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KESUBURAN TANAH & PEMUPUKAN Diabstraksikan Oleh: Smno.jurstnh.fpub.agst2012 KESUBURAN TANAH & PEMUPUKAN Diabstraksikan Oleh: Smno.jurstnh.fpub.agst2012.

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Presentasi berjudul: "KESUBURAN TANAH & PEMUPUKAN Diabstraksikan Oleh: Smno.jurstnh.fpub.agst2012 KESUBURAN TANAH & PEMUPUKAN Diabstraksikan Oleh: Smno.jurstnh.fpub.agst2012."— Transcript presentasi:

1 KESUBURAN TANAH & PEMUPUKAN Diabstraksikan Oleh: Smno.jurstnh.fpub.agst2012 KESUBURAN TANAH & PEMUPUKAN Diabstraksikan Oleh: Smno.jurstnh.fpub.agst2012

2 Diunduh dari: Kesuburan tanah Kesuburan Tanah adalah kemampuan suatu tanah untuk menghasilkan produk tanaman yang diinginkan, pada lingkungan tempat tanah itu berada. Produk tanaman berupa: bunga, buah, biji, daun, umbi, getah, akar, trubus, batang, biomassa, naungan, penampilan estetika, dan lainnya. Tanah memiliki kesuburan yang berbeda-beda tergantung sejumlah faktor pembentuk tanah yang merajai di lokasi tersebut, yaitu: Bahan induk, Iklim, Relief, Organisme, dan Waktu. Tanah merupakan fokus utama dalam pembahasan ilmu kesuburan tanah, sedangkan “tanaman” merupakan indikator utama bagi “kesuburan tanah”.

3 Cara Menjaga Kesuburan Tanah Diunduh dari: Untuk menjaga kesuburan tanah bisa dilakukan dengan cara sebagai berikut : 1.Gunakan jerami. Pada tanah sawah, biasanya setelah panen padi kita selalu membuang dan membiarkan jerami ditumpuk di pinggir sawah. Padahal jerami itu bisa kita manfaatkan untuk menyuburkan tanah. Sebarkan jerami tersebut ke lahan dan ratakan. Kemudian taburkan serbuk dolomit ke atas jerami tersebut. Fungsi dolomit untuk membantu mempercepat pelapukan daun jerami dan bisa mengatur tingkat keasaman tanah sehingga tanah bisa lebih matang dan lahan bisa segera ditanami.Setelah sekitar seminggu lahan tersebut bisa langsung dibajak dan jerami yang belum lapuk bisa dibenamkan ke dalam tanah. 2.Lubang resapan Biopori. Pada taman atau halaman rumah bisa kita lakukan metode biopori. Caranya lubangi tanah secara tegak lurus dengan menggunakan pipa besi dengan diameter sekitar cm dan kedalaman tanah sekitar 100 cm. Jarak antar lubang resapan biopori adalah cm. Kebutuhan jumlah lubang resapan biopori yang diperlukan berdasarkan luas tutupan bangunan. Bila tutupan bangunan dengan luas 20 m2 diperlukan lubang resapan biopori sebanyak 3 unit dan setiap tambahan luas tutupan bangunan 7 m2 diperluhan tambahan 1 unit lubang resapan biopori. Dalam pemeliharaannya lubang resapan biopori ini diisi sampah organik secara berkala dan mengambil sampah tersebut setelah menjadi kompos diperkirakan 2-3 bulan setelah terjadi proses pelapukan. 3.Tanaman Crotalaria.Untuk lahan kritis bisa dimanfaatkan untuk ditanami tanaman crotalaria. Akar tanaman crotalaria bisa mengikat nitrogen dan unsur lain yang sangat dibutuhkan tanah untuk menjadi subur. Daun dan batang tanaman crotalaria sangat baik dijadikan pupuk hijau (kompos) karena mengandung unsur-unsur yang sangat dibutuhkan tanah dan tanaman dibanding pupuk hijau dari tanaman lain.

