scholarly journals Atrazine and picloram adsorption in organic horizon forest samples under laboratory conditions

2007 ◽  
Vol 25 (1) ◽  
pp. 125-131 ◽  
Author(s):  
A.P. Pinho ◽  
A.T. Matos ◽  
L.A. Morris ◽  
L.M. Costa
Keyword(s):  
Mineral Soil ◽  
Significant Degree ◽  
Field Trials ◽  
Surface Flow ◽  
Organic Horizon ◽  
Management Zones ◽  
Streamside Management Zones ◽  
Direct Adsorption ◽  
Negative Adsorption ◽  
Sorption Characteristics

Adsorption of two herbicides, atrazine and picloram, displaying different sorption characteristics, were evaluated for O (organic) horizon samples collected from SMZs (streamside management zones) in Piedmont (Ultisol) of Georgia, USA. Samples were randomly collected from within 5 SMZs selected for a study of surface flow in field trials. The five SMZs represented five different slope classes, 2, 5, 10, 15 and 20%. Results indicate that 0 horizons have the potential for sorbing atrazine from surface water moving through forested SMZs. Atrazine adsorption was nearly linear over a 24-hour period. Equilibrium adsorption, determined through 24-hour laboratory tests, resulted in a Freundlich coefficient of 67.5 for atrazine. For picloram, negative adsorption was observed in laboratory experiments. This seemed to be due to interference with ELISA analyses; however, this was not confirmed. The adsorption coefficient (Kd) obtained for atrazine in 0 horizons was greater than it would have been expected for mineral soil (from 1 to 4). Picloram was not sorbed in 0 horizons at any significant degree. Although there is a significant potential for the direct adsorption of soluble forms of herbicides in SMZs, the actual value of this adsorption for protecting water is likely to be limited even for relatively strongly sorbed chemicals, such as atrazine, due to relatively slow uptake kinetics.

Streamside Management Zones Compromised by Stream Crossings, Legacy Gullies, and Over-Harvest in the Piedmont

2015 ◽  
Vol 51 (4) ◽  
pp. 1153-1164 ◽  
Author(s):  
A.J. Lang ◽  
W.M. Aust ◽  
M.C. Bolding ◽  
S.M. Barrett ◽  
K.J. McGuire ◽  
...  
Keyword(s):  
Management Zones ◽  
Streamside Management Zones

Prescribed Burning White Spruce Slash in Interior Alaska

1986 ◽  
Vol 3 (1) ◽  
pp. 16-18 ◽  
Author(s):  
John Zasada ◽  
Rodney Norum
Keyword(s):  
Organic Material ◽  
Prescribed Burning ◽  
Mineral Soil ◽  
White Spruce ◽  
Flood Plain ◽  
Organic Horizon ◽  
Forest Types ◽  
Mechanical Site Preparation ◽  
Interior Alaska ◽  
Soil Exposure

Abstract Broadcast burning following harvesting on flood-plain sites in Alaska substantially decreased residual organic material and increased exposed mineral soil. Two forest types were studied: white spruce/alder/feathermoss and white spruce/alder/lingenberry/feathermoss. The latter site contained permafrost. Fuel was reduced 67% and 81%, respectively; organic horizon thickness was decreased 43% to 2.9 in (7.4 cm) and 55% to 2.5 in (6.4 cm), respectively; and mineral soil exposure was 13% and 8%, respectively. Burning created good conditions for planting on both types. In addition, mechanical site preparation to increase mineral soil exposure appears to be necessary to achieve adequate, well-distributed regeneration from seed. North. J. Appl. For. 3:16-18, Mar. 1986.

scholarly journals Assessment of Compliance of Forestry Best Management Practices in West Virginia

2007 ◽  
Vol 31 (2) ◽  
pp. 60-65 ◽  
Author(s):  
Jingxin Wang ◽  
Joseph McNeel ◽  
William Goff ◽  
Steve Milauskas
Keyword(s):  
West Virginia ◽  
Best Management Practices ◽  
Management Practices ◽  
Management Zones ◽  
Best Management ◽  
Random List ◽  
Streamside Management Zones ◽  
Increasing Trend ◽  
Assessment Of Compliance

