ISSN:
1573-5036
Keywords:
‘AN’-value
;
Cowpea
;
Difference method
;
Fertilizer-N
;
Glycine max
;
Nitrogen-15
;
N-balance
;
N2-fixation
;
Soybean
;
Vigna unguiculata
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary The amounts of N fixed in the field in Nigeria by four cowpea and two soybean cultivars were determined at different levels of available N by the difference and the ‘AN’-value methods using non-nodulating soybean, maize and celosia as non-fixing controls. No significant differences were found between the two methods or with different controls. Grain removal and return of residues to the soil were measured and net soil-N changes calculated. N-benefits accrued from two of the cowpea cultivars when grown at low mineral-N levels, but with higher mineral-N availability, no cultivar contributed N because of inhibition of nodulation and lowered N2-fixation. Although the soybeans fixed more N than the cowpeas they caused greater net N-depletions because they sequestered a greater fraction of N in the grain.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02373704
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