Comparison and Analysis of the Main Factors Improving Wheat Water Productivity of Surface and Drip Irrigation Methods (Case study: Yazd Province)

Considering that wheat fields are mainly irrigated by surface (basin) and localized (drip) methods, this study aimed to investigate, compare and analyze the effects of total applied water and yield factors on wheat Water Use Efficiency (WUE) of each irrigation system in Yazd province. In this way, the priority of addressing each of these factors in the two irrigation systems can be determined. The results showed that in the surface irrigation method, reducing the volume of applied water has played a more important role in improving the WUE than increasing the yield. In other words, to increase the wheat WUE of surface methods, implementation of water use optimization solutions are more prioritized compared to crop yield enhancement practices. In contrast, in the case of the drip irrigation method, the crop yield enhancement solutions have played a more decisive role in improving wheat WUE. In these fields, wheat agronomic practices such as proper planting date and density, selecting suitable and high yielding varieties, proper irrigation cycle, proper fertilizer application, and pest and disease control have had a significant role in WUE of wheat, which requires high attention by the farmers to these issues. It was also observed that despite the possible reduction of applied water in drip irrigation compared to the surface method and consequent quantitative enhancement of WUE, but there may be the possibility of low and unacceptable wheat performance. This can cause economic inefficiency of the drip irrigation system for wheat. So, it is highly recommended to consider and implement the above-mentioned agronomic practices in wheat drip irrigated fields.