Natural Resources Management Doctoral Work

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Above and Belowground Effects of Nutrient Applications and Mowing Treatments on Restored North Dakota Grasslands
(North Dakota State University, 2015) Kobiela, Breanna Lyn Paradeis
Although more than half of the annual production within North American grasslands occurs beneath the soil surface, this portion is oftentimes overlooked in ecological studies. In this study, we investigated the above- and belowground responses in restored grassland plots that were subjected to different nutrient and mowing treatments. This study was conducted at two locations in North Dakota: the Dickinson Research Extension Center (DREC); and the Albert K. Ekre Grassland Preserve (Ekre). We evaluated the above- and belowground responses using visual surveys, biomass harvesting, and minirhizotrons. At the DREC site, we found the belowground variables to be relatively unresponsive to the nutrient and mowing treatments – there were no significant differences in root length, surface area, number of tips, or branches. The aboveground variables did exhibit responses to repeated nitrogen applications (200 kg/ha·yr). Nitrogen applications were found to increase aboveground biomass over the control (660 g/m2 vs. 265 g/m2, respectively) and decrease the species richness in comparison to the control (3.25 vs. 7.29, respectively). There was a decrease in the ratio of root volume to average aboveground biomass in the DREC nitrogen plots that resulted from the increase in aboveground biomass despite no apparent changes in the root systems, indicating that the root systems in the nitrogen plots were able to support significantly more aboveground biomass than similarly sized root systems in plots that did not receive nitrogen. At the Ekre site, there were no significant differences in the belowground variables attributed to mowing. However, aboveground biomass was higher in the mowed sub-plots (xM=530 g/m2) than in the control sub-plots (xC=485 g/m2). Species richness was lower in the nitrogen (xN=4.46) than in the phosphorus plots (xP=5.66). Species richness was also lower in the plots that received the high application rates (200 kg/ha·yr nitrogen or 40 kg/ha·yr phosphorus) (xH=4.30) than the low application rates (20 kg/ha·yr nitrogen or 4 kg/ha·yr phosphorus) (xL=5.90). Root growth was highest in the low phosphorus and the high nitrogen plots. There were different responses in the root variables throughout the growing season as a function of nutrient type and application rate.
Driver Attitudes and Crash Patterns in Western North Dakota Oil Counties: Links between Perceptions and Reality
(North Dakota State University, 2014) Kubas, Andrew John
Traffic safety conditions in the 17-county oil region of western North Dakota have changed considerably in recent years. Roads previously used for low-volume, agricultural purposes are presently utilized at high volumes to serve expanding oil interest. Traffic volume in the region has grown rapidly since the advent of hydraulic fracturing as a viable technique for extracting oil, especially with regard to the overweight and oversized vehicles needed for oil production. Three studies were conducted to understand how changing traffic conditions are perceived by local drivers. First, a survey questionnaire was sent to drivers in the region to measure perceptions of traffic safety priorities. County-level crash data were gathered for rural road crashes in North Dakota between 2004 and 2013 to examine statewide crash trends. Survey responses were linked to crash data and found that safety perceptions from drivers are valid: conditions in oil counties are actually more dangerous than elsewhere in North Dakota. Second, using Decision Theory as a theoretical lens to guide decision-making, crash data were queried to establish if driving conditions in certain parts of the oil region are more dangerous. Proximity to oil wells, city limits, and travel on major roadways were found to have an effect on overall crash severity. Third, written survey responses were qualitatively studied via emergent theme content analysis. Crash types relating to these themes were then subjected to cluster analysis using ArcGIS. Respondent zip codes were matched with crash zip codes to provide a mixed methods approach to understanding key traffic safety issues such as perceived danger, large truck danger, and law enforcement presence.
