Estimating crop yields

A programme which evaluates the effects of climate and environment on agricultural production has now been operating for two years. ESPACE is designed to estimate the expected harvests of main food crops before the end of the rainy season. By computing sowing dates and daily precipitation records, it produces a simulated hydrological chart upon which fairly accurate estimates of crop yield can be made. To extend such predictions over larger areas, soil surface temperatures provided by weather satellites are used to define agroclimatic zones on an annual basis. A network of 500 plots distributed throughout representative zones allows actual yields to be measured for verification at ground level. The ESPACE programme was used last year in Mali for millet, sorghum and maize, and in Senegal for groundnuts and millet. As early as September 30, initial predictions of the year's harvest could be made. In Mali, a marginal decline in production was estimated, while in Senegal a significant surplus was predicted. Such early estimates help in planning the transportation of foodstuffs within or between countries and for any preparations for food aid. In 1988, ESPACE will be extended to Niger and Burkina Faso before eventually covering all countries in the Sahel. The monitoring functions of the project are scheduled to be taken over by AGRHYMET. Research is also continuing to improve the modelling techniques that are used in order to take account of rainfall distribution patterns at the local level. The more detailed images provided by the SPOT satellite enable calculations of the percentage of land that is covered by each situation. For more details, contact: F Forest Programme CSP B P 5045 Montpellier Cedex FRANCE or P Ginies MINCOOP 20, rue Monsieur 75007 Paris FRANCEA programme which evaluates the effects of climate and environment on agricultural production has now been operating for two years. ESPACE is designed to estimate the expected harvests of main food crops before the end of the rainy season. By..