1 PERTANIAN BERKELANJUTAN Mk. AGROEKOLOGIPERTANIAN BERKELANJUTANOleh:Prof Dr Ir Soemarno, M.S.Oktober 2008
2 Dampak Pembajakan Tanah Soil is damaged considerably whenever it is ploughed and turned over.The moldboard plow brings subsoil to the surface and buries the crop residue layer so deep it is unable to decay properly.Virtually no soil residue is left on the surface, exposing the soil to erosion and impairing the water and mineral cycles.
3 Virtually no soil residue is left on the surface, exposing the soil to erosion and impairing the water and mineral cycles.
4 Dampak pembajakan tanah Today, millions of acres are being farmed without any tillage at all (no-till) or in such a way that adequate groundcover remains afterwards (ridge till, zone till, minimum till).Production systems that reduce or eliminate tillage in a manner consistent with effective weed control foster the four ecosystem processes discussed above.
5 CULTIVATION: MINIMIZE OLAH TANAH 1. Pengolahgan tanah secara dangkal2. Chisel plowing, not invert the soil3. Deep subsoiling4. Ridge tillages5. Shallow-tine, menggemburkan tanah6. Harrowing, menyiapkan bedengan7. No-till (tanam benih langsung; TABELA)8 …… etc.
6 Keaneka-ragaman: Diversify Enterprise diversification reduces financial risk by spreading income and costs (e.g., of pest control and fertilizer) out over several crops or livestock operations.Sustainability is increased when animal wastes become inputs to crop production on the same farm.
7 diversification reduces financial risk by spreading income and costs
8 Pergiliran tanaman : Rotate crops Moving from simple monoculture to a higher level of diversity begins with crop rotations, which break weed and pest life cycles, provide complementary fertilization to crops in sequence with each other—nitrogen-fixing legume crops preceding grain crops such as corn—and prevent buildup of pest insects and weeds.In many cases, yield increases follow from the "rotation effect." Including forage crops in the rotation will reduce soil erosion and increase soil quality.
9 Pergiliran tanaman : Rotate crops When planning crop rotations, it is important to consider that cultivated row crops—such as corn and soybeans or vegetables—tend to be soil-degrading. Since the soil is open and cultivated between rows, microbes break down organic matter at a more rapid pace.Furthermore, row crops have modest root systems and consequently do not contribute enough new organic matter to replace that lost from the open soil between rows; in most cases above-ground crop residues make only minor contributions to replacing lost organic matter.
10 ….. row crops have modest root systems and consequently do not contribute enough new organic matter to replace that lost from the open soil between rows; in most cases above-ground crop residues make only minor contributions to replacing lost organic matter.
11 MENYUBURKAN TANAH Animal feeds Green manure Annual seed legume ROTATION EFFECTS IN CROPSLEGUME = KACANG-KACANGANAnnual seed legumePerennial forage legumeKedelaiKacangtanahKacang hijauKac. Panjang, dllAnimal feedsGreen manureFIKSASI N2 dlm BINTIL AKARMENYUBURKAN TANAH
12 MENYUBURKAN TANAH ROTATION EFFECTS IN CROPS ANNUAL SEED LEGUME Vigna sinensis (Cowpea)Glycine max(soybeans = kedelai)Arachis hypogaea(peanut = kc.tanah)Hasil jagung dan kapas lebih baik kalau ditanam setelah cowpeaHasil jagung lebih baik kalau ditanam setelah kedelaiFIKSASI N2 dlm BINTIL AKARMENYUBURKAN TANAH
13 ROTATION EFFECTS IN CROPS FIKSASI N2 dlm BINTIL AKAR Perennial ForagesTURISENGONGlericideaFIKSASI N2 dlm BINTIL AKARMENYUBURKAN TANAH
14 CROP ROTATION EFFECTS ON SOIL KARAKTERISTIK TANAHBulk densityBahan organik tanahWater infiltrationAgregasi Tanah….TATA UDARAKETERSEDIAAN HARATATA AIRHUBUNGAN TANAH - TANAMANMemperbaiki Kualitas Tanah pd Zone PERAKARAN tanaman
15 TANAMAN PENUTUP-TANAH & PUPUK HIJAU Perennial and biennial cereal crops, annual green manures, and annual cover crops are important for building soil in field-cropping systems.The soil-building crops most appropriate for a given farm depend not only on regional factors (torrential rains, etc.) but also on the type of production system involved: each farmer will have to determine which cover crops are most appropriate to his or her system.
