“Evergreen agriculture allows us to glimpse a future of more environmentally benign farming where much of our annual food crop production occurs under a full canopy of trees”
Evergreen Agriculture – the combination of trees in farming systems (agroforestry) with the principles of conservation farming – is emerging as an affordable and accessible science-based solution to caring better for the land and increasing smallholder food production.
The huge challenge for Africa is producing more food for a growing population while at the same time combating the risks that come with climate change. However, hundreds of thousands of rainfed smallholder farms in each of four countries (Zambia, Malawi, Niger, and Burkina Faso) have been shifting to farming systems that are restoring exhausted soils and are dramatically increasing food crop yields, household food security, and incomes. The presentation will review that experience, discuss the application of conservation farming (CF) principles in African smallholder agriculture, and will outline a fresh approach through the integration of trees into these systems to create an Evergreen Agriculture, that is, an agroforestry-based conservation agriculture. Finally, it will focus on the key research issues to be tackled, and will report on the current momentum for these successes to be further adapted and scaled-up across the African continent.
What is Evergreen Agriculture?
Put simply, Evergreen Agriculture combines agroforestry with the principles of conservation farming.
Conservation farming is already practiced on around 100 million hectares of land worldwide. It involves three well-established principles:
Disturbing the soil as little as possible (i.e. minimum or zero tillage)
Keeping the soil covered with organic material such as crop residues
Rotating and diversifying crops, especially making use of leguminous species that replenish soil nutrients.
The addition of agroforestry offers multiple livelihood benefits to farmers, including sources of green fertilizer to build healthier soils and enhance crop production, and providing fruits, medicines, livestock fodder, timber and fuelwood. There are environmental benefits too, in the form of shelter, erosion control, more effective water cycles and watershed protection, increased biodiversity, greater resilience to climate change, and carbon storage and accumulation. In fact, one tropical tree can sequester at least 22.6 kg of carbon from the atmosphere each year.
Evergreen agriculture emerges as Africa’s key to food security
by Kate Melville
Crop production occurring under a full canopy of trees sounds counter-intuitive, but a unique acacia known as a “fertilizer tree” is allowing African farmers to triple maize yields. Attendees at The Hague Conference on Agriculture, Food Security and Climate Change were told yesterday that evergreen agriculture – the integration of fertilizer trees into crop and livestock-holding farms – is rapidly emerging as an affordable and accessible solution to improving production on Africa’s farms.
“Doubling food production by mid-century, particularly in Africa, will require nonconventional approaches, particularly since so many of the continent’s soils are depleted, and farmers are faced with a changing climate,” said Dr. Dennis Garrity, Director General of the World Agroforestry Centre. “We need to reinvent agriculture in a sustainable and affordable way, so that it can reduce its emissions of greenhouse gases and be adapted to climate change.”
In a recent article in Food Security, Garrity explained how evergreen agriculture has already provided benefits to several million farmers in Zambia, Malawi, Niger and Burkina Faso. Fertilizer trees draw nitrogen from the air and transfer it to the soil through their roots and leaf litter, replenishing exhausted soils with rich sources of organic nutrients. The trees bolster nutrient supply, increase food crop yields, and enhance the production of fodder, fuel and timber. These systems also provide additional income to farmers from tree products, while at the same time storing much greater amounts of carbon than other agricultural systems.
Garrity notes how farmers in Malawi have increased their maize yields by up to 280 percent when the crop is grown under a canopy of one particular fertilizing tree, Faidherbia albida. Unlike most other trees, Faidherbia sheds its leaves during the early rainy season and remains dormant during the crop-growing period. This makes it highly compatible with food crops because it does not compete with them for water, nutrients, or light – only the bare branches of the tree’s canopy spread overhead while crops of maize, sorghum, or millets grow to maturity below. The leaves and pods also provide a crucial source of fodder in the dry season for livestock when nearly all other plants have dried up. The trees may continue to provide these cost-free benefits for up to 70 to 100 years.