4 Mengelola kesuburan tanah dapat dilakukan dengan metode-metode vegetatif dan mekanik Diunduh dari: Upaya yang dapat dilakukan untuk menjaga keseburan tanah sebagai berikut: a. Metode vegetatif dilakukan dengan cara-cara : 1.Penanaman tanaman secara berjalur tegak lulus terhadap arah aliran(strip cropping). 2.Penanaman tanaman secara berjalur sejajar garis kontur (contour strip cropping). 3.Penutupan lahan yang memiliki lereng curam dengan tanaman keras (buffering) 4.Penanaman tanaman secara permanen untuk melindungi tanah dari tiupan angin (wind breaks). b. Metode mekanik yang umum dilakukan ADALAH: 1.Pengolahan lahan sejajar garis kontur (contour tilage).pengolahan lahan dengan cara ini bertujuan untuk membuat pola rongga- rongga tanah sejajar kontul dan membentuk igir-igir kecil yang dapat memperlambat alilan air dan memperbesar infiltrasi air 2.Penterasan lahan miring (terracering).penterasan bertujuan untuk mengurangi panjang lereng dan memperkecil kemiringan lereng sehingga dapat memperlambat alilan air. 3.Pembuatan pematang (guludan)dan saluran air sejajar garis kontur.pembuatan pematangan bertujuan untuk menahan alilan air. 4.Pembuatan cekdam.pembuatan cekdam bertujuan untuk memperbendung alilan air yang melewati parit-parit sehingga material tanah hasil erosi yang terangkut aliran tertahan dan terendapkan adannya cekdam menyebabkan erosi tanah dapat dikendalikan,lapisan tanah menebal,dan produktivitas tanah meningkat.

5 LIMA FAKTOR PENGELOLA AN TANAH Pengendalian GULMA. PERGILIRAN TANAMAN Penyediaan AIR YANG CUKUP, Sesuai dengan kebutuhan tanaman PENGENDALIAN HAMA & PENYAKIT PENYEDIAAN UNSUR HARA

6 DINAMIK A HARA TANAH Mempertahankan jumlah optimum unsur hara hanya dapat terlaksana dengan menciptakan keseimbangan yang baik antara penambahan dan kehilangannya Benefits of Organic Matter Increases soil CEC Stabilizes nutrients Builds soil friability and tilth Reduces soil splash Carbon Sequestration C cycling in agroecosystems has a significant impact at the global scale because agriculture occupies approximately 11% of the land surface area of the earth. Benefits of Organic Matter Reduces compaction and bulk density Provides a food source for microorganisms Increases activities of earthworms and other soil critters

7 POKOK-POKOK PENGELOLAAN KESUBURAN TANAH. 1. Suplai nitrogen dari: Sisa TanamanTanaman biasa Pupuk kandangTanaman legume Hujan & irigasiPupuk hijau Pupuk nitrogenKompos 2. Penambahan bahan organik melalui: Sisa tanaman legume dan non legume Pupuk kandang Pupuk hijau 4. Penambahan fosfat: Pupuk superfosfat, atau Pupuk lainnya 3. Penambahan kapur bila diperlukan Batu kapur kalsit atau dolomit yg biasa dilakukan 7. Penambahan unsur mikro: Sebagai garam terpisah atau campuran 5. Penambahan kalium tersedia: Pupuk kandang Sisa tanaman Pupuk Kalium 6. Kekurangan belerang diatasi dg: Belerang, gipsum, superfosfat, Amonium sulfat, Senyawa belerangdalam air hujan

8 MENGATASI KEKURANG AN NITROGEN Dinamika nitrogen Penambahan & Kehilangan N-tersedia N- tersedia dlm tanah Atmosfer Pengikatan Nitrogen Pupuk Buatan SimbiotikNon- Simbiotik Sisa tanaman Pupuk Kandang Bahan Organik Panen Tanam an Hilang Pencuci an Hilang Erosi

9 MEMPERTAHA NKAN BAHAN ORGANIK TANAH Carbon Inputs to Soil Crop residues Cover crops Compost, and Manures Carbon Substrate The majority of C enters the soil in the form of complex organic matter containing highly reduced, polymeric substances. During decomposition, energy is obtained from oxidation of the C-H bonds in the organic material. Soil Carbon Equilibrium Input primarily as plant products Output mediated by activity of decomposers It is common that from 40 to 60% of the C taken up by microorganisms is immediately released as CO2.

