摘要
本文采用15N标记底物法测定了三种不同肥力水平的红壤中微生物量氮的周转速率，结果表明三种红壤中微生物量氮的周转期分别为63天（3年菜地红砂土），89天（4年桔园黄筋泥）和251天（30年茶园黄筋泥）。微生物量氮的周转期受土壤质地、利用方式等方面的影响，较短的周转期能使土壤中的氮素更有效地通过微生物进行流通，而长的周转期则有利于土壤养分积累和保蓄。根据周转期估算，每年通过微生物周转的氮素可以达到土壤微生物量氮的15倍以上。由此可见，微生物量氮周转对红壤氮素供应和循环具有着重要的意义。
An isotope (15N) labelling technique was used to estimate the turnover of soil nitrogen through microbial biomass in red soils. The turnover times of soil nitrogen in microbial biomass were 251, 89, and 63 days, for the long--term cultivated red clayey soil (30 years of tea orchard), mid--term cultivated red clayey soil (4 years citrus orchard) and short--term cultivated red sandy soil (3 years upland), respectively. The annual fluxes of soil nitrogen through microbial biomass were 1.5 to 6 times of the microbial biomass nitrogen itself. The microbial turnover rate of soil nitrogen was closely related to the soil organic matter, and it was higher in sandy soil than in clayey soil. Obviously, microbial biomass turnover of soil nitrogen plays an important role in the availability, retaining and accumulation of soil nitrogen in red soils.
出处
《土壤学报》
CAS
CSCD
北大核心
1999年第3期387-394,共8页
Acta Pedologica Sinica
基金
国家自然科学基金
土壤圈物质循环开放实验室资助
欧共体资助
关键词
红壤
微生物量氮
周转期
Red soils,Microbial biomass nitrogen, Turnover time
