Optimal bed width for wheat following rice production with raised-bed planting in the Yangtze River Plain of China

Abstract

Waterlogging is a major threat to wheat following rice production in the Yangtze River Plain, China, where the raised-bed planting (RBP) pattern is recommended to reduce yield losses from waterlogging. Furrows used in RBP allow drainage runoff, and beds serve as planting zones. However, the optimal bed widths for wheat following rice cultivation are unknown. To adopt the most effective RBP patterns, we evaluated the effects of bed width on the volumetric soil water content (VSWC), radiation use efficiency, yield and profitability among different RBP patterns during the 2019/20 and 2020/21 growing seasons. The experiment comprised six planting patterns: conventional flat planting (FP) and five RBP patterns with different bed widths (RBP60, RBP120, RBP180, RBP240 and RBP300). The results demonstrated that VSWC increased with increasing bed width and RBP decreased VSWC in the 0–10 cm soil layer, but VSWC did not significantly decrease when the beds were excessively wide. The improved soil conditions promoted wheat canopy development and the fraction of photosynthetically active radiation (fPAR), which resulted in a significantly higher value of intercepted photosynthetically active radiation (IPAR) that eventually increased both grain yields and net revenue. The increase compared to FP was greatest for RBP180 and RBP240. There were tradeoffs between the positive growth-promoting effects and the negative effect of decreased planting area with RBP. Excessively wide beds reduced the advantages of water drainage, and excessively narrow bed widths reduced radiation resource capture. The optimal bed widths for wheat production on the Yangtze River Plain were 213.4–215.3 cm, 204.2–211.4 cm, 197.3–206.5 cm and 204.9–214.6 cm for IPAR, biomass, yield and economic benefits, respectively. Overall, RBP patterns with a 200.0-cm-bed and 25.0-cm-wide furrows are optimal for wheat after rice production under the current amount of rainfall in the Yangtze River Plain.