Boosting Soybean Yields and Raising Farmer Income in Kenya with Nutrient Management
In Kenya, three out of four people work in some aspect of agriculture and food production. Economic growth in the country is 11 times more effective at reducing poverty than growth in any other sector. Soybean production in Kenya provides the countries smallholder farmers with an alternative cash income. However, Kenyan farmers currently apply little or no fertilizer on soybeans and prefer to use it on other crops instead, which has contributed to poor soybean yields.
To combat this, a participatory diagnosis exercise was conducted with researchers, extension agents and farmer groups to estimate current yields in farmers’ fields and identify the soil constraints to soybean production. Multi-location field trials were then established between 2012 and 2015 to assess the effects of rhizobia (soil bacteria that fix atmospheric nitrogen inside legume plant root nodules) inoculation, balanced nutrient management, manure, and lime application on soybean productivity and N2 fixation potential in actual farmer field.
The results showed that Soybean yields were increased from approximately 1 t/ha to 2.4 t/ha by application of N, P, K, and micronutrients, if balanced fertilizer application was adopted. Yields were further increased to 3.0 t/ ha when manure and lime were also applied. However, inoculating soybean with rhizobia without proper plant nutrition has limited effects on nodulation and yield, particularly on infertile and degraded soils.
This successful project has developed educational training materials and provided training to 2,500 farmers and 56 extension agents on nutrient management practices for optimizing fertilizer use in soybean production. These Kenyan farmers learned that investment in fertilizer in soybean production was highly profitable, with gross margins increasing by US$400 to $1200/ha in the fertilized plots over unfertilized plots. The current annual production of soybean in Kenya and Uganda is less than 20,000 t, which is far less than the total demand of 130,000 t. The results from the project indicate that there are opportunities to reduce the deficit in regional soybean production and boost farmer income by intensifying nutrient, manure, and lime use.
Credit: Shamie Zingore/IPNI
Read more about the project here.