Are you still beating your Mother Earth?
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CTA. 2003. Are you still beating your Mother Earth?. Spore 105. CTA, Wageningen, The Netherlands.
Permanent link to this item: http://hdl.handle.net/10568/47957
Internet URL: http://spore.cta.int/images/stories/pdf/old/spore105.pdf
Too many nutrients are being lost, too fast, from our soils. It s time to put them back where they belong.
Although there are, in some cultures, no indiscrete questions but only indiscrete answers, the old trick question "Are you still beating your wife?" cuts quite close to the bone. It symbolises excessive familiarity, the power of rumour, the burden of being very well informed, the temptation to interfere. It shocks so strongly that the only response can be a laugh. The equally intrusive question "Are you still beating your Mother Earth?" fits the same bill, except that the answer "Yes" is already known. And it is no laughing matter. Next time it rains, wherever you are, go and watch the water run down a slope. Those streaks of brown you see are mud, humus, soil nutrients, organic fertilisers, particles of compost and they are running away from you. One man s loss through erosion for the brown streaks came from land that probably belonged to a man although it may have been nurtured by a woman is another man s gain. Someone, somewhere in a delta probably quite far away, in a century from now, will be quite grateful for that other person s loss of soil fertility. Do not deplete Soil fertility depletion is the fundamental cause of low per capita food production in Africa, according to Pedro Sanchez, the former director of the World Agroforestry Centre (ICRAF). Addressing the assembled captains of agribusiness at the World Agricultural Forum in St Louis, United States in May 2003, Sanchez explained that over the decades small-scale farmers have removed large quantities of nutrients from their soils without returning them as manure or fertiliser in sufficient quantities. In a flurry of statistics, he asserted that this has resulted in a very high average rate of fertility depletion: 22 kg of nitrogen (N), 2.5 kg of phosphorus (P) and 15 kg of potassium (K) per hectare of cultivated land per year over the past 30 years in 37 African countries. At scales like this, it is no longer a marginal loss, but a massive haemorrhage, well worthy of the sad modern term soil mining . When soils have been so severely depleted of nutrients, the full potential of genetically modified (GM) and improved varieties of crops cannot be realised. In such conditions, GM crops and subsidised fertilisers are not even an option in boosting crop yields. Sanchez contended that the remarkably low improvements in yield following the introduction of improved varieties (see Table) in sub-Saharan Africa are due primarily to depleted soil fertility. The way to restore and replenish fertility lies along a simpler route, according to Sanchez, whose experience is principally in Eastern and Southern Africa: a combination of N fixation through leguminous tree fallows, the use of P from indigenous phosphate rock deposits, and the transfer of additional nutrients and carbon using the leaves of the shrub Tithonia diversifolia which accumulates nutrients. Learn fertility management online Integrated Soil Fertility Management (ISFM) is the topic of a new online course in the agLe@rn series from the Asia-Pacific Regional Technology Centre (APRTC). It pays special attention to adapting ISFM options to the agronomic and socio-economic needs and interests of farmers. It also discusses the tools and data needed to analyse the impact of these options. A pilot course is due to start in late June 2003; the next session will be from 3 November to 12 December. A typical tuition fee is about US$ 225, with some scholarships available. No travel is involved: you need time, and Internet access. www.aprtc.org/aglearn/aglearn.asp No stopping the clock? In the entrance hall of the International Development Research Centre (IDRC) in Ottawa, Canada hangs a clock with two meters, one showing the rise in world population every second and the other the decrease in the world s arable land. You can also track them on the Website www.idrc.ca and imbed them in your computer. In the time you will take to read this article it s about 1,700 words, let s say 15 minutes 117 hectares of arable land will be lost. In the time between when this article was conceived (mid-March) and when it was published (June), 850,000 hectares were lost. That is roughly equal to all the arable land in Togo. Replenish in plenty In the improved fallow approach, leguminous tree species such as Sesbania and Tephrosia are interplanted with a young maize crop and allowed to grow as fallows during dry seasons. In subhumid tropical areas, they accumulate between 100 and 200 kg N in 6 24 months, depending on the frequency of the rains. The wood is harvested, and the N-rich leaves, pods and branches are hoed as so-called green manure compost and animal wastes into the soil before maize is planted for the following rainy season. Maize yields increase by a factor of 2 4, and almost attain the levels achievable by applying recommended rates of N fertiliser. This method, which won Sanchez the World Food Prize in 2002, fits snugly into the work patterns of resource-poor farmers. It also produces firewood, captures nitrates which have leached into the subsoil, recycles other nutrients, controls the notorious parasitic Striga weed, improves the soil structure and sequesters carbon from the atmosphere. This last function is a case of win-win farming on which Spore shall expound in a later issue in 2003: the capture of carbon is good for the soil and the farmer, and good for the world