,1 kg dan yang keluar (lewat outlet petak no. 18) sebesar 347,5 kg. Sehingga tanah yang mengendap di petak sawah sebesar 516,6 kg (2,05 t/ha). Pada musim kedua, total tanah masuk ke sawah sebesar 1567,1 kg dan yang keluar dari sawah (lewat outlet petak 18) sebesar 209,6 kg. Sehingga tanah yang mengendap di petak sawah sebesar 1357,5 kg (5,40 t/ha). Jumlah tanah yang mengendap pada musim kedua 2,5 kali lebih besar dibanding musim pertama. Total hara N, P, dan K dalam bentuk NH4+, NO3-PO43-, dan K+ yang terkandung dalam air irigasi dan masuk ke sawah masing-masing sebesar: 98; 478; 29; dan 237 g/ha/musim. Sedangkan total hara NH4+, NO3-, PO43-, dan K+ yang terkandung dalam air drainase dan keluar dari sawah masing-masing sebesar: 10; 161; 413; dan 35 g/ha/musim. Penambahan hara NH4+, NO3-, dan K+ pada sawah masing-masing sebesar: 88; 317; dan 203 g/ha/musim. Hara PO43- mengalami pengurangan sebesar 384 g/ha/musim.
Diunduh dari: jurnalpengairan.ub.ac.id/index.php/jtp/.../103 ……… 25/12/2012 EROSI TANAH. APLIKASI SISTEM INFORMASI GEOGRAFIS (SIG) UNTUK IDENTIFIKASI LAHAN KRITIS dan ARAHAN FUNGSI LAHAN DAERAH ALIRAN SUNGAI SAMPEAN Runi Asmaranto, Ery Suhartanto dan Bias Angga Permana Jurusan Pengairan Fakultas Teknik Universitas Brawijaya DAS Sampean merupakan daerah aliran sungai yang kondisi topografinya rata- rata sangat curam. Kondisi tata guna lahan yang sebagian besar sawah irigasi ini cukup memungkinkan terjadinya erosi. Apalagi tataguna lahan lainnya berupa ladang, semak dan sawah tadah hujan yang tanamannya merupakan tanaman berkedalaman akar rendah dan berperan besar dalam proses penyebab terjadinya kerusakan tanah, mempercepat laju erosi dan meningkatkan volume limpasan permukaan. Metode yang digunakan dalam menghitung besarnya laju erosi adalah metode MUSLE dimana metode tersebut menggunakan pendekatan dari faktor limpasan permukaan. Pengolahan data-datanya menggunakan Sistem Informasi Geografis (SIG) karena memudahkan dalam penganalisaan dan pengelompokan data. Dari hasil analisa diperoleh debit limpasan permukaan yang terjadi sebesar 247,967 m3/ dt. Total Erosivitas Limpasan Permukaan yang terjadi adalah ,73 m2/jam, hal ini memicu terjadinya laju erosi yang rata-ratanya mencapai ,94 ton/ha/thn, atau identik dengan kehilangan tanah sebesar : 258,470 cm/thn. Besarnya laju erosi pada DAS Sampean ini mengakibatkan tingkat bahaya erosi sebesar 95,54% dari luas wilayahnya termasuk sangat berat. Sedangkan untuk tingkat bahaya erosi lainnya yaitu, berat : 2,72%, sedang : 1,02%, ringan : 0,72%. Analisa kemampuan lahan didominasi kemampuan kelas VII (75,39%), yang merupakan daerah Pengembalaan Terbatas. Sedangkan ARLKT di DAS Sampean terdiri dari 3 (tiga) kawasan, yaitu Kawasan lindung (10,53%), Kawasan Penyangga (52,23%), Kawasan Budidaya Tanaman Tahunan (37,23%).
