黑土长期定位试验原状土搬迁对土壤微生物性质的影响

Effect of black soil long- term test undisturbed soil moved on soil microbial properties

通过测定黑土长期定位试验原状土整体搬迁前后四种处理（CK、NPK、M、MNPK）土壤可培养微生物数量、土壤微生物量含量及土壤酶活性变化,探讨搬迁的特定条件对土壤微生物性质的影响。结果表明,①搬迁前后5年各处理三大类微生物数量、微生物量碳、氮含量和四种土壤酶活性在0～20 cm土层中均高于20～40 cm土层;②每年在两个土层中MNPK处理的三大类微生物数量和微生物量碳、氮含量均最高,CK处理均最低,而每年在两个土层中土壤过氧化氢酶和转化酶活性CK和M处理均明显高于NPK和MNPK处理,而磷酸酶活性CK和M处理则低于NPK和MNPK处理,脲酶活性在4个处理中差异不大;③比较搬迁前后5年间各项微生物指标变化发现,各项指标年际间虽存在变化但程度不大,搬迁后2011年和2012年相对较高,同为小麦茬的搬迁前2010年和搬迁后2013年各项指标较为接近。研究说明,土壤深度和施肥对土壤各项生物指标影响较大,年际间变化也受到轮作方式的影响,搬迁对土壤微生物扰动影响远小于施肥和耕作方式等的影响。

In this study, we examined the changes in soil culturable microbial amount, soil microbial biomass content and soil enzyme activity in two soil layers （0-20 cm, 20-40 cm） with four treatments （CK, NPK, M, MNPK） in the before and after the black soil long-term test undisturbed soil moving, discussed the influences of the moving on soil microbial properties. The results showed that： ① In five years before and after the move, three categories of microorganism amount, microbial biomass C, N content and four kinds of soil enzyme activities of all the treatments in 0-20 cm soil layer were higher than those in 20-40 cm soil layer. ② In five years before and after the move, three categories of microorganism amount and microbial biomass C, N content of MNPK treatments were the highest in both soil layers, those of CK treatments were the lowest, and catalase and invertase activity of NPK and MNPK treatments were significantly lower than those of CK and M treatments in both soil layers, while phosphatase activity of NPK and MNPK treatments were higher than those of CK and M treatments, urease activity in the four treatments had little difference. ③ Comparing the changes of the microbial indicators in five years before and after the move, found that interannual changes of the microbial indicators were not large, the microbial indicators of after moving 2011 and 2012 were relatively high, and the microbial indicators of before moving 2010 and after moving 2013 as wheat stubble were similar. Based on the above results showed that, the influences of soil depth and fertilization on the microbial indicators were larger, and the influences of the interannual changes by the rotation systems, so the disturbance influences of the moving on soil microorganism were far less than the influences of fertilization, farming methods and so on.