Drying and Pretreatments Affect the Nutritional and Sensory Quality of Oyster Mushrooms
(North Dakota State University, 2014) Mutukwa, Itai
The effect two drying treatments (solar and oven), three blanching treatments (no blanching, water and steam), and four chemical treatments (no chemical, lemon juice, vinegar and potassium bisulfite) on oyster mushroom quality was investigated. Sensory quality, total phenolics, total flavonoids, ergothioneine, oxygen radical absorbance capacity, moisture, mold infestation, mineral content and protein were evaluated. Among the un-blanched samples, those that were treated with lemon juice and those without any chemical pretreatment before drying had better appearance, flavor and were more generally acceptable than those with vinegar and potassium bisulfite treatments. However, when blanching was done, samples treated with potassium bisulfite had superior sensory quality when compared to lemon juice, vinegar and the control. Solar drying caused more browning when compared to oven drying. The combination of water blanching with either lemon juice or vinegar treatments before drying resulted in higher flavonoid content. Lower ergothioneine and total phenolic compounds were observed in blanched mushrooms compared to the un-blanched ones. Total flavonoids were highest in the water blanched samples and least in the un-blanched ones. Among the chemical pretreatments, higher total phenolic compounds were observed in vinegar and potassium bisulfite treated samples. Blanching resulted in lower K, Mg, Na, S and P content when compared to the control. Mineral nutrients varied with chemical pre-treatments. Blanching followed by either lemon juice or no chemical treatment resulted in high mold infestation. Among the un-blanched samples, those treated with vinegar had the least mold infestation. Drying method, blanching, and chemical pretreatments affected oyster mushroom quality hence a need to carefully select preservation methods so as to minimize quality compromise.
Economic and Social Impacts of Rapid Shale Oil Development in Western North Dakota
(North Dakota State University, 2016) Fernando, Wannakuwatte Mitiwaduge Felix Nirmal
This dissertation comprises of five qualitative and exploratory studies. The studies focus on the social and economic impacts of rapid shale oil development, which is colloquially referred to as an “oil boom” on the communities and its members in western North Dakota. The dissertation presents a detailed exploration of the impacts and implications of the boom on community values and attitudes, quality of life, and community development. Impact of the boom on each topic is presented as an independent article or chapter. The data for the dissertation was collected through open-ended, face-to-face interviews. The findings highlight the opportunities created by the boom, barriers inhibiting community development, and the solutions necessary to achieve the community development potential created by the economic activity of the oil boom.
Evaluating Financial, Social, and Waterbird Implications of Farming Within Wetlands Imbedded in Agricultural Fields
(North Dakota State University, 2022) Toy, Dustin
Wetlands of the Prairie Pothole Region (PPR) provide many ecosystem services to the region such as floodwater attenuation, maintenance of water quality, carbon sequestration, and wildlife habitat. The biophysical process characteristics of the region that have made it beneficial for wildlife have also made the region conducive to cultivation; consequently, many wetlands (>49%) in the PPR have been drained and converted to cropland. Although wetlands are often noted for their natural ecosystem services, their contributions to agriculture are often overlooked. Understanding aspects of PPR wetlands, such as value for migrating waterbirds, how wetlands fit into farming operations, and how farmers perceive the fit of those wetlands in their operations will help to find mutually beneficial solutions to wetland management for farmers and conservation efforts. I evaluated occurrence and densities of various species of waterfowl and shorebirds within agricultural wetlands receiving different manipulations. Most manipulations reduced vegetation heights and proportions of vegetation coverage of the inundated areas of wetlands. Manipulation technique was only important for four species and varied in its effect on density and occurrence probabilities. Most species of waterfowl occurred at higher densities in the low to mid ranges of vegetation coverage. Based on data collected from farmers, I estimated about half of the area of temporary wetlands and nearly one third of the area of seasonal wetlands are planted on average. Soybean yield and profitability from cultivated portions of temporary wetlands were similar to uplands at average precipitation but were significantly lower in seasonal wetlands. Corn profitability was significantly lower for cultivated portions of temporary and seasonal wetlands for average precipitation conditions. The differences were more pronounced under wetter conditions and especially when considering the entirety of wetland area, not just the cultivated portions of wetlands. I examined farmers’ perceptions through a questionnaire regarding how they view agricultural wetlands and how wetlands fit into the respondents’ farming operations. Despite a low response rate, some informative responses may provide a foundation for further exploration of these data. The results of this dissertation may provide an opportunity for farmers and conservationists to find mutually beneficial management practices for agricultural wetlands.
