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以东北耕作黑土为研究对象,在25℃和70%WHC水分条件下进行为期35天的室内培养试验,研究了施用猪粪条件下重金属Cu、Cd对土壤氮素净转化的影响。结果表明:添加单一重金属显著抑制了土壤的硝化作用和矿化作用。与对照处理相比,添加重金属Cu、Cd处理培养结束后土壤铵态氮含量分别增加了5.83和5.39倍,硝态氮含量分别下降了84.3%和79.5%,且土壤净氮矿化速率和净硝化速率均显著低于对照处理。添加重金属的同时施用猪粪加剧了重金属对硝化作用和矿化作用的抑制,土壤净硝化速率和净氮矿化速率均显著低于单一重金属处理。添加重金属抑制了土壤反硝化作用,但同时添加猪粪在一定程度上降低了重金属离子的活性和毒性,进而减轻重金属离子对反硝化作用的抑制程度。
Taking cultivated black soil of northeast China as the research object, 35-day laboratory culture experiment was conducted at 25 ℃ and 70% WHC to study the effects of heavy metals Cu and Cd on net nitrogen transformation of soil under pig manure application. The results showed that adding a single heavy metal significantly inhibited soil nitrification and mineralization. Compared with the control treatment, the contents of ammonium nitrogen in soil increased by 5.83 and 5.39 times, and the content of nitrate nitrogen decreased by 84.3% and 79.5% respectively after the treatment with heavy metals Cu and Cd, and the net nitrogen mineralization rate and net Nitrification rates were significantly lower than the control treatment. The application of heavy metals to pig manure exacerbated the inhibition of nitrification and mineralization by heavy metals. The rates of net and net N mineralization were significantly lower than those of single heavy metals. Adding heavy metals inhibited soil denitrification, but adding pig manure at the same time reduced the activity and toxicity of heavy metal ions to a certain extent, and then reduced the inhibition of heavy metal ions on denitrification.