scholarly journals Effects of Cover Crop Species and Season on Population Dynamics of Escherichia coli and Listeria innocua in Soil

2016 ◽  
Vol 82 (6) ◽  
pp. 1767-1777 ◽  
Author(s):  
Neiunna L. Reed-Jones ◽  
Sasha Cahn Marine ◽  
Kathryne L. Everts ◽  
Shirley A. Micallef
Keyword(s):  
Escherichia Coli ◽  
Cover Crops ◽  
Cover Crop ◽  
Green Manure ◽  
Listeria Innocua ◽  
Hairy Vetch ◽  
Bacterial Populations ◽  
Content Type ◽  
E Coli ◽  
Crimson Clover

ABSTRACTCover crops provide several ecosystem services, but their impact on enteric bacterial survival remains unexplored. The influence of cover cropping on foodborne pathogen indicator bacteria was assessed in five cover crop/green manure systems: cereal rye, hairy vetch, crimson clover, hairy vetch-rye and crimson clover-rye mixtures, and bare ground. Cover crop plots were inoculated withEscherichia coliandListeria innocuain the fall of 2013 and 2014 and tilled into the soil in the spring to form green manure. Soil samples were collected and the bacteria enumerated. Time was a factor for all bacterial populations studied in all fields (P< 0.001).E. colilevels declined when soil temperatures dipped to <5°C and were detected only sporadically the following spring.L. innocuadiminished somewhat but persisted, independently of season. In an organic field, the cover crop was a factor forE. coliin year 1 (P= 0.004) and forL. innocuain year 2 (P= 0.011). In year 1,E. colilevels were highest in the rye and hairy vetch-rye plots. In year 2,L. innocualevels were higher in hairy vetch-rye (P= 0.01) and hairy vetch (P= 0.03) plots than in the rye plot. Bacterial populations grew (P< 0.05) or remained the same 4 weeks after green manure incorporation, although initial reductions inL. innocuanumbers were observed after tilling (P< 0.05). Green manure type was a factor only forL. innocuaabundance in a transitional field (P< 0.05). Overall, the impacts of cover crops/green manures on bacterial population dynamics in soil varied, being influenced by bacterial species, time from inoculation, soil temperature, rainfall, and tillage; this reveals the need for long-term studies.

scholarly journals Cover Crop and Fertility Effects on Escherichia coli Abundance in a Composted Poultry Litter-Amended Silt Loam Soil

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Sait Sarr ◽  
Mark Coyne ◽  
Maheteme Gebremedhin ◽  
Avinash Topè ◽  
Shreya Patel
Keyword(s):  
Escherichia Coli ◽  
Cover Crops ◽  
Cover Crop ◽  
Crop Production ◽  
Poultry Litter ◽  
Fecal Coliforms ◽  
Fecal Indicator ◽  
Significant Treatment ◽  
E Coli ◽  
Crimson Clover

Soil conservation practices such as cover crops can improve crop production, soil quality, and water quality. Cover crops can also influence soil microbial growth and activity. Cover cropped and manured soils can potentially store and transmit fecal bacteria (e.g., E. coli) to surface water if runoff and subsurface seepage occur. While many studies have shown the soil health benefits of cover crops, fewer studies have evaluated the extent to which cover crops influence the abundance of potential waste-borne pathogens. A two-year study (2015–2017) was conducted on a limited-resource farm in Logan County, Kentucky, USA, to quantify the abundance of the fecal indicator Escherichia coli (E. coli) bacteria (as a proxy for fecal coliforms) in treatments with and without cover crops or composted poultry litter. The cover crop consisted of a cereal rye (Secale cereale L.), Austrian winter pea (Pisum sativum L.), and crimson clover (Trifolium incarnatum L.) mix. Summer crops consisted of a no-till maize (Zea mays L.)—soybean (Glycine max L.) rotation. Soil samples were taken before and after each summer crop season and assessed to detect and enumerate E. coli. At the end of the study period, no significant treatment differences in the E. coli abundance in soil were detected (ca. 104 CFU·g−1) (p>0.05). However, season/time was a significant factor (p<0.05). We conclude that the background E. coli already present in soil was sufficiently high, inhibiting the detection of the influence of added composted litter. These indigenous E. coli were unaffected by cover crop and nutrient management but did fluctuate on a seasonal basis.

