The Environmental Food Crisis

A major challenge is to find ways of making fertilizer available to smallholders at affordable prices. There is also a need for ho- listic approaches to soil fertility management that embraces the full range of driving factors and consequences of soil degrada- tion (TSBF-CIAT, 2006). This would include the integration of mineral and organic sources of nutrients, thereby using locally available sources of inputs and maximizing their use efficiency. Irrigated land area increased rapidly until 1980 with expansion rates of more than 2% a year. In Asia in particular, it led to a steady increase of staple food production together with other elements of the green revolution package (Faures et al ., 2007). After 1980, growth in expansion of irrigated area decreased and it is assumed this trend will continue in the near future. One of the reasons is that the areas most suitable for irrigation are already used, leading to higher construction costs in new areas (Faures et al ., 2007). Another reason is the strong decline in relative food prices over the last decades, which makes it less profitable to invest in irrigation. Current irrigation systems could be improved by investing in water control and delivery, automation, monitoring and staff training. The irrigated area has remained very low in Sub-Saharan Af- rica and of the land under irrigation, 18% is not used (FAO, 2005b). In most African regions the major challenge is not the lack of water, but unpredictable and highly variable rainfall patterns with occurrences of dry spells every two years caus- ing crop failure. This high uncertainty and variability drive the risk-averse behaviour of smallholder farmers. Rarely are investments made in soil management and fertility, crop vari- eties, tillage practices and even labour in order to avoid losses in case of total crop failure (Rockstrom et al ., 2007a,b). Man- aging the extreme rainfall variability over time and space can provide supplemental irrigation water to overcome dry periods and prevent crop failure. In combination with improved soil management (in regions with severe land degradation, only 5% of the rainwater is used for crops), this should reduce the risk of total crop failure and enhance the profitability of invest- ments in crop management, for example, fertilizers, labour and crop varieties. Increasing crop canopy coverage reduces evapo-transpiration from the soil, improving soil moisture and the provision of water for the crop. RESOURCES FOR IRRIGATION

about 9 kg/ha of arable land, compared to a world average of 101 kg/ha (Camara and Heinemaan, 2006; FAOSTAT 2009). Within Africa, there are strong differences in fertilizer use between regions, with relatively high use in Northern and Southern Africa, and very low use (around 1 to 2 kg/ha) in Western and Central Africa. Taking the increase as proposed by the Africa Fertilizer Summit as a starting point, this would mean a growth of the yearly use of fertilizers from 1 to 6 mil- lion tonnes. Based on the price of fertilizer (DAP) of approxi- mately US$600/tonne (beginning of 2008), this would mean US$3 billion/year for the purchase of DAP only. A more mod- erate price of US$200/tonne would still mean US$1 billion/ year. Added to this are significant costs of and investments in transport and distribution, developing agricultural research, extension programs, capacity building, etc. Indeed, there are many reasons for this low use. One of the reasons is the high retail prices of fertilizers, especially in areas with poor infra- structure. A metric tonne of urea costs $90 in Europe, $120 kg in the harbor of Mombassa, $400 in Western Kenya and $770 in Malawi (Sanchez, 2002). A major challenge is to find ways of making fertilizer available to smallholders at affordable prices. There is also a need for holistic approaches to soil fertility management that embraces the full range of driving factors and consequences of soil degra- dation (TSBF-CIAT, 2006). This would include the integration of mineral and organic sources of nutrients, thereby using lo- cally available sources of inputs and maximizing their use effi- ciency, while reducing dependency upon prices of commercial fertilizers and pesticides. The use of perennials, intercropping and agroforestry systems, such as the use of nitrogen fixating leguminous trees, are ways to increase nutrient availability, but also enhance water availability and pest control, in a more sus- tainable manner (Sanchez, 2002).

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