Soil Science Doctoral Work

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Fate and Transport of an Estrogen Conjugate 17ß-Estradiol-17-Sulfate in Soil-Water Systems
(North Dakota State University, 2013) Bai, Xuelian
The hypothesis of this study was that a sulfate conjugated estrogen, i.e. 17β-estradiol-17- sulfate (E2-17S), could be a precursor to free estrogens detected in the environment. The objectives of were to investigate the fate and transport processes of E2-17S in various soil-water systems. Radiolabeled E2-17S was synthesized using a series of chemical for the subsequent soil batch experiments. The batch experiment results showed that E2-17S dissipated more quickly from the aqueous phase of the topsoil compared to the subsoil, demonstrating that soil organic carbon played a significant role. The aqueous dissipation of E2-17S was attributed to sorption to the soil surface and transformation to form multiple metabolites. The non-linear sorption isotherms indicated limited sorption of E2-17S, and the concentration-dependent log KOC values were 2.20 and 2.45 for the sterile topsoil and subsoil, respectively. The total radioactive residue measured in the irreversible sites was greater than the reversible sites, demonstrating that irreversible sorption was the predominant sorption process. The observed multiple metabolites suggested that E2-17S underwent complex transformation pathways. For the aqueous phase speciation, mono- and di-hydroxy-E2-17S were consistently detected under all soil conditions, which indicated that hydroxylation was the major transformation process. Also, the hydroxyl metabolites were found at higher concentrations in the topsoil than the subsoil. In the reversibly sorbed phase, free estrogens (i.e. 17β-estradiol and estrone) were detected at relatively low levels (≤ 2% of applied dose) for all soils, demonstrating that deconjugation/hydrolysis and subsequent oxidation did occur. Furthermore, both hydroxylation and hydrolysis of E2-17S took place under the non-sterile and sterile conditions. Although deconjugation was not a major pathway, E2-17S could be a precursor of free estrogens in the environment. A comprehensive one-site fully kinetic model was applied to simulate the overall governing processes in the soil-water systems and to describe the distribution of multiple metabolites in the aqueous, reversibly sorbed, and irreversibly sorbed phases. The model gave rise to a satisfactory fit for all experimental data obtained from the batch studies, and the 36 estimated parameters were derived at relatively high confidence.
Sodic Soil Swelling and Dispersion and their Implications for Water Movement and Management
(North Dakota State University, 2014) He, Yangbo
North Dakota has over 1.9 million ha of sodium-affected soils, influencing water movement and crop production. This dissertation consists of four studies examining different aspects of sodic soils. The first study surveys sodium adsorption ratio (SAR) methods to determine which is the most reliable. The second and third studies investigate the dispersion and swelling functions of sodic soils. The final study examines field spatial distribution of Na in order to propose management strategies. Analytical approaches for converting alternative to standard approaches are needed. The SAR was determined from many non-standard techniques. One hundred soils were used, SARe and 1:5 soil/water SAR1:5 determined using shaking, stirring, and a USDA-NRCS method were compared. Three of the methods influenced the SAR1:5 values. Electrical conductivity (EC), SAR, and Ca/Mg ratios influence dispersion. Three pure clay minerals (montmorillonite, kaolinite and illite) were pretreated by variable Na and cation ratios and absorbance was determined using spectrophotometer for dispersion. Calcium-Mg ratios across the same SAR did not influence clay dispersion. Dispersion increased with higher SAR and reduced EC whereas no dispersion for kaolinite. Swelling is associated with hydration of clays, which forces clay tactoids to separate. Four soil series from North Dakota field sites were used. To assess swelling, field capacity (FC) was used as proxy. The study found that soil Na and soluble salt concentrations were two important chemical factors influencing FCW. The FCW increases with increased SAR and lower levels of EC. These results indicate that maintaining an EC level above 4 dS m-1 may mitigate swelling, which is an issue considered in tile drainage. Over- and under-application of amendments in sodic soils was studied in a 8.1 ha sodic soil field. At each site, samples were taken from two depths; electromagnetic (EM38) and elevation readings were done. Elevation was significantly correlated with soil variables except for Na%. The EM38 was reliable to express soil EC and was correlated with Na% and dispersion. Therefore, conducting the EM38 and RTK may allow site-specific management of Na. Improved knowledge of sodic soils dispersion, swelling, and field distribution will benefit researchers and farmers in managing their fields.
