scholarly journals Nitrogen Uptake from Different Sources by Non-GMO Soybean Varieties

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1219
Author(s):  
Katarzyna Rymuza ◽  
Elżbieta Radzka ◽  
Andrzej Wysokiński
Keyword(s):  
Abiotic Factors ◽  
Nitrogen Sources ◽  
Isotope Dilution Method ◽  
Dilution Method ◽  
Atmospheric Nitrogen ◽  
Harvest Residues ◽  
Growing Seasons ◽  
Soybean Plants ◽  
Nitrogen Excess ◽  
Different Sources

Soybean has the ability to live in symbiosis with microorganisms and take up nitrogen from the atmosphere, fertiliser and soil reserves. The amount of nitrogen taken up from these sources depends on many biotic and abiotic factors, e.g., the rhizobium species, cultivar, as well as weather and agricultural conditions. A field experiment was conducted in eastern Poland (central Europe) in two successive growing seasons to examine the uptake of nitrogen from the atmosphere (NDFA—% nitrogen derived from the atmosphere), fertiliser (NDFF—% of nitrogen derived from fertiliser) and soil reserves (NDFS—% of nitrogen derived from the soil) for three non-GMO (non genetically modified organism) soybean cultivars: Abelina, SG Anser and Merlin. Pre-plant fertilisation of plants with nitrogen excess with the 15N isotope and the isotope dilution method were applied. Soil reserves and the atmosphere were major nitrogen sources for soybean. Soybean roots contained the most atmosphere-derived nitrogen (45.85%), the amount being lower for soil reserves (41.43%) and the lowest for fertiliser (12.72%). Harvest residues and seeds contained the most soil reserve-derived nitrogen, the amount being lower for the atmospheric nitrogen and the lowest for fertiliser-derived nitrogen. The amount of nitrogen derived from different sources in the whole soybean mass significantly depended on cultivars and years’ percentage values being affected by study years only. Less atmospheric nitrogen was accumulated in cv. Abelina roots (2.15 kg N·ha−1) compared with cv. SG Anser (3.07 kg N·ha−1) or cv. Merlin (2.89 kg N·ha−1). More atmospheric nitrogen was recorded in the post-harvest residues and seeds of cv. Abelina and SG Anser than Merlin. The content of soil reserve-derived nitrogen taken up by the whole soybean plants averaged 61.29 kg N∙kg−1, the amounts being 50.95 and 11.38 kgN∙kg−1 for nitrogen taken up from the atmosphere and fertiliser, respectively. Soybean grown in the study year with more favourable thermal and precipitation conditions (2017) took up more nitrogen from all the sources compared with the year 2018.

Nitrogen fixation in Sitka alder by 15N isotope dilution after eight growing seasons in a lodgepole pine site

1992 ◽  
Vol 22 (8) ◽  
pp. 1192-1194 ◽  
Author(s):  
Donald J. Mead ◽  
Caroline M. Preston
Keyword(s):  
Isotope Dilution ◽  
Lodgepole Pine ◽  
Plant Root ◽  
Field Studies ◽  
Isotope Dilution Method ◽  
Dilution Method ◽  
Growing Seasons ◽  
N Enrichment ◽  
Plant Root Systems

Owing to high costs and limitations of the method, there have been no field studies using 15N isotope dilution to measure the amount of N fixed by alder in the field. As part of a long-term (8-year) study of the fate of 15N-labelled fertilizer applied to lodgepole pine (Pinuscontorta Dougl. var. latifolia Engelm.) in the field in interior British Columbia, we observed much lower 15N enrichment in Sitka alder (Alnussinuata (Reg.) Rydb.) than in lodgepole pine or other understory species. Calculations using lodgepole pine, herbs, and shrubs as nonfixing reference crops all indicated that the percent of N derived from the atmosphere in Sitka alder at this site was very high, 94–99%. The long period for stabilization of residual 15N-labelled fertilizer in organic form in the soil and for establishment of plant root systems alleviated many of the problems associated with the 15N isotope dilution method. By contrast, calculations of the percent of N derived from the atmosphere at the end of the first growing season gave erratic and unreliable results.

