Life Sciences Commons^™

Shotgun Metagenomic Sequencing Data Of Sunflower Rhizosphere Microbial Community In South Africa, Olubukola Oluranti Babalola, Temitayo Tosin Alawiye, Carlos M. Rodriguez Lopez, Ayansina Segun Ayangbenro

Horticulture Faculty Publications

This dataset presents shotgun metagenomic sequencing of sunflower rhizosphere microbiome in Bloemhof, South Africa. Data were collected to decipher the structure and function in the sunflower microbial community. Illumina HiSeq platform using next generation sequencing of the DNA was carried out. The metagenome comprised 8,991,566 sequences totaling 1,607,022,279 bp size and 66% GC content. The metagenome was deposited into the NCBI database and can be accessed with the SRA accession number SRR10418054. An online metagenome server (MG RAST) using the subsystem database revealed bacteria had the highest taxonomical representation with 98.47%, eukaryote at 1.23%, and archaea at 0.20%. The most …

Soil Net Nitrogen Mineralisation Across Global Grasslands, A. C. Risch, S. Zimmerman, R. Ochoa-Hueso, M. Schütz, B. Frey, J. L. Firn, P. A. Fay, F. Hagedorn, E. T. Borer, E. W. Seabloom, W. S. Harpole, J. M. H. Knops, Rebecca L. Mcculley, A. A. D. Broadbent, C. J. Stevens, M. L. Silveria, P. B. Adler, S. Báez, L. A. Biederman, J. M. Blair

Plant and Soil Sciences Faculty Publications

Soil nitrogen mineralisation (N_min), the conversion of organic into inorganic N, is important for productivity and nutrient cycling. The balance between mineralisation and immobilisation (net N_min) varies with soil properties and climate. However, because most global-scale assessments of net N_min are laboratory-based, its regulation under field-conditions and implications for real-world soil functioning remain uncertain. Here, we explore the drivers of realised (field) and potential (laboratory) soil net N_min across 30 grasslands worldwide. We find that realised N_min is largely explained by temperature of the wettest quarter, microbial biomass, clay content and bulk density. …

Managing Nitrous Oxide Emissions In Agricultural Fields, Mark S. Coyne, Wei Ren

Plant and Soil Sciences Research Report

Agriculture is a major contributor to atmospheric nitrous oxide (N₂O) (Smith et al., 2014; Tian et al., 2015). Unfortunately, nitrous oxide destroys stratospheric ozone (O₃) which protects us from ultraviolet radiation (Cicerone, 1989) and it increases ground level O_3, whichis an air pollutant threatening human health and food production. Nitrous oxide is also 298 times more potent than an equivalent amount of carbon dioxide (CO₂) in terms of trapping and absorbing reflected solar radiation (Forster et al., 2007). Basic chemistry and physics assure us that increased levels of N₂O in the …

Seed Germination Ecology Of The Cold Desert Annual Isatis Violascens (Brassicaceae): Two Levels Of Physiological Dormancy And Role Of The Pericarp, Yuan M. Zhou, Juan J. Lu, Dun Y. Tan, Carol C. Baskin, Jerry M. Baskin

Biology Faculty Publications

The occurrence of various species of Brassicaceae with indehiscent fruits in the cold deserts of NW China suggests that there are adaptive advantages of this trait. We hypothesized that the pericarp of the single-seeded silicles of Isatis violascens restricts embryo expansion and thus prevents germination for 1 or more years. Thus, our aim was to investigate the role of the pericarp in seed dormancy and germination of this species. The effects of afterripening, treatment with gibberellic acid (GA₃) and cold stratification on seed dormancy-break were tested using intact silicles and isolated seeds, and germination phenology was monitored in …

A Response Regulator From A Soil Metagenome Enhances Resistance To The Β-Lactam Antibiotic Carbenicillin In Escherichia Coli, Heather K. Allen, Ran An, Jo Handelsman, Luke A. Moe

Plant and Soil Sciences Faculty Publications

Functional metagenomic analysis of soil metagenomes is a method for uncovering as-yet unidentified mechanisms for antibiotic resistance. Here we report an unconventional mode by which a response regulator derived from a soil metagenome confers resistance to the β-lactam antibiotic carbenicillin in Escherichia coli. A recombinant clone (βlr16) harboring a 5,169 bp DNA insert was selected from a metagenomic library previously constructed from a remote Alaskan soil. The βlr16 clone conferred specific resistance to carbenicillin, with limited increases in resistance to other tested antibiotics, including other β-lactams (penicillins and cephalosporins), rifampin, ciprofloxacin, erythromycin, chloramphenicol, nalidixic acid, fusidic acid, and gentamicin. Resistance …