Exploring Land Conservation Using Economic and Geospatial Models
(North Dakota State University, 2015) Margarit, Daniel
Three different, but related studies on conservation in North Dakota were completed. Expansion of Devil’s Lake over the past 20 years has flooded farmland, towns, and roads, causing economic damage and distress. Retirement of private land into conservation could play a role in ameliorating damages to citizens, while simultaneously improving and protecting wildlife habitat. The objective of the first study is to investigate the supply of agricultural land that might be available for conservation use at various purchase prices. It was expected that increasingly frequent flooding over the past decades would have increased the supply of land available for conservation. This was verified to be the case for the most vulnerable lands in Devil’s Lake Basin—areas below 1,460 ft. elevation and within 300 ft. of surface waters. The Conservation Reserve Program is comprised of lands that were previously farmed and have been converted into grassland. The landowners are compensated by the US government for retiring this farmland because it provides environmental benefits. Current commodity prices are giving farmers less incentive to renew their CRP contracts and many are deciding to instead farm those lands. The second study aims to identify and quantify the factors that affect a landowner’s decision to renew an expiring CRP contract or not in the Sheyenne River basin. The economic factors examined were crop prices and CRP payments. The ecological factors were slope of the land, distance to the nearest stream, and soil texture. The purpose of the final study is to estimate the increase in sediment loading due to changes in CRP enrollment, and then value the cost to society of the increased sedimentation. This will be accomplished by creating a SWAT model of the Sheyenne River. Future and hypothetical land use datasets will be substituted into the model. Every ton of sediment entering the river costs society an estimated $2.40. The model estimated 1,218.36 tons of sediment entered the river from the study area in 2005. Using the landcover conditions present in 2014, an estimated 1,661.4 tons of sediment would have entered the river across the study area, an increase of 36%.
Gauging the Perceptions of High School Students in Different Demographics on Environmental Education Topics
(North Dakota State University, 2016) Bonnell, Kory
Environmental education is a topic that has been promoted by advocates and researchers for more than three decades; however, a majority of public schools still fail to cover the fundamental basics of environmental education in their curriculum. This project seeks to understand how high school aged students (10th grade) understand three environmental concepts including: 1) recycling; 2) food production; and 3) concept of the natural environment, amongst the demographics of: 1) rural; 2) urban cluster; and 3) large metropolitan/inner city. Questionnaires were designed using the Likert Scale questions in order to quantify differing perceptions between rural, urban cluster, and large metropolitan/inner city school students. Initial focus groups were conducted to enhance the survey instrument. The survey was conducted in Minnesota with 204 tenth grade high school students; 90 from rural schools, 55 from urban cluster, and 59 from large metropolitan/inner city areas. Results indicate that students in different demographics understand recycling differently; as pupils in large metropolitan/inner city and urban cluster areas find recycling to be a priority while students in rural areas often do not view recycling as important. Students do perceive the topics of food production and nature similarly across demographics. Students have a general understanding of where their food comes from and food production. Additionally, the study found students today are spending less time watching television, but have greater access to multiple electronic devices that account for a large portion of how they spend their time. Finally, as a result of challenges throughout the research project, this study examined the issues and process of working with children in a public school setting. This research can be used by both formal and non-formal educators to understand the perceptions of the students they work with in order to better educate them.
