Investigation of the effective factors on yield gap of rice in Mazandaran province

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.