Comparison of resource utilization efficiency and comprehensive benefits among different multiple cropping rotation patterns in the middle reaches of Yangtze River

Rational and efficient utilization of light, temperature, water, soil, and other agricultural resources is the premise and guarantee of sustainable agricultural development. To optimize and promote green and efficient rotation-fallow patterns in paddy fields, the effects of different multiple cropping rotation patterns on resource utilization and comprehensive benefits were studied via field experiments for two consecutive years. The experiment had 5 treatments: milk vetch-early rice-late rice → milk vetch-early rice-late rice (treatment A, CK), milk vetch-spring soybean-autumn soybean → rape-sugar cane||spring soybean (treatment B), milk vetch-early rice-maize||sweet potato → milk vetch-spring soybean-autumn soybean (treatment C), rape-sugar cane‖spring soybean → milk vetch-early rice-maize||sweet potato (treatment D), and rotation fallow → rotation fallow (treatment E); in which “-” represents rotation, “||” represents intercropping, “→” indicates to the next year. Results showed that the rotation pattern of rape-sugar cane||spring soybean → milk vetch-early rice-maize||sweet potato (treatment D) had higher effective utilization rate of accumulated temperature and precipitation of bioavailability than the CK treatment. The annual effective accumulated temperature utilization rates of the three multiple cropping rotation modes (B, C, and D treatments) were 8.60%−39.78% higher than that of CK. In 2018 and 2019, the economic and social benefit evaluation indexes of the treatment D performed the best, with values of 0.94, 0.97, and 0.96, 1.00, respectively. The ecological benefit evaluation index results showed that the treatment B was better in 2018, and the treatment C was better in 2019, with values of 0.77 and 0.73, respectively. The two-year comprehensive benefits of different rotation fallow patterns were as follows: treatment D ˃ treatment B ˃ treatment C ˃ treatment A (CK) ˃ treatment E. Therefore, the resource utilization and comprehensive benefits of “rape-sugar cane||spring soybean → milk vetch-early rice-maize||sweet potato” performed better for double rice areas in southern China. This mode could promote better crop growth and be widely applied.