A/HRC/16/49 multiplies by 10 to 15 times, and livestock can feed on the grass that grows along the stone barriers after the rains. 27 Integration of livestock into farming systems, such as dairy cattle, pigs and poultry, provides a source of protein to the family, as well as a means of fertilizing soils; so does the incorporation of fish, shrimps and other aquatic resources into farm systems, such as irrigated rice fields and fish ponds. 17. Such resource-conserving, low-external-input techniques have a proven potential to significantly improve yields. In what may be the most systematic study of the potential of such techniques to date, Jules Pretty et al. compared the impacts of 286 recent sustainable agriculture projects in 57 poor countries covering 37 million hectares (3 per cent of the cultivated area in developing countries). They found that such interventions increased productivity on 12.6 millions farms, with an average crop increase of 79 per cent, while improving the supply of critical environmental services.28 Disaggregated data from this research showed that average food production per household rose by 1.7 tonnes per year (up by 73 per cent) for 4.42 million small farmers growing cereals and roots on 3.6 million hectares, and that increase in food production was 17 tonnes per year (up 150 per cent) for 146,000 farmers on 542,000 hectares cultivating roots (potato, sweet potato, cassava). After UNCTAD and UNEP reanalyzed the database to produce a summary of the impacts in Africa, it was found that the average crop yield increase was even higher for these projects than the global average of 79 per cent at 116 per cent increase for all African projects and 128 per cent increase for projects in East Africa.29 18. The most recent large-scale study points to the same conclusions. Research commissioned by the Foresight Global Food and Farming Futures project of the UK Government reviewed 40 projects in 20 African countries where sustainable intensification was developed during the 2000s. The projects included crop improvements (particularly improvements through participatory plant breeding on hitherto neglected orphan crops30), integrated pest management, soil conservation and agro-forestry. By early 2010, these projects had documented benefits for 10.39 million farmers and their families and improvements on approximately 12.75 million hectares. Crop yields more than doubled on average (increasing 2.13-fold) over a period of 3-10 years, resulting in an increase in aggregate food production of 5.79 million tonnes per year, equivalent to 557 kg per farming household.31 19. Sometimes, seemingly minor innovations can provide high returns. In Kenya, researchers and farmers developed the “push-pull” strategy to control parasitic weeds and insects that damage the crops. The strategy consists in “pushing” away pests from corn by inter-planting corn with insect-repellent crops like Desmodium, while “pulling” them towards small plots of Napier grass, a plant that excretes a sticky gum which both attracts 27 28 29 30 31 8 A.M. Diop, “Management of Organic Inputs to Increase Food Production in Senegal,” in Agroecological innovations. Increasing food production with participatory development, N. Uphoff (ed.), London, Earthscan Publications, 2001, p. 252. Jules Pretty et al., “Resource-conserving agriculture increases yields in developing countries,” Environmental Science and Technology, 40:4, 2006, pp. 1114−1119. The 79 per cent figure refers to the 360 reliable yield comparisons from 198 projects. There was a wide spread in results, with 25 per cent of projects reporting a 100 per cent increase or more. UNEP-UNCTAD Capacity Building Task Force on Trade, Environment and Development (CBTF), Organic Agriculture and Food Security in Africa, New York/Geneva, United Nations, 2008, p. 16. Such as improvements on cassava, for which NaCRRI developed locally-developed resistant varieties in Uganda, or improvements on tef in Ethiopia, where the Debre Zeit Agricultural Research Centre developed a new variety called Quncho. J. Pretty et al., “Sustainable intensification in African agriculture,” International Journal of Agricultural Sustainability, 9:1, forthcoming in 2011.