ON THE VALUE OF SOME PARAMETERS OF ADRENOCORTICAL GLUCOCORTICOID FUNCTION

1963 ◽  
Vol 44 (4) ◽  
pp. 499-504 ◽  
Author(s):  
M. Van Der Straeten ◽  
A. Vermeulen ◽  
N. Orie ◽  
P. Regniers
Keyword(s):  
Urinary Excretion ◽  
Adrenal Cortex ◽  
Isotope Dilution ◽  
Isotope Dilution Method ◽  
Dilution Method ◽  
Steroid Excretion ◽  
Colorimetric Methods

ABSTRACT The authors studied the correlation between cortisol production, as measured by an isotope dilution method, and the urinary excretion of total and free Porter-Silber chromogens, as well as of 17-ketogenic steroids. Although a significant correlation exists between total Porter-Silber chromogens, 17-ketogenic steroid excretion and cortisol production, discrepancies are occasionally observed. Hence, different colorimetric methods should be used to assess the glucocorticoid activity of the adrenal cortex.

scholarly journals Delayed Senescence in Soybean: Terminology, Research Update, and Survey Results from Growers

2016 ◽  
Vol 17 (2) ◽  
pp. 76-83 ◽  
Author(s):  
C. J. Harbach ◽  
T. W. Allen ◽  
C. R. Bowen ◽  
J. A. Davis ◽  
C. B. Hill ◽  
...  
Keyword(s):  
Abiotic Factors ◽  
Biotic Factors ◽  
Delayed Senescence ◽  
Plant Parts ◽  
Whole Plant ◽  
Research Findings ◽  
Survey Results ◽  
Soybean Plants ◽  
Grower Survey ◽  
Specific Symptoms

The terms used to describe symptoms of delayed senescence in soybean often are used inconsistently or interchangeably and do not adequately distinguish the observed symptoms in the field. Various causes have been proposed to explain the development of delayed senescence symptoms. In this article, we review published reports on delayed senescence symptoms in soybean, summarize current research findings, provide examples of terms related to specific symptoms, and present an overview of the results of a multi-state survey directed to soybean growers to understand their concerns about delayed soybean senescence. Some of these terms, such as green bean syndrome and green stem syndrome, describe symptoms induced by biotic factors, while other terms describe symptoms associated with abiotic factors. Some delayed senescence terms involve the whole plant remaining green while other terms include just the stem and other plant parts such as pods. In the grower survey, 77% reported observing soybean plants or plant parts that remained green after most plants in the field were fully mature with ripe seed. Most respondents attributed these symptoms to changes in breeding and choice of cultivars. At the end of this article, we standardized the terms used to describe delayed senescence in soybean. Accepted for publication 23 March 2016. Published 15 April 2016.

scholarly journals Corn Yield Loss Due to Volunteer Soybean

Weed Science ◽  
2016 ◽  
Vol 64 (3) ◽  
pp. 495-500 ◽  
Author(s):  
Jill Alms ◽  
Sharon A. Clay ◽  
David Vos ◽  
Michael Moechnig
Keyword(s):  
Loss Function ◽  
Growth Stage ◽  
Yield Loss ◽  
Corn Yield ◽  
Yield Losses ◽  
Herbicide Resistant ◽  
Growing Seasons ◽  
Previous Season ◽  
Control Volunteer ◽  
Soybean Plants

The widespread adoption of glyphosate-resistant corn and soybean in cropping rotations often results in volunteer plants from the previous season becoming problem weeds that require alternative herbicides for control. Corn yield losses due to season-long volunteer soybean competition at several densities in two growing seasons were used to define a hyperbolic yield loss function. The maximum corn yield loss observed at high volunteer soybean densities was about 56%, whereas, the incremental yield loss (I) at low densities was 3.2%. Corn yield loss at low volunteer soybean densities was similar to losses reported for low densities of velvetleaf and redroot pigweed, with 10% yield loss estimated to occur at 3 to 4 volunteer soybean plants m−2. Several herbicides, including dicamba with or without diflufenzopyr applied at the V2 growth stage of volunteer soybean, provided > 90% control, demonstrating several economical options to control volunteer glyphosate-resistant soybean in glyphosate-resistant corn. Reevaluation of control recommendations may be needed with commercialization of other genetically modified herbicide-resistant soybean varieties.

Quality criteria for the isotope dilution method with HRGC/MS

1996 ◽  
Vol 354 (7-8) ◽  
pp. 818-822 ◽  
Author(s):  
B. Henkelmann ◽  
K. -W. Schramm ◽  
C. Klimm ◽  
A. Kettrup
Keyword(s):  
Isotope Dilution ◽  
Quality Criteria ◽  
Isotope Dilution Method ◽  
Dilution Method
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