Improving nitrogen management, including the use of cover crops, in North Dakota cropping systems
(North Dakota State University, 2024) Goettl, Brady
Crop production in North Dakota covers nearly 64 million ha, playing a crucial role in the state’s economy. However, wide-spread agriculture also poses environmental risks resulting from soil erosion and loss of N to ground and surface water. To address these concerns, agriculturists must adopt practices to decrease soil erosion and responsibly manage N. Between 2020 and 2024, several studies in North Dakota focused on improving N management in two-row malting barley (Hordeum vulgare L.), explored opportunities for cover crop integration, and assessed the rotational impact cover crops on crop productivity and soil factors. Research indicated N recommendations ranging from 89 to 190 kg available N ha-1 could optimize profitability and barley quality while reducing fertilizer requirements compared to yield-goal based recommendations. Although cover crops planted following barley harvest sequestered N in the biomass preventing leaching, the subsequent two cropping years of corn (Zea Mays L.) and wheat (Triticum aestivum L.) showed no significant yield response from the cover crop. It did appear the cover crop had an impact on the wheat yield response to N, indicating a potential long-term benefit. In addition to cover crops, managing barley residue resulted in significant soil temperature differences in the spring, with greater mean daily temperatures measured where residue was removed compared to residue-mulched or cover cropped treatments; these temperature differences were attributed to increased absorption of solar radiation. The absence of mulch or cover crops, however, caused greater fluctuations and lower minimum temperature in the bare-soil treatment. Additionally, integrating interseeded cover crops into wide-row (152-cm) corn was determined to be a viable option for adding diversity to the cropping system without impacting corn yield. Through responsibly managed N recommendations in North Dakota cropping systems, dependence on N fertilizers can be reduced. The integration of cover crops can sequester N and provide erosion control without a significant impact on rotational crop yield.
A Plan to Reduce Water Poverty in the Fertile Crescent: Getting from Science to Solutions.
(North Dakota State University, 2010) Qtaishat, Tala Hussam
Water scarcity is an ever-growing worldwide problem. In particular, most Fertile Crescent (FC) countries (i.e., Iraq, Syria, Lebanon, Jordan, Palestine and Israel) face severe problems related to water scarcity. Growing demand for water resources due to increased population and improved living standards, prompted public agencies and others in the Fertile Crescent (FC), a semi-arid region, to seek better ways to manage water. Water scarcity is the most serious natural constraint to the FC's economic grow-th and development. Three potential paths to address water scarcity dilemma are ( 1) nontraditional shifts in water reallocation, (2) innovative supply augmentation methods and (3) identification of substitutes for water in production and consumption. Water reallocation within uses (e.g., agriculture) and among users (e.g., agriculture, industry and municipal) as well as supply augmentation (e.g., desalination, water importing, wastewater treatment, recycling, water conservation, reducing evapotranspiration and storage) can all play a role in extending water resources. A conceptual reallocation method and information from the scientific literature suggest that some reallocation in the name of efficiency may be beneficial. A conceptual supply augmentation method operationalized with secondary data suggests water supply augmentation may also lead to decreasing water scarcity. Ultimately, substitutes for water will be necessary to further minimize water scarcity. These solutions, along with their economic, political, cultural, and technical dimensions and constraints, are presented in a strategic plan format that identifies paths for increasing social benefit of the FC's water resources. The plan will assist decision-makers to identify and understand the constraints and the benefits related to non-conventional options. The plan posits a 20% shift in water from agriculture to municipal and industrial uses over the next 20 years, assumes reasonable supply improvements and speculates about the role of substitutes in the future. The plan further demonstrates a potential allocation of a hypothetical $100 million grant to a fictional FC water authority. These feasible, modest achievements would lessen water scarcity in the FC, by the year 2030.
Plant Blindness Represents the Loss of Generational Knowledge and Cultural Identity
(North Dakota State University, 2022) Blue, Stacie
Elders from the Turtle Mountain Band of Chippewa Indians (TMBCI) who have gathered plants within the region have seen the plant numbers reduced and species of plants disappear. Their statements of concern for the plants and their hope for increased plant diversity led to the development of the current research study. Increasing plant knowledge is vital to rebuilding and maintaining the diversity of vegetation within the forest, grassland, and wetland habitats. The present study used an online survey to assess citizens’ ability to identify plants that belong in wetland, grassland, and forest habitats in the area; names of plants; learn how citizens use plant features to find and identify plants; and where citizens gained their knowledge. The survey also gathered demographic data, which allowed authors to determine trends across different demographic groups including age and ethnicity. In total, 212 participants took the survey, the majority were female and 91% classified themselves as Native American or Alaska Native. Participants were readily able to identify forest and wetland plants correctly, but struggled distinguishing grassland plants from the other habitat types. Participants in this study demonstrated a preference for natural areas maintained for humans for recreation purposes. Although more wild habitats may not be in the top three choices for the average citizen to spend time in, forest did have the fourth highest selection. Building on the knowledge that can be learned in familiar and comfortable environments as well as moving into new and wild areas will be important in helping citizens understand the value of biodiversity and conservation in the future. Beyond the local area, this information is useful to researchers and scientists working with plant blindness and seeking to understand how people see and identify plants and how this may change across demographic groups.
