马尾松凋落物对土壤氮循环与微生物的影响

The Effects of Litters from Pinus massoniana Lamb.on Nitrogen Cycle and Microbes in Soil

为研究马尾松凋落物对土壤氮循环与微生物的影响,本文采用原位分解和室内化验相结合的方法,连续4年研究了年份和季节马尾松凋落物分解过程中土壤氮转化和微生物活性及其二者的交互作用。结果表明:(1)随着季节的变化,不同年份马尾松凋落物的分解系数呈一致的变化规律,均表现为秋季和夏季高于春季和冬季。相同季节马尾松凋落物的分解系数随着年份的增加而增加,而不同年份春季和秋季马尾松凋落物分解系数基本相等,说明年份对马尾松凋落物分解系数的影响主要集中在夏季和秋季;(2)不同年份马尾松凋落物分解过程中土壤氮含量、微生物量氮含量和氮转化率均表现为秋季和夏季高于春季和冬季,相同季节马尾松凋落物分解过程中土壤氮含量、微生物量氮含量和氮转化率随着年份的增加而增加,而不同年份春季和秋季基本相等;(3)不同年份马尾松凋落物分解过程中土壤微生物酶活性(脲酶、蛋白酶、硝酸还原酶、亚硝酸还原酶、天冬酰胺酶和N-乙酰氨基葡萄糖核苷酶)、土壤微生物呼吸(自养呼吸、异养呼吸和微生物总呼吸)和微生物代谢熵均表现为秋季和夏季高于春季和冬季,不同年份春季和秋季基本相等;(4)交互作用分析显示,年份显著影响了马尾松凋落物分解过程中土壤氮转化和微生物活性(P<0.05),季节极显著影响了马尾松凋落物分解过程中土壤氮转化和微生物活性(P<0.01),而年份和季节共同影响了马尾松凋落物分解过程中土壤氮转化和微生物活性(P<0.05)。季节对马尾松凋落物分解过程中土壤氮转化和微生物活性的影响高于年份的影响,并且年份对马尾松凋落物分解过程中土壤氮转化和微生物活性的影响主要集中在夏季和秋季。

In order to study the soil nitrogen cycle and microbial processes in the litter decomposition of Masson Pine,the effects of soil nitrogen conversion and microbial activity on the litter decomposition of Masson pine in year and season and their interaction were studied by in-situ decomposition and laboratory assay for 4 consecutive years.The results showed that:(1)With the change of seasons,the decomposition coefficient of litter of Masson pine in different years showed a consistent change rule,which was higher in autumn and summer than in spring and winter.The decomposition coefficient of litter of Masson pine in the same season increased with the increase of year,and the decomposition coefficient of litter in spring and autumn of different years was basically equal,indicating that the influence of year on the decomposition coefficient of litter of Masson pine was mainly concentrated in summer and autumn.(2)In the litter decomposition process of Masson pine in different years,the soil nitrogen content,microbial nitrogen content and nitrogen conversion rate were higher in autumn and summer than in spring and winter.In the litter decomposition process of Masson Pine in the same season,the soil nitrogen content,microbial nitrogen content and nitrogen conversion rate increased with the increase of year,and the spring and autumn were basically equal in different years.(3)Soil microbial enzyme activity(urease,protease,nitrate reductase,nitrite reductase,asparaginase and n-acetylglucosamine nucleoside enzyme),soil microbial respiration(autotrophic respiration,heterotrophic respiration and total microbial respiration)and microbial metabolic entropy during litter decomposition of Masson pine in different years were higher in autumn and summer than in spring and winter.Spring and autumn are almost equal in different years.(4)Interaction analysis showed that year significantly affected soil nitrogen conversion and microbial during litter decomposition(P<0.01).Both year and activity during litter decomposition(P<0.05),while season significantly affected soil nitrogen conversion and microbial activity season affected soil nitrogen conversion and microbial activity during litter decomposition(P<0.05).The effects of season on soil nitrogen conversion and microbial activity during litter decomposition of Masson pine were higher than those of year,and the effects of year on soil nitrogen conversion and microbial activity during litter decomposition of Masson pine were mainly concentrated in summer and autumn.