RESUMO
Based on the livestock statistical data, the nutrient content of livestock manure was calculated and the nutrient transformation from livestock manure to farmland was realized by using the method of spatializing livestock manure nutrient. On this basis, this paper calculated nitrogen load of livestock manure combining with the area of farmland and realized the estimation of nitrogen load of livestock manure and potential pollution evaluation in landmass for unit taking Daxing District in Beijing as an example. The result showed that the average, minimum and maximum nitrogen loads of farmland were 214.02 kg/hm2, 10.64 kg/hm2 and 5996.26 kg/hm2 respectively and near half of farmland was threaten by nitrogen load of livestock manure, accounting for 42.14% of the total farmland. These farmland threaten to polluted had the characters of small area and few nutrient demand and mainly located nearby the inhabitant and the scale raising. The coefficients of variation and average of available nitrogen in topsoil and subsoil were 64.3%, 53.65% and 65.93 microg/g, 45.25 microg/g respectively and the enrichment coefficient was 1.46, which explained the existing pollution risk and the influence degree of livestock manure to soil environment pollution.