Evaluation of Active Optical Ground-Based Sensors to Detect Early Nitrogen Deficiencies in Corn
(North Dakota State University, 2014) Sharma, Lakesh Kumar
Corn (Zea mays, L) is an important world crop used as livestock feed, human consumption and ethanol production. Early in-season loss of nitrogen (N) continues to be a problem in corn. Ground-based active optical sensors (GBAO) have shown very promising results in predicting crop yield. In these experiments, two GBAO sensors GS and CC were used within forty-six established corn N-rate trials in North Dakota at the six (V6) and twelve (V12) leaf growth stages in 2011, 2012, and 2013. Corn height at V6 and V12 was recorded manually at each site in all three years. At V6, the GS relationship to yield and the INSEY (INSEY = in-season estimate of yield = sensor NDVI / growing degree days from planting date) value was often improved when the sensor NDVI was multiplied times corn height. Segregating the data sets into sites with eastern high clay conventional-till sites surface soil textures (clay more than 30%) and sites with more medium textures improved all INSEY relationships compared to pooling all sites. Eastern high clay conventional-till sites and eatstern medium textured converntional-till sites were further divided into those higher in productivity (yields greater than 10 Mg ha-1) and those lower in productivity (yields less than 10 Mg ha-1). The data categories differed in their sensor relationships to yield. Within all categories, the sensor relationships at V6 were weaker than those at V12. In the lower yielding eastern high clay conventional-till sites, lower yielding eastern medium-textured conventional-till sites, and the eastern no-till sites, no significant relationship was found at V6. At V12, a relatively weak relationship was only found in the low yielding eastern medium-textured coventional-till sites. The GS and CC were found to identify S deficiency at two sites in 2013. Both sensors detected that as N rate increased, the sensor readings generally decreased. This concept could be used by practitioners to screen sites with early season S deficiency, using an N rich strip in the field.
Nitrogen Dynamics in Soils from the Red River Valley of the North
(North Dakota State University, 2015) Awale, Rakesh
The objectives of this study were to evaluate the effects of (i) N management on crop yield, N availability, and N losses from a silty clay having subsurface drainage, (ii) soil moisture and nitrification inhibitor nitrapyrin [2-chloro-6-trichloro methyl pyridine, NP] on N2O emissions, and (iii) urea N-additives on NH3 volatilization and N2O emission losses from two contrasting soil textures (silty clay and sandy loam). The mean yields for corn (Zea mays L.), wheat (Triticum aestivum L.), sugarbeet (Beta vulgaris L.), and soybean (Glycine max L.) were 7.4, 0.9, 47.0, and 2.6 Mg ha-1 in 2012, and were 8.3, 4.1, 38.3, and 3.0 Mg ha-1 in 2013, respectively, across N and drainage treatments. Applying recommended N-rate along with NP increased N availability to crops, particularly under the subsurface drained condition. Application of extra N-rate than recommended only increased N losses associated with N2O and NH3 emissions. In the laboratory, N2O emissions from urea applied at 250 kg N ha-1 to silty clay soil were 0.14, 0.96, and 4.00% of applied-N at 30, 60, and 80% WHC, respectively. At WHC ≤ 60%, NP reduced N2O emissions by 2.6 to 4.8 fold compared to urea alone. Ammonia volatilization was higher from sandy loam (0.7 to 4.3% of applied-N) than from silty clay (0.1 to 0.4% of applied-N). In sandy loam, applying urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) and polymer coated urea (PCU) reduced NH3 losses by 32.3% and 84.2%, respectively, compared to untreated-urea. In silty clay, NBPT reduced NH3 volatilization by 71.4% relative to untreated-urea. N2O emissions did not differ between soils, and were between 3.7 to 7.4% of applied-N. In sandy loam, NP, SuperU (urea containing NBPT and nitrification inhibitor dicyandiamide), and PCU reduced N2O emissions by 23.5%, 43.8%, and 51.1%, respectively, compared to urea alone. Within the scope of two years of the field study, subsurface drainage and N management influenced soil N availability more than crop yield, emphasizing the need for long term research on subsurface drainage effect on crop yield. Soil moisture, texture and N management exert strong influence on NH3 volatilization and N2O emission.
