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On the Loess Plateau, unfavorable late-sowing conditions often arise due to late harvests from the previous season or excessive rainfall during the sowing season, which can delay seed germination, reduce tiller numbers, and decrease winter wheat yields. Few studies have explored whether plastic mulching (PM) can mitigate the adverse effects of late sowing. Consequently, we conducted a 3-year field experiment from 2017 to 2020 on the Loess Plateau combining two mulching conditions [PM and no mulching (NPM)] and three sowing times (normal, 10-day late, and 20-day late sowing). We investigated the combined influence of sowing time and mulching conditions on soil hydrothermal status, crop water productivity (WP), and yield. The results revealed that delayed sowing significantly prolonged emergence times and decreased tiller numbers, leaf area index (LAI), root biomass, and aboveground biomass (AGB). The PM increased soil temperatures, advancing wheat emergence and increasing tiller numbers. Plants under PM had higher LAI, root biomass, and AGB than those under NPM. Moreover, PM reduced ineffective transpiration by accelerating the degradation of ineffective tillers, resulting in higher yields without a corresponding increase in evapotranspiration. The beneficial effects extended to spike numbers, thousand-grain weight, and harvest index. Specifically, PM combined with 10-day late sowing increased yield by 12.8 % compared to NPM combined with normal sowing. Furthermore, under 20-day late sowing, PM mitigated yield losses, reducing them from a 28.7 % decline under NPM to a 12.8 % decline when compared to normal sowing under NPM. We conclude that PM completed compensated for the yield loss under 10-day late sowing and partially alleviated losses under 20-day late sowing. Therefore, combining 10-day late sowing (accumulated air temperature before winter > 430 °C d) with PM was the optimal approach for simultaneously improving yield and WP in winter wheat seasons with unfavorable late-sowing conditions. • High early tiller count under plastic mulch (PM) benefited dry matter accumulation. • PM synergistically enhanced the yield and water productivity of late-sown wheat. • PM reduced ineffective transpiration by hastening ineffective tiller degradation. • PM combined with 10-day late sowing was optimal for wheat production. [ABSTRACT FROM AUTHOR]

Plastic film mulching (PM) has become a widely used cropping method in arid and semiarid areas. However, it is unknown how different PMs affect crop water and N utilization and their interaction under different N supplies. A two-year field experiment was conducted in the Hetao Irrigation District (HID), in northwest China. Following local irrigation practices, 500 mm border irrigation was used to grow spring maize over two growing seasons (2019 and 2020) with two N levels: high-N (225 kg N ha–1) and low-N (150 kg N ha–1). Combined with three mulching methods, the experiment had five treatments: (i) no mulching with high-N (control, CK), (ii) black plastic film with high-N (HB), (iii) transparent plastic film with high-N (HT), (iv) black plastic film with low-N (LB), and (v) transparent plastic film with low-N (LT). The 4 PM treatments had higher average soil water storage (0–120 cm) than CK. The PM treatments had the highest water consumption coefficients (K wcn) at 6–leaf to 12–leaf stage (K wc2) and milking to maturity (K wc5) stage. The HP treatments (HB and HT) had higher soil nitrogen storage than CK during the growth period. Averaged across two seasons, HB and HT had 23.9%, 29.2% respectively, higher grain yields than CK. Averaged across two seasons, the transparent PM treatments had 7.49%, 5.31%, and 1.72% higher water use efficiency (WUE), partial factor productivity of nitrogen (PFPN), and harvest index, respectively, than the black PM treatments. The PM treatments showed the relationship between water use efficiency of biomass (WUE b) and nitrogen use efficiency of biomass (NUE b), with WUE b increased, NUE b also increased. Given these results, we recommend the high-N level and transparent PM for maize cropping to increase yield and resource utilization efficiency in the HID. • Plastic film mulching (PM) redistributed soil water and NO3--N and created a better rootzone soil environment. • PM improved WUE b , accelerated maize soil nitrogen utilization and dry matter accumulation. • Transparent film mulching produced higher yield and resource use efficiency than black film and no mulching. • PM is a promising practice for water and nitrogen management in arid agricultural systems. [ABSTRACT FROM AUTHOR]

