Effect of Water Stress on the Development of Soybean Crop

The present work had the objective of evaluating the effects of the spatial variability of the main meteorological elements on soybean yield, variety M7739 IPRO from Monsoy, with an early cycle of 105 days, with sowing at the beginning of October and harvesting at the beginning of the month in February, in two agricultural years (2013/14 and 2014/15) at Santa Luzia farm, located in the municipality of Campo Verde - MT (15º42'28 ''S, 55º19'59'' W, 736 m). The meteorological data of the region were obtained through the 9th district of meteorology (9th DISME) of the National Institute of Meteorology - INMET. The coefficient of culture (kc) was defined following the development stages of the culture. The estimates of evapotranspiration (potential and crop) were determined by the water balance method and the sensitivity coefficients (ky) of the soybean crop were estimated by the expression Ky=(1-Yr/Ym)/(1-ETr/ETm), in which ky = yield response factor; Yr = actual yield of the crop; Ym = maximum yield of the crop; ETr = actual evapotranspiration e ETm = maximum evapotranspiration. The values of Ky were all lower than 1, both for the crop cycle in the 2013/14 crop year and for the crop cycle 2014/15, indicating that the soybean crop is adaptable to water deficit.