ISSN:
1573-5036
Keywords:
bean
;
15N isotope
;
nitrogen fixation
;
N fertilizer
;
phosphorus
;
potassium
;
Rhizobium tropici
;
sulphur
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract Although common bean (Phaseolus vulgaris L.) has good potential for N2 fixation, some additional N provided through fertilizer usually is required for a maximum yield. In this study the suppressive effect of N on nodulation and N2 fixation was evaluated in an unfertile soil under greenhouse conditions with different levels of soil fertility (low=no P, K and S additions; medium = 50, 63 and 10 mg kg−1 soil and high = 200, 256 and 40 mg kg−1 soil, respectively) and combined with 5, 15, 60 and 120 mg N kg−1 soil of 15N-labelled urea. The overall average nodule number and weight increased under high fertility levels. At low N applications, nitrogen had a synergistic effect on N2 fixation, by stimulating nodule formation, nitrogenase activity and plant growth. At high fertility and at the highest N rate (120 mg kg−1 soil), the stimulatory effect of N fertilizer on N2 fixation was still observed, increasing the amounts of N2 fixed from 88 up to 375 mg N plant−1. These results indicate that a suitable balance of soil nutrients is essential to obtain high N2 fixation rates and yield in common beans.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00016342
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