Greenhouse Gas Emissions and Soil Quality in Long-Term Integrated and Reduced Tillage Organic Systems
(North Dakota State University, 2016) Bhowmik, Arnab
Organic agroecosystems “rely on ecological processes, biodiversity and cycles adapted to local conditions". Soil health is “the continued capacity of soil to function as a vital living ecosystem that sustains plants, animals, and humans” and can be used to assess agroecosystems. The fertility of organic agroecosystems is dependent upon soil organic matter, an indicator of soil health that supplies much of the nitrogen (N) and carbon (C) in soil. Despite the potential to use soil health as a dynamic measure few data sets compare soil health of different organic systems. My research compares the effects of climate and key best management practices (disturbance, amendment type, and livestock integration) on C sequestration, N cycling and greenhouse gas (GHG) emissions in five organic cropping systems. The data also contribute to our understanding of how microbial community members controlling reactive N (nitrate, nitrous oxide) and C cycling contribute to or reduce GHG as well as the potential of reduced tillage organic systems to lower GHG emissions when N is coupled with C in organic materials. This dissertation research verifies that the types and quantities of N cycling microorganisms can be used as indicators of soil health to assess the impact of short and long-term management on biogeochemical processes (the transformation and cycling of elements between non-living and living matter) that reduce or contribute to global climate change in long-term organic systems. A reduction in GHG emissions benefits the public and may increase the value added of certified organic foods.
Advancing Soil Health: Linking Belowground Microbial Processes to Aboveground Land Management
(North Dakota State University, 2016) Dose, Heather Lynn
Advancing soil health lies at the intersection of belowground microbial processes and aboveground land management. However, linking microbial processes to land use is difficult. Understanding the response of soil microbes to management factors will provide agricultural producers and land managers with information regarding best management practices that not only improve soil health, but also maximize profitability. This study advances the understanding of microbial responses to land management by measuring microbial response to a) amendment application and tile drainage to remediate sodic soils, b) cover crop growth and tile drainage to ameliorate saline soils and c) tillage and fertilizer management factors on Bradyrhizobium japonicum, a symbiotic bacteria needed for biological N fixation in soybeans (Glycine max L.). Multiple time point measurements of soil microbial enzymes and functional gene copy numbers from three field experiments were used to determine microbial responses to land management. Key findings indicate that gypsum amendment applications, although effective at reducing sodicity, reduce soil enzyme activity levels in the short-term while tile drainage has no effect on microbial response to sodic soils. This work also demonstrates that the quantity of nitrifiers and denitrifiers can be used as either short–term or long–term indicators of soil health which reflect overall ecosystem health in sodic soils. In contrast to sodic soils, nitrifiers and denitrifiers are not useful indicators of soil health in saline soils as these microbial communities exhibit salinity induced community tolerance. Finally, tillage system and N availability have the greatest effect on B. japonicum numbers and activity in the soil. The lower amount of N obtained from biological N fixation in soybeans grown under no till systems reflects the reduced reliance on B. japonicum for plant N needs. Inoculated populations of B. japonicum are important for early season biological N fixation, but persistent and diverse populations of B. japonicum play an important role in late season N fixation in the lateral soybean root nodules. Overall, this work demonstrates that monitoring soil microbial activity can be useful for producers and land managers looking to improve soil health.
