Determination of optimum ranges of management factors in order to increase wheat yield in Golestan province

In this study, collecting of management information from about 700 wheat farms in Golestan province was conducted during two growing season of 2013-2014 and 2014-2015. In each of region, potential yields, the optimum crop management and simultaneously the percentage of wheat farms out of the optimal range were identify in both irrigated and rainfed conditions using boundary line analysis. So, the information were analyzed in three part of irrigated, high- and low-yield rainfed conditions. By plotting farm’s yield data scatter, against management factors, highest yields in different levels of input or management factors were selected and a boundary function was fitted to the upper boundary of data points. According to the results, potential yield for irrigated, high- and low-yield rainfed wheat were estimated equal to 6816, 5791 and 3932 kg ha-1 with a yield gap of 42, 31 and 50%, respectively. The optimum ranges of sowing date, seeding rate, plant density, frequency and the amount of nitrogen fertilizer applied, the amount of nitrogen applied after sowing, the amount of phosphorus (P2O5) and potassium fertilizers (K2O) applied and irrigation frequency were determined according to the results. Consider the optimum managements, farmers in each region can shrink the yield gap and reach potential yield result in increasing the amount of wheat production in Golestan province.