Abstract:
In order to provide a scientific basis for the large-scale application of rice-fish coculture technology, the study quantitatively analyzed the rice yield effects of rice-fish coculture in the world. 102 groups of rice yield data from published related literatures were sorted (up to December 31, 2021). Using the meta-analysis method, the comprehensive effect of rice-fish coculture on rice yield was clarified. The effects among different time, regions, field conditions, rice varieties, management methods of fertilizer, pesticide, fry stocking and feeding on rice yield were further quantified. Compared with rice monoculture, rice-fish coculture significantly increased rice yield, with an average increase rate of 17.2% (95% CI: 9.4%—25.6%). The analysis results were reliable. The results of subgroup analysis showed that there was significant difference in yield effect between different regions and climates, no significant difference between different yield estimation methods, and the yield effect was higher in foreign and tropical climate region. The yield increase rate of rice-fish coculture was relatively higher in the experimental fields where experiment was conducted after 2011, field ditch was arranged on one side (L1) and rice variety was Japonica. The yield effects of rice-fish coculture among different management methods of fertilizer and pesticide were significantly different, it was higher when fertilization times was three, fertilization pattern was single top fertilizer (TF), fertilization variety was organic and inorganic fertilizer (OIF) and pesticide was applied. On the premise of guaranteeing the yield increase effect, the application amount of fertilizer and pesticide could be appropriately reduced. Applying organic fertilizer (OF) and no pesticide could obtain dual benefits of economy and environment. The yield effects of rice-fish coculture were significantly different among fry stocking days, aquaculture models, fry densities and feeding strategies. When fish of single variety (MC) was stocked 21 to 25 days after rice transplanting without feed and the size, density and biomass were controlled within 40 g/tail, 1 tail/m
2 and 30 g/m
2, the rice-fish coculture had better yield increase effect. Rice-fish coculture can significantly increase rice yield, which is a feasible way to effectively utilize rice field resources.