Greater maize yield improvements in low/unstable yield zones through recommended nutrient and water inputs in the main cropping regions, China

摘要

Maize (Zea mays L.) is an important cereal crop grown worldwide. With the increase in human food demand but limited land and water resources, precise spatially explicit knowledge about the maize production capacity through agricultural management practices (e.g., using recommended nutrient and water inputs, RNWI, by local agronomists) is essential to guide the future policy, research, development, and investment. Here, we used a well-validated crop model (APSIM-Maize) for 1981-2010 combined with actual climatic and soil data to estimate maize yield improvements under RNWI in three main cropping regions in China (the North China Spring Maize Region, NCS; the Huanghuaihai Summer Maize region, HS; and the Southwest China Mountain Maize Region, SCM). Compared with the county-level maize actual yield in the three main cropping regions, the average maize yield could be increased by 33 % (4 Mg ha(-1)) through RNWI, while the improvements in the coefficients of variation (CVs) of grain yield and reliable grain production (RGP) were 0.11 and 32 % (69 million Mg), respectively. Except for RNWI, the average yield, CVs of yield, and RGP could still be increased by 28 % (3 Mg ha(-1)), 0.10, and 36 % (80 million Mg) through other management and technologies (OMT). Further analysis in four types of yield level-stability zones (high-stable, low-stable, high-unstable, and low-unstable zones) showed that greater contributions of using RNWI and OMT to improve maize grain yield, yield stability, and RGP were found in zones with low/unstable yield across the three regions. The findings highlighted the focus on increasing maize yield in low/unstable-yield zones could provide a greater return.