Effects of mulching method and irrigation quota on soil hydrothermal characteristics and growth of sugar beet

Objective This study aims to investigate the effects of different mulching methods and irrigation quotas on the temperature, moisture, and growth of sugar beet in the plough layer. The goal is to provide a scientific basis for the efficient utilization of water resources in sugar beet production.

Methods A split-plot experimental design was adopted. The main plots consisted of three mulching methods: no mulching (N), conventional polyethylene film mulching (P), and biodegradable film mulching (B). The sub-plots consisted of three irrigation quotas: 5 700 m³/hm² (W1, the highest level throughout the whole growth period), 4 950 m³/hm² (W2), and 4 200 m³/hm² (W3). The study analyzed the impacts of these factors on soil moisture, temperature, as well as the growth, development, yield, and quality of sugar beets.

Results The interaction between biodegradable film mulching and the 5 700 m³/hm² irrigation quota effectively increased the temperature and moisture content of the plough layer. It also promoted the increase of functional leaf area, plant height, leaf number, and dry matter accumulation in sugar beets. The BW1 treatment better met the water demands of sugar beets at various growth stages, achieving a yield of 133,196 kg/hm², which was higher than other treatments, along with the optimal sugar content and quality.

Conclusion In this study, the combination of biodegradable film mulching and a 5 700 m³/hm² irrigation quota (BW1) resulted in superior soil hydrothermal conditions compared to other treatments. This combination not only promotes the growth, yield, and sugar quality of sugar beets but also effectively reduces residual film pollution, making it suitable for application and promotion in Northern Xinjiang.