Soil fertility key to Africa’s green revolution

Lazarus Sauti

Pedro A. Sánchez, director of the Earth Institute’s Tropical Agriculture and Rural Environment Program and a senior research scholar believes that fertile soils are critical to boosting cereal crop yields in Africa.

Sánchez said replenishing soil fertility with mineral and organic fertilisers could therefore triple cereal crop yields in tropical Africa and achieve an African green revolution.

Decades of farming without adequate fertiliser, according to Sánchez, have ‘stripped the soils of the vital nutrients needed to support plant growth’.

Therefore, to improve soil fertility, countries within and across the African continent must now focus on adding organic fertilisers to their soils.

“Only organic fertilisers add carbon, feed soil microbes and help to retain soil moisture”, writes Sánchez.

The best way of applying them, he adds, is to grow leguminous trees that capture nitrogen from the air and transfer it to the soil.

“Such ‘nitrogen-fixing’ trees could capture 50–100 kilogrammes of nitrogen per hectare per year in tropical Africa – similar to the amount added by mineral fertilisers,” Sánchez noted.

More so, ‘nitrogen-fixing’ trees have the added benefit of providing fuel wood.
Sánchez also said to establish the nitrogen-fixing system, farmers have to forgo one crop, which makes it unattractive to most farmers in tropical Africa.