Effect of gypsum on moisture availability in vertisols under soybean gram sequence.

A field experiment entitled, effect of gypsum on moisture availability in Vertisols in under soybean– gram sequence was conducted during season of 2008-2009 at extra assistant director (EAD) farm, College of Agriculture, Nagpur. The field experiment was laid out in randomized block design (RBD) with seven treatments replicated thrice. Highest yield and moisture use efficiency in soybean were obtained 3 t gypsum ha-1 whereas 1.5 t gypsum ha-1 also increased yield and MUE of soybean over control. Increasing level of gypsum also increased the yield and MUE efficiency of gram. Reduction in water dispersible clay, ESP, pH, exchangeable sodium, Mg. Improvement in HC, exchangeable Ca and Ca/Mg ratio was found with higher level of gypsum but low level of gypsum i.e. 1.5 t ha-1 was also sufficient to give better result over control (no gypsum). Favourable changes in soil physical and chemical properties were mostly found in surface soil (0-30 cm) and in sub-soil (30-60 cm) effect was not significant. Increased in moisture storage in sub soil observed in gypsum applied plots over control. Result revealed that 1.5 t gypsum ha-1 was found sufficient to maintain enough electrolyte concentration and maintaining Ca/Mg ratio for improving H.