Diunduh dari: repository.ung.ac.id/.../TINGKAT_EROSI_PERM... ……… 25/12/2012 EROSI TANAH TINGKAT EROSI PERMUKAAN PADA LAHAN PERTANIAN JAGUNG DI DAS ALO-POHU PROVINSI GORONTALO Fitryane Lihawa Pusat Studi Lingkungan Universitas Negeri Gorontalo PROSIDING KONFERENSI DAN SEMINAR NASIONAL PUSAT STUDI LINGKUNGAN HIDUP INDONESIA KE – 15 SEPTEMBER 2012 DI MATARAM Fenomena pemanfaatan lahan untuk pertanian semakin meningkat, terlebih lagi setelah dicanangkannya Program Agropolitan di Provinsi Gorontalo. Pada Tahun 2003 luas pertanian lahan kering adalah ha dan Tahun 2005 meningkat hingga ha, dan pada Tahun 2010 mencapai ha (Citra Landsat Tahun 2003, Tahun 2005 dan BPS Tahun 2011). Perubahan penggunaan lahan tersebut dapat mengakibatkan kerusakan DAS yang berdampak pada rusaknya fungsi hidroorologis DAS. Salah satu DAS penyumbang sedimen terbesar ke Danau Limboto adalah DAS Alo-Pohu. Pengukuran erosi permukaan dilakukan dengan menggunakan sistem plot dengan bentuk persegi panjang. Ukuran petak yaitu lebar 2 m dan panjang 5 m dan ketinggian 20 cm di atas permukaan tanah. Untuk mengkaji pengaruh curah hujan terhadap erosi permukaan pada lahan pertanian jagung digunakan analisis regresi. Hasil pengukuran erosi permukaan pada lahan pertanian jagung dengan kemiringan lereng datar (3,5%) menunjukkan bahwa tingkat erosi permukaan sebesar 1,04 ton/ha/tahun (sangat rendah), pada lereng landai tingkat erosi permukaan sebesar 9,88 ton/ha/tahun (sangat rendah), pada lereng agak curam tingkat erosi permukaan sebesar ton/ha/tahun (rendah), dan pada lereng curam tingkat erosi permukaan sebesar ton/ha/tahun (sedang). Hasil pengamatan selama satu tahun menunjukkan bahwa erosi permukaan akan berkurang seiring dengan umur pertumbuhan jagung. Hal ini disebabkan karena telah disertai dengan tumbuhnya tanaman bawah (rumput-rumputan) pada umur jagung memasuki bulan kedua dan ketiga. Pengaruh curah hujan terhadap erosi permukaan pada lahan pertanian jagung lereng datar adalah Log Y = -3,2 + 3,11 Log X; pada lereng landai Log Y = -3,02 + 2,93 Log X; pada lereng agak curam Log Y = -2,73 + 3,74 Log X; dan pada lereng curam Log Y = 0,28 + 1,71 Log X.
Diunduh dari: ……… 25/12/2012 EROSI TANAH ANALISIS SPASIAL TINGKAT BAHAYA EROSI DI WILAYAH DAS CISADANE KABUPATEN BOGOR Tuti Herawati (Pusat Litbang Hutan dan Konservasi Alam) Jurnal Penelitian Hutan dan Konservasi Alam. Vol. VII No. 4 : , 2010 Penelitian ini bertujuan untuk menghitung tingkat bahaya erosi di DAS Cisadane berdasarkan rumus USLE menggunakan analisis GIS. Berdasarkan rumus yang digunakan, maka diperlukan empat jenis peta sebagai dasar perhitungan tingkat bahaya erosi, yaitu peta curah hujan, peta jenis tanah, kemiringan, dan peta penutupan lahan. Pada setiap peta dilakukan klasifikasi menjadi empat atau lima kelas berdasarkan standar tertentu. Proses overlay dilakukan untuk mendapatkan hasil akhir berupa tingkat bahaya erosi yang dikategorikan menjadi lima kelas yaitu sangat ringan, ringan, sedang, berat, dan sangat berat. Hasil penelitian menunjukkan bahwa tingkat bahaya erosi di DAS Cisadane meliputi sangat ringan hingga sangat berat dengan persentase luas lahan berturut-turut dari yang sangat ringan hingga sangat berat 55,85%; 15,74%; 6,33%; 0,81%; dan 0,30%. Lahan dengan tingkat bahaya erosi sangat berat meliputi luas 316 ha dan tingkat berat meliputi 851 ha. Tamansari merupakan kecamatan yang memiliki luas wilayah dengan tingkat bahaya erosi sangat berat terluas yaitu 87 ha. Beberapa kecamatan lain yang memiliki luas lahan dengan tingkat bahaya erosi berat adalah Tenjolaya, Caringain, Cijeruk, dan Nanggung. Hasil penelitian ini dapat digunakan sebagai data dasar untuk membuat rencana pengeolaan DAS yang baik.
