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Item Chemical and Biological Characteristics of Thermally and Chemically Disturbed Soil in Northwestern North Dakota(North Dakota State University, 2017) Ritter, Samantha SusanThermal desorption (TD) remediates hydrocarbon-contaminated soil by heating the soil (200 to 500 °C) to volatilize the hydrocarbons, effectively removing the contaminant from the soil. If the soil is then used for agricultural production, reclamation success can be determined by quantifying aspects of soil health. Cation exchange capacity (CEC), cation selectivity and Gibbs free energy (ΔGex) of TD-treated and untreated soil were compared. Although CEC and ΔGex differed, cation selectivities were not altered suggesting that alternative fertility management to retain previous soil productivity may not be needed. From field plots, N-transforming genes were lowered in contaminated and TD-treated soils as compared to non-contaminated soil, but the addition of surface soil (1:1 blends) increased N-cycling genes to levels reported in the literature. Thermal desorption may not alter soil chemical as much as biological metrics, but blending treated or contaminated soils with native surface soils can enhance soil function and, ultimately, productivity.Item An Evaluation of Electrical Conductivity Meters for Making In-Field Soil Salinity Measurements(North Dakota State University, 2010) Briese, Lee GalenSoil electrical conductivity (EC) can be used as a parameter to assist agricultural producers in making economically important management decisions. Since particular crops and crop varieties respond dynamically to soluble salt levels in relation to crop growth stage and soil moisture content, many management decisions regarding crop type and variety must be made prior to planting. Some crop stress factors could be removed or mitigated if a handheld EC meter could be implemented during the growing season. The objectives of this research were to 1) determine the accuracy of four handheld EC meters for measuring soil EC across a range of environmental temperatures of 15, 20 and 25° C, soil clay concentrations of 10.2, 17.8, 19.3, 32.3 and 50.4 %, and salt solutions containing NaMg- SO4 or Na-Mg-Cl at concentrations of approximately 0, 1, 2, 4 and 8 dS m-1 under controlled laboratory conditions; 2) identify functional differences of the meters that might pose problems for in-field use; and 3) determine if meter price is related to accuracy. The EC values provided by three of the handheld EC meters were significantly different than the standard meter at all treatment levels. Measurements at different temperatures of the standard KCI calibration solution (known EC 1.413 dS m ·1 ) varied by ±0.15, -0.01 to +0.16, -0.14 to -0.03, and ±0.03 dS m-1, for the Hanna Black (Hl993310), Hanna Blue {Hl98331), Field Scout, and SenslON 5 meters, respectively. When salinity was 3 dS m-1 or greater the difference between the test meters and standard meter (EC Response} was larger. Test meter measurements for the salinity by clay interaction were different than the standard meter by ±0.5, ±1, and -2.5 to +1.5 dS m-1, for EC levels of less than 3, 3 to 4, and greater than 4 dS m-1, respectively. The SenslON 5 handheld was the only meter tested that was not significantly different than the standard meter {p::; 0.48}. Test meter accuracy was highly dependent on temperature. Therefore, the most important criteria for selecting a portable meter for in-field EC measurements is the accuracy of the specific meter's temperature measurement and temperature compensation model.Item How Salinity Influences Soil Organisms: Earthworms, Archaea, Bacteria and Fungi(North Dakota State University, 2023) Castleberry, Cecelia BartleySoil salinity is a naturally-occurring issue in the Great Plains. Current standards for saline soil designation are based on plant tolerance levels. This thesis expands salinity knowledge into salinity responses of other soil organisms. I used laboratory mesocosms to examine survival and fecundity or cocoon production of earthworms in the Apporectodea complex to increasing levels of salinity, with or without supplemental organic matter (OM). I then used a split-bin design to examine earthworm choice between combinations of saline and non-saline soils, with and without supplemental OM. I found that earthworms avoided saline soils, but survival and production was steady across salinity levels and in some cases decreased with added OM. I then quantified abundance and diversity of microbial groups in field-collected saline and non-saline soils in increments to 120 cm depth. The response of microbes to depth were stronger than their responses to salinity. Both important groups of soil organisms appear tolerant to salinity levels.Item