Caixia Huang

To address water-heat constraints and environmental risks associated with plastic film mulching in winter wheat production in the semi-arid region of Northwest China, a two-year field experiment (2021–2023) was conducted in Tongwei County, Gansu Province. A single-factor randomized block design was applied, with full plastic film mulching (PM) and bare land (CK) as controls, to evaluate the effects of 3-row (S3), 4-row (S4), and 5-row (S5) corn stalk strip mulching on soil hydrothermal conditions, active carbon fractions, and yield under rainfed conditions. Results showed that straw mulching significantly enhanced soil water retention, particularly in the 0–40 cm layer, where moisture content increased by 7.70–19.28% compared with CK (p < 0.05), with S3 performing best. Treatment S5 achieved the highest accumulated temperature and reduced the soil diurnal temperature range by 20.73–35.62% (p < 0.05). Active carbon fractions were also significantly improved, especially during the jointing–grain-filling stage (BBCH 31–87). In terms of yield, S5 exhibited the greatest increase, with a 15.88% higher two-year average grain yield than CK (p < 0.05), reaching over 90% of PM. Overall, S5 demonstrated optimal synergistic regulation of water, heat, and carbon, indicating strong potential as a sustainable alternative to plastic film mulching.

Plant moisture content (PMC) serves as a crucial indicator of crop water status, directly affecting agricultural productivity, product quality, and the effectiveness of precision irrigation. Conventional methods for PMC assessment predominantly rely on destructive sampling techniques, which are labor-intensive and impede real-time monitoring. This study investigates silage maize cultivated in the Hexi region of China, leveraging multispectral data acquired via an unmanned aerial vehicle (UAV) to estimate PMC across different phenological stages. A stacked ensemble learning framework was developed, integrating Back Propagation Neural Network (BPNN), Random Forest Regression (RFR), and Support Vector Regression (SVR), with Partial Least Squares Regression (PLSR) employed for feature fusion. The findings indicate that incorporating vegetation indices into spectral variables significantly improved prediction performance. The standalone models demonstrated coefficient of determination (R²) values ranging from 0.43 to 0.69, with root mean square error (RMSE) spanning 0.61% to 1.43%. In contrast, the ensemble model exhibited superior accuracy, achieving R² values between 0.61 and 0.87 and RMSE values from 0.54% to 1.38%. This methodology offers a scalable, non-invasive alternative for PMC estimation, facilitating data-driven irrigation optimization in regions facing water scarcity.

Mulching could effectively improve the soil hydrothermal environment, improve changes in the soil structure, increase entropy, and conserve soil moisture to solve the problem of grain reduction caused by perennial drought in Northwest China. Thus, a two-growing-season field experiment (2021–2022) with five treatments (PM1, biodegradable plastic film mulching; PM2, plastic film mulching; SM1, straw strip mulching; SM2, crushed corn straw full mulching; and CK, no mulching as the control) was conducted to investigate the effects of different mulching materials on the soil hydrothermal environment, soil aggregate distribution, stability, and tuber yield of rainfed potato farmland in Northwest China. Over two growing seasons, mulching planting, on average, increased (p < 0.05) the soil moisture at the 0–200 cm depth by 9.0% relative to CK (SM2 (11.6%) > SM1 (10.3%) > PM2 (8.6%) > PM1 (7.0%)). The mulching treatments significantly regulated the soil temperature during the whole growth period, in which plastic mulching significantly increased the soil temperature of the 0–25 cm soil depth during the whole growth period by 2.1 °C (PM2 (2.1 °C) > PM1 (2.0 °C)); meanwhile, straw mulching significantly reduced the soil temperature by 1.4 °C (SM2 (0.9 °C) > SM1 (0.6 °C)). All mulching treatments improved the soil macroaggregate content and soil aggregate stability in all soil depths from 0 to 40 cm, with increases of 31.4% and 27.1% in the mean weight diameter (MWD) and 22.6% and 21.2% in the geometric mean diameter (GWD) compared with CK, respectively. Straw and plastic mulching significantly increased the fresh tuber yield by 12.5% and 12.6% compared with CK, respectively. The increases were greatest in SM2 and PM2. Crushed corn straw full mulching is difficult to sow and harvest; therefore, straw strip mulching could improve the soil hydrothermal environment, increase production, and provide an environmentally friendly technology for dryland potato production.

Mulch is an important measure for improving agricultural productivity in many semiarid regions of the world. However, the impacts of various mulching materials on soil hydrothermal characteristics, enzyme activity, and potato yield in fields have not been comprehensively explored. Thus, a two-growing-season field experiment (2020–2021) with four treatments (SSM, straw strip mulching; PMP, plastic film mulching with large ridge; PMF, double ridge-furrow with full film mulching; and CK, no mulching with conventional planting as the control) was conducted to analyze soil hydrothermal and soil enzyme activities and potato yield on the semiarid Loess Plateau of Northwest China. The results indicated that mulching practices had a positive effect on the soil moisture, with SSM, PMP, and PMF increasing by 7.3%, 9.2%, and 9.2%, respectively, compared to CK. Plastic film mulching significantly increased the soil temperature by 1.3 °C, and straw mulching reduced the soil temperature by 0.7 °C in the 0–30 cm soil layers of the whole growth period. On average, SSM, PMP, and PMF increased soil urease activity in 0–40 cm soil layers by 14.2%, 2.8%, and 2.7%, respectively, and enhanced soil sucrase activity by 19.2%, 8.6%, and 5.7%, respectively, compared with CK. Plastic film mulching increased soil catalase activity by 9.6%, while SSM decreased by 10.1%. Mulching treatments significantly increased tuber yield and water use efficiency based on dry tuber yield (WUE), and SSM, PMP, and PMF increased tuber yield by 18.6%, 31.9%, and 29.7%, enhanced WUE by 50%, 50%, and 57.0% over CK. The correlation analysis revealed that soil moisture was the main factor influencing tuber yield (r = 0.95**). Mulching could improve the soil hydrothermal environment, regulate soil enzyme activities, and promote yield increase. As a sustainable protective mulching measure, straw strip mulching is conducive to improving the ecological environment of farmland and the sustainable development of regional organic agriculture.