بهره‌وری آب در زراعت سویا و عوامل مؤثر بر آن در استان گلستان

This study was conducted with the aim of examining and analyzing water input productivity in soybean cultivation in Golestan Province, one of the main hubs of soybean production in Iran. Using data collected from 48 soybean farmers and applying various indices of partial and value-based water productivity, the research assessed the current status and its determinants. The findings revealed that the average partial physical water productivity in soybean fields was 0.74 kg of soybean per cubic meter of water, with a range between 0.26 and 2.69 kg. This variation reflects the potential for increasing productivity through improved farm management and optimal resource utilization. From an economic perspective, each cubic meter of water generated an average gross income of 115,847 IRR and a gross profit of approximately 78,719 IRR. These figures highlight the significant role of efficient water allocation in enhancing farmers’ profitability. Estimation of the water–yield function using the Cobb–Douglas form indicated that a one-percent increase in water use led to only a 0.035 percent increase in soybean yield, while the marginal productivity of each cubic meter of water was about 0.023 kg of soybean. This demonstrates that under current conditions, increasing water consumption has little effect on yield growth, and improving productivity requires technological innovation and enhanced management skills. An analysis of farmers’ individual and managerial characteristics showed that factors such as farm altitude, type of irrigation network, and irrigation method had a significant effect on water productivity. Notably, farms equipped with modern pressurized irrigation systems exhibited much higher water productivity compared to traditional farms. In contrast, variables such as farm size and seed type did not produce significant differences in productivity. The results suggest that improving water productivity in soybean cultivation, in addition to upgrading irrigation technologies and farm management, necessitates supportive policies in education, extension services, and infrastructure provision. Ultimately, the findings can serve as a basis for policymakers and planners in the agricultural sector to increase domestic oilseed production and reduce dependency on imports.