16 Perennial and biennial cereal crops, annual green manures, and annual cover crops are important for building soil in field-cropping systems.
17 Kompos, Rabuk, dan PupukCrop rotations, cover-cropping, and green-manuring are key strategies for soil building, which is the foundation of sustainable farming.However, modern production systems place high demands on land resources, requiring additional attention to soil fertility management.
18 Kompos, Rabuk, dan PupukManures and composts, especially those produced on-farm or available locally at low cost, are ideal resources for cycling nutrients on-farm.From the standpoint of overall soil and crop health, composts or aged manures are preferred.where quantities are available. Much higher rates are not unusual, especially where soil is being improved rather than maintained.
19 3. Sampah yang dapat dikomposkan 4. Limbah pertanian/ peternakan/ ORGANIC MATTER INPUTS1. Rabuk kandang2. Limbah domestik3. Sampah yang dapat dikomposkan4. Limbah pertanian/ peternakan/perikanan5. Limbah industri makanan danminuman6. Limbah agroindustri7. Bahan organik lainnya
20 INTERAKSI YANG SPEKULATIF 1. Pupuk mempengaruhi pertumbuhan gulma = tanaman2. Pupuk dapat meningkatkan gangguan Hama / Penyakit3. BO dpt mereduksi hangguan hama & penyakit4. BO dapat merangsang populasi fungi pengendali NEMATODA5. BO dapat menjerap pestisida6. BO dpt menjadi makanan alternatif bagi marginal pests
21 PUPUK - RABUK Pemupukan meningkatkan hasil/kualitas: The law of diminishing returnDosis PUPUK OptimumMinimize Fertilizer:Sistem rotasi dg legumeManure/ Bahan organikUji tanah & analisis tanamanKultivar dg kebutuhan hara rendahTeknologi aplikasiLimbah organikMusim / waktu tanamFiksasi N-biologis
22 Kompos, Rabuk, dan PupukCompost has a unique advantage in comparison to unaged manure and other organic soil amendments in that it has a (usually) predictable, and nearly ideal, ratio of carbon to nitrogen. (Parnes, 1990)Compost can be safely applied at rates of 12 tons per ha (Parnes, 1990),
23 NUTRIENT BALANCE IN THE SOIL: INPUTS RN = (AP + AR - RM - L)RN : hara dalam tanah pada akhir periode tAP : hara dalam tanah pada awal periode tAR : hara yang ditambahkan ke tanah selama periode tRM: hara yang dipanen selama periode tL : hara yg hilang selama periode tt : periode waktu tertentu
24 INTERAKSI YANG SPEKULATIF 1. Kultivasi dapat meningkatkan atau menurunkan gangguan hama atau penyakit2. Kultivasi mengendalikan gangguan gulma3. Kultivasi mempengaruhi dosis pupuk yang diperlukan4. Kultivasi meningkatkan efektivitas pestisida5. Kultivasi membenamkan/mengubur BO ke dalam tanah
25 INTERAKSI YANG SPEKULATIF 1. Herbisida mempengaruhi keparahan gangguan hama/penyakit2. Pestisida mempengaruhi organisme tanah dekomposer3. Insektisida mereduksi gangguan virus dan penyakit4. Insektisida meningkatkan populasi gulma5. Insektisida membunuh musuh alami6. Fungisida membunuh fungi tanah pengendali insek dan nematoda7. Fungisida mereduksi populasi dekomposer dan antagonist8. Pestisida menekan populasi cacing tanah9. …… ?
26 Kompos, Rabuk, dan PupukCompost has some particular advantages in row crop production, especially when used in conjunction with cover crops and green manures. In sandy soils, compost's stable organic matter is especially effective at absorbing and retaining water.Fresh plant material incorporated as green manure, on the other hand, retains its waxy leaf coating and cannot perform the same function until thoroughly digested by microbes.
27 THE NATIVE NUTRIENT POOL 1. Senyawa Organik : C, N, P, S , …...2. Pengurangan cepat karena:a. Mineralisasi dan serapan tanamanb. Mineralisasi, denitrifikasi,penguapanc. Mineralisasi dan penciciand. Erosi dan run off3. Penambahan melalui:a. Pemupukanb. Residu tanaman: akar + non akarc. Fiksasi biologisd. …...
