Vajiheh Amini Mandi; Ali Nakhzari Moghaddam; ali Rahemi karizaki; Masoumeh Naeemi
Abstract
This study is conducted to investigate the influential factors on rice yield gap in the Joibar Region, located in Mazandaran Province, by means of two methods of boundary line analysis and comparative performance analysis, in the cropping years of 2017-18 and 2018-19. It is carried out through fieldwork ...
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This study is conducted to investigate the influential factors on rice yield gap in the Joibar Region, located in Mazandaran Province, by means of two methods of boundary line analysis and comparative performance analysis, in the cropping years of 2017-18 and 2018-19. It is carried out through fieldwork and face-to-face interviews with farmers, for which purpose, totally 120 rice fields located in the studied geographical area in each crop year have been selected in such a way that they had sufficient diversity in terms of location and time. In the comparative performance analysis method, the relation between yield and all measured quantitative and qualitative variables are examined, using multiple regression method. According to the suggested protocol in the boundary line analysis method, a boundary line is fitted to the data in the data distribution diagram. Results show that according to the yield comparative performance analysis model, the yield gap of Joibar rice fields has been 1842 kg/ha, and the harvest date has played the most important role in rice yield gap. Also, according to the findings of border line analysis, the yield gap of rice fields in this region has been 874 kg/ha with the biological control being the most important factor in rice yield gap. Therefore, continuous monitoring and evaluation of crop management on farmers' fields and its identification is essential to eliminate yield gaps along with the management factors causing them.
Amir Hajjarpoor; Habibolah Kashiri
Abstract
In this study, collecting of management information from about 700 wheat farms in Golestan province was conducted during two growing seasons 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 ...
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In this study, collecting of management information from about 700 wheat farms in Golestan province was conducted during two growing seasons 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 ranges were identified in both irrigated and rainfed conditions using boundary line analysis. To do this, the information was analyzed in three parts 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 percent, 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.