氮素形态配比对添加玉米秸秆白浆土微生物学特性的影响

探讨了不同氮素形态配比(铵态氮∶硝态氮为4∶1、1∶1、1∶4)对添加玉米秸秆白浆土酶活性以及微生物生物量碳、氮含量的影响,以期筛选对于白浆土微生物学特性有优化作用的最佳氮素形态配比。结果表明,随培养时间增加,添加玉米秸秆的所有铵态氮与硝态氮配比处理白浆土的脲酶、碱性磷酸酶、蔗糖酶、蛋白酶和过氧化氢酶活性以及微生物生物量碳、氮含量均表现为先增加后降低的趋势。与培养初始时相比,培养结束时,除了过氧化氢酶活性有较大程度提高外,其余酶活性及微生物生物量碳、氮含量均不同程度地下降。与其他2个处理相比,铵硝等比例混合处理土壤脲酶、碱性磷酸酶、蔗糖酶和蛋白酶活性以及微生物生物量碳、氮含量的下降程度在一定程度上得到缓冲;同时,其对过氧化氢酶活性的促进作用更强。比较培养初始和培养结束时的结果可知,以硝态氮为主的处理对添加玉米秸秆白浆土的脲酶、蔗糖酶活性及微生物生物量氮含量有较强的抑制作用,而以铵态氮为主的处理则对碱性磷酸酶、蛋白酶、过氧化氢酶活性及微生物生物量碳含量有较强的抑制作用。

Effect of Ratios of Nitrogen Forms on Microbiological Characteristics of Albic Soil Amended with Corn Stalk

The effect of different ratios of two N forms(NH+4-N∶NO-3-N were designed for 4∶1,1∶1,1∶4 respectively) on the enzyme activities and microbial biomass carbon(C) and nitrogen(N) contents of albic soil amended with corn stalk was studied,so as to select the best ratio for optimizing the soil microbiological characteristics.The results showed that with the increase of incubation time,the urease,alkaline phosphatase,sucrase,protease,catalase activities and microbial biomass C,N contents of albic soil amended with corn stalk treated by the three ratios of NH+4-N to NO-3-N increased first and then declined.Compared with 0 d,after incubation for 180 d,except the catalase activity got a significantly promotion,the other enzyme activities and microbial biomass C,N contents decreased at different degrees.Compared with the others treatments,the treatment with NH+4-N∶NO-3-N of 1∶1 had a cushioning effect on the declining trend of urease,alkaline phosphatase,sucrase,protease activities and microbial biomass C,N contents to some extent,simultaneously had a stronger promotion on the catalase activity.Compared the results of 0 d and 180 d,the treatment with NH+4-N∶NO-3-N of 1∶4 that NO-3-N dominated in the N supply had an strong inhibitory effect on the urease,sucrase activities and microbial biomass N content of albic soil amended with corn stalk,while the treatment with NH+4-N∶NO-3-N of 4∶1 that NH+4-N dominated in the N supply had an strong inhibitory effect on the alkaline phosphatase,protease,catalase activities and microbial biomass C content.