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CN-122010603-A - Livestock and poultry solid manure aerobic composting process capable of reducing nitrous oxide production

CN122010603ACN 122010603 ACN122010603 ACN 122010603ACN-122010603-A

Abstract

The invention relates to a livestock and poultry solid manure aerobic composting process for reducing nitrous oxide production, belonging to the technical field of agriculture. The invention provides an aerobic composting process for reducing the production of nitrous oxide from livestock and poultry solid manure, which comprises the following steps of mixing the livestock and poultry solid manure with auxiliary materials, regulating the C/N ratio and the water content to obtain a mixed matrix, adding nitrifying bacteria agent and denitrification inhibitor into the mixed matrix, mixing to form a pile body, covering a molecular film above the pile body, arranging an aeration device at the bottom of the pile body for aerobic composting, and ending composting when the pile body temperature is less than or equal to 40 ℃, the water content is less than or equal to 30% and the seed germination index is more than or equal to 70%. According to the invention, the molecular film is covered, coupled with nitrification and denitrification treatment to optimize the livestock and poultry manure aerobic compost, the denitrification inhibitor is used for reducing the nitrite reduction effect, nitrites are enhanced to be converted into nitrate by nitrites, finally the emission of N 2 O is reduced, the nitrogen loss is reduced, the humification effect is enhanced, and the humus stability is improved.

Inventors

  • LI YAYING
  • ZHANG KUN
  • ZHOU CHANGMIN
  • SUN LILI
  • WU HANGTAO
  • YANG MINGHUI
  • GU WENJIE
  • LU YUSHENG
  • SHI CHAOHONG
  • ZHENG YANLING
  • XIE KAIZHI
  • WANG DAN
  • LIU CHONG
  • PENG HUANLONG

Assignees

  • 广东省农业科学院农业资源与环境研究所

Dates

Publication Date
20260512
Application Date
20260128

Claims (10)

  1. 1. The livestock and poultry solid manure aerobic composting process for reducing nitrous oxide production is characterized by comprising the following steps of: (1) Mixing the livestock and poultry solid manure with auxiliary materials, and adjusting the C/N ratio and the water content to obtain a mixed matrix; (2) Adding nitrifying bacteria agent and denitrification inhibitor into the mixed matrix obtained in the step (1) to mix to form an aerobic fermentation pile, covering a molecular film above the aerobic fermentation pile, and setting an aeration device at the bottom of the aerobic fermentation pile to perform aerobic composting, wherein the composting is finished when the temperature of the aerobic fermentation pile is less than or equal to 40 ℃, the water content is less than or equal to 30% and the seed germination index is more than or equal to 70%.
  2. 2. The process of claim 1, wherein in step (1), the mixed matrix has a C/N ratio of C: n= (16-30): 1 and a water content of 55-63%.
  3. 3. The process of claim 1, wherein in step (1), the adjunct comprises at least one of mushroom residue, rice hulls, straw, sawdust, and wheat straw.
  4. 4. The process of claim 1, wherein in step (2), the nitrifying bacteria agent comprises an oxidative nitrification-promoting bacteria species.
  5. 5. The process of claim 1, wherein in step (2) the nitrifying bacteria agent is added in an amount of 0.3-0.7g nitrifying bacteria agent per 100g dry weight of mixed matrix.
  6. 6. The process of claim 1, wherein in step (2), the denitrification inhibitor comprises sodium diethyldithiocarbamate.
  7. 7. The process of claim 1, wherein in step (2), the denitrification inhibitor is added in an amount of 0.3 to 0.7g per 100g dry weight of the mixed matrix.
  8. 8. The process according to claim 1, wherein in the step (2), the aeration amount in the aerobic compost is 0.2 to 0.3L/min per kg of mixed substrate.
  9. 9. Use of the process according to any one of claims 1-8 for composting to reduce nitrous oxide emissions.
  10. 10. Use of a process according to any one of claims 1 to 8 for increasing the humification level of compost products and/or increasing the germination rate of seeds.

