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

Abstract

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.