Prairie Conservation and Reconstruction Studies in Communication, Application, and Education
(North Dakota State University, 2016) Comeau, Paula Jean
Natural Resources Management is a combination of disciplines all working together to improve management practices, environmental education, and cross-discipline communication. Land managers and conservationist have become a group of people thrust into the public eye and to help the world make sense of the ecological and climatic changes that are taking place. For this reason, Natural Resources Management PhD’s have become a community needed to interface with the public in order to balance environmental and societal needs. This dissertation project took a renaissance approach by examining a wide range of fields. It is said that a Renaissance man is knowledgeable and proficient in a wide range of fields or they are interdisciplinary. The world is in need of a conservation renaissance to reconnect the environment back to societal values, and it is going to need an interdisciplinary approach to do so. To do this each of the three areas: communication, education, and application were explored. Communication was addressed in two parts, first through the completion of a partnered publication with United States Fish and Wildlife Services, which used a framework from education (backward design) to communicate best practices for tallgrass prairie reconstruction in North Dakota. A second document was then completed describing how the backward design model was used to optimize communication. To further connect the importance of education to Natural Resource Management, I partnered with the Minnesota State University Moorhead Regional Science Center and their curriculum based field trips; drawing artifacts were collected and examined using the coding scheme from Human Figure Drawing and cross-racial facial recognition to determine what cues are utilized in novice plant observers. The Natural Resource Management application research was conducted on conservation lands in eastern North and South Dakota comparing the spike seeding method with more traditional seeding methods.
Smooth Brome (Bromus Inermis) Phenology in the Northern Tallgrass Prairie
(North Dakota State University, 2018) Preister, Lisa
Smooth brome (Bromus inermis) invasion into tallgrass prairie has led to development of methods of control. Prescribed burning is used by the US Fish and Wildlife Service (USFWS) to manage prairie according to a provisional model developed by Willson and Stubbendieck (2000). The model recommends conducting a prescribed burn at the onset of elongation of smooth brome. The USFWS uses the 5-leaf stage as a phenological cue, signaling the initiation of elongation. Variability in smooth brome development limits the reliability of this method. Our objective was to develop an alternative method to determine when smooth brome populations reach the targeted 50% elongation by correlating accumulated growing degree days and population level plant phenological stages (mean stage count) throughout sites in North Dakota, South Dakota, and Minnesota. A linear regression model was used to determine the onset of elongation in the smooth brome population, regardless of leaf stage variation. Field and greenhouse studies confirmed accumulated growing degree days predicted the initiation of elongation. We also compared smooth brome response to different seasonal burn treatments, determining it could be decreased by burning at other times. As part of the USFWS Native Prairie Adaptive Management program, results will be used to assist management decisions regarding the timing of control.
Understanding Water Quality, Vegetation Establishment, and Stakeholder Success for The Fargo Project: A Multi-Stakeholder Led Community-Based Green Infrastructure Project.
(North Dakota State University, 2022) Riley, Jesse
The Fargo Project is a dry detention basin that holds stormwater drained from urbanized and impervious areas that serves as a component of a greater stormwater infrastructure network. The project goals were to design a multi-use green infrastructure area that would invite neighboring residents into the basin. From its conception, the project has relied on partnerships between stakeholders. A survey was developed and deployed to all stakeholder groups that participated in the community-based project to access stakeholder success. The Fargo Project was viewed as a success by most stakeholders. Project partners felt that the basin’s main goal was to serve a functional purpose as well as contain natural habitat that provided a resource to the community. This new knowledge expands on the traditional top-down governmental approach and allows more input from stakeholders. One goal of The Fargo Project was to establish native vegetation in the bottom of the basin. A study was established using five different native seed mixes planted in four replicates in the spring of 2016. Four years after planting many of the native species used in the treatments, even though planted at high densities, failed to persist or were at levels below 4% cover. Flooding during the germination and establishment phase negatively affected the long-term persistence of planted native species. This study determined that native plantings within dry detention basins come with challenges atypical to restorations in other natural habitats. Water quality at different vertical elevations within The Fargo Project basin was investigated. The vertical water quality was sampled after three large precipitation events at different stages within the basin: initial (first flush), at peak elevation, and outfall (as the basin drained). The water quality in two other dry detention basins were sampled for comparison. Most water quality analytes did not differ among the three detention basins except Total Suspended Solids which declined as the basin drained. The development of a passive vertical water quality sampling system using commonly available materials was effective at sampling vertical water quality in detention basins.
