Effects of Winter Cropping on rice Yield, Economic Benefit, and Resource Utilization Efficiency on Different Cropping Systems of Paddy Field in the Middle Reaches of the Yangtze River

Winter cropping is an effective way to solve the low resource utilization efficiency in single rice system. In order to explore the effects of winter cropping on rice yield, economic benefits and resource utilization efficiency of single rice paddy field, two different cropping systems (single and winter multiple cropping systems) including 4 treatments: middle rice (CK), Chinese milk vetch—middle rice (DC), rape—middle rice (DR) and wheat—middle rice (DW) were set up to explore their difference on productivity, economic benefit and resource utilization efficiency. The results showed that compared with CK, the rice yield was increased by improving the components of rice yield and by increasing population dry matter accumulation in winter multiple cropping system. Compared with CK, the average annual yield of DC, DR and DW increased by 1.47%, 7.41% and 3.92%. The economic benefits of DR increased by 32.1% compared with CK, while the economic benefits of DC and DW were 9.99% and 8.3% lower than CK, respectively. Winter multiple cropping increased the light allocation rate. Compared with CK, DC, DR and DW increased light allocation rate by 119.25%, 102.11% and 104.39%, respectively, but the average annual light productive efficiency was 53.33%, 40.48% and 40% lower than CK. Winter multiple cropping increased the effective accumulated temperature distribution rate. Compared with CK, DC, DR and DW increased effective accumulated temperature distribution rate by 78.61%、58.8%、60.92%, respectively, but the average annual accumulated temperature (≥ 10℃) production efficiency was 43.11%、23.88%、24.04% lower than CK, respectively. Compared with the single cropping system, the double cropping system has significant advantages in annual rice yield, dry matter accumulation, total economic benefit, light and effective accumulated temperature distribution rate. Rape—middle rice model is the optimized planting model for the middle reaches of the Yangtze River.