Rice-Duck Co-Culture 16S
Rice-duck co-culture is a typical green production model in paddy fields. This study evaluates its integrated effects combined with different fertilization regimes, providing a scientific basis for agricultural green development and ecological conservation in the Erhai Lake Basin. Eight treatments were established: no fertilization + no ducks (CK); no fertilization + ducks (D); Organic fertilizer (OM); Organic fertilizer + ducks (OM+D); Chemical fertilizer+ organic fertilizer (NPK+OM); Chemical fertilizer+ organic fertilizer+ ducks (NPK+OM+D); Chemical fertilizer (NPK); Chemical fertilizer+ ducks (NPK+D). Under identical fertilization conditions, duck rearing significantly increased rice yields; over the two-year period, the NPK+OM+D treatment consistently yielded the highest rice yields. Compared with the NPK+OM treatment, the NPK+OM+D treatment significantly improved the control of weeds, rice brown spot disease, and rice planthoppers, while also significantly increasing the accumulation of N, P, and K in the rice aboveground biomass. During the rice-duck co-cultivation period, there were no significant differences between duck-rearing and non-duck-rearing treatments in terms of soil ammonium nitrogen (NH4+-N), total nitrogen (TN) in surface water, and total dissolved nitrogen (TDN) concentrations. However, the available phosphorus (Olsen-P) content in the soil of the NPK+OM+D treatment (60.74 mg kg-1) was significantly higher than that of other treatments, approaching or entering the risk range for rapid phosphorus leaching. Furthermore, the concentration of total dissolved phosphorus (TDP) in surface water also increased significantly during the co-cultivation period. While high nutrient supply ensures high yields, the risk of phosphorus leaching must also be considered. While the NPK+OM+D treatment achieves high rice yields and promotes green pest, disease, and weed control, it must be accompanied by precise water and fertilizer management measures to reduce the risk of non-point source pollution. This approach provides a scientific basis for the green development of agriculture and ecological conservation in the Erhai Lake basin.