Influence of legume cover crops and conservation tillage on soil populations of selected fungal genera

1988 ◽  
Vol 34 (3) ◽  
pp. 201-206 ◽  
Author(s):  
C. S. Rothrock ◽  
W. L. Hargrove
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Conservation Tillage ◽  
Field Studies ◽  
Macrophomina Phaseolina ◽  
Hairy Vetch ◽  
Fusarium Spp ◽  
Crimson Clover ◽  
Legume Cover Crops ◽  
Legume Cover Crop

The influence of winter legume cover crops and of tillage on soil populations of fungal genera containing plant pathogenic species in the subsequent summer sorghum crop were examined in field studies. Legume cover crops significantly increased populations of Pythium spp. throughout the sorghum crop compared with a rye cover crop or no cover crop. This stimulation of the populations of Pythium spp. was not solely due to colonization of cover-crop residue, as populations were significantly greater at the time the legume cover crop was desiccated. Removal of aboveground residue generally decreased populations of Pythium spp. in soil. Incorporation of residue by tillage increased populations of Pythium spp. at some sampling dates. Legumes differed in the magnitude of stimulation, with hairy vetch stimulating Pythium spp. more than crimson clover. Cover crop treatments did not consistently influence soil populations of Fusarium spp., Rhizoctonia solani, Rhizoctonia-like binucleate fungi, or Macrophomina phaseolina. Macrophomina phaseolina populations were significantly greater under no tillage.

scholarly journals Carryover of Common Corn and Soybean Herbicides to Various Cover Crop Species

2017 ◽  
Vol 31 (1) ◽  
pp. 21-31 ◽  
Author(s):  
Cody D. Cornelius ◽  
Kevin W. Bradley
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Production Systems ◽  
Italian Ryegrass ◽  
Hairy Vetch ◽  
Crop Species ◽  
Cereal Rye ◽  
Crimson Clover ◽  
Crop Establishment ◽  
Biomass Reduction

The recent interest in cover crops as component of Midwest corn and soybean production systems has led to the need for additional research, including the effects of residual corn and soybean herbicide treatments on fall cover crop establishment. Field studies were conducted in 2013, 2014, and 2015 in Columbia, Missouri to investigate the effects of common residual herbicides applied in corn and soybean on establishment of winter wheat, tillage radish, cereal rye, crimson clover, winter oat, Austrian winter pea, Italian ryegrass, and hairy vetch. Cover crops were evaluated for stand and biomass reduction 28 d after emergence (DAE). Rainfall from herbicide application to cover crop seeding date was much greater in 2014 and 2015, which resulted in less carryover in these years compared to 2013. When averaged across all herbicides evaluated in these experiments, the general order of sensitivity of cover crops to herbicide carryover, from greatest to least was Austrian winter pea=crimson clover>oilseed radish>Italian ryegrass>hairy vetch>wheat >winter oat>cereal rye. Cereal rye had the fewest instances of biomass or stand reduction with only four out of the 27 herbicides adversely effecting establishment. Pyroxasulfone consistently reduced Italian ryegrass and winter oat biomass at least 67% in both the corn and soybean experiments. In the soybean experiment, imazethapyr- and fomesafen-containing products resulted in severe stand and biomass reduction in both years while flumetsulam-containing products resulted in the greatest carryover symptoms in the corn experiment. Results from these experiments suggest that several commonly used corn and soybean herbicides have the potential to hinder cover crop establishment, but the severity of damage will depend on weather, cover crop species, and the specific herbicide combination.