Fragipan Horizon Fragmentation In Slaking Experiments With Amendment Materials And Ryegrass Root Tissue Extracts, Anastasios D. Karathanasis, Lloyd W. Murdock, Christopher J. Matocha, John H. Grove, Yvonne L. Thompson

Plant and Soil Sciences Faculty Publications

Slaking experiments were conducted of fragipan clods immersed in solutions of poultry manure, aerobically digested biosolid waste (ADB), fluidized bed combustion byproduct (FBC), D-H₂O, CaCO₃, NaF, Na-hexa-metaphosphate, and ryegrass root biomass. The fragipan clods were sampled from the Btx horizon of an Oxyaquic Fragiudalf in Kentucky. Wet sieving aggregate analysis showed significantly better fragmentation in the NaF, Na-hexa-metaphosphate, and ryegrass root solutions with a mean weight diameter range of 15.5-18.8 mm compared to the 44.2-47.9 mm of the poultry manure, ADB, and FBC treatments. Dissolved Si, Al, Fe, and Mn levels released in solution were ambiguous. …

Induced Transcriptional Profiling Of Phenylpropanoid Pathway Genes Increased Flavonoid And Lignin Content In Arabidopsis Leaves In Response To Microbial Products, Mohammad Babar Ali, David H. Mcnear

Plant and Soil Sciences Faculty Publications

BACKGROUND: The production and use of biologically derived soil additives is one of the fastest growing sectors of the fertilizer industry. These products have been shown to improve crop yields while at the same time reducing fertilizer inputs to and nutrient loss from cropland. The mechanisms driving the changes in primary productivity and soil processes are poorly understood and little is known about changes in secondary productivity associated with the use of microbial products. Here we investigate secondary metabolic responses to a biologically derived soil additive by monitoring changes in the phenlypropanoid (PP) pathway in Arabidopsis thaliana.

RESULTS: This study …

Effects Of Long-Term Cattle Grazing And Woody Plant Encroachment On Soil Microbial Communities At The Santa Rita Experimental Range, Arizona, Cody Burton, Steven Archer, Rebecca L. Mcculley

Plant and Soil Sciences Presentations

Livestock grazing is considered a key driver of woody plant encroachment in dryland ecosystems worldwide. Woody plant establishment in these systems creates “islands of fertility,” in part by modifying erosional processes such that soil and plant litter are deposited beneath the shrub canopy, creating a nutrient rich soil/litter matrix that supports enhanced soil microbial biomass pools. In this study, we utilized a long-term grazing exclosure (>80 yrs) at the Santa Rita Experimental Range south of Tucson, Arizona and phopsholipid fatty acid analysis to quantify livestock grazing effects on soil microbial communities associated with the complex vegetative mosaic that characterizes …

In Situ Generated Colloid Transport Of Cu And Zn In Reclaimed Mine Soil Profiles Associated With Biosolids Application, Jarrod O. Miller, Anastasios D. Karathanasis, Christopher J. Matocha

Plant and Soil Sciences Faculty Publications

Areas reclaimed for agricultural uses following coal mining often receive biosolids applications to increase organic matter and fertility. Transport of heavy metals within these soils may be enhanced by the additional presence of biosolids colloids. Intact monoliths from reclaimed and undisturbed soils in Virginia and Kentucky were leached to observe Cu and Zn mobility with and without biosolids application. Transport of Cu and Zn was observed in both solution and colloid associated phases in reclaimed and undisturbed forest soils, where the presence of unweathered spoil material and biosolids amendments contributed to higher metal release in solution fractions. Up to 81% …

Soil Microbial Community Response To Hexavalent Chromium In Planted And Unplanted Soil, Ioannis Ipsilantis, Mark S. Coyne

Plant and Soil Sciences Faculty Publications

Theories suggest that rapid microbial growth rates lead to quicker development of metal resistance. We tested these theories by adding hexavalent chromium [Cr(VI)] to soil, sowing Indian mustard (Brassica juncea), and comparing rhizosphere and bulk soil microbial community responses. Four weeks after the initial Cr(VI) application we measured Cr concentration, microbial biomass by fumigation extraction and soil extract ATP, tolerance to Cr and growth rates with tritiated thymidine incorporation, and performed community substrate use analysis with BIOLOG GN plates. Exchangeable Cr(VI) levels were very low, and therefore we assumed the Cr(VI) impact was transient. Microbial biomass was reduced …

