A novel planting pattern increases the grain yield of wheat after rice cultivation by improving radiation resource utilization

Abstract

Waterlogging severely constrains wheat production after rice cultivation in the middle-lower reaches of the Yangtze River Plain, China. Raised bed planting (RBP) patterns may reduce waterlogging stress and increase wheat productivity. However, the physical mechanisms of resource use in wheat, particularly radiation resource use, are not well understood. The effects of planting patterns on the canopy structure, light interception (LI), intercepted photo synthetically active radiation (IPAR), radiation use efficiency (RUE) and yield of two wheat cultivars (Yannong 19 and Yangmai 25) were examined by employing two planting patterns, conventional flat planting (FP) and RBP, in 2018/19 and 2019/20. Relative to FP, RBP significantly increased wheat yield by increasing the IPAR and RUE of wheat. Yannong 19 and Yangmai 25 intercepted 4.57% and 7.14% more IPAR, respectively, averaged over the two years, under RBP than under FP. The significantly higher IPAR in RBP was ascribed mainly to the increased canopy leaf area index (LAI), and LI benefited from the improved early-season growth and delayed late-season leaf senescence, which compensated for the reduced cropping area under RBP caused by the furrows. The increased light penetration into the middle-lower canopy under RBP resulted in 1.82% and 3.55% higher RUE for Yannong 19 and Yangmai 25, respectively, compared with that under FP. The significantly higher IPAR caused by the delayed leaf senescence was the primary factor responsible for the high productivity of wheat under RBP. Our results suggest that the key factor that limits wheat production after rice cultivation is radiation capture during the critical growth period, which is low. This study suggests that RBP has promise for increasing productivity and radiation resource utilization.