28 Pengaruh bahan organik tanah 1. Pertumbuhan tanaman:a. Asam amino alanin, glisin dptdiserap tnmb. Zat tumbuh dan vitaminc. Asam di-hidroksi-stearat ……toksikd. Asam vanilat, as. Fenolkarboksilate. Pengaruh tidak langsung
29 Pengaruh bahan organik tanah 2. Sifat dan Ciri Tanaha. Warna tanah: Coklat - hitamb. Merangsang Granulasic. Menurunkan plastisitas, kohesid. Meningkatkan kemampuanmenahan aire. Meningkatkan kapasitas jerapankationf. Meningkatkan ketersediaan harag. Ekstraksi hara dari mineral-mineral
30 FIKSASI N SECARA BIOLOGIS Legume N-fixed, kg/haKac.tunggakKac. Kapri 72Kedelai 65Kac. Buncis 45Kac. Tanah 44
31 CROP RESIDUES 1. Mengandung bahan organik dan unsur hara N, P, K, ….. 2. CR = hasil biji x indeks panen3. Residu jagung: N = 43 % totalP = 41% totalK = 78% total4. Residu kedelai: N = 38% totalP = 36% totalK = 48% total5. Dikembalikan ke tanah atau dipanen ?
32 NUTRIENT BALANCE IN THE SOIL: REMOVAL 1. SOIL EROSION & RUN-OFF2. Pencucian hara = Nutrients leaching3. Denitrifikasi dan volatilisasi4. Shifts in nutrient use: FertilizerManureCrop residuesMulches
34 Kompos, Rabuk, dan PupukThere are several conventional fertilizers that should be avoided in sustainable farming because of their harmful effects on soil organisms, structure and acidity.These include ammonium sulphate will result in increasing the soil acidity (reducing pH).Penggunaan kapur-pertanian, pupuk fosfat, dan pupuk lainnya harus dilakukan berdasarkan hasil uji tanah, untuk menghindari ketidak-seimbangan hara dan pemborosan biaya yang tidak perlu.
35 PENGELOLAAN KESUBURAN TANAH Natural InputsAgro-ekologiKESUBURAN TANAHOptimum InputsOptimumCrop YieldsAgro-teknologiMinimum Losses
36 SISTEM PERTANIAN SIKLUS HARA DALAM Atmosfer TANAMAN PANEN Residu PUPUK TANAHPupuk buatanPupuk organik:Kandang, Kompos, HijauPenguapanPencucianErosiFiksasiKehilangan
37 Significant additions of lime, phosphate rocks, and other fertilizers should be guided by soil testing to avoid soil imbalances and unnecessary expenditure on inputs..
38 PENGENDALIAN GULMAWeed management poses one of the greatest challenges to the crafting of sustainable production systems.However, weed populations tend to decline in severity as soil health builds.A basic understanding of weed ecology and the influence of cropping patterns on weed communities will help growers refine their use of cultural and mechanical techniques, thereby reducing the time required for effective weed control.Tindakan pencegahan gulma menjadi bagian utama dari program pengendalian .
39 Mechanical weed control MINIMIZE HERBISIDAMechanical weed controlCrop rotationsCover croppingLive mulchesMycoherbicidesPest of weeds
40 PENGENDALIAN GULMAIn general terms, weed prevention in crops is based on developing a sound rotation, thwarting all attempts by existing weeds to set seed, and minimizing the arrival of new weed seeds from outside the field.In a grazing system, weed management may be as simple as adding other animal species such as goats or sheep to a cattle herd to convert weeds into cash.
41 Table 4. Tillage and cover crop mulch effect on weed numbers and production. Weeds/meter2Weed weight kg/meter2ConventionalNone360.66150.42Rye2.70.3Wheat0.90.21Barley0.240.27Source: Putnam et al., 1983.
42 PENGENDALIAN HAMAInsect pests can have a serious impact on farm income. In ecologically balanced farm production systems, insect pests are always present, but massive outbreaks resulting in severe economic damage are minimized.This results in good part from the presence of natural control agents—especially predatory and parasitic insects, mites, and spiders—that keep pest populations in check.To restore populations of beneficials on the farm, cease or reduce pesticide use and other practices that harm them, and establish habitats through farmscaping
43 1. Metode peramalan gangguan hama 2. Better placement & formulations MINIMIZE INSEKTISIDA1. Metode peramalan gangguan hama2. Better placement & formulations3. Cropping rotations4. Appropriate cultivations5. Time of planting/ sowing6. Controlled weed growth practices7. Biological insecticides8. Parasites & predators of pests9. Allelochemicals, pheromones, repellents10. Resistant cultivars11. Use of trap crops12. Innovative cultural techniques
44 PENGENDALIAN HAMAIPM integrates habitat modification and cultural, physical, biological, and chemical practices to minimize crop losses.Monitoring, record keeping, and life-cycle information about pests and their natural enemies are used to determine which control measures are needed to keep pests below an economic threshold.