Effects Of Commercial Diazinon And Imidacloprid On Microbial Urease Activity In Soil And Sod, C. W. Ingram, Mark S. Coyne, David W. Williams

Plant and Soil Sciences Faculty Publications

Diazinon [O,O-diethyl O-2-isopropyl-6-methyl(pyrimidine-4-yl) phosphorothioate] and imidacloprid [1-(1-[6-chloro-3-pyridinyl]methyl)-N-nitro-2-imidazolidinimine] are applied to lawns for insect control simultaneously with nitrogenous fertilizers such as urea, but their potential effect on urease activity and nitrogen availability in turfgrass management has not been evaluated. Urease activity in enzyme assays, washed cell assays, and soil slurries was examined as a function of insecticide concentration. Intact cores from field sites were used to assess the effect of insecticide application on urease activity in creeping bentgrass (Agrostis palustris Huds.) and bluegrass (Poa pratensis L.) sod. Bacterial urease fromBacillus pasteurii and plant …

Escherichia Coli Pathogen O157:H7 Does Not Survive Longer In Soil Than A Nonpathogenic Fecal Coliform, D. N. Mubiru, Mark S. Coyne, John H. Grove

Agronomy Notes

Survival rates for individual types of fecal organisms are quite different. Although some pathogens may persist as long as 5 years in soil, most fecal pathogens from human and animal waste usually die very quickly. Two to three months is sufficient in most cases to reduce pathogens to negligible numbers once they have been excreted or land-applied in animal wastes.

It is expensive and time- consuming to test for individual pathogens. Consequently, nonpathogenic fecal indicator bacteria, which are easily and inexpensively detected, are often used to study pathogen survival in soil and water. Current methods for rapidly detecting fecal indicator …

Quality Of Runoff From Four Northwest Arkansas Pasture Fields Treated With Organic And Inorganic Fertilizer, Dwayne R. Edwards, Tommy C. Daniel, John F. Murdoch, Philip A. Moore Jr.

Biosystems and Agricultural Engineering Faculty Publications

Long-term land application of animal manures, even at agronomic rates, can promote accumulation of soil phosphorus (P) which can, in turn, contribute to increased P loadings to downstream waters. The objective of this study was to assess the soil and runoff effects of replacing animal manure as a soil amendment with inorganic fertilizer (ammonium nitrate, NH₄NO₃) on fields that had been treated previously with animal manures. Runoff from two pairs of small fields (0.57 to 1.46 ha) was sampled from September 1991 to April 1994. All fields had been treated previously with animal manures; after runoff …

Nitrous Oxide Loss From Poultry Manure-Amended Soil After Rain, Mark S. Coyne, A. Villalba, Robert L. Blevins

Plant and Soil Sciences Faculty Publications

Land application of poultry wastes in Kentucky will increase as the broiler industry grows. If poultry manure stimulates N₂O loss from soil it will reduce the fertilizer N value of this waste. In contrast, stimulated N₂O loss in grass filter strips receiving the runoff from manured fields could help reduce contamination of surface water by NO⁻₃. Our objectives were to determine (i) if poultry manure stimulated N₂O loss in soil after rainfall and (ii) if there was an edge-of-field effect on N₂O loss in grass filters intercepting runoff from …

A Survey Of The Content Of Some Heavy Metals In Soil And Corn Grain In The Pond And Lower Green River Bottoms, Kenneth L. Wells, Greg Henson, George Kelley

Agronomy Notes

Corn is intensively grown along the Green and Pond Rivers in McLean, Hopkins, and Webster Counties, Kentucky, representing a major source of income to producers in those areas. However, producers in McLean County have experienced poorer corn production than expected for many years. This has been observed more on the Pond River bottoms and the Green River bottoms below the confluence of the Pond than upstream on the Green above the Pond. Some producers have speculated that their poor production may be associated with chemical pollution from the Pond River and/or nearby industrial sources. On this basis, an assumption was …

1990 Kentucky Red Clover Variety Test, L. M. Lauriault, Norman L. Taylor, Jimmy C. Henning, W. T. Edmonson

Agronomy Notes

Red clover is a high quality, shortlived perennial legume that is used in mixed or pure stands for pasture, hay, silage, green chop, and soil improvement. This species is adapted to a wide range of climatic and soil conditions and therefore is very versatile as a forage crop. Stands are generally productive for two or three years with the highest yields occurring in the year following establishment. Red clover is used primarily as a renovation legume for grass pastures. It is the dominant legume in Kentucky because it is high in seedling vigor, quality, yield, and animal acceptance.

