Agro-forestry to boost maize yield

A long term study has found out that agro-forestry can help farmers across Sub- Saharan Africa cope with the impact of climate change effects like drought and degraded soils.

The findings are critical for understanding how farmers in Malawi can endure climate change effects like year to year variation in rainfall, which has direct impact on maize yields.

According to a press release from World Agro-forestry Centre (ICRAF), this is the first long-term study to find that legume trees planted alongside maize, combined with less fertilizer is best solution for Africa’s most important food crop in coping with climate change.

The research has been conducted in a period of 12 years through three coordinated experiments, which begun in 1991 in Malawi and Zambia.

The findings indicate that farms that mix nitrogen-fixing trees and maize have consistent and relatively high yields year after year.

In Malawi, the highest average maize yield was found in fields that combined both fertilizer trees and inorganic fertilizers, but applied at just half the standard recommended amounts.

The study was done by Gudeta Sileshi, Legesse Kassa Debusho and Festus Akinnifesi, and was published in this month’s issue of Agronomy Journal of the Soil Science Society of America.

“To grow their way out of poverty, Africa’s small-scale farmers don’t just need a good harvest for one or two years, they need long-term stable, high-yield harvests,” said coauthor Akinnifesi , who is former regional coordinator for the World Agroforestry Centre, Southern Africa Regional Programme based in Nairobi, Kenya.

He added that farmers need to know which farming systems will be both stable and sustainable as the environment and climate changes.

With climate change, maize cropping systems are expected to experience even more dramatic reductions in yield. For just 1°C of warming, more than 75 percent of the present maize-growing areas in Africa are predicted to experience at least a 20 percent reduction in yield under drought conditions.

“We need well-designed long-term trials that will allow scientific assessments of different cropping systems with a changing climate in Africa,” added Debusho, a senior lecturer at the University of Pretoria.

He was optimistic that such information can guide the exploration of technological alternatives and the development of policies to improve the adaptability and sustainability of cropping system.