Effects of biodegradable film resilience and irrigation amounts on film degradation and maize growth in arid northwest China

Abstract

Biodegradable films are considered an environmentally-friendly alternative to traditional polyethylene (PE) film mulches, as they effectively reduce film pollution in the farmland when using mulched drip irrigation. However, the effects of different degradable films on soil micro-climate and maize growth have not been examined, especially under different irrigation amounts, which are critical considerations for oasis agriculture in arid areas. Therefore, we conducted a field study in 2019–2020 on maize farmland using two biodegradable films, one with an 80-day induction period (M80) and the other with a 100-day induction period (M100), and compared them with traditional PE film (MPE). Four irrigation amounts (4875, 5250, 5625, and 6000 m3 ha−1) were tested. Our results showed that weight loss rates of M80 and M100 were 7.21 times and 9.63 times higher than that of MPE, and this degradation process was slowed down with increased irrigation amounts. We attribute this mitigation to changes in soil moisture and the physiological characteristics of the crop. Using film of higher resilience together with higher irrigation amount resulted in more active photosynthesis and fluorescence, especially at the later maize growth stage, and improved maize yield compared to the other degradable film. In addition, the reduction in maize yield caused by the use of biodegradable films could be largely compensated for by applying higher irrigation amounts. Our findings recommend using M100 with an irrigation amount of 5625 m3 ha−1 for maintaining maize yields while reducing plastic pollution.