Online Master of Agricultural and Life Sciences

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https://hdl.handle.net/10919/51287

The Online Master of Agricultural and Life Sciences (OMALS), http://www.cals.vt.edu/online/, is uniquely positioned to meet the evolving and dynamic needs of today’s agricultural professionals. The program offers concentrations in the areas of agribusiness, applied animal behavior and welfare, applied nutrition and physical activity, education, environmental science, food safety and biosecurity, and leadership studies, as well as plant science and pest management. In addition to engaging classes, students benefit from the opportunity to work on-on-one with well-respected faculty in Virginia Tech's College of Agriculture and Life Sciences to complete a rigorous final project, using what they've learned and developing real-world research and communication skills. This collection showcases final projects completed by current and former OMALS students.

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Analysis of Soil Tests: Nutrients and Soil Properties to Help Farmers Improve Management Practices
Motley, Natalie M. (Virginia Tech, 2020-05-11)
Soil nutrients and properties are the foundation of plant growth and our health. The basis of our soil starts with its texture. Soil texture impacts infiltration rate and cation exchange capacity; which in turn affects water and nutrient availability in plants. Analysis of soil nutrients and properties is imperative for effectively managing adequate soil levels and helping prevent excessive amounts of fertilizer applications. While research studies were conducted to analyze specific nutrients, these studies do not provide farmers the importance of certain nutrients and soil testing on specific farmland parcels. This research study identified soil texture for three parcels of farmland in Dewitt County, Illinois, described soil sampling methodology used, and trends of periodic testing results. Analysis of the soil testing results was compared to recommended optimal soil test values. Key nutrients that were analyzed were phosphorus, potassium, and calcium, as well as pH and organic matter content. Management practices were also assessed. Most test results identified nutrients within the optimum values. Where there were slight variations, effective management of fertilizer applications were applied. Variable rate technology was used to spread fertilizers specifically to field locations in need. Management practices, including crop rotation, were used and based on soil test results, farmers were able to maintain a critical balance of adequate soil nutrients. Further, based on pH soil test results, farmers applied a liming program to regain optimal pH levels for annual crop production. While the organic matter content on one of the three parcels had declined below the Illinois average level, the other two parcels remained within the average range. Maintaining soil nutrient levels through periodic and consistent soil testing is paramount to help farmers more efficiently use limited resources for protecting the soil quality for future generations.
Assessing Per- and Polyfluoroalkyl Substances (PFAS) Presence and Distribution in the Stormwater Systems of Socioeconomically Disadvantaged Coastal Communities
Blackburn, Savanna; Harrison, Michael (Virginia Tech, 2024-05-01)
This interdisciplinary study investigates the presence of Per- and Polyfluoroalkyl Substances (PFAS) in socioeconomically disadvantaged communities within two coastal municipalities in the Virginia Coastal Plain. Utilizing a field and laboratory approach, the research aims to assess the distribution and concentration of 30 PFAS compounds across multiple environmental receptors. Initial grab-sampling conducted across four distinct sites provided preliminary data on a wide range of PFAS, employing targeted analytical techniques to evaluate their presence. The significance of the study is underscored by the ecological and public health risks associated with PFAS contamination. Results from the analysis revealed variable concentrations of PFAS compounds across the sampled locations, suggesting a relationship between urban infrastructure, environmental justice areas, and PFAS distribution. These findings contribute to the existing body of knowledge on PFAS environmental behavior, risks, and management, highlighting the need for continued monitoring and research. Additionally, the study demonstrates the critical role of interdisciplinary collaboration in addressing complex environmental health issues, providing a foundation for future research and targeted sampling strategies to mitigate PFAS risks in urban coastal settings.