too. The emission of carbon gas into the atmosphere by industry, fossil fuel consumption in transport and energy generation, and by agriculture through heavy tillage is one of the world s most guilty practices, since it is exacerbating global warming and speeding up the rate of climate change. Through a variety of mechanisms, international funds are available for farmers and communities in developing countries to sequester carbon. Replenishment can also occur through the use of man-made inorganic fertiliser, but in sub-Saharan Africa where average annual fertiliser use is 9 kg per hectare, compared with a global average of 98 kg, costs and the need for tailored mixes to suit African soil conditions stand in the way. Recent initiatives such as Marketing Inputs Regionally (see box) should help to address these issues at policy level. Keeping mum for Mother Earth Soil fertility can also be enhanced by conservation measures: contour strips and ridges, Zai holes (see Spore 87), cover plants, reduced tillage (good for carbon sequestration) and control of water run-off are among the best practices. Yet measures are needed elsewhere too: in organising reliable supplies of seedlings of fallow trees and shrubs, setting up finance systems loans and, even more important, savings and insurance to stimulate affordable input supplies, and tackling land tenure issues. As Philip Kiriro of the Kenya National Federation of Agricultural Producers (KENFAP) told a joint conference of the FAO and the International Fertilizer Industry Association (IFA) on Sustainable Fertilisation, in Rome in March 2003, "without secure access to resources, a farmer does not have the necessary incentive to invest in his land. Providing land titles is not a huge expense for governments, but it provides a strong motivation to family farmers." It all sounds so simple, and within the confines of the small plots of the small farmer, in those sparking plugs of the engine that is agriculture, perhaps it really is. But heed the earthy tones of Louise Fresco, Assistant Director-General of the FAO, whose typical Dutch attitude to life, and to soil nutrients, is the "Ja-Neen-Maar" ("Yes, No, But") model. At the FAO-IFA conference she spoke on the theme of what we know, what we guess, and what we don t know. We know that, for higher yields, we need to use fertilisers more, and that they are, particularly in Africa with its specific soils, irreplaceable. But we don t know how far we can increase their efficiencies. We guess at the potential of micronutrients, of urban waste and of organic agriculture and we need to research them more. Organic agriculture, she said, appears to be unfeasible, with its staggering greed for land, legumes and animal waste to replace mineral fertilisers. Nor do we know what changes in world diets, and consequent demands on the soil, will emerge from the coming wave of international summitry on sustainable consumption. Or what the effect will be when hydroponics (cultivation in a soil-free medium) becomes a popular form of food production. There are so many imponderables that it is tempting to seek refuge in the old saying "The answer lies in soil". Indeed so, but only if we don t lose it. Farmers efforts first The 2003 CTA seminar will revisit what the CTA Annual Report 2002 (see Between Us) calls "an old issue in African agriculture: the conundrum of low soil fertility, appropriate fertiliser regimes and the challenges of ecological management. It will review the current situation and ascertain whether or how further research and analysis, and information services, can help in enhancing farmers efforts to increase agricultural productivity in a sustainable manner." The seminar, provisionally scheduled for November, is an invitation-only event. But there will be ample opportunities for distance participation through electronic fora before, during and after the event watch for announcements in Spore and on the CTA Website. Adoption of improved varieties and contribution to yield increases (1960 1998) Region % farmer adoption % increase in yield Asia 67 88 Latin America 58 66 Middle East 81 69 Sub-Saharan Africa 76 28 Source: P Sanchez, citing Gregersen, 2001; Evenson, 2003. Launching MIR in West Africa The Marketing Inputs Regionally (MIR) project is the brainchild of the Africa division of the International Fertiliser Development Centre (IFDC). It is based on the belief that "there will not and cannot be any agricultural progress in Africa without a reliable supply of agricultural inputs" and an effective market for them, stimulated by a vibrant private sector. At present, says Henk Breman, the division s director, input markets are impeded by undisclosed private and public interests, undeveloped transport infrastructures, limited access to finance, lack of information and poor business and organisational capacities. MIR supports the efforts of the West African Economic and Monetary Union (UEMOA) and the Economic Community of West African States (ECOWAS) to create regional markets. Other partners include the Network of Farmer Organisations and Agricultural Producers of West Africa (ROPPA), the Network of Chambers of Agriculture (RECAO), the Conference of Ministers of Agriculture of West and Central Africa (CMA/WCA), private input importers and dealers, and sector ministries. An operational MIR meeting held in Togo in March 2003 identified as priority action areas: increasing awareness of transborder trade opportunities and encouraging each sector (such as food or cotton) to finance its own input consumption. What is needed is to create a basis for economies of scale, to fight monopolies, to tackle hidden agendas and to facilitate the free movement of inputs.
SubjectsCROP PRODUCTION AND PROTECTION;
- CTA Spore (English)