5种前期水分处理下黑土氮素矿化及硝化反硝化率的变化

摘要

A incubation experiment is conducted to investigate the black soil after five different water pretreatments (air-dried soil D,fresh soil O,low moisture soil W1,high moisture W2 and flooded soil S),and the mineralization,nitrification and denitrification rates under four different instant moisture are determined.The results show that the difference of the nitrogen mineralization,nitrification and denitrification rates under the five pre-treatments is great when the soil water content is respectively.Although the difference of the mineralization rates is not significant,the changes of nitrification rate and denitrification rate are obvious under the five pre-water treatments.The performance of nitrification rate is W1 ＞ O ＞ W2 ＞ S ＞ D,and the rate of denitrifica tion is opposite to the rate of nitrification.It is showed that the history of soil moisture has a strong influence on nitrification and denitrification,while the effect on mineralization is small.It is indicated that the antecedent water treatment makes a certain effect on nitrogen transformation.%室内培育实验研究5种不同水分前处理下的黑土(风干土D、保鲜土O、低水分土W1、高水分土W2、淹水土S),在4种不同含水量条件下的矿化率、硝化率及反硝化率变化.结果显示,5种前处理下黑土氮素矿化率、硝化率及反硝化率分别在土壤水含量为60％ WHC、80％ WHC和100％ WHC时差异明显.虽然在4种不同水分含量下,经5种不同水分前处理的土壤矿化率差异不显著,硝化率及反硝化率差异较为显著.硝化率表现为W1＞O＞W2＞S＞D,反硝化率与硝化率的表现截然相反.这表明,土壤水分历史对硝化反硝化有影响,而对矿化作用的影响不大,水分前处理影响土壤氮素转化.