Response Of Soybeans To Available Potassium In Three Kentucky Soils, John H. Grove, William O. Thom, Lloyd W. Murdock, James H. Herbek

Agronomy Notes

Soybeans are produced in nearly all of Kentucky's soil physiographic regions. Soybean response to potassium (K) fertilization and soil test Kvaries with soil type and location. This variation may be associated with the wide range in soil chemical and mineralogical properties among the different regions. Of particular interest are differences in that level of soil test Kat which no further yield response to K fertilizer application would be expected. The main objective of this work was to evaluate the soil K-soybean response relationship on three different field sites where soybean yields were increased by fertilizer K. Several measures of soil …

Soil Test Potassium As An Indicator Of Tobacco Response To Band Application Of Fertilizer, J. L. Sims, Kenneth L. Wells, E. C. Schwamberger

Agronomy Notes

During the past 10 years, several studies have been conducted at Lexington on the University of Kentucky Experiment Farm to compare the effect of banding fertilizer 10 to 12 inches to each side of the row with preplant broadcast applications on growth and yield of burley tobacco. Generally, banding most of the nitrogen and potassium has led to fewer problems with salt and manganese toxicity and to improved growth during the early season. However, as compared to broadcast application, banding has had varying effects on cured leaf yields. In 'some experiments banding resulted in higher yields, in other experiments in …

The Effect Of Three Tillage Systems On Bulk Density And Porosity Of A Pembroke And A Beasley Soil After Three Years, Kenneth L. Wells, John H. Grove

Agronomy Notes

Many grain producers in Kentucky use a 3 crop in 2 year rotation of corn followed by small grain-soybeans, and commonly no-till the soybeans and corn in order to intensively use sloping land for continuous grain production. Because of the intensity of machinery traffic in this system, growers are concerned that continuous no-till management may cause compaction, and that such fields may need occasional primary tillage. In order to obtain' information regarding things situation, we conducted a test for 3 years on the farm of' Philip Lyvers, in Marion County, Kentucky, in a field which was being used in a …

Adjusting Soil Ph On Heavy Textured Soils Of The Eden Hills, Kenneth L. Wells, R. M. Jones

Agronomy Notes

The Eden Hills Area (also known as The Hills of the Bluegrass) of Kentucky lies adjacent to the Inner Bluegrass Area in a crescent shape within which a large area of several counties occur. Carroll, Owen, Grant, Gallatin, Pendleton, and Robertson Counties occur almost entirely within this physiographic region and several other counties have sizable acreages within it. Soils of the area have formed largely on Ordovician aged calcareous siltstones of the Garrard Formation and interbedded calcareous shales, thin limestones, and siltstones of the Eden Formation. Soils developed from these formations occur on strongly sloping to steep landscapes and have …

In-The-Row Subsoiling Of Tobacco, Lloyd W. Murdock, George Everette, Ted Howard, Bill Green, Richard Barnhisel

Agronomy Notes

Tobacco is probably more adversely affected by soil compaction than, the other crops grown in Kentucky. ThIs Is due to the characteristIcs of the plant and the unusual cultural practIces under which it is grown.

Soil compaction increases soil density while reducing pore space and root penetration. The reduced pore space reduces the aeration of the soil, which reduces tobacco growth especially during wet periods. The effects of soil compaction on tobacco are due to both impedance of root growth and lack of aeration.

Effect Of Planting Dates Of No-Till And Conventional Corn On Soils With Restricted Drainage, James H. Herbek, Lloyd W. Murdock, Robert L. Blevins

Agronomy Notes

No-till corn is best adapted to well drained soils. It is on these soils that no-till has been most successful and the practice most widely accepted. On soils that are moderately well to somewhat poorly drained, no-till corn can also be successful but more management is required. Three areas which require more attention are weed control, nitrogen management and planting. It has long been recognized that no-tilling results in cooler soil temperatures which can delay and reduce seed germination and seedling emergence. Additional research also indicates that diseases which attack the corn seedling in the emergence stage are more prevalent …

An Estimate Of The Soil Fertility Status Of Graves And Todd Counties In Kentucky, Kenneth L. Wells, D. E. Peaslee, Marvin Davidson, William Green

Agronomy Notes

Some concern has developed during recent years that fertilizer is being used by farmers on fields with residual levels of P and K high enough that such use is not justified as a means of increasing crop yields. This has been due to increased "average" soil test values for samples routinely submitted to college soil test laboratories.

