Agroclimatic aspects in planning for improved productivity of Alfisols
1987
Sivakumar, M.V.K. | Singh, P. | Williams, J.H.
Crop yields on Alfisols, the most abundant soils in the semi-arid tropics, have remained low and unstable due to aberrant weather and soil-related constraints. With suitable examples from India and West Africa, variations in the amount and distribution of rainfall as well as its intensity are described. The role of soil constraints, such as depth, soil w2048ater storage capacity, particle size distribution, and soil moisture release characteristics in making water available for crop growth on Alfisols, is illustrated. At soil depths below 30 cm in Alfisols the recharge and depletion of soil water occurred on an annual basis whereas, in the upper 30 cm, the process occurred repeatedly with a periodicity determined by the depth, amount, and frequency of rainfall. In the upper 30 cm soil layers with decreasing capillary potential there was a large decrease in the water content, while in the lower layers this decrease was considerably less. The effect of short-term intraseasonal droughts on crop moisture status was shown to differ depending on soil depth. The timing and intensity of water stress is an important factor in assessing the crop response to drought on Alfisols. Studies conducted at ICRISAT Center showed that crop water-use efficiency on Alfisols could be improved through appropriate management practices, including the selection of suitable genotypes, crops, and cropping sys
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