沼液与园林废弃物共堆肥下的氮素转化及其微生物作用机制  

Nitrogen transformation and its microbial mechanism under co⁃composting of biogas slurry with garden waste

作　　者：梁晓烽 王虹 李玉中[3] 杨睿 张冬冬 周晚来 戚智勇 林伟 LIANG Xiaofeng;WANG Hong;LI Yuzhong;YANG Rui;ZHANG Dongdong;ZHOU Wanlai;QI Zhiyong;LIN Wei(College of Mechanical Engineering,Chengdu University,Chengdu 610106,China;Institute of Urban Agriculture,Chinese Academy of Agricultural Sciences,Chengdu 610213,China;Environmental Stable Isotope Lab,Institute of Environment and Sustainable Development in Agriculture,Chinese Academy of Agricul-tural Sciences,Beijing 100081,China)

机构地区：[1]成都大学机械工程学院,成都610106 [2]中国农业学院都市农业研究所,成都610213 [3]中国农业科学院农业环境与可持续发展研究所环境稳定同位素实验室,北京100081

出　　处：《应用生态学报》2023年第7期1745-1753,共9页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(41271526);四川省科技项目(2022YFN0028,2023YFQ0065);中国农业科学院科技创新工程项目(ASTIP)资助。

摘　　要：我国每年产生大量的园林废弃物,外加尿素和菌剂的堆肥方式使其可以被大量处置和循环利用,但该方法存在严重的氮素损失和环境问题。沼液含有一定的氮源和微生物,理论上可以作为尿素和菌剂的替代物从而减少氮素损失。本研究设置了沼液+园林废弃物(GB)、沼液+园林废弃物+尿素(GBU)和沼液+园林废弃物+尿素+菌剂(GBUM)处理,研究堆肥过程的腐熟、氮素转化及损失情况。结果表明:与GBU和GBUM处理相比,GB处理的高温期更长且更稳定,同时具有更适合堆肥的pH和电导率(EC)以及最高的发芽指数(221.8%)。GB处理NH_(3)和N_(2)O的排放速率分别为2.59 mg·kg^(-1)·d^(-1)和3.65μg·kg^(-1)·d^(-1),比GBU处理分别降低99.0%和50.0%,比GBUM处理分别降低99.4%和40.7%。δ^(18)O和δ^(15)NSP双同位素图谱技术分析显示,GB和GBU处理以反硝化作用为主,且GB处理反硝化作用贡献高于GBU处理,而GBUM处理以硝化作用为主;GB处理的N_(2)O还原程度(83.7%)大于GBU和GBUM处理。可见,与GBU和GBUM处理相比,GB处理的腐熟度更好、氮素损失更低,并通过增强反硝化作用的N_(2)O还原过程减少了N_(2)O排放。综上,沼液与园林废弃物可以在不受C/N与微生物的限制下直接共堆肥,这种方式既保护了环境,又节约了资源,在实际生产中可以实现废弃物的循环再利用。Large amount of garden waste is consecutively produced in China every year.The composting with urea and microbial inoculum makes it possible to dispose garden waste in large quantities.However,composting accom⁃panies with serious nitrogen loss and environmental problems.The biogas slurry contains considerable nitrogen nutrients and microorganisms,which theoretically could be used as alternative to urea and bacteria to reduce nitrogen loss,respectively.We set up three treatments of biogas slurry+garden waste(GB),biogas slurry+garden waste+urea(GBU),and biogas slurry+garden waste+urea+microbial inoculum(GBUM)to investigate the decomposition,nitrogen conversion and nitrogen loss in the co⁃composting process.The results showed that the high tempe⁃rature period of GB treatment was longer and more stable compared to that of GBU and GBUM treatments.The pH and EC value of GB treatment would benefit composting process and generated products with the highest germination index(GI)(221.8%).In addition,NH_(3)and N_(2)O emission rates in the GB treatment were 2.59 mg·kg^(-1)·d^(-1)and 3.65μg·kg^(-1)·d^(-1),respectively,being 99.0%and 50.0%lower than that in the GBU treatment and 99.4%and 40.7%lower than that in the GBUM treatment.The results ofδ^(18)O vs.δ^(15)NSP dual isotopocule plots approach analysis showed that the GB and GBU treatments were dominated by denitrification,and that the contribution of denitrification was higher in the GB treatment.In contrast,the GBUM treatment was dominated by nitrification.The degree of N_(2)O reduction in GB treatment(83.7%)was higher than the other two treatments.It was clear that GB treatment had the best maturity and lowest nitrogen loss in all treatments by enhancing the N_(2)O reduction process during denitrification to reduce N_(2)O emission.In conclusion,the biogas slurry and garden wastes could be directly co⁃composted without the limitation of C/N and microbial addition.The co⁃composting method could protect the environment and save resources leading to the recyc

关 键 词：园林废弃物 沼液堆肥 NH_(3) N_(2)O还原 δ^(15)NSP 

分 类 号：S141.4[农业科学—肥料学]