Objective This study aimed to explore the effects of biodegradable mulch films on plant growth, yield and quality of drip-irrigated maize in Northern Xinjiang, and screen out the suitable types of biodegradable mulch films for local application.
Methods From 2021 to 2022, a field experiment was conducted in Shihezi with four treatments: no mulch (CK), conventional PE mulch film (PF1), white biodegradable mulch film (PF2) and black biodegradable mulch film (PF3). The influences of different mulch films on growth indices, yield components and quality of maize were investigated. A demonstration trial of white biodegradable mulch film for seed-production maize was further carried out in the 9th Division of Xinjiang Production and Construction Corps in 2023.
Results In the early growth stage of maize, the soil temperature under PF3 treatment was significantly increased by 1.5 °C compared with CK, which promoted plant growth (P<0.05). As the growth period progressed, the degradation rate of black biodegradable mulch film reached 72.7%, leading to a remarkable decline in soil moisture. Compared with PF1, the net photosynthetic rate and transpiration rate of maize at the silking stage under PF3 were significantly reduced by 12.3% and 24.3% respectively, and the dry matter accumulation at harvest decreased by 16.7% (P<0.05). Neither PF2 nor PF3 had significant effects on the number of harvested ears per unit area. Nevertheless, PF3 significantly reduced the grain number per ear by 6.2% and 1000-grain weight by 6.8% in contrast to PF1 (P<0.05). Meanwhile, the grain yield, starch content, crude protein content and crude fat content of maize under PF3 treatment were decreased by 13.6%, 9.7%, 12.9% and 24.0% respectively (P<0.05). Correlation analysis revealed that the degradation rate of mulch film was significantly negatively correlated with grain yield and quality. The demonstration results of seed-production maize in 2023 showed that the yield under white biodegradable mulch film was not significantly different from that under conventional PE mulch film, and was obviously higher than that under the bare land treatment.
Conclusion For drip-irrigated maize cultivation in the arid region of Northern Xinjiang, the white biodegradable mulch film with similar degradation characteristics to the one used in this study can stabilize maize yield and quality while effectively reducing the risk of agricultural white pollution, so it is worthy of large-scale promotion. By contrast, the black biodegradable mulch film has an excessively high degradation rate, which easily causes insufficient water and fertilizer supply in the late growth stage and leads to maize yield reduction, thus it is not suitable for popularization.
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