CHANGE IN WHEAT PRODUCTIVITY WITH TIME IN LONG-TERM EXPERIMENT

The use of moving average values reduced the seasonal/irregular fluctu ations in the data effectively and gave better fit as compared to that of original set of data, For wheat crop, various degrees of polynomia ls with different bases (X-0.5, 1/X-0.5 and X) explained the trend in yield due to various treatments. Majority of the fitted curves showed initial moderate increase, followed by a downward trend in the product ivity till a later stage. The initial expected productivity ranged fro m 1525 (control) to 2544 kg/ha (NsPsKs). The productivity at last poin t of time ranged from 406 (control) to 2908 kg/ha (NsPsKs). In the med ium black soil of Junagadh, under intensive cropping system, NsPsKs tr eatment was found better as compared to rest of the treatments in whea t crop.