Poor soil fertility has caused Africa to lag behind other countries in agricultural productivity, according to a new report by the Alliance for a Green Revolution in Africa (AGRA).

Voice of America reports that while farmers in many parts of the world regularly harvest up to 5 tons of maize per hectare, those in Africa harvest just 1 ton on average.

The reasons for poor soil fertility include naturally rocky soils, persistent soil erosion and a lack of crop rotation and use of organic fertilizers.

Abed Kiwia, AGRA’s soil health program coordinator, says the organization is promoting ‘best-bet agronomic practices’ to help improve soil fertility and food production. These practices include integrating fertilizers with organic inputs such as from agroforestry trees.

According to Keith Shepherd from the World Agroforestry Centre, there is a need to “carefully target which fertilizers are appropriate where, and this needs soil and plant testing to diagnose what are the limiting nutrients.”

“We are faced with an extremely variable situation in small farming systems in Africa, and even within the same farm we have very different patches of poor and good soil as a result of past management," said Shepherd.

Read the full story: Africa food shortages blamed on poor soils

Find out more about the World Agroforestry Centre’s Land Health Decisions research program

Download the Africa Agriculture Status Report 2014