ISSN:
1573-5036
Keywords:
legumes
;
N2 fixation
;
15N analysis
;
ureides
;
xylem exudate
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract Methods for partitioning the nitrogen assimilated by nodulated legumes, between nitrogen derived from soil sources and from N2 fixation, are described as applied in peninsular Malaysia. The analysis of nitrogenous components translocated from the roots to the shoots of nodulated plants in the xylem sap is outlined, with some precautions to be observed for applications in the tropics. Some examples of the use of the technique in surverying apparent N2 fixation by tropical legumes, in studying interrow cropping in plantation systems and in assessing effects of experimental treatments on N2 fixation by food legumes, are described. Techniques for assesing N2 fixation by means of15N abundance have been used to show that applications of nitrogenous fertilizers commonly used in Malaysia for soybeans depress N2 fixation, that similar results are obtained with natural abundance and15N-enrichment methods and that, in at least two locations in Malaysia, differences between the natural abundance of15N in plant-available soil nitrogen and in atmospheric N2 are great enough to permit application to measurement of N2 fixation by leguminous crops.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02370109
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