Estimation of the Actual Amount of Wheat Irrigation Water Using the NIAZAB System and Comparing with the Farm Measurement

Accurate estimation of irrigation water quantity, water productivity and irrigation water application efficiency of cultivated wheat in Iran are important and key indicators in agricultural sector planning. The purpose of this study was to investigate the results of field and farm measurements of irrigation water and wheat yield under farmers' management and compare them with estimating the NIAZAB system in 37 Township during a crop season (2016-2017) as well as determining wheat water productivity and application efficiency. The results showed that the average amount of wheat irrigation water measured in the farms and systems were 5710 and 5894 cubic meters per hectare, respectively, and the average grain yield of wheat measured in the farms and systems were 5215 and 4949 kg, respectively. The average water productivity of wheat measured in the farms and NIAZAB system were 1 and 0.9 kg/m3. The results showed that the NIAZAB system with a normal root mean error of 0.19% and agreement coefficient of 0.93 estimates the amount of wheat irrigation water in the township scale and wheat grain yield with a normal root mean error of 0.17% and agreement coefficient of 0.95 and estimates the productivity of wheat water with a normal root mean error of 0.24%, the efficiency of irrigation water application with a normal root mean error of 0.19% and the coefficient of agreement of 0.93. The values of the efficiency coefficient of the model show that the model provides acceptable results in determining the amount of irrigation water and wheat water productivity in the country farms. Therefore, the NIAZAB system can be used to estimate the volume required for the irrigation of plants in Iran and also in the farm water management.