For this reason, studies were conducted in Graves and Todd Counties in Kentucky during the period September, 1978 to September, 1980, to determine if soil samples routinely submitted to college test laboratories do or do not accurately reflect the average soil fertility status …

Correction And Prevention Of Soil Compaction, Lloyd W. Murdock

Agronomy Notes

Soil can be compacted by both natural and man made forces. The most common cause results from tillage practices. These man induced compacted layers are often called a traffic pan, disc pan, plow pan, wheel compaction, hard pan, etc. Some compaction occurs in most soils that are tilled. If compaction is Severe enough, it may reduce plant growth and yield. Soil compaction can be corrected by subsoiling and deep plowing but they are expensive methods. Soil compaction may not be a problem if one understands compaction, its effects, and how to prevent it.

A Cropping System For Intensive Grain Production On Sloping Land, Kenneth L. Wells, H. C. Vaught, Morris J. Bitzer, M. W. Russell

Agronomy Notes

From the beginnings of Kentucky Agriculture, soil erosion and related losses in productivity have been major problems for Kentucky farmers. Improved soil conservation practices during the past forty years have been especially significant in the recovery and progress of our agricultural industry. No-tillage methods for crop production, which were pioneered in Kentucky, have proven useful in controlling erosion and holding production at high levels. During recent years, the marketplace has strongly encouraged grain production, with the unfortunate effect that many Kentucky hillsides have been returned to grain production without sufficient erosion control measures. This report describes innovations in use of …

Relationship Of Weed Control And Soil Ph To No-Tillage Corn Yields, J. J. Kells, C. E. Rieck, Robert L. Blevins, Charles H. Slack

Agronomy Notes

Atrazine and simazine are used for selective control of a broad spectrum of weeds in corn. Over 80% of the U.S. corn production is treated with one or the other of these two s-triazine herbicides. In Kentucky they are used annually on over 800,000 acres of corn, including over 200,000 acres of no-tillage corn. When added to the soil these compounds are ultimately degraded to non-phytotoxic compounds. The rate of degradation is dependent upon the physical, chemical, and biological properties of the soil. Although atrazine and simazine are chemically similar, simazine is considered to degrade slightly slower than atrazine after …

Response Of Different Crops To Various Rates Of Furnace Ash Applied As A Soil Amendment, Lloyd W. Murdock, George Everette

Agronomy Notes

Furnace ash from coal fired electrical generating steam plants has increased greatly in the last decade with the increased demand for electricity and increased restrictions on air pollution. The large volumes of ash are presenting disposal and containment problems for management of electrical generating plants. Property adjacent to the generating plants has been exposed to fly ash settling from the smoke stacks and ash over flowing from holding structures. The effects of the material on the land and its production are unknown and concern property owners.

Boron Fertilization Of Corn In Kentucky, Lloyd W. Murdock, Kenneth L. Wells, H. F. Miiller

Agronomy Notes

The need for use of boron (B) for alfalfa production has been recognized for many years in Kentucky and is presently recommended for general use as an annual topdressing on alfalfa fields. Use of B is also recommended in Kentucky for red clover fields which are to be harvested for seed. In recent years, there has been interest in use of fertilizer B for good corn production in Kentucky. Plant available B is greatly affected by soil pH and decreases with increasing soil pH. Because of this, some states recommend use of B on corn grown on soils with a …

Alfalfa Response To Varying Rates Of Phosphorus And Potassium Fertilization On Deep, Red, Limestone - Derived Soils Of The Pennyroyal Area In Kentucky, H. C. Vaught, Kenneth L. Wells, K. L. Driskill

Agronomy Notes

The Western Pennyroyal area of Kentucky consists largely of deep, well-drained limestone-derived soils occurring on an undulating to rolling landscape. A thin loess mantle overlies the limestone residuum in many areas. Soils on these landscapes are capable of good crop production, providing the basis of the rather intensive grain-hay- tobacco-livestock farming systems common to the Pennyroyal area. Because of the well-suited physical characteristics of these soils, alfalfa is a very important hay crop to this area.

Relationship Between Soil Ph And Yield Of Burley Tobacco, J. L. Sims, W. O. Atkinson, Kenneth L. Wells

Agronomy Notes

Historically, use of soil with a pH of 5.6 to 5.8 has been recommended for producing best quality burley tobacco. This recommendation for a relatively low pH resulted from the reported increases in the incidence of certain diseases, notably black root rot (Thielaviopsis basicola) and black shank (Phytophthora parasitica), in soils with pH greater than 5.8. Additionally, some researchers have reported undesirable chemical properties of cured leaf grown on soils that had been limed. However, workers at the Kentucky Agricultural Experiment Station generally have reported favorable effects from use of lime on both yield and quality of tobacco grown in …