ISSN:
1573-5036
Keywords:
Acetylene reduction
;
Lucerne
;
15N Nitrogen fixation
;
Rhizobium meliloti
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary In view of the increasing need for the exact estimation of the input of nitrogen in agroecosystems, an application of the acetylene-reduction technique was developed. The technique, consisting of a plastic bag incubation system, using propane as an internal standard of the apparent volume, made it possible to carry out repeated incubations on the same plant system. The evaluated technique included studies of the diffusion of ethylene and propane in a soil column, as well as studies of the optimal substrate concentration and grade of purity of the substrate. In addition, the conversion factor between amounts of reduced acetylene as compared wtih reduced dinitrogen was determined by15N2 incubations to be 4.41. The developedin situ acetylene-reduction technique was compared with an isotope dilution method and a total nitrogen difference method. By comparing the derived total nitrogen fixation values from each with the value derived from the acetylene-reduction method; it was shown that the values differed significantly. The acetylene-reduction method gave the highest nitrogen fixation values, the isotope dilution the lowest values and the total nitrogen difference method was intermediate. No statistical significant difference existed between the two different reference crops used in the isotope dilution method.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02197149
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