Irrigated Potato (Solanum Tuberosum L.) Yield, Quality Response and Nitrogen Losses as Influenced by Nitrogen Fertilizer Management and Cultivars
(North Dakota State University, 2017) Ghosh, Upasana
Field studies were conducted in 2015 and 2016 growing season at Northern Plains Potato Growers’ Association Irrigation site near Inkster, ND to evaluate the effectiveness of enhanced efficiency fertilizers (EEFs) in maintaining yield, quality and reducing environmental nitrogen (N) losses in irrigated potatoes (Solanum tuberosum). Two types of EEFs i.e. SuperU (urea with urease and nitrification inhibitor) and ESN (polymer coated urea); grower’s standard fertilization and unamended urea were applied in three late-sown russet potato cultivars. Our findings suggested that yield responses vary widely with respect to years, length of growing season and cultivar type. Among EEFs, ESN consistently maintained yield compared to conventional fertilization practices. In shorter growing season (114 days), no yield benefit over N rate of 225 kg ha-1 was obtained with higher N rates (280 kg N ha-1) and different N sources in all three cultivars. Determinate cultivars can be a better choice to get good yield with lower N rate in shorter growing seasons. Both of the EEFs significantly reduced N losses through ammonia (NH3) volatilization and nitrous oxide (N2O) emission compared to unamended urea and grower’s standard fertilization practice. SuperU did not reduce residual soil nitrate (NO3-) compared to unamended urea while ESN reduced residual soil NO3-. Overall, ESN or polymer coated urea (PCU) is a promising choice for reducing N losses from irrigated potatoes. Plant N status assessment is important for yield prediction. Despite of being time consuming, total N concentration in petioles gave the better estimate of crop N status compared to standard petiole NO3-N concentrations. For early season quick N status measurement, ground based active optical sensors should be used in a cultivar specific way. Nitrogen fertilization recommendation for irrigated potatoes in North Dakota should be recalibrated considering length of growing season and cultivar type.
Soil Function Following Remediation Using Ex Situ Thermal Desorption
(North Dakota State University, 2017) O'Brien, Peter
Soils perform many functions essential to human and ecosystem health, and contamination by organic compounds diminishes the ability of the soil to perform those functions. One method for remediating contaminated soils is ex situ thermal desorption (TD). This process involves excavating contaminated soil material and heating it to encourage contaminant vaporization. Gaseous contaminants are combusted in a thermal oxidizer, while the treated soil is available for reuse. While TD is a fast, reliable way to remediate contaminated soil, the ability of the soil to function after treatment is unknown. The aim of this research was to determine the viability of using TD-treated soil for agricultural production. Laboratory, greenhouse, and field experiments were conducted to compare soil properties of TD-treated soil to non-contaminated topsoil, as well as to explore the effects of mixing TD-treated soil with topsoil. Laboratory experiments found that soil organic carbon was diminished following treatment, which corresponded with an increase in saturated hydraulic conductivity and a decrease in aggregate stability. Despite these alterations, a greenhouse study found that wheat grown in TD-treated soils matched topsoil in producing mature wheat grain, but the grain was lower quality than that grown in topsoil. Further, the soil mixtures produced less grain than either material alone. These findings suggest that microorganism interactions affected the pool of nutrients available to the wheat, especially plant-available nitrogen. Under field conditions, the surface energy balance of TD-treated soils was similar to native topsoil, although the soil heat flux was slightly elevated. These findings indicated that soil temperature dynamics and evaporative fluxes are not different between TD-treated and native topsoil. Overall, this research suggests that TD-treated soils can be viable for agricultural production, but they are unlikely to match native topsoil in either production quantity or quality. Mixing TD-treated soil may mitigate some of the negative impacts of TD-treatment by reintroducing soil organic matter and biological communities, which could further enhance the rate of recovery of soil function.
Symbiotic Nitrogen Fixation in Dry Bean Cultivars
(North Dakota State University, 2018) Sanyal, Debankur
Dry Beans (Phaseolus vulgaris L.), is the second-most important grain legume, and North Dakota has ranked first in dry bean production. The overarching research question of my project is whether we can increase the nitrogen (N) fixing potential of dry bean cultivars with inoculation and compare the nitrogen (N) fixing potential of common dry bean cultivars. Field experiment was conducted to compare peat and liquid inoculants during 2016 and 2017 growing seasons. In the field study, N2 fixation was estimated by stable isotope (15N) dilution technique. Liquid inoculant (70.5±5.9 kg ha-1) showed similar potential to the peat based inoculant (60.5±4.7 kg ha-1) for N2 fixation, however, inoculation treatments did not increase the N2 fixation over uninoculated (control). Further, it was investigated the nifH gene (marker for N2 fixation) expression in the dry bean-Rhizobium phaseoli symbiotic system. It was found that the relative normalized nifH gene expression significantly correlates (r = 0.82) with the total amount of N2 fixed, indicating the genetic control of symbiotic efficiency. Study on N-assimilatory genes, NR for nitrate reductase and GS for glutamine synthetase, showed that N2 fixation alone could not support plant N need in the later stages of growth (i.e. late flowering) and supplementary application of mineral-N is necessary for better plant growth and economic-yield. Dry bean cultivars did not response to inoculation and genetically, they differed significantly in N2 fixation potentials.
