秸秆与生物质炭施用对土壤温室气体排放的影响差异

采用室内培养试验,向土壤中添加小麦秸秆和不同量生物质炭,同时比较探究秸秆与生物质炭施用对土壤温室气体排放及微生物活性的影响差异。试验共设5个处理:土壤(S)、土壤+1%小麦秸秆(WT)、土壤+1%生物质炭(BC1)、土壤+2%生物质炭(BC2)和土壤+4%生物质炭(BC4)。在培养期内,施秸秆处理土壤CO2排放量比对照处理S显著增加约12.60%~2005.63%,而施生物质炭处理降低约51.49%~97.93%。施秸秆处理的温室气体增温潜势(GWP)是对照处理S的1.12~19.24倍,而施生物质炭处理,即处理BC1、BC2和BC4的GWP分别降低了0.27%~64.06%,15.78%~94.01%和29.43%~92.28%。小麦秸秆施用会明显增加土壤温室气体排放,增加温室效应;而添加生物质炭对土壤CO2、N2O排放表现出一定的抑制作用,并明显减弱温室气体增温潜势,即生物质炭能明显减弱温室效应。添加小麦秸秆促进土壤微生物生物量碳的增加,提高FDA水解酶、脲酶、过氧化氢酶、磷酸酶活性;生物质炭施用一段时间后对土壤过氧化氢酶活性表现为显著激活作用。

Effects of Biochar and Wheat Straw Returning on Soil Greenhouse Gases Emission

Global warming has become one of the most serious environmental problems to human beings, and soil is an important source of greenhouse gas emissions. The application of wheat straw and biochar to soil plays an important role in soil carbon and nitrogen conversion and micro-gas metabolism; however, few studies have focused on the soil microbial activity and soil greenhouse gas emission by the application of wheat straw and biochar. This study adopted an indoor culture experiment, using soil added by wheat straw and biochar, to explore the effects of wheat straw and biochar on soil greenhouse gas emission and soil microbial activity. Five treatments were set up, that is, soil (S), soil+1% wheat straw (WT), soil+1% biochar (BC1), soil+2% biochar (BC2), soil+4% biochar (BC4). The results showed that the addition of wheat straw significantly increased the amount of greenhouse gas emissions in the soil, the application of wheat straw presented a sizable contribution to the greenhouse effect according to the dynamics of global warming potential (GWP).With the increase of culture time, the addition of biochar showed a certain inhibitory effect on soil N₂O emission. The addition of wheat straw could promote the increase of soil microbial biomass carbon to a certain extent, and promote the activities of FDA hydrolysis, urease, catalase, and phosphatase. The soil catalase activity was significantly activated by the application of biochar after a certain period.