Chemical Monitoring of a Primary Water Supply: Lake Pelham in Culpeper, Virginia
Morgan, John (Virginia Tech, 2011-12)
Over the last decade there has been an increase in public and government concern over water quality in the United States, especially water bodies that are sources of drinking water. A study conducted by the United States Geologic Survey (USGS) and the National Water-Quality Assessment (NAQWA), has indicated that nutrient concentrations in streams and groundwater in basins with significant agricultural or urban development are substantially greater than naturally occurring or “background” levels (Dubrovsky, 2010). Various academic studies throughout the United States have demonstrated that many water sources are in danger of being severely polluted, with accelerated eutrophication occurring in many lakes. Specifically, the EPA, who has the task of monitoring these water bodies along with the USGS, has tightened the regulations about point and non-point sources of pollution, in an attempt to reduce the amount of eutrophication in sensitive water bodies. Lake Pelham, located in Culpeper, Virginia has experienced an increase in water quality problems; specifically an increase in nutrients in the lake, causing significant algae blooms. Increasing concern over the amount of nutrients found in lakes, rivers, streams and other water ways (i.e. the Chesapeake Bay) have yielded an increase in the amount of money spent on studies, both at the Federal (EPA) and state level (DEQ). Furthermore, several counties and towns have taken it upon themselves to conduct monitoring programs on their local water sources, to ensure the health of potable water as well as the health of their constituents. The objectives of this research program for Lake Pelham were to: 1.) conduct a literature review of similar surface water systems to highlight current trends in nutrient concentrations 2.) measure and monitor the total phosphorus and nitrogen levels in the lake and examine relationships between nutrient concentrations, water temperature, dissolved oxygen content, and pH and 3.) outline future actions for monitoring Lake Pelham and possible preventive actions for nutrient control. In 2010, the interaction between pH, temperature, nitrogen and phosphorous was investigated. The total nitrogen concentration of Lake Pelham is highly dependent on the leachate entering the lake. Large increases in nitrogen occur during even the smallest rainfall events, suggesting nitrogen is entering the lake from the surrounding environment. The current study indicates that the mean annual average total nitrogen concentration of the lake is approximately 10 mg/l. This value provides a baseline which can be used while the total nitrogen is being monitored over the next several years. In previous years, an increase in pH values (< 1.0 between test dates) was associated with algal blooms in the lake and necessitated the treatment with copper sulfate. Between 1992 and 2010, the nitrogen concentration doubled and the phosphorus concentration increased 7 fold. Algae concentrations and pH fluctuation decrease as the water temperature decreases. Similar to nitrogen, phosphorus concentrations in the lake increase with rainfall events suggesting a relationship to runoff and/or leeching entering from the surrounding watershed. Even during lower water levels, similar to what occurred in August of 2010, when the lake was 15 inches below peak level, a small rainstorm had a large impact on the amount of phosphorus entering the lake requiring the addition of copper sulfate. The trophic state for Lake Pelham was calculated from the average values of the total phosphorus measured in the lake over 2010 and the Secchi disk readings from the same time period. The Tropic State Index (TSI) was calculated to be 59.75 when using the total concentration of phosphorus in Lake Pelham. The TSI calculated from the Sechhi Disk values was 54.5. This gives a average TSI value of 57.1, which indicates that the lake is in a eutrophic state. This was the first attempt at determining the trophic state of Lake Pelham. The study is an important first step for understanding nutrient loading in Lake Pelham and applying protective measures to preserve water quality. Similar to a study conducted in King County, Washington, long term data (decade or more) and in depth statistical analysis will be needed to explain the seasonal variability of Lake Pelham.
