BULK DENSITY OF SURFACE SOILS AND PEAT IN THE NORTH CENTRAL UNITED STATES

1989 ◽  
Vol 69 (4) ◽  
pp. 895-900 ◽  
Author(s):  
D. F. GRIGAL ◽  
S. L. BROVOLD ◽  
W. S. NORD ◽  
L. F. OHMANN
Keyword(s):  
Bulk Density ◽  
Forest Floor ◽  
Mineral Soil ◽  
Loss On Ignition ◽  
North Central ◽  
Dummy Variable ◽  
The North ◽  
A Value ◽  
Central United States ◽  
Surface Mineral

Relationships between bulk density (BD) and loss on ignition (LOI) for forest floor, shallow mineral soil (0–25 cm depth), and peat were described by exponential functions. The data were collected in forests across the North Central US. For forest floor, predicted BD, BDp = 0.073 + 2.369 exp(− 0.073 LOI), R2 = 0.75, (BDp in Mg m−3 and LOI in percent dry wt), and for surface mineral soil, BDp = 0.669 + 0.941 exp(− 0.240 LOI), R2 = 0.95. For peat, BDp = 0.043X + 4.258 exp(− 0.047 LOI), R2 = 0.89, where X is a dummy variable with a value of 0 for surface peat (0–25 cm depth) and 1 for subsurface peat (25–175 cm). Key words: Bulk density, loss-on-ignition

scholarly journals Genetic Variation of Sclerotinia sclerotiorum from Multiple Crops in the North Central United States

PLoS ONE ◽  
2015 ◽  
Vol 10 (9) ◽  
pp. e0139188 ◽  
Author(s):  
Laura Aldrich-Wolfe ◽  
Steven Travers ◽  
Berlin D. Nelson
Keyword(s):  
United States ◽  
Genetic Variation ◽  
Sclerotinia Sclerotiorum ◽  
North Central ◽  
The North ◽  
Central United States

Relation of algal biovolume to chlorophyll a in selected lakes and wetlands in the north-central United States

1995 ◽  
Vol 52 (2) ◽  
pp. 416-424 ◽  
Author(s):  
James W. LaBaugh
Keyword(s):  
United States ◽  
North Dakota ◽  
Chlorophyll A ◽  
Linear Relation ◽  
Algal Biomass ◽  
Open Water ◽  
Light Penetration ◽  
North Central ◽  
The North ◽  
Central United States

Algal chlorophyll a is commonly used as a surrogate for algal biomass. Data from three lakes in western Nebraska, five wetlands in north-central North Dakota, and two lakes in north-central Minnesota represented a range in algal biovolume of over four orders of magnitude and a range in chlorophyll a from less than 1 to 380 mg∙m−3. Analysis of these data revealed that there was a linear relation, log10 algal biovolume = 5.99 + 0.09 chlorophyll a (r2 = 0.72), for cases in which median values of chlorophyll a for open-water periods were less than 20 mg∙m−3. There was no linear relation in cases in which median chlorophyll a concentrations were larger than 20 mg∙m−3 for open-water periods, an occurrence found only in shallow prairies lakes and wetlands for years in which light penetration was the least.

Enhanced Biodegradation of Herbicides in Soil and Effects on Weed Control

1987 ◽  
Vol 1 (4) ◽  
pp. 341-349 ◽  
Author(s):  
R. Gordon Harvey ◽  
J. H. Dekker ◽  
Richard S. Fawcett ◽  
Fred W. Roeth ◽  
Robert G. Wilson
Keyword(s):  
Weed Species ◽  
North Central ◽  
Herbicide Degradation ◽  
Proso Millet ◽  
The North ◽  
Central United States ◽  
Enhanced Biodegradation ◽  
Long Time ◽  
Previously Treated ◽  
Repeated Use

Research conducted since 1979 in the north central United States and southern Canada demonstrated that after repeated annual applications of the same thiocarbamate herbicide to the same field, control of some difficult-to-control weed species was reduced. Laboratory studies of herbicide degradation in soils from these fields indicated that these performance failures were due to more rapid or “enhanced” biodegradation of the thiocarbamate herbicides after repeated use with a shorter period during which effective herbicide levels remained in the soils. Weeds such as wild proso millet [Panicum miliaceumL. spp.ruderale(Kitagawa) Tzevelev. #3PANMI] and shattercane [Sorghum bicolor(L.) Moench. # SORVU] which germinate over long time periods were most likely to escape these herbicides after repeated use. Adding dietholate (O,O-diethylO-phenyl phosphorothioate) to EPTC (S-ethyl dipropyl carbamothioate) reduced problems caused by enhanced EPTC biodegradation in soils treated previously with EPTC alone but not in soils previously treated with EPTC plus dietholate. While previous use of other thiocarbamate herbicides frequently enhanced biodegradation of EPTC or butylate [S-ethyl bis(2-methylpropyl)carbamothioate], previous use of other classes of herbicides or the insecticide carbofuran (2,3 -dihydro-2,2 -dimethyl-7-benzofuranyl methylcarbamate) did not. Enhanced biodegradation of herbicides other than the thiocarbamates was not observed.

Processing Snap Bean Variety Responses to Applied Nitrogen and Irrigation in the North Central United States

2015 ◽  
Vol 107 (4) ◽  
pp. 1401-1410 ◽  
Author(s):  
Yi Wang ◽  
Matthew D. Ruark ◽  
Amanda J. Gevens ◽  
Don T. Caine ◽  
Amanda L. Raster ◽  
...  
Keyword(s):  
United States ◽  
Snap Bean ◽  
North Central ◽  
The North ◽  
Bean Variety ◽  
Central United States ◽  
Applied Nitrogen
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