Document Type : Original Article
Authors
1 Assistant Professor, Department of Agricultural Engineering Research, Agriculture and Natural Resources Research and Education Center of Semnan (Shahrood), Agricultural Research, Education and Extension Organization (AREEO), Shahrood, Iran.
2 Assistant Professor, Department of Agricultural and Horticultural Research, Agriculture and Natural Resources Research and Education Center of Semnan (Shahrood), Agricultural Research, Education and Extension Organization (AREEO), Shahrood, Iran.
Abstract
Introduction
Food security and increasing self-reliance in basic crops are important pillars of the country's economic development plans. One of the most important challenges to this self-reliance is the low water productivity in the strategic crop of wheat. An effective and practical solution is to use water optimally and save it. Pressure irrigation increases applied water efficiency by preventing water waste. The advantages of irrigation with the Rainflat system include reduced initial annual irrigation costs compared to the drip tape irrigation method, quick and easy installation without the need for welding, easy and quick assembly and reinstallation, no need for specialized personnel and special tools for installation and assembly, and the ability to use it to irrigate multiple fields. The water productivity index is used to evaluate optimal water consumption in analyses and decision-making. This index is affected by the irrigation schedule. An irrigation schedule is the amount of crop water requirement that is provided to the crop through irrigation intervals. It is believed that if the crop water requirement is used correctly and appropriately in modern irrigation methods, in addition to reducing costs, it is possible to save water consumption by increasing irrigation efficiency and help strengthen groundwater aquifers. Therefore, this study was conducted to investigate the effect of irrigation intervals and different amounts of water in the rain flat sprinkler irrigation method on wheat yield and water productivity.
Methodology
This study was conducted in order to investigate the effect of irrigation interval and irrigation water amount on yield and water productivity of wheat in the years 2019 to 2021 in the form of split plots experiment based on randomized complete blocks design in three replications. The experiment was carried out in agriculture research and education center of Semnan (Shahrud). The soil texture was sandy loam. The main plots included 3 irrigation intervals (4, 5 and 6 days) and the sub-plots included three levels of irrigation (100, 80 and 60%). Sprinkler irrigation pipes (laterals) were placed at 4-meter intervals between crop rows. The net irrigation water requirement was calculated using the Penman-Monteith method and at the end, the amount of water consumption, wheat yield, and water productivity were determined and the best treatment was identified.
Results and Discussion
Irrigation interval treatments of 4 and 5 days with grain yield of 5410.6 and 5016.1 kg/ha and water productivity of 1.169 and 1.077 kg/m3 were in the superior statistical group. The treatments of 100 and 80 percent irrigation requirement with average yields of 5520.7 and 5218.4 kg/ha had the highest yield, and the treatment of 80 percent irrigation requirement with water productivity of 1.130 kg/m3 had the highest water productivity. The interaction effect of experimental treatments on the studied traits was effective. Thus, the treatments of 4-day irrigation interval with 100% and 80% water requirement and 5-day irrigation interval with 100% water requirement were superior with grain yields of 6352.4, 6172.5, and 6105.5 kg/ha, respectively. The 4-day irrigation interval with 80% water requirement had the highest water productivity of 1.336 kg/m3.
Conclusions
The results showed that in the rain flat irrigation method, increasing the irrigation interval to 6 days compared to the irrigation interval of 4 and 5 days reduced the yield by 35.55 and 30.48 percent and water productivity by 35.55 and 29.61 percent. Because the irrigation interval treatments of 4 and 5 days were in the superior statistical group in terms of yield and water productivity, the best irrigation interval is 5 days. By reducing the percentage of irrigation water supply to 60% of the water requirement, compared to 80 and 100% of the water requirement, yield decreased by 39.17 and 42.50%, respectively. However, in terms of water productivity, the treatment of 80% irrigation requirement with an average water productivity of 1.130 kg/m3 had the highest water productivity and was placed in the superior statistical group. Although the treatment with a 4-day irrigation interval with 80% water requirement did not have a statistically significant difference in yield compared to the 4- and 5-day irrigation intervals with 100% water requirement. but it had the highest water productivity among the irrigation treatments. Therefore, with the rain flat irrigation method, the percentage of water requirement can be reduced by 20% in the 4-day irrigation interval.
Keywords
Main Subjects
)