Richard Kablan1, Russell Yost2, Mamadou Doumbia3, A. Yoroté3, Y. Toloba3, S. Sissoko3, M. Vaksman3, M. Sissoko3, and L. Dioni3. (1) Tropical Plant and Soil Sciences, University of Hawai`i at Manoa, Room 102, 3190 Maile Way, Honolulu, HI 96822, (2) 3190 Maile Way, Room 102, St. John Building, University of Hawaii, Department of Tropical Plants & Soil Science, Honolulu, HI 96822, (3) LaboSEP, Institut d'Economie Rurale, BP. 262, Bamako, Mali
Food insecurity is becoming more and more common in West Africa. This occurs in spite of rainfall of 800 to 1200 mm/year. Field studies show that a majority of the rainfall is lost in runoff due to low infiltration in soils that crust easily. Research in three West African countries shows that Aménagement en courbes de Niveau (ACN), a holistic management of water on a farmer's field decreases soil water erosion, increases soil water infiltration, increases crop yields, leads to spontaneous trees regeneration , and increased ground water recharge. In this study mean infiltration rate over three year periods was 7.48 cm/h on ACN sites whereas that of the No ACN site was only 4.49 cm/h. Fields with ACN showed up to 94% less runoff than fields using conventional farming practices. Crop yield increases of 50% for millet, sorghum and maize were recorded, especially in years with low rainfall. Soil carbon increase between 12 to 26 % over several years has been measured in fields with 5years or more with ACN in both Mali and The Gambia. Quantitative evidence indicates that the reduction in runoff and increase soil water infiltration due to ACN results in more recharge of groundwater (upward of 150 percent more). Deep rooted trees such as Shea butter trees (Vitellaria paradoxa) and other species benefit from the deep water infiltrated into the soil to increase growth and regeneration of trees thought to have disappeared. The permanent ridges used in the ACN approach capture the first rains and enable earlier planting of photoperiod-sensitive varieties of crops, giving them more time to grow and accumulate biomass before producing grain. Food security and farmer income increases substantially under the system.
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