Fertilizer Management Strategies of Soybean (Glycine Max, L. Merrill) in Northcentral and Northwestern North Dakota
(North Dakota State University, 2019) Augustin, Christopher Lee
Soybean (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.
Soil Moisture Prediction Using Meteorological Data, Satellite Imagery, and Machine Learning in the Red River Valley of the North
(North Dakota State University, 2021) Acharya, Umesh
Weather stations provide key information related to soil moisture and have been used by farmers to decide various field operations. We first evaluated the discrepancies in soil moisture between a weather stations and nearby field; due to soil texture, crop residue cover, crop type, growth stage and duration of temporal dependency to recent rainfall and evaporation rates using regression analysis. The regression analysis showed strong relationship between soil moisture at the weather station and the nearby field at the late vegetative and early reproductive stages. The correlation thereafter declines at later growth stages for corn and wheat. We can adduce that the regression coefficient of soil moisture with four-day cumulative rainfall slightly increased with an increase in the crop residue resulting in a low root mean square error (RMSE) value. We then investigated the effectiveness of machine learning techniques such as random forest regression (RFR), boosted regression trees (BRT), support vector regression, and artificial neural network to predict soil moisture in nearby fields based on RMSE of a 30% validation dataset and to determine the relative importance of predictor variables. The RFR and BRT performed best over other machine learning algorithms based on the lower RMSE values of 0.045 and 0.048 m3 m-3, respectively. The Classification and Regression Trees (CART), RFR and BRT models showed soil moisture at nearby weather stations had the highest relative influence for moisture prediction, followed by the four-day cumulative rainfall and Potential Evapotranspiration (PET), and subsequently followed by bulk density and Saturated Hydraulic Conductivity (Ksat). We then evaluated the integration of weather station data, RFR machine learning, and remotely sensed satellite imagery to predict soil moisture in nearby fields. Soil moisture predicted with an RFR algorithm using OPtical TRApezoidal Model (OPTRAM) moisture values, rainfall, standardized precipitation index (SPI) and percent clay showed high goodness of fit (r2=0.69) and low RMSE (0.053 m3 m-3). This research shows that the integration of weather station data, machine learning, and remote sensing tools can be used to effectively predict soil moisture in the Red River Valley of the North among a large diversity of cropping systems.
The Biogeochemistry of Soil at Depth Within the Wetland Landscape of the Prairie Pothole Region
(North Dakota State University, 2021) Werkmeister, Carrie Elaine
The impact of agricultural practices on wetland ecosystems in the Prairie Pothole Region (PPR) has long been recognized but little is understood about impacts on the biogeochemistry of the wetlands at depth. Understanding the relationship of multi-elements within the wetland and surrounding landscape can aid in wetland restoration and provide guidance for wetland management. The objectives of this study were to: 1) identify biogeochemical characteristics of PPR wetlands; 2) identifying differences or similarities in biogeochemical characteristics of the landscape; 3) assess the vertical variation in chemical composition at depth in wetland, wetland and fringe, footslope and backslope soils; and 4) interpret the soil chemistry of undisturbed sites (good quality; prairie vegetation) and disturbed sites (poor quality; cultivated) relative to differences in landscape position locations. A field study was conducted on six disturbed (DW) and 6 undisturbed (UW) wetlands with evaluation of fringe (F), footslope (FS), or backslope (BS) positions. Using redundancy analysis (RDA) with selected environmental variables models of element concentrations at depth in each position were generated. The RDA ordination plots of element concentrations to depth of 1m was constrained by variables sand, silt, clay, depth, bulk density, site, organic matter, electrical conductivity, and pH. Pearson correlation coefficients between soil properties and the five most prominent soil elements differed between landscape positions. Anthropogenic activity likely influenced the subsurface hydrology but differed in physical and chemical properties. These differences appear to be related to the vegetation, levels of soil disturbance of surrounding landscapes and unique chemical and physical characteristics of parent material.
