Abstract:A pot experiment under natural rainfall with three red soils developed on parental materials of red clay, sandstone and granite was investigated to estimate the maximum safe pig manure loading capacity in Ecological Experimental Station of Red Soil, Chinese Academy of Sciences. The research area represent a typical subtropical moist climate with a mean annual temperature of 18.9℃ and a rainfall of 1 946 mm. The maximum safe pig manure loading capacities of the three soils were estimated by monitoring NH4+-N, NO3–-N and total phosphorus in leaching water, the peanut production and the accumulation of available nutrients in the soil from 2012 to 2014. The results showed that the maximum safe application rate of pig manure was P 100 kg/(hm2×a) for red clay soil, and P 50 kg/(hm2×a) for sandstone and granite soils with half of conventional chemical fertilizers from the viewpoint of groundwater and soil environment protection. From the viewpoint of crop production, the safe application rate of pig manure should be no more than P 100 kg/(hm2×a) for red clay soil, and P 200 kg/(hm2×a) for sandstone and granite soils. Taking economic interests and environmental impacts into account, the maximum safe pig manure loading capacity could be P 100 kg/(hm2×a) for red clay soil, and P 50 kg/(hm2×a) for sandstone and granite soils with half of conventional chemical fertilizers, equivalent of 24 000 kg/(hm2×a) and 12 000 kg/(hm2×a) of fresh pig manure with moisture of 69%.