Abstract The compliance of forestry best management practices (BMP) was assessed based on 116 randomly selected sites harvested between November 2003 and March 2004 in West Virginia. Landowners were contacted to gain permission for site visits according to the random list. The landowners also were interviewed to identify their knowledge and satisfaction about the harvest and BMP. Four checklists were used to assess 29 BMPs on haul roads, skid trails, landings, and in streamside management zones (SMZ). A general increasing trend in BMP compliance was noted in this statewide BMP assessment with an overall BMP compliance of 74%. Results also indicated that the BMP compliances averaged 81% on haul roads, 68% on skid trails, 80% on landings, and 55% in SMZs.

Effect of boron on clubroot of canola in organic and mineral soils and on residual toxicity to rotational crops

2014 ◽  
Vol 94 (1) ◽  
pp. 109-118 ◽  
Author(s):  
A. Deora ◽  
B. D. Gossen ◽  
S. F. Hwang ◽  
D. Pageau ◽  
R. J. Howard ◽  
...  
Keyword(s):  
Plasmodiophora Brassicae ◽  
Mineral Soil ◽  
Organic Soil ◽  
Field Trials ◽  
Growth And Yield ◽  
Broadcast Application ◽  
Residual Toxicity ◽  
Negative Effect ◽  
Soil Site ◽  
Mineral Soils

Deora, A., Gossen, B. D., Hwang, S. F., Pageau, D., Howard, R. J., Walley, F. and McDonald, M. R. 2014. Effect of boron on clubroot of canola in organic and mineral soils and on residual toxicity to rotational crops. Can. J. Pant Sci. 94: 109–118. Application of boron (B) has been reported to reduce clubroot severity in various Brassica spp., but residual B can have phytotoxic effects on other crops in the rotation. The objective of this study was to test the efficacy of broadcast application of B for clubroot suppression in canola (B. napus) and the effect of residual B on wheat, barley, field pea and canola. Field trials to assess clubroot suppression by B at various rates (1 to 64 kg B ha−1) were conducted in organic (Ontario) and mineral soils (Alberta, Quebec) heavily infested with Plasmodiophora brassicae in 2011 and 2012. Phytotoxicity was not observed in canola until applications rates exceeded 48 kg B ha−1. Boron did not reduce clubroot incidence at any site, irrespective of rate, and only reduced severity at the organic soil site at 6 wk after seeding. There was a small increase in shoot weight and yield of canola with increasing B application rates at the organic soil site. The potential phytotoxicity of residual B (4 to 16 kg B ha−1) was assessed in mineral soils in Ontario and Saskatchewan in 2012. Toxicity symptoms were noted initially in most of the crops, but seedlings recovered quickly and there was no significant reduction in fresh weight at harvest or seed yield of most of the cultivars. The present study indicates that pre-plant broadcast application of B delays clubroot development and increases vegetative growth and yield compared with non-treated plants in organic soil. Also, even high residual rates (16 kg ha−1) of application are unlikely to have a negative effect on crops in rotation in mineral soil. However, the effect of B application on canola yield found in this study was not sufficient to justify application for commercial canola production, even where clubroot is prevalent.

scholarly journals Long-Term Warming Alters Carbohydrate Degradation Potential in Temperate Forest Soils

2016 ◽  
Vol 82 (22) ◽  
pp. 6518-6530 ◽  
Author(s):  
Grace Pold ◽  
Andrew F. Billings ◽  
Jeff L. Blanchard ◽  
Daniel B. Burkhardt ◽  
Serita D. Frey ◽  
...  
Keyword(s):  
Climate Change ◽  
Microbial Communities ◽  
Soil Carbon ◽  
Carbon Cycling ◽  
Temperate Forest ◽  
Mineral Soil ◽  
Soil Microbial Communities ◽  
Organic Horizon ◽  
Soil Microbial ◽  
Carbohydrate Degradation

