Effects of wide-range precision sowing and row spacing on water consumption and grain yield of wheat.

Abstract

The mechanism for water-saving and high-yield of wide-range precision sowing technology remains unclear. We investigated the impact of wide-range precision sowing on the physiological characteristics of root system, water consumption, and grain yield of wheat 'Jimai 22' during the growing seasons of 2017-2019. We set up two planting modes: wide precision sowing and conventional strip sowing, and three row spacings of 20 cm, 25 cm, and 30 cm under water-saving cultivation with supplemental irrigation to examine the effects of planting modes on root biomass and senescence characteristics of wheat, water utilization characteristics, interplant evaporation, grain yield, and water utilization efficiency. The results showed that the 25 cm treatment (K25) led to an increase in root weight density, root soluble protein content, and root activity by 7.2%-23.9%, 8.7%-25.1%, 10.7%-29.9%, and 7.3%-27.6%, 8.0%-38.5%, 15.2%-32.7%, respectively, compared to the other treatments. At the same row spacing, the wide-range precision sowing treatment showed a significantly higher soil water storage consumption and proportion to total water consumption compared to the conventional strip-tillage treatment. Additionally, irrigation and interplant evaporation were lower in the wide-range precision sowing treatment. The K25 treatment exhibited significantly higher water consumption and modal coefficient of water consumption from flowering to ripening than other treatments. Furthermore, it had significantly higher seed yield, water utilization efficiency, and irrigation utilization efficiency than the other treatments. We found that a 25 cm spacing in the lower rows and density of 180-270 plants·m^-2 was the water-saving and high-yielding planting pattern of wide-range precision sowing wheat in Huang-Huai-Hai region.