scholarly journals Nitrogen accumulation in three legumes and two cereals with emphasis on estimation of N2 fixation in the legumes by the natural 15N-abundance technique

1990 ◽  
Vol 9 (1) ◽  
pp. 25-30 ◽  
Author(s):  
T. Yoneyama ◽  
P. T. C. Nambiar ◽  
K. K. Lee ◽  
B. Srinivasa Rao ◽  
J. H. Williams
Keyword(s):  
N2 Fixation ◽  
Nitrogen Accumulation ◽  
Natural 15N Abundance ◽  
15N Abundance

N2-Fixation in Field Settings: Estimations Based on Natural 15N Abundance

1986 ◽  
Vol 13 (6) ◽  
pp. 699 ◽  
Author(s):  
G Shearer ◽  
DH Kohl
Keyword(s):  
N2 Fixation ◽  
Small Difference ◽  
Sampling Strategy ◽  
Field Evaluation ◽  
Field Conditions ◽  
Site Specific ◽  
Natural 15N Abundance ◽  
Advantages And Disadvantages ◽  
Growing Body ◽  
15N Abundance

This paper reviews a growing body of literature on the use of variations in the natural abundance of 15N to estimate the fractional contribution of N2-fixation to N2-fixing systems. This method is based on the small difference in 15NN abundance which frequently occurs between N derived from N2-fixation and N derived from other sources. The requirement of the method is that this difference be significant. Whether this requirement is met is site specific and must be empirically established at each site of interest. Advantages and disadvantages of this method are compared with those of more conventional methods. Sources of error, including heterogeneity of 15NN abundance of non-atmospheric N sources are considered. Tests of the method, under both greenhouse and field conditions, are described. Estimates based on this method compare favourably with other methods for field evaluation of N2-fixation, provided that the site and the sampling strategy are appropriate for application of the method. Applications of the method in several ecosystems are described.

Pattern of natural 15N abundance in lakeside forest ecosystem affected by cormorant-derived nitrogen

2006 ◽  
pp. 69-86 ◽  
Author(s):  
Kayoko Kameda ◽  
Keisuke Koba ◽  
Satoru Hobara ◽  
Takashi Osono ◽  
Masakazu Terai
Keyword(s):  
Forest Ecosystem ◽  
Natural 15N Abundance ◽  
15N Abundance

Sowing time and tillage practice affect chickpea yield and nitrogen fixation. 2. Nitrogen accumulation, nitrogen fixation and soil nitrogen balance

1996 ◽  
Vol 36 (6) ◽  
pp. 701 ◽  
Author(s):  
CP Horn ◽  
RC Dalal ◽  
CJ Birch ◽  
JA Doughton
Keyword(s):  
Nitrogen Fixation ◽  
N2 Fixation ◽  
N Balance ◽  
Grain Legume ◽  
Nitrogen Accumulation ◽  
Soil Nitrate ◽  
Soil N ◽  
Tillage Practice ◽  
Sowing Time ◽  
N Accumulation

Following long-term studies at Warra, on the western Darling Downs, chckpea (Cicer anetinum) was selected as a useful grain legume cash crop with potential for improvement of its nitrogen (N) fixing ability through management. This 2-year study examined the effect of sowing time and tillage practice on dry matter yield, grain yield (Horn et al. 1996), N accumulation, N2 fixation, and the subsequent soil N balance. Generally, greater N accumulation resulted from sowing in late autumn-early winter (89-117 kg N/ha) than sowing in late winter (76-90 kg N/ha). The amount of N2 fixed was low in both years (15-32 kg N/ha), and was not significantly affected by sowing time or tillage. The potential for N2 fixation was reduced in both years due to high initial soil nitrate levels and low total biomass of chickpea because of low rainfall. Nitrogen accumulation by grain was higher under zero tillage (ZT) than conventional tillage (CT) for all sowing times, and this affected the level of grain N export. The consequence of low N2 fixation and high N export in chickpea grain was a net loss of total soil N, (2-48 kg N/ha under CT and 22-59 kg N/ha under ZT). Management practices to ensure larger biomass production and lower soil nitrate-N levels may result in increased N2 fixation by chickpea and thus a positive soil N balance.

scholarly journals Natural 15N abundance in soils and plants in relation to N cycling in a rangeland in Inner Mongolia

2010 ◽  
Vol 3 (3) ◽  
pp. 201-207 ◽  
Author(s):  
Y. Xu ◽  
J. He ◽  
W. Cheng ◽  
X. Xing ◽  
L. Li
Keyword(s):  
Inner Mongolia ◽  
N Cycling ◽  
Natural 15N Abundance ◽  
15N Abundance
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