Fertilizer Management Strategies of Soybean (Glycine Max, L. Merrill) in Northcentral and Northwestern North Dakota(North Dakota State University, 2019) Augustin, Christopher LeeSoybean (Glycine max L. Merrill) is a new cash crop for north central and northwestern North Dakota producers. Soils and climate in these new soybean areas differ from those regions where the current fertilizer recommendations were based. Northcentral and northwestern North Dakota is more undulating, drier, cooler, and has differencing soils than eastern North Dakota and Minnesota. A three-year study to evaluate soybean best management practices was conducted during the 2016 to 2018 growing seasons. Each year, the study consisted of two sites and 12 treatments. By design, one site was on acidic (pH < 6) soil while the other was on alkaline (pH > 7.3) soil. Both site treatments were: untreated check, inoculated with rhizobia (B. japonicum L.), broadcast urea (55 kg ha-1), broadcast MAP (monoammonium phosphate, 11-52-0) (110 kg ha-1), in-furrow 10-34-0 (28 L ha-1), in-furrow 6-24-6 (28 L ha-1), foliar 3-18-18 (28 L ha-1) at V5 and R2 growth stages, and foliar 3-18-18 (28 L ha-1) with sulfate (1.1 kg ha-1) at V5 and R2. The acidic sites alone included two treatments of sugar beet (Beta vulgaris L.) waste lime (4.4 Mg ha-1 and 8.8 Mg ha-1). The alkaline sites alone received treatments of iron ortho-ortho-EDDHA (1.8% Fe) (7.1 L ha-1), and sodium (naked- without Fe) ortho-ortho-EDDHA (7.1 L ha-1). Treatments did not impact soybean yield, protein content or oil content at the 95% significance level. Sugar beet waste lime surface applied at planting at rates of 4.4 Mg ha-1 and 8.8 Mg ha-1 increased soil pH to a depth of 10 cm over the course of the growing season.Item Redistribution and fate of applied ¹⁵N-enriched urea under irrigated continuous corn production(North Dakota State University, 1996) Schindler, Frank VincentUnderstanding the redistribution and fate of N is essential for justification of Best Management Practices (BMP). This project was conducted on a Hecla fine sandy loam (sandy, mixed, Aquic Haploboroll) soil at the BMP field site near Oakes, North Dakota. One objective of this investigation was to evaluate the residence times of N03- -N in 20 undisturbed lysimeters and its infiltration time through the soil profile to tile drains. Corn (Zea mays L.) was fertilized with 135 kg N ha -1 as ¹⁵N-enriched urea plus 13.5 and 48.1 kg N ha -1 preplant for 1993 and 1994, respectively. Urea-N was band applied to 20 and 10 undisturbed lysimeters at 2.0 and 5.93 atom percent (at %) ¹⁵N in 1993 and 1994, respectively. Average resident times of N03- -N in the lysimeters was 11.7 months. Lysimeter and tile drainage indicate the presence of preferential pathways. Residence times of N03- -N depend on frequency and intensity of precipitation events. Another objective was to determine what portion of the total N in the crop was from applied urea-N and what portion was from the native soil-N. Nitrogen plots received ¹⁵N enrichments of 4.25 and 5.93 at % ¹⁵N in 1993 and 1994, respectively. At the end of the 1993 and 1994 growing season, 41.5% and 35.7% of the labeled fertilizer N remained in the soil profile, while the total recovery of applied ¹⁵N in the soil-plant system was 86.2% and 75.4%, respectively. Low recoveries of applied N may have been the result of soil or aboveground plant biomass volatilization, or denitrification or preferential flow processes. Further research needs to be conducted with strict accountability of gaseous loss and the mechanism(s) responsible.Item Influence of Amendments on Chemical and Biological Properties of Sodic Soils(North Dakota State University, 2016) Breker, Maria ChristineImproving productivity of sodic soils has become a concern in North Dakota because of the desire for more land for producing crops. Field and incubation studies were conducted to determine the impacts of different amendments (flue-gas desulfurization gypsum, sugar beet processing by-product lime, and langbeinite) on the chemical and biological properties of two sodic soils. The field study evaluated the amendment effects on the chemical conditions of the soil and the impact on alfalfa yield and quality. Differences were not observed in percent sodium (%Na) in the first 17 months and alfalfa yield was not impacted by the treatments except for the high rate of langbeinite. The incubation study investigated the effects of amendments on both the chemical and biological properties of the soil. Spent lime increased the cumulative respiration but was not impacted by gypsum or langbeinite. Labile carbon (C) was negatively correlated with %Na and electrical conductivity (EC).Item Sugarbeet Yield and Quality Response to Nitrogen Fertilizer Rate and In-Season Prediction of