Hostname: page-component-76fb5796d-vvkck Total loading time: 0 Render date: 2024-04-29T16:16:47.443Z Has data issue: false hasContentIssue false

AGRONOMIC AND FINANCIAL BENEFITS OF PHOSPHORUS AND NITROGEN SOURCES IN WESTERN KENYA

Published online by Cambridge University Press:  01 July 2009

BASHIR JAMA*
Affiliation:
World Agroforestry Centre (ICRAF), P.O. Box 30677, NairobiKenya Alliance for a Green Revolution in Africa (AGRA) Eden Square, Block #1, 5th Floor, P.O. Box 66773, Westlands, 00800, Nairobi, Kenya
ABEDNEGO KIWIA
Affiliation:
World Agroforestry Centre (ICRAF), P.O. Box 30677, NairobiKenya AGEBB Consultants, P.O. Box 9819, City Square, 00200, Nairobi
*
§Corresponding author: bjama@agra-alliance.org

Summary

A better understanding of the agronomic and economic benefits of integrating organic and inorganic fertilizers is essential for their wide-scale dissemination and adoption in smallholder farming systems in developing countries. Field studies were conducted for 10 cropping seasons (1996–2000) on a Kandiudalfic Eutrudox soil to compare the effects of Minjingu phosphate rock (MPR) and triple superphosphate (TSP) on the yield of maize (Zea mays), in combination with three nitrogen (N) sources: urea, Tithonia diversifolia and Sesbania sesban leafy biomass. Urea and tithonia were applied to provide 60 kg N ha−1. Phosphorus (P) from either MPR or TSP was added either once at 250 kg P ha−1 at the beginning of the experiment or annually at 50 kg P ha−1 for five years, the two rates representing two P recapitalization strategies. From the second year, potassium (K) was added to half of each plot to correct for the deficiency that emerged. Over the 10 cropping seasons, the agronomic and economic benefits of the two P recapitalization strategies were similar and were not influenced by the P sources used. With N and K application, both P sources resulted in at least a two-fold maize grain yield increase over the control with no P application that averaged 1.1 tons ha−1. Comparing the N sources, although urea and tithonia had similar net benefits when P was applied, the total cost associated with tithonia was considerably higher. Without P application, sesbania fallow was the most financially attractive option. Sesbania fallows as an N source were also least sensitive to increases in the price of fertilizers and the cost of labour although the financial benefits of this system remained low in the absence of P and K application.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2009

