ISSN:
1573-5036
Keywords:
legume-cereal association
;
15N
;
nitrogen fixation
;
nitrogen fertilization
;
nitrogen transfer
;
reference crop
;
Vicia sativa
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract This study was conducted to examine the effects of varying N rates and cropping systems (mixedversus pure stand) on the suitability of oats (Avena sativa L.) for estimating N2 fixed in sequentially harvested vetch (Vicia sativa L.) over two growing seasons (1984–85 and 1985–86). The N rates were, 20 and 100 kg N ha−1 in 1984–85 and 15 and 60 kg N ha−1 in 1985–86. In the 1984–85 season, vetch at maturity derived 76 and 63% N from fixation at the high and low N rates respectively. The corresponding values for the second season were 66 and 42%. Except in the 1985–86 season when some significantly higher values of % N2 fixed were estimated by using the reference crop grown at the higher (A-value approach) than at the lower N rate (isotope-dilution approach), both approaches resulted in similar measurements of N2 fixed. In the 1984–85 season, similar values of N2 fixed were obtained using either the pure or mixed stand oats reference crops. Although in the 1985–86 season, the mixed reference crop occasionally estimated lower % N2 fixed than pure oats, total N2 fixed estimates were always similar (P〈0.05). Thus, in general, N fertilization and cropping system of the reference crop did not significantly influence estimates of N2 fixation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02220802
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