Guan'gai paishui xuebao (Mar 2023)
Water Consumption and Water Use Efficiency of Soybean Are Impacted by Irrigation Method
Abstract
【Objective】 Irrigation modulates water movement in soil and its bioavailability to crop roots. This study is to investigate the effect of different irrigation methods on water consumption and water use efficiency of soybean during its whole growth period, with an aim to help develop water-saving irrigation. 【Method】 The field experiment was conducted in 2021 in Wuwei, Gansu province. It compared four irrigation methods: drip irrigation under film mulching, drip irrigation without mulching, border irrigation with film mulching, and border irrigation without mulching. The Bowen ratio-energy balance system was used to continuously monitor the changes in microclimate, crop growth and yield, water consumption (ET) and water use efficiency (WUE). 【Result】 ①Film mulching increased net radiation (Rn) of the soybean by 6.58 W/m2, compared to no mulching; Soil temperature increased by 1.30 ℃ relative to drip irrigation. ②irrigation method and mulching affected physiological indexes of the soybean both at significant levels. Film mulching increased the leaf area index (LAI) significantly by 18.29%, compared to no mulching, while the border irrigation increased the LAI by 5.45%, compared to drip irrigation. ③Film mulching and drip irrigation reduced the ET significantly over the whole growth period, with the mulched drip irrigation having the least ET - 378.92 mm, compared to other treatments. ④Among all environmental and biological factors, Rn and LAI are correlated with ET positively and most significantly. ⑤The yield of soybean under mulched drip irrigation was 18.07%, 5.27% and 11.17% higher than that of non-mulched drip irrigation, film mulched border irrigation, and non-mulched border irrigation, respectively. Film mulching increased WUE by 25.93% compared to no mulching, and drip irrigation increased WUE by 34.62% compared to border irrigation. The mulched drip irrigation increased WUE by 31.15%, 42.86% and 70.21%, respectively, compared to non-film mulched drip irrigation, film-mulched border irrigation and non-film mulched border irrigation. 【Conclusion】 Compared to drip irrigation without film, border irrigation with film and border irrigation without film, the yield of drip irrigation under film increased by an average of 11.51%, ET decreased by 24.13%, and WUE increased by 48.07% and irrigation water use efficiency improved by 46.57%; Taking into account the water consumption, yield and water use efficiency of soybean, drip irrigation under film provided a more benefit growth environment for soybean growth and significantly reduced ET and increased yield.
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