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Anderson, J. M. and Ingram, J. S. I. (1993). Tropical Soil Biology and Fertility: A Handbook of Methods. Wallingford, UK: CAB International.Google Scholar
Bromfield, A. R., Hancock, I. R. and Debenham, D. F. (1981). Effects of ground PR and elemental S on yield and P uptake of maize in western Kenya. Experimental Agriculture 17: 383387.CrossRefGoogle Scholar
Buresh, R. and Niang, A. (1997). Tithonia diversifolia as a green manure: Awareness, expectations and realties. Agroforestry Forum 8: 2931Google Scholar
Buresh, R., Smithson, P. and Hellums, T. D. (1997). Replenishing soil phosphorus in Africa. Soil Science Society of America 51: 111149.Google Scholar
CIMMYT. (1988). From Agronomic Data to Farmer Recommendations: An Economic Training Manual. Completely revised edition. Mexico, D. F.Google Scholar
FEWSNET. (2002). Kenya food security update. www.fews.net/pages/countryarchive.Google Scholar
Gachengo, C., Palm, C., Jama, B. and Othieno, C. (1999). Tithonia and senna green manures and inorganic fertilizers as phosphorus sources for maize in western Kenya. Agroforestry Systems 44: 2136CrossRefGoogle Scholar
Ikerra, S. T., Semu, E., and Mrema, J. P. (2006). Combining Tithonia diversifolia and Minjingu phosphate rock for improvement of P availability and maize grain yields on a chromic acrisol in Mororgoro, Tanzania. Nutrient Cycling in Agroecosystems 76: 249260.CrossRefGoogle Scholar
Jama, B., Swinkels, R. A. and Buresh, R. J. (1997). Agronomic and economic evaluation of organic and inorganic phosphorus in western Kenya. Agronomy Journal 89: 597604CrossRefGoogle Scholar
Jama, B., Buresh, J. R. and Place, F. (1998). Sesbania tree fallows on phosphorus-deficient sites: maize yield and financial benefit. Agronomy Journal 90: 717726CrossRefGoogle Scholar
Jama, B. A., Palm, C. A., Buresh, R. J., Niang, A. I., Gachengo, C., Nziguheba, G. and Amadalo, B. (2000). Tithonia diversifolia as a green manure for soil fertility improvement in western Kenya: a review. Agroforestry Systems 49: 201221.CrossRefGoogle Scholar
Jama, B. A. and van Straaten, P. (2006). Potential of East African phosphate rock deposits in integrated nutrient management strategies. Anais da Academia Brasileira de Ciências 78: 781790.CrossRefGoogle ScholarPubMed
Jayne, T., Govereh, J., Wanzala, M. and Demeke, M. (2003). Fertilizer market development: a comparative analysis of Ethiopia, Kenya, and Zambia. Food Policy 28: 293316.CrossRefGoogle Scholar
Lauriks, R., Wulf, R., Carter, S. E. and Niang, A. (1999). A methodology for the description of border hedges and the analysis of variables influencing their distribution: a case study in western Kenya. Agroforestry Systems 44: 6986.CrossRefGoogle Scholar
Lijzenga, M. (1998). Maize response to NPK in relation to fertility indices in western Kenya. MSc thesis. Wageningen Agricultural University, The Netherlands.Google Scholar
Maroko, J. B., Buresh, R. J., and Smithson, P. C. (1999). Soil phosphorus fractions in unfertilized fallow-maize systems on two tropical soils. Soil Science Society of America Journal 63: 320326.CrossRefGoogle Scholar
Mwaura, F. and Woomer, P. (1999). Fertilizer retailing in the Kenyan Highlands. Nutrient Cycling in Agroecosystems 55: 107116,CrossRefGoogle Scholar
Ndufa, J. K., Shepherd, K. D., Buresh, R. and Jama, B. (1999). Nutrient uptake and growth of young trees in a P-deficient soil: Tree species and phosphorus effects. Forest Ecology and Management. 122: 231241.CrossRefGoogle Scholar
Niang, A., Gathumbi, S. and Amadalo, B. (1996). The potential of short duration improved fallow for crop productivity enhancement in the highlands of western Kenya. East Africa Agriculture & Forestry Journal 62: 103114.CrossRefGoogle Scholar
Nziguheba, G., Palm, C. A., Buresh, R. J. and Smithson, P. C. (1998). Soil phosphorus fractions and adsorption as affected by organic and inorganic sources. Plant and Soil 198: 159168.CrossRefGoogle Scholar
Palm, C. A., Myers, R. J. K. and Nandwa, S. M. (1997). Organic-inorganic nutrient interactions in soil fertility replenishment. In Replenishing Soil Fertility in Africa, 193217 (Eds Buresh, R. J., Sanchez, P. A. and Calhoun, F.). Soil Science Society of America Special Publication 51: Soil Science Society of America, Madison WI, USA.Google Scholar
Place, F., Barret, C. B., Freeman, H. A., Ramisch, J. J. and Vanlauwe, B. (2003). Prospects for integrated soil fertility management using organic and inorganic inputs: evidence from smallholder African agricultural systems. Food Policy 28: 365378.CrossRefGoogle Scholar
RATIN. (2008). Production and harvesting update. Regional Agricultural Trade Intelligence Network (RATIN). East Africa Food and Trade Bulletin, March 2008. No. 48. Available online at www.ratin.net/bulletin.asp (Accessed 28 January 2009).Google Scholar
Sanchez, P. A. (2002). Soil fertility and hunger in Africa. Science 295, 20192020.CrossRefGoogle ScholarPubMed
Smaling, E. M. A., Stroorvogel, J. J. and Windmeijer, P. N. (1993). Calculating soil nutrient balances in Africa at different scales: II. District scale. Fertilizer Resources 35: 237250.CrossRefGoogle Scholar
Smithson, P. C., Jama, B., Delve, R., van Straaten, P. and Buresh, R. J. (2001). East African phosphate resources and their agronomic performance. In Direct Application of Phosphate Rock and Related Technology: Latest Developments and Practical Experiences. Conference Proceedings, Kuala Lumpur, Malaysia, July 16–20, 2001. International Fertilizer Development Center, Muscle Shoals, Alabama, USA.Google Scholar
Stroorvogel, J. J., Smaling, E. M. A. and Janssen, B. H. (1993). Calculating soil nutrient balances in Africa. I. Supranational scale. Fertilizer Research 35: 227235.CrossRefGoogle Scholar
Swinkels, R. A., Franzel, S., Shepherd, K. D., Ohlsson, E. and Ndufa, K. J. (1997). The economics of short rotation improved fallows: Evidence from areas of high population density in western Kenya. Agricultural Systems 55: 99121.CrossRefGoogle Scholar
Van Kauwenbergh, S. J. (1991). Overview of phosphate deposits in East and Southeast Africa. Fertilizer Research 30: 127150.CrossRefGoogle Scholar
Van Straaten, P. (2002). Rocks for Crops: Agrominerals for sub-Saharan Africa. Nairobi, Kenya: ICRAF.Google Scholar