Description

Livestock and poultry solid manure aerobic composting process capable of reducing nitrous oxide production Technical Field The invention relates to the technical field of agriculture, in particular to a livestock and poultry solid manure aerobic composting process for reducing nitrous oxide production. Background In the aerobic fermentation process, the pH value is increased due to the degradation of protein, and partial anaerobic areas in the heap body are generated, so that nitrogen in the raw materials can be easily dissipated in the form of gaseous ammonia, nitrous oxide and the like, on one hand, the ammonia dissipation causes environmental problems such as odor pollution and the like on the periphery, the generation of nitrous oxide aggravates the greenhouse effect, and on the other hand, the problems such as low nutrient content, poor fertilizer efficiency and the like in the finished organic fertilizer are caused. Based on the nitrogen cycling mechanism, the N 2 O and N 2 forms of nitrogen loss from the aerobic composting process mainly resulted from denitrification, where the warming effect of N 2 O was 273 times that of CO 2 in the sixth IPCC assessment report (IPCC 2022). In order to reduce nitrous oxide emission of material nitrogen in the agricultural solid waste treatment process and ensure nutrient preservation of the organic fertilizer, the production of N 2 O should be controlled by mainly utilizing the regulation and control of nitrification and denitrification reaction. Most of the existing livestock and poultry solid manure aerobic composting emission reduction technologies are physical adsorption or chemical treatment, wherein the physical adsorption has the problem of re-release after the site occupation is complete, and the chemical treatment is easy to bring secondary pollution. In addition, the emission is reduced, the smooth proceeding of the aerobic fermentation is difficult to ensure in the prior art, part of humification reaction is sacrificed, and the quality of the finished organic fertilizer is reduced. Therefore, how to reduce the generation of N 2 O and ensure the sufficient humification degree of the compost in the process of aerobic composting of solid manure of livestock and poultry is a technical and technological difficulty at present. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide an aerobic composting process for livestock and poultry solid manure, which reduces nitrous oxide production. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: In a first aspect, the present invention provides an aerobic composting process for reducing nitrous oxide production comprising the steps of: (1) Mixing the livestock and poultry solid manure with auxiliary materials, and adjusting the C/N ratio and the water content to obtain a mixed matrix; (2) Adding nitrifying bacteria agent and denitrification inhibitor into the mixed matrix obtained in the step (1) to mix to form an aerobic fermentation pile, covering a molecular film above the aerobic fermentation pile, setting an aeration device at the bottom of the aerobic fermentation pile to perform aerobic composting, and ending composting when the temperature of the aerobic fermentation pile is less than or equal to 40 ℃, the water content is less than or equal to 30%, and the seed germination index is more than or equal to 70%. According to the invention, the molecular film is covered, coupled with nitrification and denitrification treatment to optimize the aerobic composting of the livestock and poultry manure, the denitrification inhibitor is used for reducing the reduction effect of nitrite, and nitrites are enhanced to convert the nitrite into nitrate, so that the emission of N 2 O is finally reduced, the nitrogen loss is reduced, the humification effect is enhanced, and the stability of humus is improved. As a preferred embodiment of the process according to the invention, in step (1), the mixed matrix has a C/N ratio of CN= (16-30): 1 and a water content of 55-63%. In the invention, the C/N ratio refers to the absolute mass ratio of the total carbon element (C) to the total nitrogen element (N) in the material. As a preferred embodiment of the process according to the invention, in step (1), the mixed matrix has a C/N ratio of C: N= (18-28): 1 and a water content of 58-62%. As a preferred embodiment of the process according to the invention, in step (1), the mixed matrix has a C/N ratio of C: N= (20-25): 1 and a water content of 59-60%. The mixed matrix C/N ratio can also be at least one of 21:1, 22:1, 23:1 and 24:1 (C: N), and the water content is 60%. As a preferred embodiment of the process of the invention, in the step (1), the C/N ratio of the auxiliary material is C: N= (25-30): 1, the water content of the auxiliary material is 20-40%, As a preferred embodiment of the process of the present invention, in the step (1), the auxil