improving soil fertility and nutrient management in developing countries

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Fertilizer use and crop production worldwide,Green revolution & fertilizer,Soil organic matter build-up & fertilizer,Fertilizers and the environment,Soil Fertility in Asia,Soil Fertility in Africa,Future needs for research and outreach


  • 1.Improving Soil Fertility andNutrient Management in Developing Countries K.F. BronsonTexas A&M and Texas Tech University

2. Outline World fertilizer consumption/crop production 1961-2002/malnutrition Green revolution & fertilizer Soil organic matter build-up & fertilizer Fertilizers and the environment Nut mgt in Asia -- Central Asia -- South Asia -- SE Asia Nut mgt in Africa -- West Africa Future needs for research and outreach 3. Fertilizer use and cropproduction worldwide 4. World cereal production and total fertilizer2500 160 consumption, 1961-2002 (FAOSTAT) 1402000 Fertilizer consumption (mill Mt) 120 Cereral production (mill Mt) 1001500 80Cereal production1000Fertilizer consumption 60 40500 2000 1961 1964 1967 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000Africa is an exception Year 5. Productionper capitaandProductionArea percapita 6. Percent of population malnourished for 1990-2001454035Percent of pop undernourished301990-1992251999-2001201510 5 0 Devg Asia India Bang China Indo Sub-Africa Niger Mali S.A. Brazil Colum Countries 7. Calories/person/day for 1990-2001350030001990-19921999-20012500Calories/person/day200015001000 500 0 Devg Asia India Bang China Indo Sub-Africa Niger Mali S.A. Brazil Colum CountriesNote: World avg 2700-2800 cal, USA avg 3500-3800 cal 8. Fertilizer and the greenrevolution 9. Response of tall, traditional rice and semi-dwarf rice toN fertilizer, Philippines, 1968 yield (t/ha)6.005.00Tall, native varietyIR84. 0204060 80 100120 Nitrogen rate (kg/ha) 10. African Exception (Avery, 2000) Africa has been low population with lowinput/low yield bush fallow. 25 % goodcropland not used Green revolution efforts targeted Asia,were not transferable to Africa Poor record keeping Poor governance 11. Why hasnt the green revolution beensuccessful in Africa? (Evenson&Gollin) No elite germplasm for cassava, beanssorghum, millet Crops are more diverse & mostly dryland Large landholdings for cash crops 12. Fertilizer and soil organic matter 13. Total soil organic C and total soil N in 0-15 cmInceptisol after 30 yr of rice-wheat-jute cropping,West Bengal, India (Manna et al., 2006) Nutrient Total organic C Total N managementg/kgmg/kg Control5.1 c 422 f N5.7 d 660 d NP 6.3 c 750 c NPK7.4 b 867 b NPK + FYM7.9 a 927 a 14. Crop residue removal 15. Advantages of organic manures Boost yields, retard yield declines Provide N, P, micronutrients Fortify seeds with micronutrients Build-up soil organic matter Improve soil physical properties Improve soil water relations 16. Limitations of organic manures Availability/transport costs Nutrient imbalance (i.e. manure is about2:1 N:P2O5, plants need 5-7:1 N:P2O5) Variability in composition Potential for polluting surface waters Limited nutrient availability in 1st year Pathogens 17. Fertilizer and the environment 18. Nitrous oxide fluxes in irrigated rice as affected by N fertilizer source and mid-season drainage,4Los Banos, Philippines, 1993 dry season.3.532.5N2O (mg N/m2/d)21.5UreaAmmonium sulfate10.50 0 20 40 60 80 100 120-0.5 Days after transplanting 19. Methane fluxes in irrigated rice as affected byN fertilizer source and mid-season drainage, Los Banos, Philippines, 1993 dry season. 40 35 30CH4 flux (mg C/m2/d) 25 20 UreaAmmonium sulfate 15 10 5 0020 40 60 80 100 120 -5 Days after transplanting 20. Cadmium content of phosphate rockmg /kg mg/kg P2O5 Igneous DepositsSouth Africa 1 3Former USSR1 3 Sedimentary DepositsChina2 7Morocco 2680Senegal 87241North Florida620North Carolina38128Western US92292 21. Other environmental issues Eutrophication of surface waters Nitrate contamination of surface andground waters Arsenic contamination of groundwater Aral Sea crisis 22. Soil Fertility in Asia 23. Fertilizer use and grain production in India 160 20 18 140Rice and wheat production (milln Mt) 16Fertilizer cionsuption (milln Mt) 120 14 100 12 8010 8 60 6 40 Rice productionWheat production 4 20 Fertilizer consumption 200 1919191919191919191919191919191919202067697173757779818385878991939597990103 Year 24. Chlorophyll meter and leaf color chart for in- season N monitoring in Asia 25. Rice grain yields as affected by chlorophyll meter-based management, Ludhiana, India, 1997N Total N Cultivarmanagementapplied kg N/ haPR-106PR-111---------- Mg ha-1 -----------Well-fertilized 2405.80 a 7.02 areferenceChlorophyll 90 6.08 a 6.51 ameter-basedFixed-timing 1206.14 a 6.54 aZero-control0 4.42 b 4.72 b 26. Urea and singlesuperphosphate fertilization in Eastern Uzbekistan 27. Uzbek farmers fertilization survey What is your cotton seeding rate (kg/ha)? 60 What is your seedcotton yield goal (t/ha)? 2.9 How much total urea do you apply (kg/ha)? 488 How much superphosphate do you apply (kg/ha)?421 How much potash do you apply (kg/ha)? 