45 PENGENDALIAN HAMABiological control—the use of living organisms to control crop pests—is one of the pillars of IPM.Biocontrol agents may be predatory, parasitic, or pathogenic; they may also be either "natural" (from naturally occurring organisms such as wild beneficial insects) or "applied" (meaning the organisms are introduced).Biocontrol agents include insects, mites, bacteria, fungi, viruses, and nematodes.Certain beneficial nematodes (Steinernema species, for example) transmit pathogens to their prey, and could be seen as a form of indirectly applied biocontrol.
46 PENGENDALIAN PENYAKIT The first step toward preventing serious disease problems in any cropping system is the production of healthy plants nurtured by a microbially active soil.Healthy soil suppresses root diseases naturally; the primary means to create disease-suppressive soil is to add biologically active compost at appropriate rates to a soil with balanced mineral levels.Supplemental strategies include crop rotation, resistant cultivars, good soil drainage, adequate air movement, and planting clean seed.
47 PENGENDALIAN PENYAKIT Biorational fungicides include compost teas (which add beneficial fungi capable of preventing colonization of the crop by pathogens) baking soda, and plant extracts.As with insect pest management, integrated management principles should be applied, including monitoring of environmental conditions, to determine whether preventive fungicidal sprays are required.
48 1. Metode peramalan penyakit 6. Menanam kultivar yang Toleran / tahan MINIMIZE FUNGISIDA1. Metode peramalan penyakit2. Pergiliran Tanaman3. Aplikasi - placement4. Waktu / musim tanam5. Disease antagonists6. Menanam kultivar yang Toleran / tahan
49 RINGKASANSustainable farming meets economic, environmental, and social objectives simultaneously; because these three objectives always overlap, they are managed together.Economic sustainability requires selecting profitable enterprises and doing comprehensive financial planning.Social sustainability involves keeping money circulating in the local economy, and maintaining or enhancing the quality of life of the farm family.Environmental sustainability involves keeping the four ecosystem processes (effective energy flow, water and mineral cycles, and viable ecosystem dynamics) in good condition.
50 RINGKASANManaging economics, society, and environment simultaneously depends on clear goal-setting, effective decision making, and monitoring to stay on track toward the goal.Wise decisions allow us to extract our living from the land as the interest, while preserving the social, water, and soil capital. As a result, the capability of the landscape and community resources will not be compromised over time by our activities.
51 Some specific land-use strategies to achieve sustainability include: RINGKASANSome specific land-use strategies to achieve sustainability include:keeping the soil covered throughout the year;avoiding moldboard plowing;increasing biodiversity wherever possible through crop rotation, intercropping, use of sod or cover crops, farmscaping, and integrated pest management;applying animal manures or compost;diversifying enterprises and planning for profit;integrating crop and animal enterprises;minimizing tillage, commercial fertilizer, and pesticides;buying supplies locally;employing local people; andincluding quality of life in your goals.
52 Pertanian berkelanjutan didefinisikan sbb: Sustainable agriculture was also addressed by the 1990 farm bill [Food, Agriculture, Conservation, and Trade Act of 1990 (FACTA), Public Law , Title XVI, Subtitle A, Section 1603].Pertanian berkelanjutan didefinisikan sbb:Stated by: “the term sustainable agriculture means an integrated system of plant and animal production practices having a site-specific application that will, over the long term:Memenuhi kebutuhan sandang dan pangan manusiaMelestarikan kualitas lingkungan dan sumberdaya alam yang menjadi tumpuan ekonomi-pertanianMenggunakan secara efisien sumberdaya tidak-pulih dan sumberdaya pertanian, serta mengintegrasikan siklus biologis alami dan pengendalian biologisMelestarikan viabilitas ekonomis dari kegiatan usahataniMeningkatkan kualitas hidup petani dan masyarakat keseluruhan.”