Herbicide selection to terminate grass, legume, and brassica cover crop species

2019 ◽  
Vol 34 (1) ◽  
pp. 48-54
Author(s):  
Kara B. Pittman ◽  
Charles W. Cahoon ◽  
Kevin W. Bamber ◽  
Lucas S. Rector ◽  
Michael L. Flessner
Keyword(s):  
Active Ingredient ◽  
Cover Crops ◽  
Cover Crop ◽  
Field Studies ◽  
Weed Suppression ◽  
Hairy Vetch ◽  
Crop Species ◽  
Rating Data ◽  
Crimson Clover ◽  
And Control

AbstractCover crops provide a number of agronomic benefits, including weed suppression, which is important as cases of herbicide resistance continue to rise. To effectively suppress weeds, high cover crop biomass is needed, which necessitates later termination timing. Cover crop termination is important to mitigate potential planting issues and prevent surviving cover crop competition with cash crops. Field studies were conducted in Virginia to determine the most effective herbicide options alone or combined with glyphosate or paraquat to terminate a range of cover crop species. Results revealed that grass cover crop species were controlled (94% to 98%) by glyphosate alone 4 wk after application (WAA). Overall, legume species varied in response to the single active-ingredient treatments, and control increased with the addition of glyphosate or paraquat. Mixes with glyphosate provided better control of crimson clover and hairy vetch by 7% to 8% compared with mixes containing paraquat 4 WAA. Mix partner did not influence control of Austrian winter pea. No treatment adequately controlled rapeseed in this study, with a maximum of 58% control observed with single active-ingredient treatments and 62% control with mixes. Height reduction for all cover crop species supports visible rating data. Rapeseed should be terminated when smaller, which could negate weed suppressive benefits from this cover crop species. Growers should consider herbicide selection and termination timing in their cover crop plan to ensure effective termination.

Evaluating Cover Crops and Herbicides for Glyphosate-Resistant Palmer Amaranth (Amaranthus palmeri) Control in Cotton

2016 ◽  
Vol 30 (2) ◽  
pp. 415-422 ◽  
Author(s):  
Matthew S. Wiggins ◽  
Robert M. Hayes ◽  
Lawrence E. Steckel
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
The United States ◽  
Palmer Amaranth ◽  
Amaranthus Palmeri ◽  
Hairy Vetch ◽  
Cereal Rye ◽  
Crimson Clover ◽  
Legume Cover Crops ◽  
Herbicide Programs

Glyphosate-resistant (GR) weeds, especially GR Palmer amaranth, are very problematic in cotton-producing areas of the midsouthern region of the United States. Growers rely heavily on PRE residual herbicides to control Palmer amaranth since few effective POST options exist. Interest in integrating high-residue cover crops with existing herbicide programs to combat GR weeds has increased. Research was conducted in 2013 and 2014 in Tennessee to evaluate GR Palmer amaranth control when integrating cover crops and PRE residual herbicides. Cereal rye, crimson clover, hairy vetch, winter wheat, and combinations of one grass plus one legume were compared with winter weeds without a cover crop followed by fluometuron or acetochlor applied PRE. Biomass of cover crops was determined prior to termination 3 wk before planting. Combinations of grass and legume cover crops accumulated the most biomass (> 3,500 kg ha−1) but by 28 d after application (DAA) the cereal rye and wheat provided the best Palmer amaranth control. Crimson clover and hairy vetch treatments had the greatest number of Palmer amaranth. These cereal and legume blends reduced Palmer amaranth emergence by half compared to non–cover-treated areas. Fluometuron and acetochlor controlled Palmer amaranth 95 and 89%, respectively, at 14 DAA and 54 and 62%, respectively, at 28 DAA. Cover crops in combination with a PRE herbicide did not adequately control Palmer amaranth.

scholarly journals Effectiveness of Cover Crop Termination Methods on No-Till Cantaloupe

Agriculture ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 66
Author(s):  
Ted S. Kornecki ◽  
Corey M. Kichler
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Hairy Vetch ◽  
Two Stage ◽  
Cereal Rye ◽  
Crimson Clover ◽  
Termination Rate ◽  
Growing Seasons ◽  
No Till ◽  
Crop Planting

