Climate-adapted variety selection and optimal planting density for improving maize yield in the Guanzhong region,...

Suboptimal densities and regional environmental heterogeneity often constrain maize yield intensification. Increasing planting density and selecting climate-adapted varieties are therefore critical for improving grain yield.

The study was conducted at 33 sites in the Guanzhong region from 2017 to 2021, addressing uncertainty in density-variety selection for local maize production. Six varieties (including widely grown and newly introduced types) were tested at four planting densities (45 000-90 000 plants ha^-1), and their combined effects on yield and agronomic traits were assessed. Results showed that increasing planting density improved grain yield and economic returns. The experimental results identified 75 000-90 000 plants ha^-1 as the optimal density range for the region; within this range, yields increased by 6.24-27.31% compared with traditional lower densities (45 000-60 000 plants ha^-1). All six varieties responded positively to increased planting density, with Shandan 650 and Shandan 8806 showing the greatest yield gains. Specifically, adopting a planting density of 75 000 plants ha^-1 with varieties such as Shandan 650 could maximize economic returns while minimizing seed-cost risks to local farmers in the Guanzhong region. Grain yield was closely associated with climatic conditions during the growing season, with higher precipitation in eastern Guanzhong contributing to superior yields. Furthermore, optimizing 100-kernel weight and the ear-to-plant height ratio may help stabilize yields in medium- and low-yielding fields.

Ultimately, these findings provide a practical yield-enhancement strategy, offering useful references for transforming low-productivity fields into high-yield systems in similar monsoon-influenced rotation zones worldwide. © 2026 Society of Chemical Industry.