ISSN:
1432-0789
Keywords:
Mollisol
;
N interaction
;
N availability
;
N fertilizers
;
N immobilization
;
N mineralization
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Geosciences
,
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary Three Illinois Mollisols were incubated for 2 weeks at 25°C after treatment with different amounts of glucose and/or 15N-labelled (NH4)2SO4 or 15N-labelled KNO3. The objectives were: (1) to compare the immobilization and interaction of NH inf4 sup+ −N and NO inf3 sup- −N with the native soil N, and (2) to study the relationship between immobilization of applied N and the added N interaction. As determined, immobilized N refers to forms not extractable with 2 MKCl (immobilized 15N+clay-fixed 15NH inf4 sup+ ). In all cases, both NH inf4 sup+ −N and NO inf3 sup- −N were actively immobilized and transformed into organic forms in the presence of glucose. In the absence of glucose, a higher proportion of NH inf4 sup+ than NO inf3 sup- was recovered in organic forms. Although the three soils differed considerably in the amounts of applied N immobilized, similar trends in N immobilization were observed. A positive added N interaction occurred with all soils, the magnitude increasing with the rate of N addition. In the absence of glucose, higher added N interactions were obtained for NH inf4 sup+ than NO inf3 sup- , whereas there was very little difference between NH inf4 sup+ and NO inf3 sup- in the presence of glucose. The results indicate that under conditions of rapid immobilization (e.g., in the presence of glucose), NH inf4 sup+ and NO inf3 sup- will show comparable interaction with the native soil N, whereas in unamended soil, the extent of this interaction will be greater with NH inf4 sup+ than with NO inf3 sup- . Significant correlations were observed between applied N immobilized and the added N interaction only in one soil having a high initial mineral N content.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00336288
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