Journal article

Publication year: 1995

Pages: 563-569

Journal: Journal of Plant Nutrition and Soil Science

Volume number: 158

Issue number: 6

ISSN: 0044-3263

Publisher: Wiley-VCH Verlag

Abstract: 

Applied inorganic N is rapidly immobiliezed in soils, provided that organic carbon is available to soil microbes. This newly immobilized N is highly accessible to remineralization and may therefore be an important source of N for crop growth.

The objective of our study was to determine the extractability of newly immobilized inorganic N as organic N fraction in EUF and 10 mM CaCl2 soil extracts. A soil incubation experiment was carried out over 80 days and the immobilization of applied (15NH4NO3)-N-15 was induced by addition of cellulose. For both extraction procedures a 'different method' was used to estimate the apparent immobilization of inorganic N, the remineralization of the newly immobilized N and its extractability as an organic N fraction (Norg). In addtion, the isotopic composition of EUF extractable organic and inorganic N was determined.

Apparent net immobilization took place in cellulose amended soil up to day 30 of incubation. This newly immobilized N was highly accessible to remineralization. 47 % of the newly immobilized N (labelled and unlabelled) was apparently remineralized from day 30 to 80. Labelled N was completedly immobilized on day 16 and 29 % was release again up to day 80. Both extraction methods failed to extract this potential of remineralizable N as an extractable Norg fraction. The results of the present study showed that EUF and CaCl2 extractable Norg was unsuitable as index for easily mineralizable N in cases where remineralization of newly immobilized N plays a major role.

Harvard Citation style: Appel, T. and Brunet, M. (1995) Extractability of newly immobilized nitrogen by electro-ultrafiltration (EUF) and CaCl2 extraction, Journal of Plant Nutrition and Soil Science = Zeitschrift für Pflanzenernährung und Bodenkunde, 158(6), pp. 563-569

APA Citation style: Appel, T., & Brunet, M. (1995). Extractability of newly immobilized nitrogen by electro-ultrafiltration (EUF) and CaCl2 extraction. Journal of Plant Nutrition and Soil Science = Zeitschrift für Pflanzenernährung und Bodenkunde. 158(6), 563-569.