Effects of sprayable degradable film mulching on cotton growth and yield under drip irrigation

Abstract

AbstractMulched drip irrigation is a highly effective water-saving technique that is commonly employed in arid regions. However, the residual plastic film left behind in the soil poses a significant challenge to the sustainable growth of agriculture. To address this issue, sprayable degradable film, which is both biodegradable and non-polluting, represents a superior alternative to the traditional plastic film. This study aimed to investigate the relationship between cotton growth and development, physiological characteristics, yield, and water use efficiency under varying dosages of sprayable degradable film. The goal was to mitigate the hazards of residual film. A field experiment was conducted in Xinjiang, Northwest China to test the effects of five different mulching conditions: SF1 (1900 kg of sprayable degradable film per ha), SF2 (2200 kg of sprayable degradable film per ha), SF3 (2500 kg of sprayable degradable film per ha), PF (plastic film), and NF (no film mulching). Results showed that mulching with the sprayable degradable film had a positive impact on the soil hydrothermal environment, promoted root growth, significantly increased plant height and leaf area, and enhanced physiological characteristics compared to the no film mulching treatment, which ultimately improved yield and water use efficiency. The study found that cotton root length density, root weight density, and net photosynthesis showed significant linear relationships with yield. Compared to the NF, the yield of sprayable degradable film treatments increased by 11.79%, 14.39%, and 15.00%, and the water use efficiency increased by 21.88%, 23.96%, and 30.21%, respectively. The maximum yield and water use efficiency were observed in PF treatment, with 5345 kg ha-1and 1.28 kg m-3, respectively. The yield and water use efficiency of SF3 was close to PF. In general, applying moderate amounts of sprayable degradable film at a rate of 2500 kg ha-1can significantly boost cotton growth, improve photosynthetic characteristics, and increase cotton yield and water use efficiency. This study presents an effective agronomic strategy for managing residual film contamination while maintaining stable cotton yield.