In a no-till system, there are many different methods available for terminating cover crops. Mechanical termination, utilizing rolling and crimping technology, is one method that injures the plant without cutting the stems. Another popular and commercially available method is mowing, but this can cause problems with cover crop re-growth and loose residue interfering with the planter during cash crop planting. A field experiment was conducted over three growing seasons in northern Alabama to determine the effects of different cover crops and termination methods on cantaloupe yield in a no-till system. Crimson clover, cereal rye, and hairy vetch cover crops were terminated using two different roller-crimpers, including a two-stage roller-crimper for four-wheel tractors and a powered roller-crimper for a two-wheel walk-behind tractor. Cover crop termination rates were evaluated one, two, and three weeks after termination. Three weeks after rolling, a higher termination rate was found for flail mowing (92%) compared to lower termination rates for a two-stage roller (86%) and powered roller-crimper (85%), while the control termination rate was only 49%. There were no significant differences in cantaloupe yield among the rolling treatments, which averaged 38,666 kg ha−1. However, yields were higher for cereal rye and hairy vetch cover crops (41,785 kg ha−1 and 42,000 kg ha−1) compared to crimson clover (32,213 kg ha−1).

scholarly journals Comparison of Mixtures vs. Monocultures of Cover Crops for Fresh-market Tomato Production With and Without Herbicide

HortScience ◽  
1998 ◽  
Vol 33 (7) ◽  
pp. 1163-1166 ◽  
Author(s):  
John R. Teasdale ◽  
Aref A. Abdul-Baki
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
C:N Ratio ◽  
Weed Suppression ◽  
Hairy Vetch ◽  
Fresh Market ◽  
Vicia Villosa ◽  
Tomato Production ◽  
Crimson Clover ◽  
Marketable Fruit

Hairy vetch (Vicia villosa Roth), crimson clover (Trifolium incarnatum L.), and rye (Secale cereale L.) and mixtures of rye with hairy vetch and/or crimson clover were compared for no-tillage production of staked, fresh-market tomatoes (Lycopersicon esculentum Mill.) on raised beds. All cover crops were evaluated both with or without a postemergence application of metribuzin for weed control. Biomass of cover crop mixtures were higher than that of the hairy vetch monocrop. Cover crop nitrogen content varied little among legume monocrops and all mixtures but was lower in the rye monocrop. The C:N ratio of legume monocrops and all mixtures was <30 but that of the rye monocrop was >50, suggesting that nitrogen immobilization probably occurred only in the rye monocrop. Marketable fruit yield was similar in the legume monocrops and all mixtures but was lower in the rye monocrop when weeds were controlled by metribuzin. When no herbicide was applied, cover crop mixtures reduced weed emergence and biomass compared to the legume monocrops. Despite weed suppression by cover crop mixtures, tomatoes grown in the mixtures without herbicide yielded lower than the corresponding treatments with herbicide in 2 of 3 years. Chemical name used: [4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one](metribuzin).

Preplant-Postemergence Herbicides for Legume Cover-Crop Control in Minimum Tillage Systems

1990 ◽  
Vol 4 (2) ◽  
pp. 332-336 ◽  
Author(s):  
James L. Griffin ◽  
Seth M. Dabney
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Subterranean Clover ◽  
Field Studies ◽  
Application Time ◽  
Hairy Vetch ◽  
Crimson Clover ◽  
Legume Cover Crops ◽  
Legume Cover Crop ◽  
Postemergence Herbicides

Field studies were conducted to compare preplant-postemergence-applied paraquat, glyphosate, SC-0224, and HOE-39866 on subterranean clover, crimson clover, and hairy vetch cover crops. Subterranean clover control with paraquat at 1.1 kg ai/ha was about 80 and 100% when applied in early April and early May, respectively, regardless of spray volume (190 vs. 370 L/ha). Glyphosate and SC-0224 at 1.7 and 2.8 kg ai/ha applied in April controlled about 53% of subterranean clover. Subterranean clover control with HOE-39866 at 0.8 kg ai/ha applied in April was excellent. Paraquat at 0.6 kg ai/ha and HOE-39866 at 0.8 kg/ha regardless of application time controlled both crimson clover and hairy vetch. Grain sorghum and soybean yields following the legume cover crops generally were similar for the herbicide treatments.

scholarly journals Genotypic-Phenotypic Discrepancies between Antibiotic Resistance Characteristics of Escherichia coli Isolates from Calves in Management Settings with High and Low Antibiotic Use

2011 ◽  
Vol 77 (10) ◽  
pp. 3293-3299 ◽  
Author(s):  
Margaret A. Davis ◽  
Thomas E. Besser ◽  
Lisa H. Orfe ◽  
Katherine N. K. Baker ◽  
Amelia S. Lanier ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Gene ◽  
Resistance Genes ◽  
Antibiotic Use ◽  
Dairy Calf ◽  
Bacterial Populations ◽  
Content Type ◽  
Exact Test ◽  
E Coli ◽  
Fisher’S Exact Test

