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Wonder tree could be one answer to food scarcity in Africa

Nairobi (Kenya), 28 August 2009 - The World Agroforestry Congress held at the UN's Africa headquarters in Nairobi (Kenya) has offered some tree-planting solutions which could help the African continent deal with climate change and also provide a long-term solution to the continent's food scarcity problems.

Dennis Garrity, the Director General of the World Agroforestry Centre, highlighted some of the centre's most recent research, which is designed to increase maize production in Africa by up to four times by planting trees that act as organic fertilizers.

"We have evidence of how maize yields have doubled and tripled for smallholders, without an overall increase in labour or the need to apply nitrogen fertilizers," said Garrity.

Garrity told the Congress the secret to higher maize yields lay in a tree called Faidherbia.

This tree has a special nitrogen-fixing property and an unusual habit known as "reverse leaf phenology".

Unlike other trees, Faidherbia sheds its leaves and goes dormant during the early rainy season.

Its leaves grow again only in the dry season. This means that it is extremely compatible with food crops because it does not compete with them for water, nutrients or light.

According to the Agroforestry Centre, farmers in Malawi testify the tree is like a "fertilizer factory in the field", as it takes nitrogen from the air, fixes it in the leaves and subsequently incorporates it into the soil.

The Agroforestry Centre's research showed that in Malawi maize yields increased by 280 per cent in the zone under the tree canopy compared with the zone outside the tree canopy. In Zambia, unfertilized maize yields in the vicinity of Faidherbia trees averaged 4.1 tonnes per hectare, compared to 1.3 tonnes nearby but beyond the tree canopy.

The latest research was welcomed by Kenyan officials, environmentalists and agronomists at a time when Kenya is asking for emergency food aid in order to prevent widespread famine.

Maize is the staple food for many African countries, but when grown as a mono-crop over many years it drains the soil of vital nutrients.

On average, maize yields on the 27 million hectares on which it is grown in Africa are one tenth the equivalent of American yields. One of the reasons is limited use of fertilizers, but the Faidherbia tree - pending some further research on its impact on the water table - may now provide a natural and widespread fertilizer fix.

Plant Trees or El Nino and Climate Change will Claim Lives

The congress also emphasized how tree-planting can provide farmers with everything from nuts and fruits to windbreaks, erosion control, and fuel for heating, timber for housing and fertilizer to improve much needed food security.

Founder of the Greenbelt Movement and Nobel Prize laureate Wangari Maathai emphasised the urgency of planting trees to help Africa adapt to the more extreme weather conditions brought on by climate change. Maathai said that climate change, like a disease, can easily kill a body already weakened by decades of environmental mismanagement.

Maathai made her plea to an audience of African journalists in the context of a fast approaching El Nino:

"We need to prepare for El Nino. We need to plant trees and have vegetation covering the soil. We need to dig trenches and cut off drains that to allow water to go into the ground. It cannot wash away to the rivers, which will then wash away all the top soil. Let's not wait for the governments, let us do it ourselves."




Further Resources

While Farmers Frequently Blamed for Forest Loss, New Study Shows about Half of Farmlands Worldwide H

2nd World Agroforestry Congress Welcoming Remarks by UNEP Executive Director, Achim Steiner

World Agroforestry Centre

Billion Tree Campaign


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