Simulation of Yield and Determination of Planting Date of Rainfed and Irrigated Wheat Based on Climatic and Environmental Factors in Kermanshah Province by AquaCrop Model

Wheat is one of the most important strategic agricultural products which is crucial in providing food for the people of our country. The aim of this study was to assess the performance of AquaCrop plant simulation model, as one of the newest models, in determining the yield and planting date of rainfed and irrigated wheat in Kermanshah province. For this purpose, the rainfed and irrigated wheat yield was simulated by AquaCrop model using daily climatic data of five synoptic stations, including precipitation, maximum and minimum temperatures, potential evapotranspiration, wind speed and sunshine hours in a 22-year (1992-2013) period, as well as other environmental information. Among the dates entered to the model, the date that had the highest yield was selected as the best planting date. The results showed that from the point of view of yield, Ravansar and Sarpole-Zahab plains are more susceptible for planting rainfed and irrigated wheat, respectively. Wheat yield showed great sensitivity to changes in planting date. Planting dates in the stations were proposed from October 10 to November 20 for rainfed wheat, and from October 10 to November 10 for irrigated wheat, that match well with the actual dates of planting in the region. In general, AquaCrop model well simulated the different stages of growth and yield of rainfed and irrigated wheat according to the climatologic conditions of Kermanshah Province, and therefore could be an important tool to evaluate the potential wheat yield in the province and other regions with similar climates.