10 PENTINGNYA Ca & Mg Keseimbangan Ca dan Mg Penambahan dan kehilangan Ca dan Mg tersedia dalam tanah Sisa tanaman & Pupuk Kandang Pupuk Komersial Mineral Tanah KAPUR PANEN TANAMAN Hilang pencucian Hilang Erosi

11 MEMPERTAHANKAN KETERSEDIAAN FOSFAT. Siklus P Kehilangan & Penambahan P- tersedia P-tersedia dalam tanah Sisa tanaman Pukuk kandang Pukuk komersial Mineral P- tanah Bahan Organik Tanah Terangkut tanaman Hilang Pencucian Hilang Erosi Fiksasi

12 KETERSEDIAAN KALIUM Tanah mineral umumnya mengandung cukup banyak kalium, kisaran 40 ton setiap hektar lapisan olah tanah. Namun demikian hanya sebagian kecil yangtersedia bagi tanaman Kehilangan & Penambahan Kalium: K-tersedia tanah Pupuk komersial Sisa tanaman & Pupuk Kandang Mineral-K lambat tersedia Terangkut tanaman Kehilangan pencucian Kehilangan erosi Kehilangan Fiksasi

13 The Soil Food Web In 1 teaspoon of soil there are… 5 or more Earthworms Up to 100 ……………. Arthropods 10 to 20 bacterial feeders and a few fungal feeders ……. Nematodes Several thousand flagellates & amoeba One to several hundred ciliates ……. Protozoa 6-9 ft fungal strands put end to end ………. Fungi 100 million to 1 billion …………. Bacteria

14 Classical C Pools Nonhumic substances—carbohydrates, lipids, proteins Humic substances—humic acid, fulvic acid, humin BOT berpengaruh terhadap: -Plant nutrition -Soil and Plant health -Soil physical, chemical and biological properties

15 BOT FRAKSI RINGAN The light fraction (LF) with a density of ~1.6 gm cm-3 is relatively mineral free and consists of partially decomposed plant material, fine roots and microbial biomass with a rapid turnover time. The LF is a source of readily mineralizable C and N, accounts for ~50% of total soil C and declines rapidly under cultivation. BOT --- FRAKSI BERAT --- The Heavy Fraction The heavy fraction (HF) is organic matter adsorbed onto mineral surfaces and sequestered within organomineral aggregates. The HF is less sensitive to disturbance an chemically more resistant than the LF.

16 Bacteria vs. Fungi Bacteria are smaller than fungi and can occupy smaller pores and thus potentially have greater access to material contained within these pores. Bacteria are less disrupted than are fungi by tillage practices commonly used in agriculture. Bacteria vs. Fungi Fungi tend to be selected for by plant residues with high C/N ratios. Fungi have a greater influence on decomposition in no-till systems in which surface residues select for organisms that can withstand low water potentials and obtain nutrients from the underlying soil profile.

17 Bacteria vs. Fungi Fungi often produce more cell wall than cytoplasmic material when starved for N, and thus can extend into new regions of the soil without requiring balanced growth conditions. The filamentous growth structure of a fungus permits it to access C in one location and nutrients in another.

18 KANDUNGAN BAHAN ORGANIK TANAH How organic matter in soil influences the soil-plant relationship? 1.Decomposed organic matter provides nutrients for plant growth (Mineralization) 2.It determines the soil’s temperature, air ventilation, structure and water management 3.It contains bioregulators which affects plant growth 4.It contains bioregulators, which affects plant growth (enzymes, hormones, etc.) 5.Its carbon and energy content is the soil’s energy battery for future use 6.It determines the soil’s capacity to compensating, regenerating and protecting the environment regenerating and protecting the environment

19 PENTINGNYA BOT 1.Organic material in the soil is essentially derived from residual plant and animal material, synthesised by microbes and decomposed under influence of temperature, moisture and ambient soil conditions 2.Soil organic matter is extremely important in all soil processes 3.Cultivation can have a significant effect on the organic matter content of the soil 4.In essentially warm and dry areas like Southern Europe, depletion of organic matter can be rapid because the processes of decomposition are accelerated at high temperatures 5.Generally, plant roots are not sufficiently numerous to replace the organic matter that is lost MANFAAT BOT ➢ Storehouse for nutrients ➢ Source of fertility ➢ Contributes to soil aeration thereby reducing soil compaction ➢ Important ‘building block’ for the soil structure ➢ Aids formation of stable aggregates ➢ Improves infiltration/permability ➢ Increase in storage capacity for water. ➢ Buffer against rapid changes in soil reaction (pH) ➢ Acts as an energy source for soil micro-organisms