53 Menggunakan secara efisien sumberdaya tidak-pulih dan sumberdaya pertanian, serta mengintegrasikan siklus biologis alami dan pengendalian biologis
54 Melestarikan viabilitas ekonomis dari kegiatan usahatani
55 Melestarikan kualitas lingkungan dan sumberdaya alam yang menjadi tumpuan ekonomi-pertanian
56 Sustainable Agriculture: Environmentally friendly methods of farming that allow the production of crops or livestock without damage to the farm as an ecosystem, including effects on soil, water supplies, biodiversity, or other surrounding natural resources.The concept of sustainable agriculture is an “intergenerational” one in which we pass on a conserved or improved natural resource base instead of one which has been depleted or polluted.Terms often associated with farms or ranches that are self-sustaining include “low-input,” organic, “ecological,” “biodynamic,” and “permaculture.”
57 SUSTAINABLE AGRICULTURE? WHAT ISSUSTAINABLE AGRICULTURE?Sustainable agriculture is a way of raising food that is healthy for consumers and animals, does not harm the environment, is humane for workers, respects animals, provides a fair wage to the farmer, and supports and enhances rural communities.
58 Konservasi dan Preservasi Characteristics of SUSTAINABLE AGRICULTURE :Konservasi dan PreservasiWhat is taken out of the environment is put back in, so land and resources such as water, soil and air can be replenished and are available to future generations.The waste from sustainable farming stays within the farm’s ecosystem and cannot cause buildup or pollution. In addition, sustainable agriculture seeks to minimize transportation costs and fossil fuel use, and is as locally-based as possible.
59 Characteristics of SUSTAINABLE AGRICULTURE : BiodiversityFarms raise different types of plants and animals, which are rotated around the fields to enrich the soil and help prevent disease and pest outbreaks.Chemical pesticides are used minimally and only when necessary; many sustainable farms do not use any form of chemicals.
60 Animals are treated humanely and with respect, and are well cared for. Characteristics of SUSTAINABLE AGRICULTURE :Animal welfare.Animals are treated humanely and with respect, and are well cared for.They are permitted to carry out their natural behaviors, such as grazing, rooting or pecking, and are fed a natural diet appropriate for their species.
61 Sustainable farmers help strengthen rural communities. Characteristics of SUSTAINABLE AGRICULTURE :Kelayakan EKonomiFarmers are paid a fair wage and are not dependent on subsidies from the government.Sustainable farmers help strengthen rural communities.
62 Workers are treated fairly and paid competitive wages and benefits. Characteristics of SUSTAINABLE AGRICULTURE :Socially just.Workers are treated fairly and paid competitive wages and benefits.They work in a safe environment and are offered proper living conditions and food.
64 Sustainable agriculture integrates three main goals--environmental health, economic profitability, and social and economic equity.Sustainability rests on the principle that we must meet the needs of the present without compromising the ability of future generations to meet their own needs.Therefore, stewardship of both natural and human resources is of prime importance.Stewardship of human resources includes consideration of social responsibilities such as working and living conditions of laborers, the needs of rural communities, and consumer health and safety both in the present and the future.Stewardship of land and natural resources involves maintaining or enhancing this vital resource base for the long term.
65 Sistem pertanian berkelanjutan A systems perspective is essential to understanding sustainability.The system is envisioned in its broadest sense, from the individual farm, to the local ecosystem, and to communities affected by this farming system both locally and globally.An emphasis on the system allows a larger and more thorough view of the consequences of farming practices on both human communities and the environment.A systems approach gives us the tools to explore the interconnections between farming and other aspects of our environment.A systems approach also implies interdisciplinary efforts in research and education. This requires not only the input of researchers from various disciplines, but also farmers, farmworkers, consumers, policymakers and others.
66 Making the transition to sustainable agriculture is a process. For farmers, the transition to sustainable agriculture normally requires a series of small, realistic steps. Family economics and personal goals influence how fast or how far participants can go in the transition.It is important to realize that each small decision can make a difference and contribute to advancing the entire system further on the "sustainable agriculture continuum."The key to moving forward is the will to take the next step.Finally, it is important to point out that reaching toward the goal of sustainable agriculture is the responsibility of all participants in the system, including farmers, laborers, policymakers, researchers, retailers, and consumers. Each group has its own part to play, its own unique contribution to make to strengthen the sustainable agriculture community.
67 PERTANIAN & SUMBERDAYA ALAM Water.When the production of food and fiber degrades the natural resource base, the ability of future generations to produce and flourish decreases.The decline of ancient civilizations in the world is believed to have been strongly influenced by natural resource degradation from non-sustainable farming and forestry practices.Water is the principal resource that has helped agriculture and society to prosper, and it has been a major limiting factor when mismanaged.