Using Light Detection and Ranging (LiDAR) Technology to Assess Bird-Habitat Relationships: A Case Study from the Northwoods of Maine
(North Dakota State University, 2012) Newton, Wesley Eugene
Airborne light detection and ranging (LiDAR) is a remote sensing technology that quantifies the travel time of photons emitted in pulses from a LiDAR instrument to travel to and reflect back from objects. Knowing the travel time for the photons and accounting for the speed of light, distances to objects from the instrument can be quantified. When LiDAR is acquired over forested areas some of the pulses will find canopy openings and "penetrate" to the ground with others striking the canopy at various heights above the ground, generating an XYZ point-cloud of eastings, northings, and elevations. Capitalizing on the information in these point-clouds from a June, 2003, acquisition in forested areas of Maine, we characterized the vertical profile of the canopy from which we computed LiDAR-derived explanatory variables for empirical modeling of various response variables (i.e., forest stand metrics, bird species abundance). The first aim of the research reported in this study was to assess the ability of LiDAR-derived explanatory variables to predict forest stand structure than can then be used as input in a suite of habitat-models that predict New England wildlife occurrences (called ECOSEARCH). Using regression analyses and field-collected data, we determined that LiDAR does a good job of predicting various forest stand metrics for the over- and understory (Adj. R2 >0.60 for 14 of 20 models developed). The second aim was to assess the ability of LiDAR-derived explanatory variables to directly predict mean bird abundance within forested areas during their breeding season. We derived a set of minimally correlated LiDAR-derived explanatory variables and used these in regression analyses to predict mean bird abundance from field surveys. Results indicate that LiDAR-derived explanatory variables were useful for predicting the mean abundance of 17 bird species (all with Adj. R2 > 0.2, with 5 models having Adj. R2 > 0.4). The third aim was to utilize the LiDAR-derived habitat-models and apply these across two study sites under varying management scenarios for assessments and planning purposes. Using a simple Euclidean distance metric and under various but realistic assumptions we were able to ascertain optimal management scenarios for five focal bird species.
Visitors' values of natural resources and cultural resources on Dakota Prairie National Grasslands
(North Dakota State University, 2010) Steele, Bruce Richard
Managing Dakota Prairie National Grasslands requires an understanding of visitor relationships to nature and culture. As national grasslands continue to draw visitors for recreation, relaxation, and wildlife observation the value visitors place on associated resources is important to the management decision process. At the request of the Forest Service, the study focus was specifically on national grasslands visitors. The objectives were to 1) determine the value stakeholders have on our natural resources, 2) determine the value stakeholders place on cultural resources, and 3) national grasslands visitors' perceptions on the origin of federal policies concerning natural and cultural resources. Thus, visitors including interest groups and range scientists were primary sources of data. Qualitative analysis methods were used to determine that for visitors, natural resources were valued more than cultural resources. Furthermore, the general perception of visitors was that policies concerning natural resources originate at local levels whereas cultural resources policies originate at the federal level. Public school systems have had little inclusion of environmental education in their curriculum and the Forest Service has been responsible to keep visitors informed about national grassland ecology. Because the Forest Service mission does not include the preservation of cultural resources there is little initiative by the Forest Service to protect those resources. Therefore, damage to cultural artifacts on national grasslands by uninformed visitors is likely. The future of national grasslands management clearly rests on the integration of natural and cultural resources training and education for both employees and visitors.