Diunduh dari: balittanah.litbang.deptan.go.id/.../hsuganda_sayura... ……… 25/12/2012 EROSI TANAH PENGKAJIAN PENERAPAN TEKNIK KONSERVASI TANAH PADA LAHAN USAHATANI BERBASIS TANAMAN SAYURAN DI SENTRA TEMBAKAU H. Suganda dan Ai Dariah Pengkajian Penerapan Teknik Konservasi Tanah BALITTANAH – LITBANG - DEPTAN. Studi ini bertujuan untuk mendapatkan informasi tentang penerapan teknik konservasi tanah dalam usahatani sayuran di daerah sentra tembakau, Kabupaten Temanggung. Penelitian dilaksanakan tepatnya di tengah lokasi demontrasi plot penerapan teknologi konservasi tanah dengan luas lahan 2,85 ha di Desa Batursari dengan 13 orang petani kooperator, dan 2,53 ha di Desa Kledung dengan 10 orang petani kooperator. Pengamatan berlangsung mulai musim hujan (MH) 2006/07 sampai dengan MH 2007/08. Tanah di dua lokasi tersebut tergolong Andisol. Teknik konservasi tanah yang diterapkan adalah cara mekanik dengan tambahan rumput penguat teras. Hasil penelitian menunjukkan bahwa dengan menerapkan teknik konservasi tanah ternyata erosi pada lahan sayuran di sentra tembakau dapat diturunkan sebanyak 38,4 % - 66,2 %, bahkan kehilangan tanah akibat erosi dapat ditekan menjadi < 6,0 t/ha. Rumput penguat teras (paspah) dengan luasan 1 m2, dapat menghasilkan hijauan 3,6-4,0 kg, cukup untuk kebutuhan sehari pakan domba yang bobotnya sekitar 20 kg. Penerapan konservasi tanah dapat mengurangi laju kehilangan hara akibat erosi dan mempertahankan kesuburan tanah. Petani kooperator di Desa Kledung yang sudah menerapkan teknik konservasi tanah, lahannya relatif lebih subur dibanding dengan lahan petani kooperator di Desa Batursari, sehingga rata-rata pendapatannya per tahun lebih tinggi dari Rp
Diunduh dari: ……… 25/12/2012 ANCAMAN KEKERINGAN SAWAH KERING, WARGA SHALAT ISTISQO’ Petani Nagari Canduang Koto Laweh was-was jika musim kemarau terus berlanjut hingga sebulan ke depan. Irigasi yang berada di nagari itu tidak lagi mampu mengalirkan air ke lahan pertanian. Sebab debit air semakin berkurang sejak kemarau bulan lalu. Menanggapi persoalan yang terjadi, pemerintah nagari menganjurkan masyarakat untuk melaksanakan shalat minta hujan (istisqo’). ”Semoga hujan yang turun bisa menjadikan tanaman kami bisa kembali tumbuh subur,” harap Wan saat berbincang dengan Padang Ekspres di salah satu warung kopi di Jorong Tigo Alua Nagari Koto Laweh.
Diunduh dari: Sawah-di-Lebak-Kekeringan/6……… 25/12/2012 ANCAMAN KEKERINGAN HEKTARE SAWAH DI LEBAK KEKERINGAN Rabu, 8 Agustus :20 WIB Metrotvnews.com, Lebak: Kekeringan sawah di Kabupaten Lebak, Provinsi Banten, hingga saat ini mencapai hektare akibat kemarau yang terjadi belakangan ini. "Kekeringan ini tentu berdampak terhadap berkurangnya produksi pangan“. Ia mengatakan pihaknya terus melakukan penyelamatan tanaman padi yang mengalami kekeringan dengan pengoptimalan pompanisasi terpadu. Diperkirakan dari hektare itu dipastikan seluas hektare bisa diselamatkan dengan pengairan menggunakan pompanisasi terpadu. Sedangkan hektare terancam gagal panen. Sebagian besar areal persawahan yang terjadi kekeringan itu di daerah sawah tadah hujan. Sawah tadah hujan itu disebabkan tidak memiliki saluran irigasi yang memadai. Akibat kekeringan ini, petani mengalami kerugian hingga miliaran rupiah apabila tanaman padi mereka gagal panen. Saat ini, biaya produksi rata-rata Rp5 juta per hektare.
