Abstract: To analyze the effect of straw mulching on animal husbandry, the land bearing capacity （LBC） of livestock and poultry manure gained by the pig equivalent method and the summation method comparing straw mulching with not mulching respectively were calculated. The results showed that compared with PM, the amount of manure in Heilongjiang Province and phosphorus in the manure calculated by SM increased by 37.5% and 28.5% respectively, while the amount of the nitrogen in the manure decreased by 28.8%, the LBC of the manure nitrogen increased by 40.4% （not mulching） and 9.4% （mulching）, and the LBC of the manure phosphorus decreased by 22.1% （not mulching） and 8.4% （mulching）. Straw mulching decreased the LBC of the manure nitrogen and phosphorus by 70.1%, 67.7% （PM） and 76.7%, 62.0% （SM） respectively. With straw mulching, the provincial indexes of the nitrogen and phosphorus LBC were 1.23, 1.60 （PM） and 1.34, 1.46 （SM）. And without straw mulching, the indexes of the nitrogen and phosphorus LBC were 4.10, 4.94 （PM） and 5.76, 3.85 （SM）. In the case of straw not mulching, both nitrogen and phosphorus LBC （calculated by SM and PM） of all cities in this province were more than the amount of livestock and poultry （ALP）. In the case of straw mulching, the nitrogen LBC of Hegang City, Suihua City, Daqing City and phosphorus LBC of Daqing City were less than the ALP （PM）, the nitrogen LBC of Daqing City and phosphorus LBC of Qiqihar City, Suihua City, Mudanjiang City, Daqing City were less than the ALP （SM）. Nutrients from straw mulching decreased the land bearing capacity of manure and the development potential of animal husbandry.

Key words: livestock and poultry manure, land bearing capacity, straw mulching, index of land bearing capacity