Abstract
A laboratory incubation experiment was conducted to study the effect of indigenous inorganic N on the immobilization of applied N and on the occurrence of an added N interaction (ANI). Samples of six Mollisols from Illinois were incubated with 15N-labelled (NH4)2SO4 (100 or 200 mg N kg-1 soil), with or without the use of 0.01 M CaCl2 to extract inorganic N (mainly NOinf3sup-) before incubation. From 6 to 49% of the N applied was immobilized, higher percentages being obtained with unextracted soils than with the extracted soils and with the higher rate of N addition. Net mineralization of native N occurred in both the unextracted and extracted soils, but was more extensive in the unextracted soil and increased with the addition of N. The increases were accompanied by a positive ANI, which usually exceeded the amount of applied N immobilized and increased with the rate of addition. The ANI values observed with extracted soils were attributed to increased mineralization of native organic N.
Original language | English (US) |
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Pages (from-to) | 103-108 |
Number of pages | 6 |
Journal | Biology and Fertility of Soils |
Volume | 18 |
Issue number | 2 |
DOIs | |
State | Published - Jul 1 1994 |
Keywords
- Added N interaction
- Mollisols
- N immobilization
- N mineralization
- Priming effect
ASJC Scopus subject areas
- Microbiology
- Agronomy and Crop Science
- Soil Science