In fact, data shows that small farms almost always produce far more agricultural output per unit area than larger farms, do so more efficiently, and produce food rather than export crops and fuels. This holds true whether we are talking about industrial countries or any country in the third world. This is widely recognized by agricultural economists as the “inverse relationship between farm size and output.” When I examined the relationship between farm size and total output for fifteen countries in the third world, in all cases relatively smaller farm sizes were much more productive per unit area—2 to 10 times more productive—than larger ones.
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. 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.
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 crops), 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.
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 and traps pests. The system not only controls pests but has other benefits as well, because Desmodium can be used as fodder for livestock. The push-pull strategy doubles maize yields and milk production while, at the same time, improves the soil. The system has already spread to more than 10,000 households in East Africa by means of town meetings, national radio broadcasts and farmer field schools.
20. Agroecology is also gaining ground in Malawi, a country that has been at the centre of attention in recent years. Malawi successfully launched a fertilizer subsidy programme in 2005-2006, following the dramatic food crisis due to drought in 2004-2005. However, it is now implementing agroforestry systems, using nitrogen-fixing trees, to ensure sustained growth in maize production…By mid-2009, over 120,000 Malawian farmers had received training and tree materials from the programme, and support from Ireland has now enabled extension of the programme to 40 per cent of Malawi’s districts, benefiting 1.3 million of the poorest people. Research shows that this results in increased yields from 1 t/ha to 2–3 t/ha, even if farmers cannot afford commercial nitrogen fertilizers…An optimal solution that could be an exit strategy from fertilizer subsidy schemes would be to link fertilizer subsidies directly to agroforestry investments on the farm in order to provide for long-term sustainability in nutrient supply, and to build up soil health as the basis for sustained yields and improved efficiency of fertilizer response. Malawi is reportedly exploring this “subsidy to sustainability” approach.
21…One key reason why agroecology helps to support incomes in rural areas is because it promotes on-farm fertility generation. Indeed, supplying nutrients to the soil does not necessarily require adding mineral fertilizers. It can be done by applying livestock manure or by growing green manures. Farmers can also
establish a “fertilizer factory in the fields” by planting trees that take nitrogen out of the air and “fix” it in their leaves, which are subsequently incorporated into the soil. That, in essence, is the result of planting Faidherbia albida, a nitrogen-fixing acacia species indigenous to Africa and widespread throughout the continent. Since this tree goes dormant and sheds its foliage during the early rainy season at the time when field crops are being established, it does not compete significantly with them for light, nutrients or water during the growing season; yet it allows a significant increase in yields of the maize with which it is combined, particularly in conditions of low soil fertility. In Zambia, unfertilized maize yields in the vicinity of Faidherbia trees averaged 4.1 t/ha, compared to 1.3 t/ha nearby, but beyond the tree canopy. Similar results were observed in Malawi, where this tree was also widely used. The use of such nitrogen-fixing trees avoids dependence on synthetic fertilizers, the price of which has been increasingly high and volatile over the past few years, exceeding food commodity prices, even when the latter reached a peak in July 2008. In this way, whatever financial assets the household has can be used on other essentials, such as education or medicine.