The widespread adoption of returning crop residue to regulate soil properties and improve yields has been well-established. However, the long-term effects of residue return on soil organic carbon (SOC) and yield in film-mulched farmland, especially under future climate conditions, are still unclear. To address this issue, we utilized the SPACSYS model, which was calibrated with 5-year (2016–2020) field experiment data from various mulching and fertilization treatments in the Hetao irrigation district in northwest China. Furthermore, we investigated the impacts of climate change on SOC storage in 20 cm and maize yield with calibrated SPACSYS model driven by 27 global climate models under two climate scenarios (SSP245 and SSP585) from CMIP6. We considered multiple combinations of agronomic options: five residue return levels (R1: 20%; R2: 40%; R3: 60%; R4: 80%; R5: 100%) and three return depths (D1: surface applied; D2: 10 cm; D3: 20 cm) to evaluate the effects of residue return on SOC storage and yield. We found that yield at a high fertilization rate with transparent film mulching (HT) would increase by 10.1% under SSP245, 15.3% under SSP585 in 2021–2060 compared to the baseline (1981–2020). By contrast, the yield would decrease by 5.8% under SSP245, 21.7% under SSP585 in 2061–2100. SOC storage under HT would decrease by 9.4–12.7% and 18.4–41.4% in 2021–2060 and 2061–2100, respectively. We determined that the optimal treatment involves returning 100% of residue to a depth of 20 cm (R5D3). Under R5D3, yield showed an increasing trend in both two future periods; the SOC storage decreased by 4.8–6.8% in 2021–2060 and increased by 3.9–16.1% in 2061–2100 compared to the baseline under HT. Our results highlight the potential of residue return to increase yield while maintaining soil health when film mulching is adopted. • SPACSYS model simulated yield and soil organic carbon (SOC) content well. • SOC stocks show a declining trend in the future without residue return. • Residue return can mitigate negative effects of climate change on yield and SOC. • The optimal choice for augmenting SOC and yield is 100% residue return at 20 cm. [ABSTRACT FROM AUTHOR]

Future climate change (FCC) and water scarcity significantly affect agricultural production in arid areas. Plastic film mulching (PM) combined with large irrigation amounts is popular for agricultural production in these areas. Crop model is an important tool for studying FCC's effect on crop production and its countermeasures. In this study, after calibration and validation using measured values from a two-year field experiment, the SPACSYS (v 6.0) and modified DSSAT-CERES-Maize (v 4.7.0.0) models were used to evaluate the implementation of six management systems (three mulching measures: transparent film, black film, no film; two fertilization levels: high, low) and to optimize management measures under FCC. Both models well simulated maize's anthesis and maturity dates, the final aboveground biomass, yield, and topsoil soil water content (SWC) compared with the measured values. SPACSYS simulated the maize growth and SWC under nitrogen stress better than DSSAT. Total 27 global climate models (GCMs) were used to drive DSSAT and SPACSYS models with different irrigation schemes, including three irrigation amounts (I1, I2, I3) and four irrigation ratios (the proportion of total irrigation amount in different growing stages: T1, T2, T3, T4) to simulate crop phenology and yield under FCC in future decades (2040s and 2080s). Both models advanced the anthesis date (by 8.1–16.2 d in the 2040s and 12.8–20.3 d in the 2080s), maturity date (by 12.7–18.9 d in the 2040s and 19.1–24.8 d in the 2080s), and length of reproductive growth period (by 3.6–6.1 d in the 2040s and 5.8–11.0 d in the 2080s). The I1T1 scenario under transparent film mulching produced the highest yields (12.14–16.07% in the 2040s and 5.36–6.07% in the 2080s higher than the average). The I3T4 scenario maintained stable yields in the 2040s, decreasing by nearly 20% in the 2080s. Consequently, the I3T4 scenario could be the optimal management practice for balancing yield and irrigation for maize production in this arid area in the future decades. • DSSAT and SPACSYS can reasonably simulate maize yield under plastic film mulching (PM). • SPACSYS and DSSAT showed advanced phenological dates and shorten the reproductive period under climate change. • The 400 mm irrigation schemes under PM achieved stable yields for future climate change. • PM is a long-term agricultural practice for arid agricultural systems. [ABSTRACT FROM AUTHOR]