Evaluation of soybean varieties under drought stress in the farm

The importance of soybean in agronomic systems is mainly due to the ability of plants to use atmospheric nitrogen through symbiosis with microorganisms in the soil. Studies have shown that different varieties within a species are different in terms of the nodulation and nitrogen fixation efficiency. In this study, 8 lines and varieties of agronomic soybean were compared in order to identify the most appropriate varieties. Simple correlation coefficients between traits showed a positive correlation between wet and dry weight of root nodules and seed yield per unit area and also showed positive correlation between nitrogen content of grain and plant with seed yield per plant unit. Stepwise regression analysis was performed by determination of nitrogen content of plant as dependent variable and traits such as biological yield, plant height and grain yield per plant remained in the model (R2 = 0.93). Analysis of correlation coefficients indicated that the direct effects of biological and seed yield on plant nitrogen rate were most remarkable and the most effect was related to biological yield.