ABSTRACTAs Earth's climate warms, soil carbon pools and the microbial communities that process them may change, altering the way in which carbon is recycled in soil. In this study, we used a combination of metagenomics and bacterial cultivation to evaluate the hypothesis that experimentally raising soil temperatures by 5°C for 5, 8, or 20 years increased the potential for temperate forest soil microbial communities to degrade carbohydrates. Warming decreased the proportion of carbohydrate-degrading genes in the organic horizon derived from eukaryotes and increased the fraction of genes in the mineral soil associated withActinobacteriain all studies. Genes associated with carbohydrate degradation increased in the organic horizon after 5 years of warming but had decreased in the organic horizon after warming the soil continuously for 20 years. However, a greater proportion of the 295 bacteria from 6 phyla (10 classes, 14 orders, and 34 families) isolated from heated plots in the 20-year experiment were able to depolymerize cellulose and xylan than bacterial isolates from control soils. Together, these findings indicate that the enrichment of bacteria capable of degrading carbohydrates could be important for accelerated carbon cycling in a warmer world.IMPORTANCEThe massive carbon stocks currently held in soils have been built up over millennia, and while numerous lines of evidence indicate that climate change will accelerate the processing of this carbon, it is unclear whether the genetic repertoire of the microbes responsible for this elevated activity will also change. In this study, we showed that bacteria isolated from plots subject to 20 years of 5°C of warming were more likely to depolymerize the plant polymers xylan and cellulose, but that carbohydrate degradation capacity is not uniformly enriched by warming treatment in the metagenomes of soil microbial communities. This study illustrates the utility of combining culture-dependent and culture-independent surveys of microbial communities to improve our understanding of the role changing microbial communities may play in soil carbon cycling under climate change.

Forest soil disturbance intervals inferred from soil charcoal radiocarbon dates

2003 ◽  
Vol 33 (12) ◽  
pp. 2514-2518 ◽  
Author(s):  
Daniel G Gavin
Keyword(s):  
Forest Soil ◽  
Forest Fires ◽  
Mineral Soil ◽  
Soil Disturbance ◽  
Organic Horizon ◽  
Radiocarbon Dates ◽  
Soil Charcoal ◽  
Old Growth Forest ◽  
Soil Disturbances ◽  
Tree Uprooting

Forest soil disturbance intervals are usually too long to measure using plot-based studies, and thus they are poorly understood. The mean soil disturbance interval (MSDI) in an old-growth forest on the west coast of Vancouver Island was estimated from radiocarbon dates of charcoal from organic and mineral soil horizons. Two assumptions are required to estimate the MSDI: (1) charcoal from forest fires is deposited within the organic horizon and eventually mixed into deeper mineral horizons by soil disturbances, and (2) the probability of soil disturbance is spatially homogeneous and affected only by the time since the last fire or the last soil disturbance. The MSDI is then estimated by the rate at which the proportion of undisturbed sample sites (determined by the proportion of sites with charcoal from the most recent fire in the organic horizon) decreases with increasing time since the last fire. Soil charcoal evidence of time since fire was determined at 83 sites using 141 radiocarbon dates. The estimated MSDI was greater on slopes (ca. 2010 years) than on terraces (ca. 920 years). The long periods between soil disturbances, especially on slopes, are consistent with other evidence from the study area that suggests infrequent tree uprooting is the predominant mode of soil disturbance.

Streamside Management Zones Affect Movement of Silvicultural Nitrogen and Phosphorus Fertilizers to Piedmont Streams

2013 ◽  
Vol 37 (1) ◽  
pp. 26-35 ◽  
Author(s):  
Joseph M. Secoges ◽  
Wallace M. Aust ◽  
John R. Seiler ◽  
C. Andrew Dolloff ◽  
William A. Lakel
Keyword(s):  
Nitrogen And Phosphorus ◽  
Management Zones ◽  
Streamside Management Zones ◽  
Phosphorus Fertilizers
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