Wetland Assessment and Nutrient Dynamics in North Dakota
(North Dakota State University, 2013) Meyers, Lindsey Michele
Wetlands provide a variety of services and functions. Studies have highlighted the importance of wetlands in water purification, groundwater replenishment, flood control, sediment and nutrient retention and export, biodiversity, and climate change mitigation and adaptation. Additionally, wetlands are assets to food, fiber, cultural values, recreation, and tourism. These ecosystem services are provided to society free of charge and when eliminated can have negative implications. Therefore, wetland management is important, as wetlands can be lost to agriculture and urbanization. Monitoring wetland condition is a tool to analyze human impact on wetlands. Various types of wetland assessments have been created to measure biological condition. These include vegetative, rapid, functional, and intensive assessments. Data collected from assessments can be utilized for further study and analysis in addition to measuring condition. Physical characteristics can be identified that correlate with wetland condition, which provide clues to how well a wetland is functioning. Wetlands are important to nutrient cycling and storage. The levels of nutrients in vegetation, soil, and water may vary based on parent material, surrounding land use, hydrology, the type of wetland, and types of species present. Wetlands can filter excess nutrients from agricultural and urban runoff to a certain extent. High nutrient loads can cause eutrophication and anoxia and affect the biological community and wetland function. High levels of nutrients and disturbance have been correlated with exotic species invasion and decreased diversity. Stable isotopes of nitrogen and carbon have been applied to measure anthropogenic impact, nutrient sources, and denitrification levels. Four studies were completed during the summers of 2011 and 2012 on wetland assessment and nutrient dynamics across the state of North Dakota. The results indicated the importance of land use regarding wetland condition and nutrient levels. Wetlands in cropland tended to have lower floristic quality and biological condition and higher stable isotope δ15N values. Additionally, levels of phosphorus, nitrogen, and carbon differed by plant type with some indication that cattail invasion alters nutrient cycling. Furthermore, classification and regression tree modeling links wetland buffer, soil, and water data to wetland condition.
Winter Wheat Management for Improving Soil Quality and Reducing Greenhouse Gas Emissions
(North Dakota State University, 2014) Aher, Gabriel Garang
Carbon dioxide (CO2) and nitrous oxide (N2O) concentrations in the atmosphere have greatly increased in recent times. Intensive agricultural practices, combustion of fossil fuels, deforestation, and wetland drainage have been linked to increased greenhouse gases (GHG) levels. Although scientists are not unanimous in their belief that the increases in GHG is a cause behind recent global temperature rise, there is evidence that increases in GHG might directly increase global temperatures and unpredictable weather occurrences. Since human activity may be partially behind the rise in GHG emissions, it follows that changes in agricultural management might reduce the rate of GHG increases or even mitigate existing increases. Agricultural management practices proposed to mitigate GHG emissions in agricultural soils include conservation tillage, diversified cropping systems, and crop residue management. The objective of this study was to determine the impacts of high-residue no-till systems in a diverse rotation using seven cropping systems in which winter wheat (Triticum aestivum L.) was included or not included. The study was imposed on existing rotations present at the Conservation Cropping Systems Project (CCSP) farm near Forman, ND. The CCSP site was established in 2001 under no-till production and managed by the Wild Rice Soil Conservation District. Analysis of 2006 and 2010 soil organic carbon (SOC) data showed no significant difference between winter wheat rotation treatments and rotation treatments without winter wheat. Analysis of 2012 SOC data resulted in greater SOC in the corn (Zea mays L.)-soybean (Glycine max L.) rotation and lower SOC in the spring wheat (Triticum aestivum L.)-winter wheat (Triticum aestivum L.)-cover crop-soybean rotation. Some rotations had greater SOC than others, but the differences were not related to whether or not winter wheat was included in the rotations. Analysis of residue showed a greater C:N ratio and greater potential N requirement for the subsequent crop in fresh residue compared to aged residue. The COMET-VR model used to estimate SOC levels overestimated SOC in greater diversified rotations and underestimated SOC in lower diversified rotations. No-till production and crop residue retention can increase SOC levels, improve soil quality, and increase SOC sequestration in cropping systems.

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