ISSN:
1432-0789
Keywords:
Cereal-legume intercropping
;
Residual fertilizer N
;
Crop residues
;
Nitrogen-15
;
Organic N fractions
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Geosciences
,
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary Under greenhouse and field conditions, after the harvest of maize-cowpea intercropping, soils were analysed for total, ammonium and organic N fractions and fertilizer 15N residues. Growing cowpea as the sole crop or in intercropping with maize results in increased relative amounts of the acid hydrolysable organic N fractions in soil. After sole cropping of maize 70% of the residual fertilizer N was found in the acid hydrolysable fraction while after intercropping it was 80%–92%. The fertilizer and soil N labelling with 15N in identical but alternate series provided information on the nitrogen fixed by cowpea and left in the soil as crop residues. Under field conditions the cowpea plant residues left after cropping contained 170 kg N ha−1 in sole cropping and 105 kg N ha−1 in intercropping with maize. The N assimilated by cowpea-Rhizobium symbiosis was mainly present in the acid hydrolysable forms, particularly in the α-amino N fraction and ammonium N fraction.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00256990
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