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Evergreen agriculture: re-greening Africa's landscape

The benefits that trees provide are best sustained by integrating them into agriculturally productive landscapes (© Charlie Pye-Smith/ICRAF)
The benefits that trees provide are best sustained by integrating them into agriculturally productive landscapes
© Charlie Pye-Smith/ICRAF

With climate change, increasing populations, reduced landholdings and declining soil productivity, the outlook for Africa's farms may look bleak. However, whilst forest cover is declining, the number of trees on farms is increasing. And where there are trees, farmers have access to fodder, timber, fruit and fuel, plus shade for their crops. In Malawi, yields have increased by up to 280 per cent where maize is grown under the canopy of Faidherbia albida trees. In Niger, around 4.8 million hectares of Faidherbia-dominated agroforests enhance millet and sorghum production.

The transformation of agriculture into agroforestry is well underway across not only Africa but the globe, says Dennis Garrity of the World Agroforestry Centre. "Over a billion hectares of agricultural land, almost half of the world's farmland, have more than 10 per cent of their area occupied by trees and 160 million hectares have more than 50 per cent tree cover." He continues, "The benefits that trees provide are best sustained by integrating them into agriculturally productive landscapes."

Production and conservation

Maize farmers are boosting their yields by planting fertiliser trees (© Charlie Pye-Smith/ICRAF)
Maize farmers are boosting their yields by planting fertiliser trees
© Charlie Pye-Smith/ICRAF

One of the greatest benefits of evergreen agriculture - integrating trees with annual food crops to provide year round plant cover - is that a wide variety of tree species can be planted to provide households with the goods and services that they need. And, not only do the trees provide food and income, but they also enhance soil fertility and water conservation. The nitrogen-fixing Faidherbia, for example, has a deep penetrating tap root, making it resistant to drought and, unlike most trees, it sheds its leaves in the rainy season to provide valued biomass, which is applied as a mulch. In Zambia and Malawi more than 100,000 farmers have extended their conservation farming practices to include cultivating food crops within agroforests of Faidherbia trees.

Gliricidia sepum, another fertiliser tree intercropped as a shrub, is cut back during cropping to provide biomass, fodder and fuel. Besides increasing soil fertility, weeds are suppressed and water filtration and the amount of carbon stored in the soil increases. "Agroforestry systems provide much greater carbon offset opportunities than any other climate mitigation practice in agriculture," states Garrity.

Progress in Malawi, Kenya, Niger and Senegal

In 2005, through the work of the World Agroforestry Centre and partners, around 100,000 smallholder farmers in Malawi were benefiting from planting fertiliser trees. However, through scaling-up of agroforestry systems as a result of Malawi's Agroforestry Food Security Programme, supported by Irish Aid, a further 200,000 farm families have benefited in the last four years from increased food production and nutrition. The programme provides seeds, nursery materials and training for a range of agroforestry practices, including the planting of fertiliser trees, which particularly benefit the poor.

Many farmers have increased their income by growing indigenous fruit trees like African plum (© ICRAF)
Many farmers have increased their income by growing indigenous fruit trees like African plum
© ICRAF

Malawi is not the only African country to be supporting an upscaling of agroforestry. Kenya has introduced a bold policy under its new Greening Kenya Initiative to achieve ten percent tree cover whilst Ethiopia has made a commitment to increase agroforests to 15 million ha by 2015, particularly focusing on desertified areas with a low density of trees. In West Africa, the re-greening of the Sahel, well documented in Niger, is spreading to include Faidherbia parklands across Mali's Seno Plains as well as in Senegal. Producing maize, sorghum, and millet under these agroforests has been shown to dramatically increase their drought resilience in dry years due to positive soil moisture regimes, and a better microclimate.

South Asian network

Based on the rapid expansion and success of evergreen agriculture in Africa, in early 2011 the World Agroforestry Centre supported the launch of the South Asia Network of Evergreen Agriculture, including universities, research centres, NGOs, and government agencies across eight countries. The newly formed network will assist natural regeneration of indigenous trees in arid and dry lands, identify other tree species especially for replenishing soil fertility, and suggest scale-up mechanisms for large scale adoption by farming communities. Prosopis cineraria, for example, is already widely grown in agroforestry systems on millions of hectares across Rajasthan to provide shade for crops, as well as fodder, fuel and timber. Acacia tortillis is used in the dryland systems of central India, as one of the few species that can tolerate very harsh, arid environments.

Trees provide fodder, timber, fruit, fuel, and shade for crops (© Charlie Pye-Smith/ICRAF)
Trees provide fodder, timber, fruit, fuel, and shade for crops
© Charlie Pye-Smith/ICRAF

In Africa, work on evergreen agriculture also continues, with preparatory work for national programmes underway in Tanzania, Mali and 12 other countries, supported by the World Agroforesty Centre and partners. A key priority is to intensify research on genetics and propagation, to underpin scaling up. Policy support at national and international levels will be essential, as well as developing diverse partnerships and building capacity within national systems to scale up research and development on evergreen agriculture.

"We see evergreen agriculture as nothing less than the radical, but entirely practical, pathway to a reinvention of agriculture," concludes Garrity. "The opportunities provided by evergreen agriculture should inspire the next generation. We need to take heart at the success already achieved and grab onto the momentum."

Date published: September 2011

 

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