Wheat response to tillage and irrigation

A field experiment was conducted during Rabi 2003-04 to compare the effect of various tillage and irrigation treatments on yield of wheat grown under cotton-wheat cropping system. The experiment was arranged in a split plot design with four tillage treatments (T1: one pass of rotavator, T2: one pass of rotavator + one pass of cultivator, T3: one pass of rotavator + two pass of cultivator, and T4: one pass of rotavator + three pass of cultivator) in the main plots and four irrigation levels (I1: irrigation at 35%, 50%, 65% and 80% depletion levels) in subplots with three replications. Phosphorus in the form of DAP @ 125 kg ha-1 was incorporated during seedbed preparation. Nitrogen in the form of Urea was applied @ 125 kg ha-1 in two splits: one-half at first and the other half at second irrigation. Grain yield data were statistically analyzed by analysis of variance technique and treatments were compared and ranked with LSD. The results showed that wheat yield was affected significantly in all treatments. However, effect of tillage on grain yield was non-significant at more number of tillage operations. Maximum yield of 3.60 t ha-1 was obtained from plot irrigated at 65% depletion level under T2 treatment consisting of one pass of rotavator plus one pass of cultivator. The lowest yield of 1.72 t ha-1 was obtained with irrigation at 80% depletion level under T1 tillage treatment. The yield was the lowest because of moisture stress as the result of delaying irrigation till 80% depletion. Based on the result of this study, it may be concluded that increased tillage not necessarily increases grain yield of irrigated wheat under cotton-wheat cropping system in the study area.