Effects of different combinations of planting density, row spacing and row direction on field microclimatic conditions and grain yield of maize

Corn production is critical for food security in China. The lack of coordination between corn varieties and cultivation techniques has often resulted in low production. "Xundan 20" is a compact and high-yield corn variety with large planting area. It has been recommended as a suitable variety for cultivation in Anhui Province by China's Ministry of Agriculture. To realize the full yield potential of "Xundan 20" in Anhui Province, the effects of different configuration of planting density, row spacing and row direction on field microclimatic conditions and grain yield formation were studied. The results suggested that increasing maize plant row spacing increased daily average wind speed and illumination. Also increasing maize plant row spacing decreased accumulated temperature and daily average relative humidity. Under the same density and row spacing, daily average wind speed and illumination in east-west planting patterns were higher than those in south-north planting patterns. However, accumulated temperature and daily average relative humidity showed the opposite trends for the planting pattern directions. Grain yield of east-west planting patterns was higher than that of south-north planting patterns. Under the same row direction, corn grain yield was significantly different under different planting densities and row spacing. Under planting density of 60 000 plants·hm^-2, optimal population structure was established at row spacing of 50 cm and the east-west row direction, and corn grain yield reached 10 582.5 kg·hm^-2. Concurrently, field microclimatic factors such as temperature, humidity, light intensity and wind speed were well coordinated. This study provided basic guiding principles for improved cultivation of "Xundan 20" in Anhui Province of China.