Evapotranspiration (ET) is an important channel for water transport and energy conversion in land–air systems, and the spatial quantification of actual ET is crucial for water resource management and scheduling in arid areas. Using the Surface Energy Balance Algorithm for Land (SEBAL) model and satellite images, this study determined the actual ET during the growing season of 2020 in the Shiyang River Basin of northwest China and investigated the driving mechanism of ET using a principal component regression. The results showed that the ET obtained using the Penman-Monteith equation exhibited a good correlation with the ET estimated using SEBAL (R² = 0.85). Additionally, SEBAL overestimated ET to some extent compared to the Moderate-Resolution Imaging Spectroradiometer (MODIS) ET (MOD16) product. The daily ET (ET_d) in the Shiyang River Basin showed a single-peak variation during the growing season, with the maximum value occurring around mid-July. Spatially, the ET gradually increased from northeast to southwest with the variation in the land use/land cover (LULC) type. Among the six LULC types, ET_d was higher for woodland, water body, and grassland, all exceeding 5.0 mm/d; farmland and built-up land had ET_d close to 3.9 mm/d; and barren land had the lowest ET_d of below 2.5 mm/d. Furthermore, the standardized regression coefficients indicated that the Normalized Difference Vegetation Index (NDVI) is the main driving factor influencing ET. Overall, the SEBAL model has the potential to estimate spatially actual ET, and the study results provide a scientific basis for water resource accounting and hydrological analysis in arid areas.

In order to optimize the appropriate drought resistance measures in the implementation of high-efficiency and intensive production of maize seed, in 2018 and 2019, maize cultivation experiments with different drought resistance measures were carried out in the arid area of northwest China, including water retention agent (SA), white plastic film mulch (WF), black plastic film mulch (BF), straw mulch (SM), and open ground flat seed as control (CK). A total of five treatments were conducted. Ten specific indicators contained four types of attributes, namely the yield, quality, water use efficiency (WUE), and economic benefit of maize seed production, aimed at constructing a multilevel evaluation system. To improve the reliability of evaluation results, subjective and objective weights of indexes were calculated using the analytic hierarchy process (AHP) and entropy weight method (EWM), respectively. Then, based on the integrated weighting method of game theory (GT), the combined weights of subjective and objective unity were obtained. Finally, with the help of the technique for order preference by similarity to ideal solution (TOPSIS), a comprehensive benefit evaluation model was established to screen out the optimal drought resistance measures. Compared with CK, different drought resistance measures significantly improved the grain quality of seeds-production corn, and the average annual yield and WUE of black and white film treatments were improved by 49.57% and 42.97% and by 65.67% and 58.21%, respectively. This proved that black film mulching (BF) could significantly increase the yield and WUE of maize seed production and effectively improve grain quality, which could be used as the best drought-resistant cultivation mode for maize seed planting in Hexi and similar areas.

Limited water resources and low water productivity limit the sustainable development of agriculture in northwest China. In this study, drip irrigation under plastic film was used to achieve an optimal water deficit irrigation (WDI) scheme for the cultivation of indigowoad root (Isatis tinctoria L.). Field water control experiments were conducted in 2016 and 2017. Evaluation of WDI schemes was carried out by considering five indices: water consumption, yield, water use efficiency (WUE), indigo, and (R,S)-goitrin. To enhance the reliability of results, the analytic hierarchy process (AHP) and entropy weight method (EWM) were adopted to calculate the combined weight of the evaluation index. Finally, an improved technique for order of preference by similarity to ideal solution (TOPSIS) that integrated AHP–EWM weights was used to construct a unified, comprehensive evaluation model of indigowoad root under mulched drip irrigation that would produce high yield while saving water. The evaluation results indicated that mild WD (specifically, the V1G1 treatment) was continuously exerted during the vegetative and fleshy root growth periods, which enhanced the WUE and improved the quality of indigowoad root to a certain extent without significantly reducing the yield. These results provide a scientific basis for irrigation of indigowoad in northwest China and other areas with a similar environment.

To explore the response of soil organic carbon (SOC) and carbon components to surface coverage in wheat fields in semi-arid rainfed regions, a two-year field experiment was conducted under three treatments: straw strip mulching (SM), transparent plastic film mulching (PM) and no mulching (CK). We researched the dynamic feature of soil organic carbon (SOC) and its components at different growth stages of winter wheat under different mulching methods, including microbial biomass carbon (MBC), dissolved organic carbon (DOC), mineralizable carbon (PCM) and easily oxidized carbon (EOC). The results showed that SOC and its components in different soil layers decreased with an increase of soil layer depth. Compared with CK, the SM treatment increased SOC in the 0–40 cm soil layer by 2.83–8.92%, MBC by 12.09–18.40%, DOC by 3.73–9.79%, PCM by 4.82–12.48% and EOC by 6.01–11.68% during the different periods, and an overall increase was greater in the 0–20 cm soil layer than in the 20–40 cm soil layer. The impact of PM on SOC was less significant compared with CK; MBC and PCM had an overall positive effect, and DOC and EOC behaved differently from year to year. In conclusion, SM can improve SOC and its components content in dryland of northwest China, which is conducive to the sustainable management and efficient utilization of maize straw resources and has significant ecological benefits.

As the most effective irrigation method in arid and semi-arid regions, drip irrigation under mulch could general comprehension of the production efficiency of agricultural irrigation water, and reduce agriculture consumption of water resources. The paper has carried out an investigation over a two year period (2020–2021) in a semi-arid climate in the Hexi Oasis region of China, aiming at determining the influence of regulated deficit irrigation (RDI) under mulch on the growth, yield, water use efficiency (WUE), irrigation water use efficiency (IWUE) and quality of pumpkin at different growth stages. A total of nine treatments with three irrigation levels (75–85% field capacity, 65–75% field capacity, and 55–65% field capacity) have been used in four growing periods of pumpkin (seedling, vine extension, fruit expansion, and maturation stages). The results have shown that light water deficit treatment at the seedling stage had the highest water use efficiency (12.47 kg/m³) without significantly affecting yield (45,966.90 kg/ha), and improved pumpkin fruit quality. It was concluded that light water deficit at the seedling stage and adequate irrigation at other development stages was the optimal irrigation strategy for pumpkin growth. The results of this research provide theoretical and technical support for efficient water-saving plantation and industrialization of pumpkin in the Hexi Oasis.

To investigate the feasibility of replacing plastic film with straw in semi-arid areas and establishing coordinated cultivation technology for high winter wheat yield and efficient resource utilization, a two-year field experiment was conducted under six treatments, specifically CK (no-mulching), S1 (59% of the field area straw mulched), S2 (50% of the field area straw mulched), S3 (42% of the field area straw mulched), BM (full-cover transparent plastic mulch), and HM (full-cover black plastic mulch). The effects of mulching measures on soil moisture, water consumption characteristics, yield and water use efficiency (WUE) of winter wheat farmland in rain-fed semiarid regions were studied. The results showed that, compared with CK, straw strip mulching reduced total water consumption by 15.39 mm on average, the soil organic carbon content at the 0–40 cm soil layer increased by 4.68%, yield by 6.90%, WUE_r by 11.27%, and WUE_b by 16.51%. Compared with CK, the total water consumption and soil organic carbon content in each growth period of plastic film mulching were not significantly different, but the yield, WUE_r, and WUE_b increased by 16.28%, 15.29%, and 25.50%, respectively. Among the three straw strip mulching treatments, treatment S3 had the highest yield, which was equivalent to that of plastic film mulching. The S3 treatment with 42% of the field area straw mulched is recommended in this stusy as the optimal replacement of plastic film mulching in semi-arid environments.