Response of dryland crops to climate change and drought-resistant and water-suitable planting technology for spring maize

Climate change has a high impact on agriculture. While this issue is currently limited to the analysis of meteorological data, long-term monitoring of associated crop phenology and soil moisture remains inadequate. In this study, temperature and precipitation (1957–2020) were recorded, crop growth (1981–2019) data were collected, and field experiments were conducted at central and eastern Gansu and southern Ningxia China. Mean temperature increased by 0.36 °C and precipitation decreased by 11.17 mm per decade. The average evapotranspiration (ET) of winter wheat in 39 years from 1981 to 2019 was 362.1 mm, demonstrating a 22.1 mm decrease every 10 years, but the ET of spring maize was 405.5 mm over 35 years (1985–2019), which did not show a downward trend. Growth periods of wheat and maize were shortened by 5.19 and 6.47 d, sowing dates were delayed by 3.56 and 1.68 d, and maturity dates advanced by 1.76 and 5.51 d, respectively, every 10 years. A film fully-mulched ridge–furrow (FMRF) system with rain-harvesting efficiency of 65.7–92.7 % makes rainwater infiltrate deep into the soil. This leads to double the soil moisture in-furrow, increasing water satisfaction rate by 110–160 %. A 15-year grain yield of maize increased by 19.87 % with the FMRF compared with that of half-mulched flat planting. Grain yield and water use efficiency of maize increased by 20.6 % and 17.4 % when the density went from 4.5×104 to 6.75×104 plants ha-1, and improved by 12.0 % and 12.7 % from 6.75×104 to 9.0×104 plants ha-1, respectively. Moreover, responses of maize yield to density and density corresponding to the maximum yield varied highly in different rainfall areas. The maize density should be determined by one mm rainfall planting nearly 174 plants, harmonizing crop growth and water use. Therefore, management strategies should focus on the adjustment of crop planting structure, FMRF water harvesting system, and water-suitable planting to mitigate the adverse effects of climate change and to enhance sustainable production of maize in the drylands.