Complicated Composting: Persistent Pyridine Carboxylic Acid Herbicides
Reimer, Julie (Virginia Tech, 2013-05)
This paper reviews pyridine carboxylic acid herbicide impacts on compost. Pyridine carboxylic acid herbicides are not completely broken down during grass growth, harvest and drying of hay, in the digestive tract of livestock, or during composting. These herbicides are a popular choice for broadleaf weed control because of this persistence: they remain effective for months or years. Pyridine carboxylic acids are also more effective than the common herbicide 2, 4-dichlorophenoxyacetic acid and can be applied to pastures with grazing livestock because they have low mammalian toxicity. The growth-inhibitory action of naturally occurring pyridine compounds has been researched since the discovery of α-picoline-γ-carboxylic acid in the early 1900’s. These pyridine carboxylic acid compounds mimic plant growth hormones called auxins, causing plants to grow abnormally and then die. Plants injured by auxinic herbicides have poor seed germination, twisted growth, cupped or enlongated leaves, misshapen fruit, reduced yields, and ultimately die. Picloram (4-amino-3,5,6-trichloropyridine-2-carboxylic acid) was developed by Dow Chemical Company as a systemic herbicide for herbaceous weeds and woody plants in rights-of-way, forestry, rangelands, pastures, and small grain crops. Clopyralid (3,6-dichloropicolinic acid) was also developed by Dow Chemical Company to control annual and perennial broadleaf weeds in crops and turf. Another Dow herbicide, aminopyralid (4-amino-3,6-dichloro-2-pyridine carboxylic acid), is used for broad leaf weed control in pastures. Aminocyclopyrachlor (6-amino-5-chloro-2-cyclopropylpyrimidine-4-carboxylic acid) is the first pyrimidine carboxylic acid herbicide and was developed by DuPont for weed and brush control on uncultivated non-agricultural areas, uncultivated agricultural areas, industrial sites, and natural areas. Clopyralid compost contamination was reported in 2000 at four different facilities including Washington State University. In Vermont, compost samples were tested and found to contain aminopyralid, clopyralid, and picloram in 2012. Across the U.S. since 2000, there have been many reports of apparent plant injury from compost contaminated with auxinic herbicides. Because of the limited testing facilities and expense of chemical testing, the majority of these reports remain anecdotal. If the history of a compost feedstock is unknown, bioassays are recommended to test compost for the presence of auxinic herbicides. Even though pyridine carboxylic acid herbicides are sold with proper labeling and restrictions, compost contamination is continuing. Adjustments should be made for the registered uses of these herbicides, and herbicide applicators need improved education about the implications of contaminating compost feedstock.
Conservation Programs and White-tailed Deer Ecology
Royeen, David D. (Virginia Tech, 2019-05-07)
White-tailed deer have reached historical numbers since nearly being wiped out due to overhunting and habitat loss. This paper seeks to review the rebound of white-tailed deer populations, specifically analyzing the role conservation practice and habitat management have played. A brief history of private land contracts in the United States is established before relating deer ecology to habitat availability. The importance of deer from the perspective of humans as well as the ecosystem is highlighted in an effort to encourage and promote conservation and habitat preservation efforts. This work seeks to answer the question “How do conservation programs influence white-tailed deer behavior and what steps can land managers take to protect wildlife on their property?”. A list of recommendations for land owners is given to share best-practice policies for governing a healthy population of white-tailed deer. Lastly, study limitations and constraints of this paper are analyzed to promote transparency and identify areas of concern with data collection.
Effects of Bioretention Cell Media Composition on the Removal of Nitrogen and Phosphorus
Shultz, Keeva (Virginia Tech, 2016-12-19)
Bioretention cells are engineered systems used in urban areas as stormwater treatment to remove unwanted nutrients from runoff. The objectives of the paper are to examine existing studies to determine effects of media composition, media depth, specific species of plants, and temperature on the removal/immobilization of nitrogen (N) and phosphorus (P) in bioretention cells. After reviewing studies performed to date, a number of conclusions can be reached regarding recommendations for bioretention cells to remove N and P. More times than not, N is removed through nitrification-denitrification within the media, and P is removed through sorption. Multiple studies investigating the appropriate media textures concluded that a sandy loam or sandy soil with the addition of at least 3% water treatment residuals (WTR) should be used in bioretention cells to help with removal of P. A specific organic matter (OM) recommendation could not be determined, but a positive correlation with NH4 removal supports the Virginia Department of Conservation and Recreation guidelines of 3-5% addition of OM. N removal was higher when a saturated zone plus organic matter was used versus an unsaturated cell zone without organic matter. The pH of the bioretention cell should be between 6 and 7. The suggested media depth should be 50 to 90 cm. Certain species perform better with respect to nutrient removal efficiencies, and it is recommended that Carex spp. be utilized when possible. Nitrogen removal is higher when both vegetation and a saturated zone are present in a bioretention cell. Native species are convenient for cell maintenance purposes, but not all native species help remove N and P more efficiently. Although temperature does have an effect on nitrification-denitrification and P sorption through slowing infiltrations rates because of frozen soil, the results show that overall performance of the bioretention cell is not negatively affected.
