Gypsum and lime increase soybean and maize yield and decrease drought stress

ABSTRACT During the maize and soybean cultivation process, water deficit occurs frequently and can reduce grain yield. Gypsum can be used to mitigate yield losses. This study aimed to evaluate the influence of gypsum application, with and without lime, on soil chemical properties and maize and soybean yield, in a no-till system. The experimental design was completely randomized, with six gypsum doses (0 t ha-1, 0.5 t ha-1, 1 t ha-1, 2 t ha-1, 4 t ha-1 and 8 t ha-1), lime application and four replications, for maize. For soybean, a 6 x 2 factorial scheme, with six gypsum doses (0 t ha-1, 0.5 t ha-1, 1 t ha-1, 2 t ha-1, 4 t ha-1 and 8 t ha-1), with and without lime application, and four replications was used. Soil chemical attributes and maize and soybean grain yield were evaluated. Gypsum increases the Ca2+ levels, redistributes Mg2+ to the 10-20 cm and 20-40 cm depth layers and decreases the Al3+ contents in the 20-40 cm layer. Liming increases pH in the 0-10 cm depth layer and pH is not affected by the gypsum application. Gypsum increases maize and soybean grain yield, with response up to the 2 t ha-1 dose, with increments of 9.3 %, for maize, and 11.4 % and 11.3 %, respectively with and without lime, for soybean.