A meta-analysis of ecological functions and economic benefits of co-culture models in paddy fields

The co-culture of rice and poultry/aquatic animals has become a popular strategy to ensure the critical ecological functions and economic benefits of this ecosystem in recent years. Yet, quantitative synthetic effects of co-culture models on ecological functions and economic benefits in paddy fields are poorly understood. This study conducted a meta-analysis of 4707 observations from 224 published papers on the outcomes of co-culture models in paddy fields. On aggregate, co-culture models significantly reduced CH₄ emissions by 14.8 % as compared with rice monoculture, but did not affect rice yields, N₂O emissions, and greenhouse gas intensity (GHGI). However, significant differences in rice yields, CH₄ emissions, GHGI, and economic benefits were observed among various co-culture models and rice-growing regions. Particularly, the co-culture models in East Asia significantly increased rice yields (+2.2 %), reduced CH₄ emissions (–22.1 %), and GHGI (–9.4 %). Importantly, co-culture models improved rice grain quality. Furthermore, co-culture models increased soil fertility (7.8–16.2 %), nutrients content in paddy water (26.2–87.0 %), and net ecological and economic benefits (31.7–71.1 %), while decreasing diseases, pests, and weeds (37.0–84.6 %) in paddy fields. Additionally, we suggest that the production of poultry or aquatic animals that alters input and output would increase net income, and it is necessary to develop co-culture models in paddy fields according to regional differences in the agricultural environment. Therefore, our study provides a reference for maximizing ecological and economic benefits of suitable co-culture models in rice-planted areas.