Environmental Impacts of Acid Mine Drainage in the Appalachian Region
Burns, Pamela J. (Virginia Tech, 2022-05-10)
Coal mining in the Appalachian region was not regulated with respect to environmental effects until the 1960’s and 1970’s. The lack of appropriate mining impact regulations and management protocols caused detrimental effects to the environment, natural resources, wildlife, and residents within the region. As time progressed, Appalachia residents, scientists, mining companies and many others started to notice dramatic changes in the environment within the region due to active mining operations and abandoned coal mine-lands. Acid mine drainage (AMD) was discovered and has since been well-documented for its acidic and metalliferous properties. AMD is a harmful water pollutant caused by the oxidation of pyrite and other sulfides which become exposed to surface conditions during mining operations. The pyrite, or other sulfur-containing minerals, react with surface and shallow subsurface water and oxygen causing a chemical reaction which results in sulfuric acid. The AMD then enters rivers and streams where it affects aquatic species, wildlife, humans, and the pH of waters. By the 1960’s, altered ecosystems were observed due to mining overburden (spoil) disposal methods such as the “shoot and shove” method of contour surface (strip) mining. These methods impaired natural resources by contaminating water sources with acidity, heavy metals and bulk salts. As mining operations progressed in the pre-regulated era, mined lands were often abandoned leaving sulfidic materials exposed leading to the release of associated metals such as Al, Cd, Cu, Ni, and Zn which led to extreme water quality issues as toxicity became notable in contaminated streams causing teratogenic effects on fish and wildlife populations. Later, the Surface Mining Control and Reclamation Act of 1977 (SMCRA) was created to guide and regulate the environmental impacts of active and past coal mining operations. In particular, water quality protections implemented by SMCRA have made a significant improvement to the overall health and restoration of both active and abandoned mine lands (AML) in the Appalachian region.
The Evaluation of Winter Wheat Response to Nutrient Sources of Sulfur and Application Timing
Lee, Michelle V.; Oakes, Joseph C.; Reiter, Mark S.; Thomason, Wade E. (Virginia Tech, 2023-09-11)
Enhanced efficiency fertilizers (EEFs) have gained considerable interest in recent years as human population trends demand greater productivity from cropping systems while minimizing human health and environmental concerns from nutrient loss. Previous research has shown EEFs to be beneficial in diverse cropping systems, but research into their use in winter wheat development has been limited. This study assessed the effects of Sulfur (S) sources derived from three EEF products in comparison to a commonly used commercial product (Ammonium Sulfate) and a control (no S) as well as the effect of application timing of S on the production of tillers and grain yield of winter wheat. Field trials were conducted over a 3-year period in Warsaw, VA and Westmoreland County, VA. During the early growing season of winter wheat, the tissue samples and aerial normalized difference vegetation index (NDVI) values of before and after the mid-winter application indicated that there was some response to application timing of S, but with the exception of the Warsaw 2021 second tissue sampling S percentage analysis, there was no significant response from the sources of S tested. As the growing season progressed, NDVI values measuring tiller density showed no significant difference, which later corresponded with the end of the growing season, as there was no grain yield response to source of S or application timing of S. Overall, the S additives from the EEFs tested did not consistently impact wheat tiller development or grain yield and are therefore cost prohibitive.
Foliar Fertilization of Soybean in North Carolina and Southeastern Virginia
Lilley, Dylan T. (Virginia Tech, 2020-05-17)
The purpose of this project was to determine the need for foliar fertilization of soybean. The objectives for this research were (1) to determine soybean plant tissue and yield response to foliar fertilization with commercially sold products and (2) to evaluate profitability of applying such products. Experiments were conducted during the 2019 growing season at four locations in North Carolina and southeast Virginia. Six foliar fertilizers containing formulations of macro, secondary, and micronutrients were applied to R3-stage soybean and compared to an untreated control. Plant tissue samples were collected immediately before application and two weeks afterward to measure the change in tissue nutrient concentration. FertiRain significantly increased iron plant tissue concentration by 8% at two locations. Sure-K significantly reduced loss of nitrogen and phosphorus in the tissue by 7% at one location. Smart B-Mo significantly increased boron plant tissue concentration by 41% at three locations. Smart Quatro increased zinc plant tissue concentration by 27% at one location. HarvestMore UreaMate increased copper tissue concentration by 13% at three locations and zinc by 14% at another, but reduced copper and potassium plant tissue concentration by 17% and 10%, respectively, at one location. Despite plant tissue concentration increases of select nutrients, none of the foliar fertilizers affected yield at any location; therefore, profit decreased by $3.82 to $22.11 per acre, depending on cost of the product at the applied rate. Despite the lack of yield response to foliar fertilizers tested, soybean may respond positively under different environments, hence further research is necessary to determine the need for foliar fertilization.