20 Degradation: HILANGNYA BOT 1.During field operations, fresh topsoil becomes exposed and dries rapidly on the surface 2.Organic compounds are released to the atmosphere result from breakdown of soil aggregates bound together by humic materials 3.Unless the organic matter is quickly replenished, the system is in a state of degradation leading eventually to un- sustainability 4.The removal of crop residues in dry ecosystems, which are inherently marginal, can cause such systems to be quickly transformed from a stage of fragility to total exhaustion and depletion FAKTOR YG PENGARUHI BOT Natural factors: ➢ Climate ➢ Soil parent material: acid or alkaline (or even saline) ➢ Land cover and or vegetation type ➢ Topography – slope and aspect Human-induced factors: ➢ Land use and farming systems ➢ Land management (cultivation) ➢ Land degradation

21 FAKTOR IKLIM PENGARUHI BOT: Temperature: OM decomposition rapid in warm climates OM Decomposition is slower for cool regions Result: Within zones of uniform moisture and comparable vegetation -- Av total OM increases 2x to 3x for each 10 deg C fall in mean temperature Moisture: OM decomposition rapid in warm climates OM Decomposition is slower for cool regions Result: Under comparable conditions Av total OM increases as the effective moisture increases

22 Sumber: pgsgrow.com/blog/tag/organic-gardening/

23 23 Structure of soil, indicating presence of bacteria, inorganic, and organic matter Sumber:

24 PUPUK - PEMUPUKAN Fertilizer is one management option used almost universally Must replace soil nutrients lost by harvest Over-fertilization can result in dangerous pollution Technology has increased fertilizer efficiency

25 PENGELOLAAN KESUBURAN TANAH Goals regarding fertility –Increase yield –Reduce costs/unit production –Improve product quality –Avoid environmental pollution –Improve environmental health & aesthetics

26 TUJUAN PENGELOLAAN KESUBURAN TANAH Efficient land managers: spend 50% increase in yields Fertilizers may not be profitable if: –Water is the most limiting factor –Other growth hindrances – insects, diseases, acidity, extreme cold –Increased yield has less market value than the cost of buying/app of fertilizer

27 Fertilizers – generally most profitable farm input Soil fertility problems usually the easiest to solve Soil nutrients typically present in finite amounts, don’t replenish themselves Crops typically contain: (in rank of amount found in the plant) N, K, Ca, P, Mg, S TUJUAN PENGELOLAAN KESUBURAN TANAH

28 Utilizing fertilizers may help cut unit cost of production by maximizing yield –Improved fertility = improved yields, improved aesthetic appeal Environmental concerns abound –Fertilizer laws viewed as lax by some –Farmers may be the primary cause of non-point-source pollution TUJUAN PENGELOLAAN KESUBURAN TANAH

29 –Three common pollutants: Nitrates –Percolate through to groundwater –Not safe to drink –Cause “Blue-baby” syndrome – inhibits oxygenation of blood –Becoming common near heavily fertilized fields, feedlots, dairies Phosphates –Pollute surface waters by runoff –Promotes algae growth in rivers/ponds –Depletes available oxygen in the water for fish TUJUAN PENGELOLAAN KESUBURAN TANAH

30 –Wise use of fertilizers must be encouraged, actually improve the environment Crops, trees, etc. - remove more CO2, decrease sediment, dust, erosion Plays important role for future of the planet TUJUAN PENGELOLAAN KESUBURAN TANAH

31 PENGELOLAAN LAHAN Large- & Medium-Scale Management –Large-Scale Low levels of operational precision, little reliance on sophisticated technology May be most feasible/profitable for some Simple & low-tech Some shy away from high tech for other reasons

32 Disadvantages –Some parts of field may receive too much/little fertilizer or pesticide –Less than optimal yields –Inefficient use of fertilizers & pesticides –Higher cost of production/unit –Environmental pollution due to over application Advantages –Minimal technological training & instrumentation needed –Field operations can be performed w/ standard, readily available, cheaper equipment PENGELOLAAN LAHAN

33 –Medium-Scale Subdivide field into two+ management units –Delineation may be based on: »Soil types »Past management differences »Farmer’s observations Ex. High, medium, low N application areas in the field Same equipment/technology needs as for large-scale management farmers PENGELOLAAN LAHAN

