Co-cultivation of rice and aquatic animals: Improving soil fertility and providing more rice in China

Over the last few years, the co-culture of rice and aquatic animals (CRAA) has been developed intensively with an area of 2.878 million hectares in China owing to its important economic benefits. However, at this rapid development process, a systematic and quantitative analysis on how CRAA affects rice yield and soil fertility has remained unexplored in actual field conditions. For this, we performed a meta-analysis of the CRAA effects on the rice yield and soil fertility with 1028 comparisons from 278 publications during 1987–2024. Yield and soil fertility varied by co-culture modes, regions, management practices and initial soil conditions. Our results indicated that the rice-amphibians co-culture had a better effect on crop yield and soil fertility than that of fish, waterfowl and crustaceans. In different regions, CRAA had the greatest benefits for soil fertility, and it caused the highest increases in rice yield by 11.27 % in south of China than that in other regions. Furthermore, we found that in acidic soils (pH<7) with TN≤ 1.5 g kg⁻¹ provide a better soil environment for rice growth under CRAA. And the yield of the indica rice showed a more obvious advantages under CRAA treatments. In different fertilization schemes, the chemical fertilizer combined with organic fertilizer (CF+OF) increased rice productivity and soil properties, which was higher than that of sole chemical fertilizer. In general, the increase of rice productivity is closely associated with the improvement of soil fertility in CRAA. Our results indicated that CRAA improved sustainable soil fertility and rice yield in China.