Analysis of the treatment technology and resource utilization mode of livestock and poultry manure in Northeast China

Northeast China is the main grain production base with a large planting land for the cash crops of corn, soybean and rice in China. Animal husbandry can also be the promising potential to the waste territory, rich feed resources, and environmental carrying capacity. However, the livestock manure is difficult to be returned to the farmland nearby, due to the relatively simple planting structure of crops. It is very necessary to fully utilize the organic fertilizer for the soil organic matter, in order to avoid the degradation of agricultural ecological function. This study aims to explore the application status of livestock manure treatment and utilization modes in Northeast China. A field investigation was selected from the 272 livestock and poultry farms in Heilongjiang, Jilin and Liaoning provinces. A systematic analysis was performed on the breeding livestock and inventory, the volume of livestock excrement, as well as the treatment technologies, facilities and equipment. The parameters of manure returning to farmland were finally summarized to evaluate the utilization modes of livestock manure. The results showed that dry-dung cleaning was the main cause of manure collection, accounting for 94.35% of all the modes. Composting was dominated in the treatment technology of solid manure, accounting for 86.93% of the field tests. The proportion of manure composting time of more than 30 d accounted for 92.86%, which fully met the requirements of technical specifications for livestock manure composting. The area of feces storage facilities for all kinds of livestock also met the high requirements of construction specifications for the feces resource utilization facilities of large-scale livestock farms. The liquid manure was mainly treated by manure storage, accounting for 68.18% of the investigated farms. The storage time of liquid manure from pig and poultry farms was close to 90 d, where more than 80% of dairy farms reached 180 d. The storage capacities of dairy farms were less than the standard requirements of construction specifications for the feces resource utilization facilities of large-scale livestock farms. The storage capacity should be considered from the liquid manure production volume and storage time. Corn was dominated in the planting crop in the study area, accounting for 78.13% of all crops. There was a lower area of farmland matching for manure returning at present, compared with the demand area of livestock manure land carrying capacity. The application mode of solid manure was the most in the artificial fertilization, accounting for 88.00% of the total. The application modes of liquid manure were the two most in flood irrigation and sprinkler irrigation, accounting for 54.17% and 37.50% of the total, respectively. The time of manure returning to farmland was focused mainly on two periods, March to April and September to October. The volume of manure fertilization was less than 150 m³/hm². On the whole, the technical mode of the manure resource utilization was dominated by the dry-dung cleaning with solid manure composting and liquid manure storage. The findings can provide a strong reference for the promotion and policy-making of manure treatment and resource utilization in Northeast China.