ISSN:
1573-5036
Keywords:
Glycine max
;
nitrogen fixation
;
sulfur assimilation
;
sulfur remobilization
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract During pod filling, a grain legume remobilizes vegetative nitrogen and sulfur to its developing fruit. This study was conducted to determine whether different nitrogen sources affected N and S assimilation and remobilization during pod filling. Well-nodulated plants fed 1.0 mM KNO3, 0.5 mM urea, or 2.5 mM urea assimilated 0%, 37%, or 114% more N, respectively, and 25%, 46%, or 56% more S, respectively, than did the average non-nodulated control plant fed 5.0 mM KNO3. Thus, N source during pod filling greatly affected both N and S assimilation. Depending upon N source, plant N concentration during pod filling decreased from 2.96% to between 1.36% and 1.82%. Non-nodulated control plants fed 5.0 mM KNO3 had the highest residual N at harvest. During the same treatments, plant S concentration decreased from 0.246% to a relatively uniform 0.215%. Thus, during pod filling, vegetative N was seemingly remobilized more efficiently (38–54%) than was S (13%). N source also affected seed yield and seed quality. Non-nodulated control plants fed 5.0 mM KNO3 produced the lowest yield (21.1 g seeds plant-1), whereas well nodulated plants fed 1.0 mM KNO3, 0.5 mM urea, or 2.5 mM urea produced yields of 26.2 g, 31.8 g, and 36.7 g seeds plant-1, respectively. Non-nodulated plants fed 2.5 mM urea yielded 28.6 g of seeds plant-1. Seed N concentrations of non-nodulated plants and nodulated plants fed 2.5 mM urea were high, 6.30% and 6.11% N, respectively, whereas their seed S concentrations were low, 0.348% and 0.330% S, respectively. N sources that produced both a relatively high seed yield and seed N concentration (i.e., a relatively high total seed N plant-1) produced a proportionately smaller increase in total seed sulfur. Consequently, seed quality, as judged solely by seed S concentration, was lowered.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1004313326745
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