68 PERTANIAN & SUMBERDAYA ALAM Ketersediaan Air & Penggunaannya In the world, an extensive water storage and transfer system has been established which has allowed crop production to expand to very arid regions.In drought years, limited surface water supplies have prompted overdraft of groundwater and consequent intrusion of salt water, or permanent collapse of aquifers.Several steps should be taken to develop drought-resistant farming systems even in "normal" years, including both policy and management actions:improving water conservation and storage measures,providing incentives for selection of drought-tolerant crop species,using reduced-volume irrigation systems,managing crops to reduce water loss, ornot planting at all.
69 PERTANIAN & SUMBERDAYA ALAM KUALITAS AIRThe most important issues related to water quality involve contamination of surface waters by pesticides, nitrates and selenium.Temporary solutions include the use of tolerant crops, low-volume irrigation, and various management techniques to minimize application of any agrochemicals in crops cultivation.In the long-term, some farmland may need to be removed from production or converted to other uses. Other uses include conversion of row crop land to production of drought-tolerant forages, Integrated Pest Management to minimize the impacts of pesticides on its environment.
70 Energy. Pertanian & Sumberdaya Alam Modern agriculture is heavily dependent on non-renewable energy sources, especially petroleum.The continued use of these energy sources cannot be sustained indefinitely, yet to abruptly abandon our reliance on them would be economically catastrophic.However, a sudden cutoff in energy supply would be equally disruptive.In sustainable agricultural systems, there is reduced reliance on non-renewable energy sources and a substitution of renewable sources or labor to the extent that is economically feasible.
71 Many agricultural activities affect air quality. Farming and Natural ResourcesUDARAMany agricultural activities affect air quality.These include smoke from agricultural burning; dust from tillage, traffic and harvest; pesticide drift from spraying; and nitrous oxide emissions from the use of nitrogen fertilizer.Options to improve air quality include incorporating crop residue into the soil, using appropriate levels of tillage, and planting wind breaks, cover crops or strips of native perennial grasses to reduce dust.
72 Farming and Natural Resources Soil.Soil erosion continues to be a serious threat to our continued ability to produce adequate food.Numerous practices have been developed to keep soil in place, which include reducing or eliminating tillage, managing irrigation to reduce runoff, and keeping the soil covered with plants or mulch.
73 Budidaya Tanaman Farming and Natural Resources Sustainable production practices involve a variety of approaches.Specific strategies must take into account topography, soil characteristics, climate, pests, local availability of inputs and the individual grower's goals.Despite the site-specific and individual nature of sustainable agriculture, several general principles can be applied to help growers select appropriate management practices:Selection of species and varieties that are well suited to the site and to conditions on the farm;Diversification of crops (including livestock) and cultural practices to enhance the biological and economic stability of the farm;Management of the soil to enhance and protect soil quality;Efficient and humane use of inputs; andConsideration of farmers' goals and lifestyle choices.
74 PERTANIAN & SUMBERDAYA ALAM Selection of site, species and variety. Preventive strategies, adopted early, can reduce inputs and help establish a sustainable production system.When possible, pest-resistant crops should be selected which are tolerant of existing soil or site conditions.When site selection is an option, factors such as soil type and depth, previous crop history, and location (e.g. climate, topography) should be taken into account before planting.
75 PERTANIAN & SUMBERDAYA ALAM Diversity.Diversified farms are usually more economically and ecologically resilient.While monoculture farming has advantages in terms of efficiency and ease of management, the loss of the crop in any one year could put a farm out of business and/or seriously disrupt the stability of a community dependent on that crop. By growing a variety of crops, farmers spread economic risk and are less susceptible to the radical price fluctuations associated with changes in supply and demand.Properly managed, diversity can also buffer a farm in a biological sense. For example, in annual cropping systems, crop rotation can be used to suppress weeds, pathogens and insect pests.Also, cover crops can have stabilizing effects on the agroecosystem by holding soil and nutrients in place, conserving soil moisture with mowed or standing dead mulches, and by increasing the water infiltration rate and soil water holding capacity.
76 PERTANIAN & SUMBERDAYA ALAM Diversity.Optimum diversity may be obtained by integrating both crops and livestock in the same farming operation.This was the common practice for centuries until the mid-1900s when technology, government policy and economics compelled farms to become more specialized.