ABSTRACTWe hypothesized that bacterial populations growing in the absence of antibiotics will accumulate more resistance gene mutations than bacterial populations growing in the presence of antibiotics. If this is so, the prevalence of dysfunctional resistance genes (resistance pseudogenes) could provide a measure of the level of antibiotic exposure present in a given environment. As a proof-of-concept test, we assayed field strains ofEscherichia colifor their resistance genotypes using a resistance gene microarray and further characterized isolates that had resistance phenotype-genotype discrepancies. We found a small but significant association between the prevalence of isolates with resistance pseudogenes and the lower antibiotic use environment of a beef cow-calf operation versus a higher antibiotic use dairy calf ranch (Fisher's exact test,P= 0.044). Other significant findings include a very strong association between the dairy calf ranch isolates and phenotypes unexplained by well-known resistance genes (Fisher's exact test,P< 0.0001). Two novel resistance genes were discovered inE. coliisolates from the dairy calf ranch, one associated with resistance to aminoglycosides and one associated with resistance to trimethoprim. In addition, isolates resistant to expanded-spectrum cephalosporins but negative forblaCMY-2had mutations in the promoter regions of the chromosomalE. coliampCgene consistent with reported overexpression of native AmpC beta-lactamase. Similar mutations in hospitalE. coliisolates have been reported worldwide. Prevalence or rates ofE. coliampCpromoter mutations may be used as a marker for high expanded-spectrum cephalosporin use environments.

scholarly journals Legume and Grass Cover Crops for Seedless Watermelon Production

2002 ◽  
Vol 12 (2) ◽  
pp. 245-249 ◽  
Author(s):  
M. Rangappa ◽  
A.A. Hamama ◽  
H.L. Bhardwaj
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Fruit Weight ◽  
Fruit Yield ◽  
Soluble Solids ◽  
Control Treatment ◽  
Hairy Vetch ◽  
Crimson Clover ◽  
Legume Cover Crops ◽  
Seedless Watermelon

Although there is increasing interest in reducing the use of nitrogen (N) fertilizers due to the potential of unused N causing pollution of surface and groundwater, N is a major nutrient for plant growth. Our objective was to determine the potential of using winter legume cover crops to meet the N needs of seedless watermelon (Citrullus lanatus), a potential cash crop for farmers in Virginia. Fruit number, fruit weight, fruit yield, and fruit quality traits (flesh to rind ratio, water content, total soluble solids, sugar content, and pH) of seedless watermelons were evaluated in replicated experiments in Virginia at three locations during 1997-98 and two locations during 1998-99 following cover crop treatments consisting of crimson clover (Trifolium incarnatum), hairy vetch (Vicia villosa), crimson clover + rye (Secale cereale), hairy vetch + rye, and a bareground control treatment that received 100 lb/acre (112 kg·ha-1) of N. At all five locations, the bareground control treatment resulted in fewer fruit [1803 fruit/acre (4454 fruit/ha)], lower fruit weight [9.8 lb (4.5 kg)], and lower fruit yield [8.9 tons/acre (20.0 t·ha-1)] compared to the four cover crop treatments. The crimson clover + rye and hairy vetch treatments resulted in highest numberof fruit [2866 and 2657 fruit/acre (7079 and 6563 fruit/ha), respectively], whereas the highest fruit yield was obtained following hairy vetch [21.2 tons/acre (49.8 t·ha-1)], hairy vetch + rye [20.3 tons/acre (45.5 t·ha-1)], and crimson clover + rye [19.6 tons/acre (43.9 t·ha-1)]. Cover crop treatments did not affect the quality of watermelon flesh. The seedless watermelon fruit averaged 1.4 flesh: 1 rind ratio, 90% water content, 9.5% total soluble solids, 8.0% sugar, and a pH value of 5.9. These results indicated that legume cover crops, such as crimson clover and hairy vetch, can be successfully used to produce seedless watermelons, in a no-till system, without any use of N fertilizers with dryland conditions.

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