34 Does improve efficiency of farm inputs Can reduce excessive applications of chemicals/fertilizers –May do spot treatments/applicatio ns w/in a field due to field observations Small-Scale Management (Precision Farming) –Global Positioning System (GPS) – network of U.S. satellites w/ a signal detection system used to locate positions on the ground PENGELOLAAN LAHAN

35 –Soil sample fields on a grid –Data collection points no more than a few feet apart –Each sample site mapped using GPS –Custom applicators can custom apply fertilizers at variable rates that change constantly as the applicator travels the field – variable rate application, site-specific management, precision farming PENGELOLAAN LAHAN

36 –Potential to substantially decrease fertilizer/chemical application rates –Berpotensi menurunkan biaya sarana produksi –Does require expensive technology, equipment & extensive technical knowledge PENGELOLAAN LAHAN

37 Metode baku penentuan kesuburan tanah Use w/ precision farming to minimize inputs Accuracy of sample is key!!!! PENGAMBILAN CONTOH TANAH

38 Depth & Number of Samples –Sampling depth – 7-12” for typical soil analysis Shallower depth for no-till/sod crops – acid-layer can form at very top of soil structure For accurate N analysis – 24-36” depth –For composite sampling – fewer # samples decreases accuracy of analysis PENGAMBILAN CONTOH TANAH

39 Sampling Frequency, Time, & Location –New land, land new to you – yearly for 1 st few yrs until you understand the soil –Every 2-3 yrs, unless concern for environmental problems –Analysis – determines which nutrients can be made available in the soil & which will need to be supplied –Samples often pulled in fall to provide enough time for analysis/amendments PENGAMBILAN CONTOH TANAH

40 Spring sampling is more accurate, but conditions may not be favorable, or not sufficient time –Sampling row crops problematic Can hit a fertilizer zone Hard to get enough representative samples PENGAMBILAN CONTOH TANAH

41 Uniformity of Sampling Areas –Examine field for differences in soil characteristics, past treatments –PERHATIKANLAH: Uniformity of productivity Topografi dan relief Tekstur tanah Struktur tanah Drainage Kedalaman/warna topsoil Pengelolaan hama-penyakit tanaman PENGAMBILAN CONTOH TANAH

42 –Sampling area Each composite sample should represent <12.5 ac –Grid sampling can be as small as you need –5-10 ac grids are common Providing Detailed Soil & Cropping Background –Helps to provide w/ soil analysis to increase accuracy of fertilizer recommendations PENGAMBILAN CONTOH TANAH

43 –Perhatikan juga hal-hal berikut: Previous crop Crop (s)) to be grown Realistic yield goal Last liming & fertilization rates Manure applications Soil series (if known) Drainage info If irrigation used

44 UJI TANAH = Soil Tests Law of the Minimum: growth of the plant is limited most by the essential plant nutrient present in the least relative amount (first-limiting) Soil Acidity Evaluation –pH measured w/ electrode & solution –Lime requirement – amount of lime required to achieve desired pH Reported as buffer pH

45 Uji tanah untuk N –No good tests for soil available N –Most states provide N recommendations based on yrs of field plots trials on various crops, soils, management, fertilizers –N recommendations consider: Previous crops Estimates N carryover N needed to decompose residues Projected yields Climate UJI TANAH = Soil Tests

46 –Lab N tests accurate, but nearly impossible to interpret Some will discourage N testing –Behavior of carryover N unpredictable – can make analyses invalid Leaching Denitrification Mineralization Climate UJI TANAH = Soil Tests

47 –N recommendations based on yield goals rather than soil reserves –Corn Rule – #N/bu of yield goal How much N should be recommended for corn following corn, expected yield 120 bu/ac? How much N should be recommended for corn following soybeans, expected yield 195 bu/ac? UJI TANAH = Soil Tests

48 Soil Tests for P & K –Widely used to predict probability of crop response to fertilization –Survey: 47% soil tested medium to low for P 43% soil tested medium to low for K P & K soil levels declining in many states –P testing Quite reliable – soil P is very stable from yr to yr UJI TANAH = Soil Tests

49 Most soil P unavailable to crops Soil test extracts & measures what may actually be available –K testing Tests both exchangeable & soluble reserves Conflicting testing procedures over which is most accurate –Some estimate upper threshold needs ~ #/ac (above which no response to K fertilizer) –Others - 335#/ac on clay soils (calculated based on soil CEC – higher CEC = decreased available K) –Some experimentation w/ soil probes checking K, NO 3, PO 4, SO 4 UJI TANAH = Soil Tests