Forest Reclamation of Coal Mined Sites in the Appalachian Region
Erwin, Zachary (Virginia Tech, 2017-10-02)
Efforts to restore forested plant communities on coal-mined sites in the eastern USA have increased over the years. Up until the late 1970s, Appalachian coal mining operations frequently transformed forested lands into grasslands. The Surface Mining Control and Reclamation Act of 1977 (SMCRA) legislated specific requirements for reclaiming lands mined for coal. Early post-SMCRA reclamation strategies focused on the establishment and maintenance of herbaceous plant species and used other techniques that were largely not suitable for forest growth. Major limitations included appropriate soil pH, soil compaction, and use of species that competed with tree seedlings. Strategies for successful forest establishment and growth were developed through experimentation with revegetation practices on mined sites and observations of existing productive forest stands on non-mined sites. Building on this research, the Appalachian Regional Reforestation Initiative (ARRI) was established in 2005 to focus on re-forestation efforts in the eastern US. A collaborative approach to improving forest vegetation (Forestry Reclamation Approach; FRA) was developed by scientists and adopted by the mining industry and its regulators. The FRA prescribed five steps that were deemed most critical to successful forest establishment. These steps include: (1) create a suitable rooting medium for good tree growth that is no less than 1.2 m (4 feet) deep and comprised of topsoil, weathered sandstone and/or the best available material, (2) loosely grade the topsoil or topsoil substitutes, (3) use ground covers that are compatible with growing trees, (4) plant the right mix of tree species, and (5) use proper planting techniques. The FRA has been used successfully and widely throughout the Appalachians to reclaim surface coal mined sites and establish native tree species. Use of the FRA can improve other forest services such as timber production, carbon sequestration, and wildlife habitat.
Historic and Present-Day Environmental Issues Involving Tomato Plasticulture and Shellfish Aquaculture on Virginia’s Eastern Shore
Templeton, Jennifer (Virginia Tech, 2013-05)
The Eastern Shore of Virginia, located on the Delmarva Peninsula, is known for its agricultural commodities, especially Solanum lycopersicum, Crassostrea Virginia, and Mercenaria mercenaria. For decades, controversy has surrounded the two industries. Runoff from fields of tomatoes grown in plastic mulch was thought to have caused mass casualties of shellfish in hatcheries in the tidal creeks and bays of the Eastern Shore. The impervious surface of the plastic mulch decreases infiltration of rainfall and increases runoff velocity and volume. Several studies have sought to determine the effect of plasticulture systems on water quality, which in turn affects aquaculture production. Many chemicals, including pesticides and copper, are applied to tomatoes grown in a plasticulture system to reduce disease, weed, and pest pressure. When applied after plastic mulch has been laid, these chemicals can wash off of the plants and the plastic mulch during a rain event. Unfortunately, studies have shown that copper, as well as other chemicals used in tomato production, have a detrimental effect on shellfish growth and survival. Increased amounts of sediment in runoff waters due to erosion of fields also have negative effects on shellfish production. After the threat of regulation in the late 1990s, the tomato industry on the Eastern Shore has been working closely with several agencies to implement best management practices (BMPs) for the reduction of erosion and runoff. These conservation practices have been proven effective in reducing impacts on water quality. Water quality monitoring should be continued to determine whether the implementation of these BMPs is indeed decreasing tomato production’s negative impact on the aquaculture industry on the Eastern Shore of Virginia.