Diunduh dari: kekeringan……… 25/12/2012 ANCAMAN KEKERINGAN ANTARA. 20 Juni 2011 | 14:10 WIB 450 Ha sawah di Indramayu terancam kekeringan INDRAMAYU: Sekitar 450 hektare sawah di Desa Soge, Indramayu, Jawa Barat, terancam gagal panen akibat kekeringan. Pasokan air memasuki musim kemarau semakin sulit dan diperkirakan ratusan hektare sawah akan terancam gagal panen akibat kekeringan. Dua sungai pemasok air, yaitu kali Prawan dan Kali Persijat, debitnya semakin menurun. Jika hujan tidak turun, diperkirakan tanaman milik petani setempat yang baru berusia kurang dari dua bulan akan kering akibat pasokan air terhambat. Petani kurang memperhatikan cuaca. Mereka terlalu memaksakan tanam padi, padahal mulai memasuki kemarau. Musim tanam tahun sebelumnya pasokan air cukup melimpah, sehingga mereka terlena diperkirakan hujan masih panjang. Menurut dia, petani di daerah pantura Indramayu harus tanggap memperkirakan pasokan air hujan karena lahan pertanian masih mengandalkan tadah hujan. Lahan pertanian di sepanjang pantai pesisir utara Indramayu memasuki kemarau setiap tahun mengalami kekeringan, sementara musim hujan sawah sering terendam akibat banjir..
Diunduh dari: bekasi-kekeringan ……… 25/12/2012 ANCAMAN KEKERINGAN ANTARA. 12 September 2011 | 19:51 WIB HEKTARE SAWAH DI KABUPATEN BEKASI KEKERINGAN BEKASI (bisnis-jabar.com): Dinas Pertanian Kota Bekasi, Jawa Barat, mencatat sekitar hektare persawahan di wilayahnya mengalami kekeringan akibat debit air yang terus menurun selama musim kemarau. Sumber air dari waduk Jatiluhur melalui kali Tarum Barat terus menyusut selama musim KEMARAU. Saluran irigasi sawah di 23 kecamatan di Kabupaten Bekasi, saat ini sudah kering seiring berkurangnya debit air tersebut. Wilayah paling parah di bagian selatan, seperti Kecamatan Cibarusah, Cikarang Selatan, Serang Baru, dan Kecamatan Setu. Pompanisasi dilakukan untuk menjaga target produksi beras di Kabupaten Bekasi sebanyak 631 ribu ton setiap kali panen tetap terjaga.
Diunduh dari: ……… 25/12/2012 ANCAMAN KEKERINGAN PULUHAN HEKTARE SAWAH KEKERINGAN Puluhan hektare sawah di Dukuh Klampok, Desa Sendangsikucing, Kecamatan Rowosari mengalami kekeringan sejak satu pekan ini. Akibat kekeringan, tanaman padi berumur satu minggu terancam mati. Petani kesulitan mendapatkan pasokan air dari saluran irigasi karena lokasinya jauh. “Jika dalam jangka waktu tiga hari ke depan, pasokan air tidak ada, tanaman padi terancam mati,” (Menurut petani Sulaemi). Setiap musim kemarau tiba, puluhan hektare sawah di dukuhnya kekurangan air. Selain itu, puluhan hektare sawah di perbatasan Desa Bulak- Sendang si kucing juga kekurangan air. Pemerintah diharapkan dapat membuat saluran irigasi yang permanen agar air dapat mengairi lahan pertanian.