50 Uji Tanah untuk Ca dan Mg –Related to need for lime –Well-limed soils rarely Ca & Mg deficient –Mg deficiency more common than Ca Coarse-textured or acidic soils Many yrs using non-Mg containing lime –Uji tanah untuk Mg : Exchangeable soil Mg % Mg saturation of soil colloids Ratio of K:Mg UJI TANAH = Soil Tests

51 Uji tanah untuk S dan B –S testing inaccurate – acts much like N Can test – but must take variability into account –Boron level recommendations <1.0 ppm – deficient for plant growth ppm – adequate >5.0 ppm – excess/toxicity risks UJI TANAH = Soil Tests

52 Uji tanah untuk kebutuhan hara mikro: –Difficult to develop accurate tests due to relatively infrequent need for field supplementation –Can be done, if requested for a specific need –Adds expense to soil analysis UJI TANAH = Soil Tests

53 Bagaimana Uji-Tanah yang bagus? –Analyses recalibrated regularly based on field trial studies –Validity of analysis related directly to accuracy of sample, information provided to the lab –Soil analyses generally very valid for: P, K, soluble salts, pH, lime Other tests should only be used on as-needed basis –Extra cost –Less accurate UJI TANAH = Soil Tests

54 ANALISIS TANAMAN Cara untuk memastikan ketersediaan hara dalam tanah Analisis Tanaman vs. Uji Tanah –Plant most accurate report on what nutrients are actually available –Plant analysis leaves little to no room for amendments to the soil –When deficiencies are acknowledged, yield usually already affected

55 –When is plant analysis most helpful? Treatment of an easily- corrected deficiency Long-growing crops: turf, tree fruits, forests, sugar cane Quick Tests in the Field –Can test for N, K status in plants Collect ~20 leaves for sample –Must be random from different locations –Don’t select only affected- looking leaves ANALISIS TANAMAN

56 Chop/mix, squeeze sap & test Most effective for greenhouse/nursery growers –Amendments can easily be made –High possible economic losses Total Plant Analysis –Done in a lab –Should be tested by stage of development –Random sampling key ANALISIS TANAMAN

57 –Indicate part of plant sampled & be consistent –Dry to prevent spoilage (confounds results) –Wrap in paper and mail w/ complete report – complete history, information critical ANALISIS TANAMAN

58 Interpreting Plant Analyses –Accurate interpretation difficult if not all critical information provided –Element classified as deficient if below threshold nutrient levels Levels change through season, stage of development, etc. –Some general disagreement from scientists on what threshold levels are ANALISIS TANAMAN

59 Critical Nutrient Range –CNR – ranges at which nutrients are: Visually deficient Hidden deficient Slightly deficient Sufficient supply Toxic ANALISIS TANAMAN

60 –Chlorosis – yellowish to whitish appearance to foliage, stem –Necrosis – dead tissue –Causes: disease, insect damage, salt accumulation, stress, nutrient deficiencies –Some visual symptoms same for many diseases/deficiencies ANALISIS TANAMAN Gejala Defisirensi Hara

61 –Nutrients are relocated in the plant by two pathways Xylem – water-carrying vessels –All nutrients can pass through Phloem – sugar-carrying vessels –Not all nutrients can relocate –Mobile nutrients – travel freely –Immobile nutrients – can’t be moved from their location in the plant –Mobile nutrient deficiencies tend to occur on older leaves – plant sacrifices old for new tissue ANALISIS TANAMAN

62 –Immobile nutrient deficiencies – symptoms on shoot/root tips, fruits Can’t be treated from the soil w/ fertilizer – plant can’t send Ca (ex) to the ripening fruit –Mobile nutrients: N, P, K, Cl, Mg, S –Immobile nutrients: Cu, Mn, Zn, Fe, Mo, S –Very immobile nutrients: B, Ca ANALISIS TANAMAN

63 REKOMENDASI PUPUK Different labs make different recommendations Traditional philosophies being challenged: Dosis aplikasi pupuk P Rekomendasi N berbasis hasil tanaman

64 Menyusun rekomendasi pemupukan: –Must have sufficient plot data to correlate yields & nutrient needs –Once a general amount of fertilizer is known: Subtract for manure application Subtract for residual P or N Add/subtract for N, P, S because of soil organic matter levels – can count on them supplying some REKOMENDASI PUPUK