Identification and Diagnosis of Long-Term Problem Areas in Fields of Agronomic Crops
Broaddus, Michael G. (Virginia Tech, 2017-12-21)
Since farming began, those who tilled the soil and planted and harvested crops have noticed areas within boundaries of their fields that do not produce as well as other areas. Centuries ago, nomadic farmers attributed these events to the wrath of unhappy gods or witches’ curses. However, with today’s technologies farmers can do better. Farmers today must also produce more to meet the food demands of a growing world population. To maintain their competitive advantage, American farmers need to be producing crops more efficiently than other producers in the world’s agricultural commodity markets. The objective of this paper is to educate producers to recognize what they need to test for and how to evaluating test results when dealing with problem areas in fields. Two different problem areas within two different soybean (Glycine max) fields were observed, analyzed, and tested in Caroline County during the 2017 growing season. Farmers verified that problem areas existed for years, and so in both fields, both problem areas as well as adjacent non-problem areas were tested for soil fertility, soybean nutrient content, and nematodes. Comparative tests confirmed that the problematic areas in both fields had inadequate fertility and low pH, and detrimental population levels of nematodes, which were exacerbated by low pH and inadequate fertility. Nematode species varied by site but included root knot (Meloidogyne spp.), dagger (Xiphinema spp.), and sting (Belonolaimus spp.) nematodes. The comparative tests also confirmed that of the two problem spots, the problem spots in both fields were the same soil series as the remainder of the field. Site A’s problem area had a low pH, low potassium, and 1660 root knot nematodes per 500 mg of soil. A root knot population over 170 is detrimental to a soybean. Other diseases found included charcoal rot (Macrophomina phaseolina) and fusarium root rot and wilt (Fusarium spp). Soybeans in the problem area in Site A were 50% shorter than the rest of the field and contained few pods at the R6 growth stage. Site B’s problem area soybean stand was 50% shorter than the rest of the field and also had considerably fewer pods. Site A’s problem area also suffered from a low pH, and phosphorus was yield limiting from both low pH and low soil levels. Site B also had detrimental levels of nematodes, with 160 sting nematodes and 440 dagger nematodes, in addition to fall panicum (Panicum dichotomiflorum) and large crabgrass (Digitaria sanguinalis). In conclusion, problem spots in fields present a problem for farmers in Virginia that need evaluating, and when evaluating, all factors such as soil fertility, environmental aspects, pests, and genetic potential should be considered.
Late Season Application of Nitrogen in Virginia Corn Production Systems
Jones, R. Trent (Virginia Tech, 2019-12-17)
Agriculture is a leading industry in the state of Virginia producing an economic impact of $70 billion annually in the state. A portion of Virginia’s agricultural industry is driven by the production of corn, soybean, and wheat crops in rotation. In 2019, as market prices for those commodities remain weak, farmers must evaluate the feasibility of implementing innovative technologies and practices in their growing systems in order to improve their production efficiency. This paper evaluates nitrogen application strategies at the developmental stages when nitrogen inputs have the greatest positive impact on yield. Specifically, this paper reviews several studies that have assessed delayed application of sidedressed nitrogen to corn until later physiological developmental stages in order to determine if this practice would be a good option for producers who want to increase their production efficiency. This review confirms that nitrogen plays an important role in crop development and rate and timing of nitrogen application can significantly influence crop yield. Though it is apparent nitrogen has a major impact on yield potential, no definite conclusion can be drawn from the studies reviewed here that directly relate the application of nitrogen past the V10 developmental growth stage to statistically significant positive yield increase. Of five Virginia study locations reviewed, evaluating application of additional nitrogen at V12-VT only one location found a statistically significant yield increase of 1082.74 kg ha-1 (16.1 bu/a). Additionally, delaying nitrogen sidedress applications up to V10 did not negatively impact corn yield in studies conducted in Missouri and Oklahoma, indicating that a later sidedress window may be considered by Virginia corn growers. While there is no conclusive evidence that suggests yield will reliably increase when N applications are made later in the season, other benefits of late season application were identified in this review. Supplemental benefits include the ability to make fertilizer application decisions based on plant tissue and soil diagnostic testing completed during the growing season, the ability to spread workload throughout the growing season, and reduced potential for nitrogen lost to the environment.
Mapping Stream Health Throughout Grayson County, Virginia by Testing Benthic Macoinvertebtares
Buchanan, Jonathan (Virginia Tech, 2022-12-24)
Grayson County, Virginia is home to some of the largest Christmas tree productions in the United States. With this production comes the use of a multitude of pesticides, including the insecticide Sniper, Dimethoate, and Safari; the miticide Endivor and the herbicide Roundup. These pesticides have a varying effect on aquatic life, especially on benthic macroinvertebrates. This project focused on collecting benthic macroinvertebrate samples scattered throughout Grayson County and then analyzing the samples to determine what the stream health is at the current time of year. Overall, the stream health is good and has a lot of macroinvertebrates that are sensitive to pollution present. Future research on this project should include testing throughout different times of year (spring and summer) as well as testing upstream and downstream of Christmas tree farms, the following experiment was conducted upstream of Christmas tree farms.