Proposed Nonparametric Tests for the Simple Tree Alternative for Location and Scale Testing in a Mixed Design
(North Dakota State University, 2022) Khalawi, Fouad
Six nonparametric tests are proposed for the mixed design consisting of a randomized complete block design (RCBD) and a completely randomized design (CRD). The proposed tests are designed to test for differences in location and/or scale for a simple tree alternative. The tests are a combination of the Fligner-Wolfe test, modified Page’s test, and modified Ansari-Bradley test. A simulation study is conducted to determine how well the proposed tests maintain their significance levels. Powers of the six proposed tests are estimated under a variety of cases: changing the underlying distribution, changing the number of treatments, increasing the variance between the CRD and RCBD portion, changing the proportions of the number of blocks in the RCBD to the sample size for each treatment in the CRD, and changing the parameter arrangements. A recommendation for which test has higher power depends on whether the underlying distribution is symmetric or asymmetric.
Evaluating Ornamental Grasses for the Challenging Rain Garden Environment
(North Dakota State University, 2022) Nelson, Randy
Four experiments were conducted to determine the growth and survival of seven species of perennial ornamental grasses, tufted hairgrass [Deschampsia cespitosa (L.) P. Beauv.], switchgrass (Panicum virgatum L.), big bluestem (Andropogan gerardii Vitman), Chinese silvergrass (Miscanthus sinensis Andersson), little bluestem [Schizachyrium scoparium (Michx.) Nash], blue grama grass [Bouteloua gracilis (Kunth) Lag. ex Griffiths], and feather reed grass [Calamagrostis x acutiflora (Schrad.) Rchb.], when subjected to cyclical flood and drought, varying submergence depths and durations, NaCl, and NaCl with petroleum hydrocarbons. Chinese silvergrass and switchgrass survived cyclical soil flooding and drought and submergence for 7-d at a depth of 30 cm while maintaining an acceptable amount of foliar damage. All grasses survived cyclical flood and drought when the soil VWC was maintained at 14% suggesting all seven grasses can withstand periodic soil flooding as long as the water is not too deep. As water depth and duration increased from 4-d to 7-d, little bluestem, blue grama grass, and feather reed grass suffered significant foliar damage. Tufted hair grass and big bluestem suffered significant foliar damage when submerged for 2-d. Switchgrass and feather reed grass survived NaCl loads of up to 6.7 Mg∙ha-1 and maintained a visual damage rating less than three making them suitable for planting in rain gardens or bioretention systems receiving NaCl runoff. Switchgrass also tolerated motor oil at rates up to 5% in combination with NaCl at rates up to 6.7 Mg∙ha-1. Switchgrass would be an ideal grass for planting in areas receiving both contaminates. Tufted hair grass has limited tolerance to NaCl or motor oil and should not be planted in areas that may receive those contaminates in stormwater runoff. Big bluestem and little bluestem have limited tolerance to NaCl but some tolerance to motor oil and may be candidates for planting in areas receiving only motor oil in stormwater runoff. Chinese silvergrass and blue grama grass can tolerate moderate levels of NaCl and motor oil while maintaining a visual damage rating of four or less and would be candidates for planting in areas that receive moderate amounts of both pollutants in stormwater runoff.
Corn Response to Sulfur in the Red River Valley
(North Dakota State University, 2022) Goyal, Diksha
Sulfur (S) deficiency symptoms are becoming common to crops grown in the Red River Valley of North Dakota and Minnesota. Corn (Zea mays L.) response to incremental sulfate-S (0, 11, 22, 33, and 44 kg S ha-1) was studied (n=12) during the 2018-2020 growing seasons in a series of experiments. Corn yield and S uptake did not respond to S fertilizer (P≥0.05) additions, but yield varied across sites. Ten out of 12 sites showed an increase in grain yield over control but not significant. Corn, spring wheat (Triticum aestivum L.), and sugar beet (Beta vulgaris L.) responses to S forms were also studied. Only spring wheat showed a significant (P≤0.05) response to S forms. Growers should follow the current recommendation to apply 11 kg S ha-1 to compensate for the grain S removal and avoid grain yield loss to S in susceptible areas of fields.

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