Land degradation and declining soil fertility are major threats to agricultural productivity and food production, particularly in the drylands of sub-Saharan Africa, where land management practices, high fertiliser prices and water shortages contribute and exacerbate the problems. The World Resources Institute have previously calculated that to eradicate food insecurity we need to produce 69% more calories between 2006 and 2050, while at the same time protecting the world’s water, climate and ecosystems. A new report by the WRI entitled Improving Land and Water Management, instalment four of their Creating a Sustainable Food Future series, outlines some of the land and water management practices that can mitigate land degradation and increase agricultural output. They highlight four practices that are particularly promising, which along with raising yields and productivity can increase incomes, natural capital and resilience to climate change. These are:
Agroforestry – the integration of trees and shrubs onto farms
Conservation agriculture – the combination of reduced or no tillage, crop rotations and on-farm conservation of crop residues or cover crops
Rainwater harvesting – the use of on-farm systems such as bunds, pits and trenches, to collect rainfall and prevent water loss from soils
Integrated soil fertility management – the incorporation of prudent and targeted use of fertiliser with organic alternatives such as manure, compost, leaf litter, crop residues and phosphate rock
The report provides evidence of the impacts these farming practices can have, for example, the combination of conservation agriculture and crop rotations has resulted in 50% higher yields of maize in Zambia. These practices can be combined with each other as well as with more conventional technologies e.g. microdosing of fertilisers.
Implementing and combining these four techniques at scale will require much coordination between different users of the landscape, warranting an integrated landscape approach that acknowledges and plans for multiple land uses. Adoption of these practices is currently low and the main barriers to successful scaling include poor knowledge dissemination, weak land tenure systems and poor coverage of extension services. The potential of these improved land and water management practices has been calculated: if implemented on some 75 million hectares of cropland, with an expected increase in yields of 50%, farmers would produce 22 million tons more food each year, equating to an extra 615 kilocalories per person per day for 285 million people living in Africa’s drylands. [Read more…]
One Billion Hungry: Can We Feed the World? 