Search

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]