Soil moisture conservation

Resource-poor farm families in the seasonally-dry tropics suffer increasing insecurity of food and water supplies. Loss of soil porosity, caused by rain impact and/or damaging tillage, limits rates and amounts of water infiltration and percolation, provokes loss by runoff and thus diminishes possibilities for groundwater recharge. Water stress in plants has quicker, more direct and more severe effects on yields than soil erosion. Stress provokes closure of leaf stomata, reducing rates of transpiration and photosynthesis. A better understanding of the dynamic inter-relations, at microscopic level, within the soil/water/plant/atmosphere system enables development of improved soil-porosity management methods, of which organic materials and processes are essential parts. Large-scale in-field experiences in East Africa and South America, show many significant benefits, including more benign river-flow and increased and cheaper crop production, following application of these concepts.