Motivation, Scale, and Production Features of Silvopasture Among Early Adopters in the Southeastern U.S.
Barbini, Lindsey; Fike, John H.; Poudel, Sanjok; Pent, Gabriel J. (Virginia Tech, 2022-12-17)
Silvopasture is an intensive land management practice that involves the intentional integration of trees, livestock, and forages under one management unit. Employing silvopasture practices provides short-term and long-term economic benefits to the producer, while improving the environment through carbon sequestration, water holding, improving soil conditions, and providing aesthetics. Alabama and Georgia have long growing seasons, a diverse population of plant species, and forest areas which could potentially make ideal areas for more silvopasture adoption. The purpose of this case study is to understand the perception and motivations behind silvopasture adoption among early adopters by developing an in-depth analysis of the motivation, scale, and production measures from the perspective of producers in this region. Four candidates managing silvopasture were interviewed through teleconferencing and their responses to the series of questions were documented. The results showed very diverse livestock operations within the silvopasture system such as goat production, cow-calf, organic dairy farming, and cow-calf with stocker cattle. Establishment though thinning existing woodland areas was performed by all producers, with one planting hardwoods also. Utilizing land area and environmental health appeared to be a strong motivation amongst most producers. Results coincided with previous studies performed that showed the most challenges came from managing invasives, forage species for optimal yields and lack of information or resources available. Aesthetics was highly valued amongst all producers, with several producers mentioning using the system for future agribusiness endeavors. All producers were satisfied with their decision to establish silvopasture, while only two stated they would continue to dedicate more land area to silvopasture in the future.
Nutrient Availability in Wheat During Growing Season Comparing Poultry Litter and Inorganic Fertilizer
Schronce, Heather; Thomason, Wade E.; Langston, David B.; Rideout, Steven (Virginia Tech, 2022-08-22)
Winter wheat production in North Carolina is continuing to expand. Commercial fertilizer costs are also continuing to rise and growers are looking for other options for plant nutrients. Poultry litter is a common fertilizer source that has been used in the past and is more popular now due to being a cheaper alternative to inorganic fertilizer. However, not all poultry litter is created equal in terms of nutrient content and in order to know what is in the litter, manure analysis must be performed. It is also unclear how much the litter breaks down within the first cropping season and how much of the nutrients are available for plant uptake. Thus, a study was performed to evaluate the nutrient availability of poultry litter compared to inorganic fertilizer during the 2021-2022 wheat growing season. The study took place in Lawndale, North Carolina on a field farmed by Toluca Grain and Hay. During the growing season, tissue samples were collected from each treatment (1- nonfertilized control, 2- poultry litter fertilized, and 3- inorganic fertilizer) and analyzed for N, P, and K nutrient levels. At harvest, each plot sample was weighed in a weigh wagon, and a smaller sample from each plot was tested using a certified scale for test weight and moisture content. There were no significant differences in yield and test weight between the poultry litter and inorganic fertilizer treatments. However, the poultry litter tissue samples and final soil samples showed higher levels of phosphorus and potassium than the other treatments. Poultry litter proved to be an effective alternative fertilizer to inorganic fertilizer at a lower cost.
An Overview of Renewable Energy and its Effects on Wildlife and the Environment
Dodds, Richelle (Virginia Tech, 2016-05-12)
As concern over greenhouse gas (GHG) emissions from conventional fossil fuel sources rises, energy developers look toward renewable resources as prime candidates for “cleaner” and “greener” energy production. This paper provides an overview of the main environmental and wildlife effects of five of the major renewable energy sources: wind, solar, geothermal, biomass, and hydro. Examples of the effects of pollution, habitat degradation, land use, species mortality, and Endangered Species Act (ESA) listed species are discussed. Avoidance and mitigation suggestions are reviewed. Before-after-control-impact assessments and habitat conservation plans can aid a developer in siting of a renewable energy project. The developer must weigh the economical and environmental costs of a project. Mitigation efforts should be made before construction, however, these efforts are not always clear and can be lost without proper enforcement. Early and continuous contact between developers and regulatory agencies can prevent increases in project time. Ignoring species and environmental protection guidelines up front can cause increased costs later on to mitigate the disturbances. Areas lacking research and viable data are addressed. Additional research is needed on species located in energy-rich habitats, particularly for ESA-listed species and species that are believed to be strongly affected by the new development. Currently, plans for carbon-based energy production are duplicated and utilized for environmental and species conservation with regards to renewable energy. In order for wildlife and environmental specialists to effectively plan for renewable energy developments and perform effective mitigation efforts, additional rigorous studies will need to be conducted. These plans will need to be tailored to each renewable energy source in order for environmental planners to recognize the differences between them.
