Wheat Potential Yield and Gap Estimation in Qazvin Plain of Iran

Wheat, as the most important product in the food basket of Iranians, providing more than 40 percent of the daily energy of each person, is an irreplaceable and plays important role in cultivation pattern. Due to the position of this crop in food security, investigating the effects of various factors affecting the yield as well as estimating the potential yield and yield gap can significantly help the planning ability of agricultural sector managers. 

In this research, World Food Studies (WOFOST) model was used to estimate the potential yield of irrigated wheat in Qazvin Plain of Iran. The meteorological statistics were converted into the standard unit required by the model using mathematical models, and the field observations were used to calculate yield gap, and also ARCGIS was used for yield gap and actual yield maps generation. 

The model performance was statistically evaluated using coefficient of determination (R2) t-test, Root Mean Square Error (RMSE), Normalized Root Mean Square Error (NRMSE/RMSEn), Maximum Error (ME) and coefficient of Efficiency (E). The results showed that the WOFOST model had a sufficient efficiency for predicting the concerned indicators. The average potential yield of irrigated wheat in the studied area (2013-2022) was about 8.6 tons per hectare and the yield gap was 51 percent.

Finally, the WOFOST model was evaluated to be accurate and efficient for estimating the potential yield of irrigated wheat in the studied area, and among the known influencing factors on yield, annual rainfall and soil quality effect on potential yield achievement significantly, also the production gap reducing. Therefore, in the future breeding programs for wheat, focusing on cultivars with higher water use efficiency and higher fertilizer use efficiency can ensure a sustainable food security in Iran.