Optimization of irrigation-nitrogen-straw management measures for summer maize under future climate conditions in the Guanzhong Plain of China

Future climate change poses substantial challenges to food production systems. Identifying the future climate change trends in the Guanzhong Plain and developing optimal high yield and efficiency farmland management strategies for summer maize under future climatic conditions are crucial for safeguarding China’s food security. This study aims to investigate future climate change trends in the Guanzhong region and identify water-nitrogen (N)-straw management practices that can ensure high productivity and resource use efficiency for summer maize under future climatic conditions. We calibrated and validated the Agricultural Production Systems Simulator (APSIM) model using data from four seasons of field experiments. Historical meteorological data from 11 stations in the Guanzhong Plain, spanning from 1970 to 2015, were used to evaluate the accuracy of meteorological data simulations from 25 Global Climate Models (GCMs) under the Coupled Model Inter-comparison Project Phase 6 (CMIP6). By integrating the calibrated APSIM model with the selected GCMs, the optimal water-nitrogen-straw strategies were selected from 208 setting strategies under future climate scenarios. The UKESM1–0-LL model demonstrated consistently high S-scores across all meteorological indicators. Under both Shared Socio-economic Pathways2–4.5 (SSP245) and Shared Socio-economic Pathways5–8.5 (SSP585) scenarios, the average temperature during the summer maize growing season (from mid-June to the end of September) in Guanzhong Plain is projected to gradually increase, while precipitation is expected to exhibit considerable interannual variability. The calibrated APSIM model effectively simulated maize yield, biomass, and water use efficiency responses to various field management practices. During wet years under both climate scenarios, precipitation was sufficient to meet crop growth requirements, eliminating the need for irrigation. In normal years, supplemental irrigation of 30 mm and 20 mm at the three-leaf stage increased maize yield by 5.78–6.84 % and 5.73–6.25 % under the SSP245 and SSP585 scenarios, respectively. In dry years, applying 30 mm of supplemental irrigation at both the three-leaf and tasseling stages led to a yield improvement of 9.80–18.49 % and 7.69–12.22 % under the SSP245 and SSP585 scenarios, respectively. For N application, under SSP245 scenario, the optimal N application rate was 160 kg N ha⁻¹ in wet and dry years, and 170 kg N ha⁻¹ in normal years. Under SSP585 scenario, the optimal N rate was 160 kg N ha⁻¹ in wet and normal years, and 170 kg N ha⁻¹ in dry years. Under optimized water and N management, straw incorporation increased maize yield by 4.85–9.15 % and WUE by 5.93–6.85 % across different hydrological years under SSP245 scenario, while under SSP585 scenario, it enhanced yield by 5.76–6.27 % and WUE by 5.60–6.27 %. Our results provide specific water-nitrogen-straw field management strategies for addressing future climate change in the Guanzhong region. These strategies can ensure stable crop yields while enhancing resource use efficiency, thereby promoting sustainable agricultural development. Furthermore, other studies can adopt the same approach to evaluate crop yield suitability and resource management strategies over large regions under future climate scenarios. • Four-season field experimental data were used to calibrate and validate the APSIM model. • The trends of climate change in Guanzhong Plain under different scenarios were quantified. • The yield and water use efficiency of summer maize were improved by straw incorporation into field. • The irrigation and N application strategies under different hydrological years were optimized.