Potassium Critical Limit and Response to Soybean in Swell-Shrink Soil, Akola, Maharashtra

The emerging role of K in a number of biotic and abiotic stress situations is discussed including those of diseases and pests, frost, heat/drought, and salinity. A net house investigation was undertaken with 15 soils belonging to swell-shrink soils of Central Research Farm of Akola to determine the critical limit of K and response of soybean (Glycine max L. culture plant JS-335) to K application. The plants were grown up to 45 days and per cent Bray’s value was calculated for each soil which varied from 69.56 to 96.15. The critical limit of K in swell-shrink soil extracted by neutral normal ammonium acetate in statistical method is 143 kg ha-1 and 148 kg ha-1 for soil in graphical method. The critical limit of K for soybean plant at 45 days growth was 0.43 per cent by statistical method and 0.47 per cent by graphical method.