Long-term study shows increased maize yields using fertilizer trees

Thursday, November 1, 2012

Farmers across sub-Saharan Africa are maintaining high yields of maize by integrating fertilizer trees with their crops.

A 12-year study by the World Agroforestry Centre was recently published in the Agronomy Journal of the Soil Science Society of America.

The study shows how farmers in Malawi and Zambia are increasing their maize yields through intercropping leguminous Gliricidia trees which absorb nitrogen from the area and transfer it to the soil. The leaves of the tree also provide organic matter that nourishes the soil.

More than half of the area cropped in sub-Saharan Africa is under maize but this system “is in crisis”, with yields in many areas either stagnating or declining mainly due to decreasing soil fertility.

Most farmers in these countries cannot afford fertilizers and as a result their crops are less productive. They are also faced with the challenges of unpredictable rainfall, drought and soils which continue to degrade.

The study is the first to look at the long-term impacts on yields, says Gudeta Sileshi, regional representative for the Centre’s Southern Africa Program, “Now we know this is not just a temporary phenomenon. For maize farmers who can't afford fertilizers, agroforestry with nitrogen-fixing trees offers a stable increase in production, allowing them to feed their families and replenish the soil.".

The study is titled: Can Integration of Legume Trees Increase Yield Stability in Rainfed Maize Cropping Systems in Southern Africa.

Read the full story on Science Daily: Research Shows Legume Trees Can Fertilize and Stabilize Maize Fields, Generate Higher Yields
Or SciDev.Net: Intercropping 'boosts maize yields by 50 per cent'