Abstract: 【Objective】 Excessive application of phosphorus has not only caused the depletion of phosphate rock resources, but also increased the risk of environmental pollution. Livestock manure has always been used as a good alternative resource for chemical phosphorus. However, due to the complex composition and various influencing factors in the transformation process of phosphorus in animal manure, its effectiveness compared to that in chemical fertilizers has long been controversial. Clarifying the phosphorus replacement value of livestock manure, and the accurate proportion of organic fertilizer phosphorus replacing chemical fertilizer phosphorus, can provide the supporting data for rational application of organic fertilizer phosphorus.【Method】In this study, composted pig manure, chicken manure, cattle manure and chemical fertilizer were selected as the research materials. The application rate of P2O5 was set at 6 levels, which were 0, 20, 40, 60, 80 and 100 mg·kg-1 dry soil, respectively. A soil column experiment was conducted to investigate the effects of phosphorus in manure and chemical fertilizer on wheat yield, phosphorus uptake and the content of soil available phosphorus. Furthermore, the relative substitution equivalent of phosphorus in three kinds of manure was statistically analyzed.【Result】 (1) The content of organic and inorganic phosphorus in the three kinds of manure varied much. The proportion of organic phosphorus accounted for 25.9%, 17.6% and 56.5% of total phosphorus in pig, chicken and cattle manures, respectively. The liable phosphorus (H2O-P and NaHCO3-P) was the main phosphorus fraction for the cattle manure, while there was more phosphorus fraction attributed to highly stable phosphorus (HCl-P) in chicken manure and pig manure. (2)There was no significant difference in grain yield between different phosphorus supply with the same application rate. The phosphorus uptake of wheat with chemical fertilizer was slightly higher than that treated with three kinds of manure.?(3) In this study, when the seasonal recovery rate of phosphorus was used as a reference index, the chemical fertilizer equivalent value in chicken, pig and cattle manures to the commercial mineral phosphorus (super phosphate) were 80.3%, 84.3% and 90.4%, respectively . The relative substitution equivalents of pig manure were 90.0%, 93.6%, 80.6%, 80.2%, when the relative substitution equivalents of three kinds of manure were calculated by using the regression function between the chemical phosphorus and grain yield, biomass, phosphorus uptake of grain or total phosphorus uptake, respectively. The relative substitution equivalents of chicken manure were 78.4%, 87.9%, 73.4%, 67.6%, and that of cattle manure were 89.6%, 99.9%, 90.0%, 87.3%. (4) Both the manure and chemical fertilizer could increase the content of available phosphorus in soil, but the manure showed a slight effect than the chemical fertilizer. 【Conclusion】 Based on the integrated methods for calculating substitution equivalent of the present experimental condition, phosphorus in pig manure can replace 85.7% of equivalent chemical fertilizer P, and chicken manure and cow manure can replace 77.6% and 91.4%, respectively.

Key words: livestock manure, phosphorus, wheat yield, phosphorus uptake and utilization, relative substitution equivalents