期刊
PLANT AND SOIL
卷 228, 期 1, 页码 73-82出版社
KLUWER ACADEMIC PUBL
DOI: 10.1023/A:1004860329146
关键词
carbon mineralisation; CO2 respiration; green manure; N-mineralisation; nitrification; temperature
We examined the decomposition of Medicago lupulina, Melilotus alba and Poa pratensis at 3, 9, and 25 degreesC during 4 weeks. There was a strong temperature effect on the rate of CO2 evolution, and thus the extent of energy exhaustion from the added substrates. However, there was no concomitant retardation of N mineralisation at low temperatures. In the analysis of variance of mineralized N the residue type gave a 10 times larger contribution to the regression than the temperature (T), whereas for CO2 evolution residue type and temperature were equally important contributors. This indicates that although the temperature has a statistically significant effect on N-mineralisation it is substantially less than compared with the effect on carbon mineralisation in the materials examined. The retardation of carbon mineralisation was least strong in Melilotus alba that had a relatively low cellulose content, and a higher content of low molecular compounds. Though more research will be necessary to consolidate and explain this phenomena, it is likely that an important factor is a decrease in the bioavailability of C-rich polymers at low temperatures, and thus a preferential utilization of N-rich low molecular substances. Nitrification was not effectively deterred at 3 degreesC. Thus, in terms of management, it is pertinent to reconsider the timing of green manure and catch crop incorporation in cool temperate climate regions, since the rapid release of nitrogen, coupled with the relatively undeterred nitrification may result in a high N leaching risk by early incorporation, but a low risk for N immobilization at late incorporation, if N rich residues are used.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据