Analysis On The Substitution Potential Of Livestock And Poultry Waste To Chemical Fertilizer

Anhui is a major province of planting and livestock and poultry breeding in China,with large consumption of chemical fertilizer and rich manure resources.The temporal and spatial distribution characteristics of the quantity of manure resources,the amount of returning land and the nutrient demand of crops are not clear.The potential of manure returning and chemical fertilizer reduction is not clear.Returning livestock and poultry waste to the field is the main measure to realize the resource utilization of waste,promote the reduction of chemical fertilizer,save cost and increase efficiency,and it is also an important way to promote the green and sustainable development of agriculture.It is of great significance to study the application of chemical fertilizer and crop nutrient absorption at different regional levels from temporal and spatial scales,and to grasp the characteristics of distribution and utilization of nutrient resources in different regions,so as to provide countermeasures and basis for rational distribution and efficient utilization of livestock and poultry nutrient resources and fertilizer reduction.This paper collates a large number of statistical yearbook data and documents of Anhui Province and 16 cities from2000 to 2020.The changing trend and development status of livestock and poultry and planting industry were analyzed from the point of view of time and space.The substitution potential of livestock and poultry waste to chemical fertilizer was discussed.Based on the crop nutrient demand,the chemical fertilizer reduction amount and fertilizer reduction potential of different regionswere estimated.The main conclusions are as follows:（1）Compared with 2000,crop nutrient demand and chemical fertilizer application reached 272.1×10⁴t and 289.9×10⁴t respectively in 2020,an increase of 39.3%and 14.5%respectively.Based on nutrient demand,in 2020,the excessive use of chemical fertilizers was 17.8×10⁴t.The application of chemical fertilizer in agricultural land in 11 cities has a certain potential to reduce chemical fertilizer.（2）Compared with 2000,the total nutrients in livestock manure and urine in 2020 was41.0×10⁴t,among which,N 19.7×10⁴t,P 6.3×10⁴t,K 15.1×10⁴t.When all waste resources are returned to the field,the replacement potential of manure is 14.1%.Livestock waste N,P₂O₅and K₂O nutrients can replace 15.2%,6.4%and 24.3%of chemical fertilizer consumption respectively.Anhui province has a large amount of waste resources and great potential to replace chemical fertilizer.（3）Compared with 2000,the surplus of chemical fertilizer in Anhui Province in 2020was 35.31×10⁴t,a decrease of 66.5%.The excessive input of nitrogen fertilizer and phosphorus fertilizer in Anhui Province was 28.11×10⁴t and 61.68×10⁴t respectively.On the whole,the crop yield of our province has increased steadily in recent years,and the utilization efficiency of chemical fertilizer has been improved,so the application of chemical fertilizer has a certain potential to reduce application.