【作者】 张毅；

【导师】 陈玉香；

【作者基本信息】 吉林大学 ， 农业生物环境与能源工程， 2024， 硕士

【摘要】 随着中国现代农业的发展,每年会产生大量的秸秆和畜禽粪便,秸秆难以降解的特点以及畜禽粪便的污染性,引发了一系列严重的环境问题,寻求这些农业废弃物的合理开发与利用,是农业面临的重要难题。蚯蚓堆肥因其能耗较低、管理简易的优点,在当前堆肥研究中引起了极大的关注,在蚯蚓堆肥中添加生物炭可以改善堆肥底物理化性质、酶活力以及微生物群落,然而生物炭的不同添加时间以及不同添加量会对堆肥产生不同的影响,目前关于这一方面的研究相对较少。本论文通过在第0、15、30天分别添加5%、10%、15%的生物炭于常规堆肥和蚯蚓堆肥中,共设置24个试验组,进行了堆肥过程中氮代谢相关理化性质、酶活力、NH₃和N₂O排放量、微生物群落的分析研究。主要研究结果如下:（1）生物炭导致蚯蚓堆肥前期的p H值升高,电导率先上升后波动,生物炭处理组EC值变化范围为672-1035μs cm^-1,碳氮比提高,且下降速率高于对照组。生物炭提高了蚯蚓堆肥全氮、铵态氮（NH₄⁺-N）、硝态氮（NO₃^--N）的含量,降低了中期亚硝态氮（NO₂^--N）的含量,提高了蚯蚓堆肥可溶性有机氮的含量,第30天添加10%的生物炭可溶性有机氮含量为900 mg kg^-1。生物炭提高了蚯蚓堆肥第45天的微生物量氮含量,第0天添加15%生物炭的分组在第30天微生物量氮含量为454.88 mg kg^-1。（2）生物炭的添加提高了蚯蚓堆肥前期氨单加氧酶的活力、羟胺氧化还原酶以及亚硝酸盐氧化还原酶的活力,其中第0天添加15%生物炭处理的AMO活力在第7天时提高了约11%,羟胺氧化还原酶的活力在第15天时提高了10%,亚硝酸盐氧化还原酶活力在整个堆肥期间均得到提升。生物炭抑制了硝酸盐还原酶的活力,第0天添加15%生物炭处理的硝酸盐还原酶活力在第15天时为2.35 mg kg^-1h^-1。生物炭提高了蚯蚓堆肥脲酶的活力,第0天添加5%的生物炭在第30天的脲酶活力为4052 mg kg^-1 h^-1。同时,生物炭的添加降低了蚯蚓堆肥前中期转化酶的活力。（3）第0天添加15%的生物炭,蚯蚓堆肥的NH₃排放量减少了约70%,累积排放量为3 g m^-2,明显低于对照组的10 g m^-2。第15天添加10%的生物炭减少了蚯蚓堆肥约60%的N₂O排放。（4）生物炭提高了蚯蚓堆肥的微生物群落多样性,第30天添加10%生物炭处理的Shannon指数逐渐增大,Simpson指数逐渐缩小。优势菌属中,Nitrosospira和norank＿f＿Nitrosomonadaceae占据主导地位。第30天添加10%的生物炭增加了蚯蚓堆肥Nitrosospira的相对丰度,有利于硝化反应的进行。更多还原

【Abstract】 With the development of modern agriculture in China,a large amount of straw and animal manure will be produced every year.The characteristics of straw that are diffi-cult to degrade and the polluting nature of animal manure have triggered a series of serious environmental problems,and the search for the rational development and utili-zation of these agricultural wastes is an important problem faced by agriculture.Ver-micomposting has attracted great attention in current composting research because of its low energy consumption and easy management.Adding biochar to vermicomposting can improve the physical and chemical properties,enzyme activity,and microbial com-munity of the compost bottom,however,different adding times and different adding amounts of biochar will have different effects on the compost,and the current research on this aspect is relatively small.In this thesis,the physical and chemical properties of nitrogen metabolism,en-zyme activity,NH₃,and N₂O emissions,and microbial communities were analyzed by adding 5%,10%,and 15%of biochar to conventional compost and vermicompost on the 0th,15th,and 30th days,respectively,with a total of 24 experimental groups.The main research results were as follows:（1）Biochar led to an increase in p H and a fluctuation in electrical conductivity in the pre-composting period of vermicomposting,and the electrical conductivity value of the biochar-treated group varied in the range of 672-1035μs cm^-1,and the carbon to nitrogen ratio increased and decreased at a higher rate than that of the control group.Biochar increased the content of total nitrogen,ammonium nitrogen（NH₄⁺-N）and ni-trate nitrogen（NO₃^--N）in vermicompost,decreased the content of nitrite nitrogen（NO₂^--N）in the middle period,and increased the content of soluble organic nitrogen in vermicompost,and the content of soluble organic in vermicompost with the addition of10%biochar on the 30th day was 900 mg kg^-1.Biochar increased the content of micro-bial biomass nitrogen in vermicompost on the 45th day.The microbial biomass nitrogen of vermicompost was 454.88 mg kg^-1 on day 30 for the subgroup with 15%biochar added on day 0.（2）The addition of biochar increased the activity of ammonia monooxygenase,hydroxylamine oxidoreductase and nitrite oxidoreductase in the pre-composting period of vermicomposting in the group of earthworms,in which the activity of ammonia monooxygenase was increased by about 11%on day 7,the activity of hydroxylamine oxidoreductase by 10%on day 15,and the activity of nitrite oxidoreductase was in-creased throughout the whole composting period.nitrite oxidoreductase vigor was en-hanced throughout the composting period.Biochar inhibited nitrate reductase activity,which was 2.35 mg kg^-1 h^-1 at day 15 with 15%biochar on day 0.Biochar increased urease activity in vermicomposted earthworms,which was 4,052 mg kg^-1 h^-1 at day 30with 5%biochar added on day 0.At the same time,the addition of biochar decreased the activity of urease in the first and middle stages of vermicomposting.the activity of the enzyme in the pre-composting phase of vermicomposting.（3）The addition of 15%biochar on day 0 reduced NH₃ emissions from vermicom-posting by about 70%,with a cumulative emission of 3 g m^-2,which was significantly lower than that of the control group of 10 g m^-2.10%biochar on day 15 reduced N₂O emissions from vermicomposting by about 60%.（4）Biochar increased the diversity of microbial communities in vermicompost.Shannon index gradually increased and Simpson index gradually decreased in the 10%biochar treatment on day 30.Among the dominant genera,Nitrosospira and nor-ank＿f＿Nitrosomonadaceae dominated.The addition of 10%biochar on day 30 in-creased the relative abundance of Nitrosospira in the vermicompost and favored the nitrification reaction.更多还原