Comparison of crop productivity, economic benefit and environmental footprints among diversified multi-cropping systems in South China

Diversified multi-cropping system with high productivity and low environmental costs is crucial for the development of sustainable agriculture in different regions. However, the information on this practice has still been limited in the South China. This study compared different diversified multi-cropping systems including peanut-rice-fallow (P-R-F), peanut-rice-ryegrass (P-R-R), soybean-rice-ryegrass (S-R-R), feed corn-rice-milk vetch (FC-R-M), sweet corn-rice -milk vetch (SC-R-M) and zucchini-rice-milk vetch (Z-R-M), with the conventional double-rice system (CK). A newly proposed agricultural environmental footprint index (EFI) framework was introduced to quantify the comprehensive environmental costs of different systems. Results indicated that the annual productivities of P-R-R and FC-R-M rotation systems significantly increased by 39.91 % and 25.06%, respectively, compared to the CK. The economic benefits of P-R-R and FC-R-M were 53.71 % and 16.67 % higher than the CK, respectively, with significant differences. The EFIs based on unit farmland area, crop productivity and economic benefit of the P-R-R and FC-R-M systems were 17.07 %-40.68 % lower than the CK, respectively, showing the lower environmental costs. Therefore, the P-R-R and FC-R-M were recommended as alternatives of double-rice cropping in the South China. In addition, the results in-dicated that the fertilization and irrigation practices were the key points for improving the rotation systems. This study provided valuable information for the transition of rice-based cropping system in South China. It was also a reference for the development of sustainable agriculture in the world's subtropical agricultural system.