Livestock feces pollution evaluation and grazing capacity prediction in Gansu province

The present study evaluated the environment impacts of livestock feces and estimated the quantity capacity of livestock development space in the future by calculating and analyzing data between 2001 and 2010 in Gansu Province. The gross of livestock feces gradually increased. The amounts of livestock discharge varied in different cities and the capacity of livestock feces in each hectare had reached the maximum. The worse part is that cultivated land soil had been polluted in some cities. The influence of livestock increased gradually and presented various effects in different cities. Compared with COD, TN and TP of livestock excrement and urine were main pollutants of the water body. The warning value analysis indicated that livestock feces pollution in Gansu was not serious although it was imbalanced in different area. The livestock had overloaded in some cities like Jiayuguan City, however, cities like Gannan and Dingxi have larger development space.