Dear K. Damodara Chari

Please have a look at this useful link.

https://crops.extension.iastate.edu/cropnews/2017/08/how-drought-affects-soil-health

Thanks!

One of the obvious effects of drought on soil health is the lack of nutrient uptake by crops, as water is the major medium for moving nutrients into plants as a result of water uptake.

https://crops.extension.iastate.edu/cropnews/2017/08/how-drought-affects-soil-health

Please refer to this report from UNFAO: RAINWATER, LAND PRODUCTIVITY AND DROUGHT, www.fao.org/docrep/006/y4690e/y4690e08.htm

Repeated deficit of rainfall in semi-arid areas would enhance the unfavourable cations like Mg and Na on soil exchange complex because of the precipitation of favourable cation like Ca as calcium carbonate. With time subsoils would become ill drained and will not be able to release water for plant growth between the rains.This way yield of crops would be much less.

Rainfall deficit affects the nutrient mineralization through reduced biological activity of the soil. In turn this effect lead to reduced availability of soil nutrients and crop nutrient uptake.