65 Laporan Uji Tanah –Labs usually full-service Soil, plant, manure, irrigation water testing REKOMENDASI PUPUK

66 KUALITAS PUPUK Fertilizer grade – amounts of N, P, K in a fertilizer required by law to be listed Also required: –Weight of material, manufacturer Optional: –Filler composition, acidity in soil potential Menghitung jumlah pupuk N, P, K

67 Amounts listed as: elemental N, phosphate, potash (not direct indication of elemental P, K supplied) Acidity & Basicity of Fertilizers –Most affect soil acidity in some regard Superphosphate, Triplesuperphosphate, Potash – neutral MAP, DAP, all N fertilizers – acidifiers KUALITAS PUPUK

68 Solubility & Mobility in Soil –Function of: Elemental charge Tendency to form insoluble compounds Adsorption ability Soil texture Water movement Concentration of other ions KUALITAS PUPUK

69 –Contoh-contoh Mobilitas P dalam tanah snagat terbatas, hanya beberapa cm –Pupuk P harus ditempatkan pada zone jangkauan akar N dapat bergerak mengikuti pergerakan air tanah KUALITAS PUPUK

70 Menghitung pupuk majemuk / Campuran: –Mixing ammonium nitrate & TSP to get 1 ton mixture of How much of each do we need? –How about if we needed a fertilizer for a customer? What might we use for each ingredient? How much of each would we need? PERHITUNGAN PUPUK

71 Weights of Fertilizer to Apply –Planting corn expected to yield 125 bu/ac How much N do we need? Soil analysis recommended 88#/ac phosphate How much ammonium nitrate & TSP do we need? What is our final application rate? PERHITUNGAN PUPUK

72 Perhitungan yang melibatkan aplikasi pupuk cair –Use dry fertilizer calculation if sold by weight –If sold by volume, usually applied by volume PERHITUNGAN PUPUK

73 APLIKASI PUPUK Starter (Pop-Up) Fertilizers –Addition of fertilizer w/ the seed during planting, dribbled in a strip near the see, banding w/in 2” of seed –Most beneficial for P, K – some for N, but not as necessary –Advantages: Cold soils Low nutrient levels in the root zone Fast-growing plants

74 –Disadvantages: Slows planting Can burn seedling, if placed too close Broadcast Application –Uniform application across entire surface –Left on surface, or incorporated –Somewhat less efficiency of fertilizer Especially when not incorporated quickly Why? APLIKASI PUPUK

75 –Reasons to broadcast: Only practical method of application – pastures, turf, etc. Low-fertility soils needing high fertilizer rates Easy, cheap, personal preference Flexible – split applications, ability to add after crop is growing APLIKASI PUPUK

76 Deep Banding –Application of strips into the soil –Either between/side of row, where the seed may be planted –Typically 4-12” depth –Knifing in anhydrous most common Gas able to dissolve in soil water before it escapes Losses can be high if dry, sandy APLIKASI PUPUK

77 –Disadvantages: Strong equipment needed High fuel costs Danger of dealing w/ anhydrous –Advantages: High yield response potential Puts fertilizer where most roots are, very efficient use APLIKASI PUPUK

78 Split Application –Divided total fertilizer rates delivered in 2+ applications –Reasons to split applications If large applications are needed – increase efficiency of nutrient use Soil conditions dictate – risk for high nutrient losses Control vegetative growth in early stages APLIKASI PUPUK

79 –Advantages: Increased efficiency of N utilization Provide a “boost” to the plant during growth –Disadvantages: Extra pass through field Not effective for P, K because of immobility APLIKASI PUPUK

80 Side-Dressing or Topdressing –Side-dressing – surface or shallow band application put on after crop is growing Broadcast, surface stripped, sprayed, knifed –Principles to consider: Decreases potential N losses Added in the furrow to allow water to help w/ infiltration Not effective for P, K APLIKASI PUPUK

81 Point Injector Application – place P, K into soil in the root zone w/out significant root damage –Used more in small plots, gardens –Push stick, rod into soil, fill w/ fertilizer, cover –Effective for: fruit trees, grapes, shrubs, etc. –Not common in field use APLIKASI PUPUK