Diunduh dari: Sawah-Alami-Kekeringan ……… 25/12/2012 ANCAMAN KEKERINGAN Jum'at, 07 September 2012 | 00:51 WIB BELASAN RIBU HEKTARE SAWAH ALAMI KEKERINGAN TEMPO.CO, Surabaya - Kepala Bidang Produksi Tanaman Pangan Dinas Pertanian Jawa Timur, Achmad Nurfalakhi, mengatakan 13,9 ribu hektare sawah bertanaman padi di Jawa Timur mengalami kekeringan. Sebagai dampak akibat kekeringan sawah, sejumlah tanaman padi mengalami puso (gagal panen). Dinas Pertanian Jawa Timur mencatat, kekeringan paling luas terjadi di Kabupaten Bojonegoro seluas hektare, Lamongan hektare, Tulungagung seluas hektare, Trenggalek hektare dan Ngawi 948 hektare. Gagal panen yang dialami petani, menurut dia, terbagi dalam berbagai kriteria. Seluas 2.977,49 hektare padi mengalami gagal panen 100 persen dan hektare gagal panen 75 persen. Selain itu, seluas hektare mengalami kekeringan sedang (gagal panen 50 persen) dan seluas hektare mengalami kekeringan ringan (gagal panen 25 persen). TEMPO/Marifka Wahyu Hidayat
Diunduh dari: ……… 25/12/2012 ANCAMAN CEKAMAN AIR American-Eurasian J. Agric. & Environ. Sci., 5 (2): , 2009 EFFECTS OF DROUGHT STRESS ON GROWTH AND YIELD OF RICE (ORYZA SATIVA L.) CULTIVARS AND ACCUMULATION OF PROLINE AND SOLUBLE SUGARS IN SHEATH AND BLADES OF THEIR DIFFERENT AGES LEAVES A. Mostajeran and V. Rahimi-Eichi One of the main problems of rice cultivation and production is the lack of water resources, especially during periods of low rainfall which affect the vegetative growth rate and the amount of yield. In this study the effect of low water supply on the number of heading per hill, number of grain per hill, dry weight of vegetative tissues and panicle and 1000 grain weight in three new cultivars of rice including 216, 829 and Zayandeh-Rood were measured under submerged and non-submerged conditions in a randomize complete block design with three replicates. Simultaneously, the variation in proline and total sugars in sheaths and blades of leaves at different ages was determined. The data indicated that Zayandeh-Rood cultivar showed the lowest reduction in shoot dry weigh and the number of tillers per hill under non- submerged conditions. Furthermore, the panicle weight and the number of filled grains per spike were higher in Zayandeh-Rood cultivar than the other cultivars. In addition, the result of this study show that Zayandeh-Rood cultivar in which originated from local cultivars, have higher ability in solute accumulation such as proline and total carbohydrates than the other new lines. Due to correlation between drought tolerance of Zayandeh-Rood and solute accumulation, it may be suggested that the solute accumulation is one of the mechanisms for drought tolerance in rice.
Diunduh dari: 25/12/2012 ANCAMAN CEKAMAN AIR. Ying Yong Sheng Tai Xue Bao Jul;17(7): EFFECTS OF WATER STRESS DURING GRAIN-FILLING PERIOD ON RICE GRAIN YIELD AND ITS QUALITY UNDER DIFFERENT NITROGEN LEVELS. Cai Y, Wang W, Zhu Z, Zhang Z, Lang Y, Zhu Q To examine the effects of nitrogen (N) supply and water stress on rice grain yield and its quality, a pot experiment was conducted at Yangzhou University. Three rice cultivars were grown under two N levels (high N and normal N) from initial heading, and two water conditions (well watering and water stress) were installed for each of the two N levels from flowering to maturity. The results showed that when the plants of test cultivars were grown under normal N level, water stress markedly reduced the grain-filling percentage and grain weight, resulting in a significant decrease of grain yield by 11.6% to approximately 14.7%. Though the head- milled rice had a slight increase, the percentage of chalkiness was significantly increased by 18.7% to approximately 33.1%, which resulted in an inferior performance in grain-apparent quality. In contrast, when the plants were grown under high N level, water stress increased the grain yield by 18. 8% to approximately 22.2% because of the increase of grain-filling percentage and grain weight. As compared with well watering, water stress decreased the percentages of chalky grain and chalkiness by 15.3% to approximately 37.2% and 13.7% to 29.9%, respectively, which improved the performance of grain-apparent quality. The pronounced effects of N application and water treatment were observed on the RVA profile and cooked quality. Under both two N levels, water stress decreased the peak viscosity and breakdown (except for Yangdao 6) while increased the setback. According to the performance in the indices of cooked quality, the palatability became poor when subjected to water stress under normal N level, as the result of the increase of hardness and cohesiveness. In contrast, under high N level, water stress availed the ascending of viscosity at the early stage when rice flours were pasting, peak viscosity and breakdown were increased, and setback was decreased, suggesting that the palpability got well. It was concluded that mild water stress during grain-filling period was benefit for the development of high quality grain when rice plants were grown under high N level.