32 28. Uzbek farmers survey for wheat What is your wheat seeding rate (kg/ha)? 250 What is your yield goal (t/ha) ? 4.3 How much urea do you apply (kg/ha)? 452 How much superphosphate do you apply (kg/ha)?419 How much potash do you apply (kg/ha)? 3 How often is your soil sampled and tested at thelocal lab? No (100%) 29. Soil test results from three districts in Ferghanavalley, March, 2003Quva (11)Bagdod (12)Okhunboboev (12) Low MedHigh Low MedHigh LowMedHighNitrate100%100% 66%34%P55% 45% 100%34%34%34%K18%82% 100% 100%1:1 pH7.7 (0.4) 8.1 (0.2)8.0 (0.2)ECa6.0 (0.6) 2.0 (0.2)1.8 (0.3)(mmo/cm)a irrigation water 30. Establishment of N and P fertilizerrate trials in 2005 Three locations (Quva, Ristan, and Bagdod) Soil tests (LaMotte) done 0-15 cm RCB design, N x P factorial, three reps Plot size 15 M x 8 (0.09 m rows) Urea-N rates of 0, 80, 160, and 240 kg N/ha Single superphosphate rates of 0, 45, and 90 kgP2O5/ha 31. Nutrient managementrecommendations forUzbekistan Farmers are applying ~ 2 X the N and Pfertilizer needed for the yield levels. Fertilizer timing can probably be simplified.Phosphorus can be applied just once, pre-plant. Urea applications might be reducedto two splits (pre-plant and squaring). Recommend N and P fertilizer rate trials. 32. Soil Fertility inAfghanistan Soil pH ranges from 7.5-8.8 (Mean 8.2) CaCO3 ranges 3-42% (Mean 23%) Phosphorus and deficiencies are widespread. 46 % soils < 10 ppm Olsen-P 66 % soils < 0.5 ppm DTPA-Zn Potassium is generally adequate 33. Fertilizer use Only on irrigated fields, mainly wheat Average of 152 kg diammonium phosphate(18-46-0) (27 kg N/ha, 70 kg P2O5/ha) Average of 150 kg urea/ha (70 kg N/ha) intwo splits Infrequent response reasons? Little manuring 34. Cereal production in Afghanistan, 1964-2003 (FAO, 2003) 35. Challenges for future of agriculture in Afghanistan Soil & Crop Mgt Cash crop replacement for opium poppy Research no-till wheat for dryland Inexpensive implements to band P fertilizer Access to Zn fertilizer Rebuild cotton gins for cotton production Training of agric. Scientists (undergraduateand graduate level) 36. Soil Fertility in Africa 37. Productionper capitaandProductionArea percapita 38. Agronomically, what has changed in 40-50 years? SoilP levels have probably decreased overall if~5 kg P/ha is removed per yearExpansion into more marginal landsYield has decreasedFallow frequency and duration have decreasedOther problems associated with land degradation,e.g. soil crusting, wind and water erosion, etc.,increase. 39. Soil nutrient depletionin Africa,Smaling et al., 1997 40. Consumption, production, export, and import of mineral fertilizer in Sub-Saharan Africa 1988-1999 (IFDC Website) 1988/89: 1,182,000 mt 1998/1999: 1,282,000 mt Totals for1990- 1991- 1992- 1993- 1994- 1995- 1996- 1997- 1998- 1999- 2000- Sub-Saharan 19911992199319941995199619971998199920002001 Africa(x 1000 mt N + P2O5+K2O) Consumption 12461267128713411212107313051252123213031230 Production547 543 573 539 376 348 327 272 314 296 167 Exports 207 190 179 171 134 110 95117 157 103 83 Imports 1058933 109610901026827 12161162116011461164Despite recognition of acute P and other nutrient deficiencies for ~ 50 y, no realsign of progress in fertilizer consumption 41. Improving Crop Production under low soil P fertility Regional Phosphate Rock Partially acidulated PR Water soluble P fertilizers (SSP, TSP)-- Regional SSP/TSP production-- Import SSP/TSP/DAP Genetic Approach Agroforestry/VAM 42. Geologic IronyBationo,Christianson, andMokwunye, 1989. 43. Grain yields as affected by Kodjari phosphate rock (PR) and TSP, Burkina Faso (Frederick et al., 1992) MilletSorghumMaizePhosphorus ------------------------ kg/ha -------------------------TreatmentsControl596 9162219PR 698(68)1006 (39) 2464 (35)PAPR 728(88)1103 (81) 2839 (88)TSP74511462919RAE (relative agronomic effectiveness are in parentheses) 44. Grain and seedcotton yields as affected by Tilemsi phosphate rock (PR) and SSP, Mali, 1989-1992(Bationo et al., 1997) SSP Tilemsi PRSougoumba------------- kg/ha ---------------Sorghum1.43 (11)a1.52 (27)aCotton 1.42 (33) 1.39 (55)TinfoungaMaize2.61 (22) 2.26 (27)Cotton 1.61 (33) 1.41 (55) aP source rates in kg P/ha/yr are in parentheses 45. Agroforestry Faidherbia albidaAfrican winterthorn/Mimosa VAM&Bradyrhizobium 46. Soil available P as affected by distance from Faidherbia albida 30Payne et al CropSoil depthBRAY I P (mg kg-1)Sci. 38:1585-1591. 20 100 cm5020 100 0 5 1015 DISTANCE (m) 47. Needs for soil fertilityresearch/education/capacitybuilding 48. Research/extension education/capacity building needs for improving soil fertility & nutrient management India/South Asia More balanced fertilization, moremanure and residue Afghanistan Cotton, hort crops, P, micronutrients Uzbekistan more efficient irrig., rationalize N and P,i.e. less application/more for export Southeast Asia improve NUE in rice w/LCCs,urea briquettes, green manures, P, animal manure West Africa PAPR, N, lime, HYVs, animal waste Training of agric. Scientists (undergraduate,graduate/post-docs/visiting)


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