82 Fertigation – application of fertilizer w/ irrigation water –Can apply large quantities of nutrients –Very effective for N Some see 30-50% more efficient use of N Cut of 50% in N rates w/ same/better yield –Must be careful of potential problem w/ salts APLIKASI PUPUK

83 1.Mampu memupuk pada saat puncak kebutuhan tanaman 2.Immediate/convenient application 3.Most effective on soils w/ poor nutrient retention & for mobile nutrients 4.Chemigation also possible – not discussed in depth here APLIKASI PUPUK

84 Foliar Application – foliage wetted to maximize nutrient absorption through leaf stomata & epidermis –Feasible for: N supplementation, pesticides, micronutrients, etc. –Guidelines: Only suited for applications of small amount (can burn plant) Decreased rates can be used APLIKASI PUPUK

85 Need wetting agent to help the spray to distribute evenly across surface Helpful when root conditions restrict nutrient uptake Quick response/remedy to deficiency (also short residual) Wind must be calm, humidity >70%, temp <85° F APLIKASI PUPUK

86 Fertilizing in Paddy & Other Waterlogged Soils –Paddy rice – production on water covered soils Water 2-6” deep One of very few crops that tolerate anaerobic conditions –Difficult to fertilize due to high nutrient loss risks APLIKASI PUPUK

87 Great focus on increasing efficiency of fertilizer use Research Real-time sensors in soils that immediately detect nutrient deficiency Transgenic plants Fertilizer Efficiency – fraction/percentage of added fertilizer that is actually used by the plant EFISIENSI PUPUK

88 Typical fertilizer efficiencies: –30-70% for N –5-30% for P –50-80% for K Maximum profits rarely at maximum yields –Last amounts of fertilizer to produce more yield cost more than yield increase –Management also key Use of BMP’s increasing –Encourage environmental protection –Couple w/ agronomic success –Increase economic yields, leading to sustainable ag EFISIENSI PUPUK

89 Plant Root Systems –Some plants better scavengers than others –Absorption greatly affected by fertilizer distribution –Smaller root system = shorter growing season = >dependence on fertilizer –Growth rates & size also effect amount of nutrients demanded EFISIENSI PUPUK

90 Gulma: –Response to fertilizer much like crops –N fertilization may increase weed growth > crop growth –Application method can also affect weed growth Ex – broadcast fertilizer can tend to help weeds get good start EFISIENSI PUPUK

91 Interaksi Pupuk dengan Air: –Availability of nutrients directed impacted by soil water content –Drip fertigation may be most efficient use of water & fertilizer Common in greenhouses Can be effective in field use –Israeli farming uses drip irrigation EFISIENSI PUPUK

92 Memupuk yang efisien: –Guides to optimal fertilization: Avoid large additions of N or K (50#/ac +) on sandy soils – use split application Avoid broadcast applications of urea & ammonia on warm/moist soils – volatilizes easily – incorporate Avoid N losses on poorly drained soils by using ammonium Band P Menggunakan pupuk starter EFISIENSI PUPUK

93 1.Keep N & K fertilizers out of seedling zone to avoid burn 2.Reduce leaching by avoiding application before rain or irrigation 3.Foliar apply, if feasible/appropriate 4.Know nutrient demands of crop 5.Improve management 6.Remember law of minimum 7.Uji Tanah

94 Many benefits of using manure: Recycles nutrients Potential to reduce pollution Adds C to soil Improve aggregation, infiltration, microbial vigor Risks: Increased weed pressure High cost of obtaining/applying if you don’t own it PUPUK KANDANG

95 Tidak semudah aplikasi pupuk buatan komersial Ancaman pencemaran air. Nutrient Production & Recovery –Production rates predictable & measurable –Ration has heavy influence on nutrients in manure Risiko Pupuk Kandang

96 Manure & Nutrient Budgets –Generous applications of manure no longer norm Some states require & enforce strict manure management guidelines –Restricted application due to soil P levels instead of N –Manure still can’t meet plant needs alone Crops remove much higher levels of nutrients/ac PUPUK KANDANG

97 Penggunakan pupuk kandang 1.Most recognize advantages of using manure 2.Manure production unevenly distributed in farmland 3.Expensive to transport very far 4.Too abundant in areas, not enough land for application

98 –Keseimbangan tiga faktor berikut: Supply crop nutrients Dispose of waste Protect environment –More focus on manure later PUPUK KANDANG


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