77 PERTANIAN & SUMBERDAYA ALAM Diversity.Mixed crop and livestock operations have several advantages:First, growing row crops only on more level land and pasture or forages on steeper slopes will reduce soil erosion.Second, pasture and forage crops in rotation enhance soil quality and reduce erosion; livestock manure, in turn, contributes to soil fertility.Third, livestock can buffer the negative impacts of low rainfall periods by consuming crop residue that in "plant only" systems would have been considered crop failures.Finally, feeding and marketing are flexible in animal production systems. This can help cushion farmers against trade and price fluctuations and, in conjunction with cropping operations, make more efficient use of farm labor.
78 PERTANIAN & SUMBERDAYA ALAM Pengelolaan TanahA common philosophy among sustainable agriculture practitioners is that a "healthy" soil is a key component of sustainability; that is, a healthy soil will produce healthy crop plants that have optimum vigor and are less susceptible to pests.While many crops have key pests that attack even the healthiest of plants, proper soil, water and nutrient management can help prevent some pest problems brought on by crop stress or nutrient imbalance.Furthermore, crop management systems that impair soil quality often result in greater inputs of water, nutrients, pesticides, and/or energy for tillage to maintain yields.
79 PENGELOLAAN TANAH. reducing tillage, PERTANIAN & SUMBERDAYA ALAM In sustainable systems, the soil is viewed as a fragile and living medium that must be protected and nurtured to ensure its long-term productivity and stability.Methods to protect and enhance the productivity of the soil include:using cover crops,compost and/or manures,reducing tillage,avoiding traffic on wet soils, andmaintaining soil cover with plants and/or mulches.
80 PERTANIAN & SUMBERDAYA ALAM Efficient use of inputs. Many inputs and practices used by conventional farmers are also used in sustainable agriculture.Sustainable farmers, however, maximize reliance on natural, renewable, and on-farm inputs. Equally important are the environmental, social, and economic impacts of a particular strategy.Converting to sustainable practices does not mean simple input substitution. Frequently, it substitutes enhanced management and scientific knowledge for conventional inputs, especially chemical inputs that harm the environment on farms and in rural communities.The goal is to develop efficient, biological systems which do not need high levels of material inputs.
81 PERTANIAN & SUMBERDAYA ALAM Penggunaan Sarana-Produksi secara Efisien. Growers frequently ask if synthetic chemicals are appropriate in a sustainable farming system.Sustainable approaches are those that are the least toxic and least energy intensive, and yet maintain productivity and profitability.Preventive strategies and other alternatives should be employed before using chemical inputs from any source.However, there may be situations where the use of synthetic chemicals would be more "sustainable" than a strictly nonchemical approach or an approach using toxic "organic" chemicals.For example, one grape grower switched from tillage to a few applications of a broad spectrum contact herbicide in the vine row.This approach may use less energy and may compact the soil less than numerous passes with a cultivator or mower.
82 PERTANIAN & SUMBERDAYA ALAM Consideration of farmer goals and lifestyle choices.Management decisions should reflect not only environmental and broad social considerations, but also individual goals and lifestyle choices.For example, adoption of some technologies or practices that promise profitability may also require such intensive management that one's lifestyle actually deteriorates.Management decisions that promote sustainability, nourish the environment, the community and the individual.
83 MENGAPA sustainability PERLU DILAKUKAN ? Kesuburan tanah menurun karena erosi dan BO rendahHPT tidak terkendali, karena ekosistem tidak stabilPencemaran lingkungan dan gangguan terhadap kesehatan manusia sebagai akibat penggunaan bahan-bahan kimia pertanianSumber BBM akan habis karena bersifat “non renewable”Ketergantungan proses produksi terhadap input dari luar tinggi, pada akhirnya petani tidak berdayaPenggunaan “external input” semakin tidak efisien, sehingga petani rugiKualitas hasil panen rendah menyebabkan harga rendah dan keuntungan petani berkurang
84 UNTUK APA DILAKUKAN ?Agar kesuburan tanah dan lingkungan hidup dapat terjaga kelestariannyaAgar hasil panen ( kuantitas, kualitas dan kontinyuitas ) dapat ditingkatkanAgar input produksi ( external input ) dapat dihemat dan biaya produksi tidak semakin tinggiAgar petani lebih mandiri, tidak tergantung dari pabrik pupuk dan pestisida