Yield and Quality Using Active-Optical Sensor(North Dakota State University, 2016) Subedi, KeshabNitrogen (N) management is one of the important factors in sugarbeet production. Under-application of N-fertilizer results in lower root yield while over-application of N-fertilizer can result in decreased sugar concentration and recoverable sugar. In recent years active-optical sensors have been investigated for in-season prediction of sugarbeet yield and quality and to make N management decisions. This study was conducted at four sites in the Red River Valley to determine the sugarbeet yield and quality response to N fertilizer rates and to determine the relationship of NDVI with sugarbeet yield and quality. The yield response to N fertilizer rates was significantly quadratic, however, sugar concentration did not show response to N fertilizer rates. In-season NDVI readings were strongly related with root yield and sugar yield. Active sensing during the growing seasons shows promise as a means to predict sugarbeet root yield and sugar yield.Item Superabsorbent Polymer Effects on Soil Physical Properties and Use as a Compaction Alleviation Amendment in Surface Coal Mine Reclamation(North Dakota State University, 2019) Ostrand, Megan SueSurface coal mine reclamation is challenged by alterations in soil characteristics, compaction being the most plant-yield reducing. Superabsorbent polymers (SAPs) ability to retain large volumes of water gives them the potential to alter soil properties. Laboratory objectives were to determine how SAPs alter water retention, liquid limit (LL), evaporation, saturated hydraulic conductivity (Ksat), and compression across five soil series. Increasing SAP application rates to 0.2% significantly increased plant available water (PAW), stage one evaporation duration, LL, stage two evaporative water loss, and significantly decreased stage one evaporative water loss, Ksat, and compression for various soil series. Field study investigated how SAP, deep ripping (R) and mulch (M) impacted penetration resistance and spring wheat yield (Triticum aestivum). Application of 0.04% SAP improved yields similar to R. Penetration resistance decreased with R, and SAP application showed reduction similar to R. While SAPs show potential as a reclamation tool, application longevity needs evaluation.Item Nitrogen and Phosphorus Recalibration for Sunflower in North Dakota(North Dakota State University, 2016) Schultz, Eric CharlesSunflower is one of the most important annual crops grown for edible oil in the world and is grown in North Dakota and the northern Great Plains more than any other region in the United States. Sunflower production and sunflower itself has evolved significantly since commercial cultivation began in the 1970s. In order to properly update fertility requirements of nitrogen and phosphorus in the northern Great Plains to correspond to this evolution, sunflower yield and oil concentration response to nitrogen and phosphorus fertilizer was investigated based on a twoyear (2014-2015) study. Highly significant statistical relationships between sunflower yield and oil concentration were found with nitrogen fertilizer rate but were not found with phosphorus fertilizer rate. This indicates that nitrogen fertilizer application rates used for sunflower need to be determined by current documented responses and that phosphorus fertilizer may not be needed to produce optimal yield and oil concentration of sunflower.Item Shifting Perspectives: Desocialization and the Journey Toward Critical Consciousness(North Dakota State University, 2010) Mathers, Angela MarieThe purpose of this study was to investigate how a service-learning course fosters students' development of a critical consciousness. Participants of this research study were students who participated in the 2009 International Service Seminar, a three-credit course that culminated with a service trip to Antigua, Guatemala. Interviews were conducted with participants that focused on students' experiences both during the class and in the year since the completion of the course. Utilizing critical pedagogy literature, I focused on the work of Jennifer Moon (1999) and Ira Shor (1992) to analyze the processes through which students gain critical consciousness. What became clear in my analysis is that desocialization was a significant component of the process of moving toward critical consciousness. In fact, the highly personal ways in which desocialization was woven into each students' experiences in the course, demonstrated that the journey toward critical consciousness occurs in a jagged manner. Understanding the nature of the desocialization process provides instructors of service learning courses the opportunity to foster critical consciousness in a more successful manner.