氯化苦熏蒸处理对土壤氮矿化和硝化作用的影响

结合室内培养和田间试验定量研究了氯化苦熏蒸对土壤氮矿化及硝化作用的影响。通过测定室内氯化苦处理20周内土壤中矿质态氮的含量,得出在前11周内土壤中NH4+-N含量一直增加,硝化作用过程受到明显抑制。11周后硝化作用微生物逐渐恢复,硝化作用受抑制程度减弱,NH4+-N含量开始减少;进行室内氯化苦不同浓度处理,随着处理浓度的增加,土样中NH4+-N含量也依次增加。田间氯化苦熏蒸处理后部分土壤微生物被杀死,使得土壤微生物体内有机态氮转化为无机态氮,短期内能增加土壤中矿质态氮含量。田间不同地块氯化苦熏蒸处理后NH4+-N和矿质态氮含量均有升高,并随着施药量的增加土壤中NH4+-N和矿质态氮也逐渐增加。

Effect of Chloropicrin on Soil Nitrogen Mineralization and Nitrification

Soil fumigation has profound effects on N mineralization and nitrification.A quantification of effects on N mineralization and nitrification can be used to optimize N fertilizer advice.Soil mineral N was quantified through lab incubation and field experiment.The concentration of NH_4~+-N increased during the first 11 weeks in lab after chloropicrin fumigation.Nitrification was strongly inhibited.Nitrifying organisms tended to recover and the concentration of NH_4~+-N decreased after 11 weeks.The concentration of NH_4~+-N increased as the concentration of chloropicrin increased in a short term lab study.The concentration of NH_4~+-N and mineral N also increased in field after chloropicrin fumigation on two experimental sites.Theconcentration of NH_4~+-N and mineral N also increased with the dosage of chloropicrin increased in field experiment.