首页 | 本学科首页   官方微博 | 高级检索  
     


Activity of nitrifiers in relation to nitrogen nutrition of plants in natural ecosystems
Authors:J. W. Woldendorp  H. J. Laanbroek
Affiliation:(1) Institute for Ecological Research, Boterhoeksestraat 22, 6666 GA Heteren, The Netherlands
Abstract:Three aspects of the nitrate production in natural ecosystems are discussed,i.e. the population biology of nitrifying bacteria, the nitrate-producing activity of these organisms and the uptake of nitrate by higher plants. It is concluded that the three methods used in enumerating the nitrifying bacteria,i.e. the Most Probable Number method, the Fluorescent Antibody technique and the Potential Nitrification Rate, all have serious drawbacks and count different segments of the nitrifying populations.From the number of nitrifying bacteria no reliable estimate of the rate production can be obtained and also estimates that are made using field-incubation and15N–NH4+ techniques do not yield reliable data. Possibly the best results can be obtained using Schimel's method to estimate the actual nitrification rate using15N–NO3, but this method has still not been tested under different sets of soil conditions.From the nitrate reductase activity and the chemical composition of the plant a picture can be obtained of the quantities of nitrate and ammonium that have been taken up. However, it is shown that nitrate and ammonium are taken up in different proportions that they are produced. It is concluded that the various parameters have to be studied simultaneously, preferably in defined systems with plants, in which the participating organisms are known.
Keywords:chemolithotrophs  natural ecosystems  nitrate  nitrate reductase  nitrification  population  production  rhizosphere  uptake
本文献已被 SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号