Pharmaceutical Pollution in Private Drinking Water and Septic Systems
Collins, Matalin B. (Virginia Tech, 2023-05-14)
Safe drinking water is a priority for public health. Around 13% of the population of the United States gets their drinking water from a private well, and around 25% use a septic system as a form of onsite wastewater treatment. Both private wells and septic systems directly affect the quality of groundwater; septic systems contribute to the risk of contamination, especially in areas where the soil is not properly equipped to filter contaminants. An emerging contaminant of global concern is pharmaceuticals in the environment and how they impact organisms. Pharmaceuticals can enter the environment through a few different pathways such as wastewater. Pharmaceuticals can enter the environment through the soil or water in private systems like septics. Examining private water systems will help mitigate the growing concern of pharmaceutical pollution and how pharmaceuticals can lead to more threats such as the spread of antimicrobial resistance. This paper acts as an overview of private water systems and pharmaceuticals in these private systems.
Plant Date, Yield, and Nitrogen Management for Strawberries in the Coastal Plain of Virginia
Deitch, Ursula (Virginia Tech, 2016-04-25)
Fresh market strawberry (Fragaria × ananassa) availability in mid to late -April signals the beginning of locally available fresh fruit and vegetables for the mid-Atlantic region. Of the 290 acres of fresh market strawberries grown in Virginia annually, the majority are produced in the coastal plain of Virginia using intensely managed annual hill production systems. The objective of this study was to evaluate the potential yield of strawberries, determine how yield components change with planting date and cultivar, and assess the fertility management techniques recommended by Virginia Cooperative Extension’s Commercial Vegetable Production Guide for strawberries. June-bearing cultivars ‘Camarosa’ and ‘Chandler’ were grown in Painter, Virginia during the 2012-2013 season. Three planting dates (Sept. 21, 28, and Oct. 5) were assessed while evaluating the cultivars performance. Petiole nitrate-N readings and leaf tissue were collected at initial flower and mid-flower to evaluate the accepted fertigation recommendations. The cultivar trial yielded between 7,205 – 21,393 lbs./acre. Overall, ‘Camarosa’ yielded highest with the early planting date (Sept. 21; 21,393 lbs./acre). As the planting dates moved later into the fall, ‘Camarosa’ lost yield while the yield for ‘Chandler’ remained constant and averaged 9,705 lbs./acre. Harvest pick data also indicated that ‘Camarosa’ out performs ‘Chandler’ both early and late in the season for berry number and yield. Petiole nitrate-N and leaf tissue data suggested that excess N fertilization leads to lower yields. In conclusion, strawberry cultivar ‘Camarosa’ should be a standard for farmer’s in the mid-Atlantic and planted late to mid-September while continuously monitoring and adjusting N fertility as needed.
Precision Agriculture’s Impact on Nutrient Management in Agronomic Crops
Goff, Lauren P. (Virginia Tech, 2019-12-17)
The world population is exponentially growing and is expected to reach over 9 billion people by 2050. In order to feed the growing population, producers will have to rely on new technologies to increase yields. Globally there is focus on global warming and pollution that can damage ecosystems. A way to solve both of these conundrums is through understanding of nutrient cycles and the implementation of precision agriculture techniques to create a nutrient management system that meets the needs of the plants, but yet prevents unnecessary losses from the cycles. Studies show promise in the implementation of precision agriculture systems, with increased yields and better nutrient use efficiencies. However, studies show that there is variation between plots and areas, proving that more studies need to be conducted to determine the impact of precision agriculture on nutrient management.

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Browsing Online Master of Agricultural and Life Sciences by Department "Crop and Soil Environmental Sciences"

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