Abstract: In order to make clear the discharged amount, pollution status, and biogas-producing potential of the livestock and poultry excrements in China, the main parameters for estimation were ascertained based on relevant references, and the discharged amount, pollutant contents, and farmland loading of the excrements in 2009 were estimated, according to the related statistic data. The farmland loading of the excrements nitrogen and phosphorus was assessed by alarming values and classification grades, and the biogasproducing potential of the excrements was predicted. In 2009, the discharged amount of the excrements in China was 330 million tons, with 72.7 million tons of BOD and 80.4 million tons of COD, and the average farmland loading of the excrements was 26.8 kg·hm^-2, with the nitrogen and phosphorus loadings being 158.42 kg·hm^-2 and 47.92 kg·hm^-2, respectively. The alarming and classification grading showed that the livestock and poultry breeding industry in China had little effects on the environment in pastoral areas, but the manure nitrogen caused varying degrees of environmental pollution in rural areas except those in Shanxi and Heilongjiang provinces, and the manure phosphorus pollution existed in all rural areas. The biogasproducing potential of the excrements was 1.2×10¹¹ m³, and that in large- and medium-sized livestock and poultry breeding farms was responsible for 2.4×10¹⁰ m³, corresponding to about 1.35×10¹⁰ m³ of natural gas. To fully use the excrements for biogas production would be an important way for environmental protection and energy source structural adjustment.

Key words: covariance analysis, canonical correspondence analysis, distribution pattern, growth form, karst.