Diunduh dari: 25/12/2012 ANCAMAN CEKAMAN AIR BIOLOGIA PLANTARUM (PRAHA) 26 (4) : , 1984 EFFECT OF WATER STRESS AT DIFFERENT DEVELOPMENTAL STAGES OF FIELD-GROWN RICE AJoY K. BISWAS and M. A. CHOUDHVRI Water-stress for 10d at different developmental stages, affected relative water content and leaf water potential of plants. Subsequent rewatering removed these effects. Water stress lowered the contents of chlorophyll, protein, RNA and the activity of catalase, while it increased free proline accumulation and activities of protease, RNase and peroxidase. An overall improvement in biochemical parameters was achieved as soon as the stress was withdrawn by watering and this was reflected in subsequent developmental stages. Water-stress at the reproductive stages induced similar changes as in the vegetative stage but the removal of stress could not improve these parameters to the same extent as at the vegetative stage. In consequence, stress applied at the vegetative stage augmented yield parameters but when applied at the reproductive stage it significantly reduced the yield.
Diunduh dari: 25/12/2012 ANCAMAN CEKAMAN AIR Study of water stress effects in different growth stages on yield and yield components of different rice (Oryza sativa L.) cultivars Hemmatollah Pirdashti, Zinolabedin Tahmasebi Sarvestani, Ghorbanali Nematzadeh and A. Ismail. Australian Agronomy Conference th AAC, 4th ICSC. Water stress affects plant growth and development and ultimately, reduces grain yield of irrigated lowland rice. A field experiment was conducted during to evaluate the effect of water stress on the yield and yield components of four rice cultivars commonly grown in Mazandaran province, Iran. The cultivars used were Tarom, Khazar, Fajr and Nemat. The different water stress conditions were water stress during vegetative, flowering and grain filling stages and well-watered was the control. Water stress at vegetative stage significantly reduced plant height of all cultivars. Water stress at flowering stage had a greater grain yield reduction than water stress at other times. The reduction of grain yield largely resulted from the reduction in fertile panicle and filled grain percentage. Water deficit during vegetative, flowering and grain filling stages reduced mean grain yield by 21%, 50% and 21% on average in comparison to control respectively. The yield advantage of two semidwaf varieties, Fajr and Nemat, were not maintained under drought stress.
Diunduh dari: ……… 25/12/2012 ANCAMAN CEKAMAN AIR. Journal of Agricultural Biotechnology and Sustainable Development Vol. 2(6), pp , June 2010 EFFECT OF WATER DEFICIT AT GRAIN REPINING STAGE ON RICE GRAIN QUALITY M. Fofana, M. Cherif, B. Kone, K. Futakuchi and A. Audebert. Rice production is usually reduced by water stress that can evenly occur during rice cycle in West Africa under bimodal rainfall pattern. In order to determine the effects of water stress on rice grain quality, experiments were conducted on upland site (on ferralsol) at the main AfricaRice research center at M’be, 30 km North of Bouaké, Côte d’Ivoire. The rice varieties CG14 (Oryza glaberrima), WAB (Oryza sativa), and NERICA1 (cross WAB x CG14) were sown at 25 × 25 cm spacing during the dry season cropping period of 2000, 2001 and Irrigation line (Boon irrigation) was used to supply water until flowering stage. Water was then supply manually from the milky stage of each variety to its full ripening stage. Physical (husking yield, milling recovery, and head rice ratio), chemical (amylose and proteins contents) and cooking parameters (cooking time, volume expansion, rice flour gelatinization temperature, consistency and viscosity) of the harvested grains were determined in the laboratory. The results showed a significant difference (p < 0.05) between all the parameters in comparison with the checks samples and stressed crop. In general, NERICA 1 showed better physical and cooking quality traits than its parents. Rice samples from plots subject to lower water availability during repining stage showed higher protein content for all varieties studied. Increase in the average protein content of stressed samples were 31, 11.8 and 13.3% times, respectively for NERICA 1, CG14 and WAB , where (using the protein content of check plots as 100%) NERICA 1 showed higher husking yield, total mean milling recovery and head rice ratio for samples collected on stressed plots than the glaberrima and the sativa samples recorded on similar plots. Finding showed that cooking properties that meet West African rice consumers’ preferences for cooked rice were more improved for NERICA 1 than its parents in comparison with samples collected from stressed plots. It is concluded that moisture stress at ripening stage should be further investigated as potential indirect means of improving rice grain quality.