Scholarly Works, School of Plant and Environmental Sciences

Permanent URI for this collection

https://hdl.handle.net/10919/97229

Browse

Now showing 1 - 20 of 1204

Intensifying impacts of compound drought and heatwave events on water use efficiency in U.S. corn and soybean
Yan, Hua; You, Yongfa; Jiao, Wenzhe; Pan, Naiqing (Elsevier, 2025-12-15)
The increasing frequency and intensity of compound drought and heatwave events pose a severe threat to agricultural water use efficiency (WUE), amplifying risks to global food security and water resource sustainability. While compound extremes can trigger unprecedented disruptions in agricultural water-carbon dynamics compared to single extreme events, their effects on WUE remain poorly understood. To address this gap, this study examines the spatiotemporal variations in U.S. corn and soybean WUE in response to compound drought and heatwave events from 1960 to 2018. Using superposed epoch analysis, we found that compound drought and heatwave events reduced WUE by 14.7% in corn and 11.3% in soybean compared to normal conditions. These compound events also resulted in greater reductions in yield and evapotranspiration than single drought or heatwave events. While the impacts of both single and compound extremes were generally short-lived, with WUE recovering in the following year, long-term trends reveal intensifying effects: compound drought and heatwave events have shown intensified adverse impacts on 37.5% of corn and 46.2% of soybean production areas. This intensification is closely linked to the role of temperature, which was consistently identified as the dominant climatic driver of WUE responses under drought, heatwave, and compound extremes. These findings underscore the urgent need to prioritize compound drought and heatwave events in agricultural impact assessments and develop targeted adaptation strategies to mitigate their intensifying effects on agricultural WUE.
Exploring the fluorinome of PFAS-impacted groundwater using 21 tesla FT-ICR mass spectrometry
Lu, Wenchao; Babcock-Adams, Lydia; Sharifan, Hamidreza; Kornuc, John J.; Hao, Shilai; Higgins, Christopher P.; Young, Robert B.; McKenna, Amy M.; Blotevogel, Jens (Elsevier, 2026-01)
Non-targeted analysis of complex per- and polyfluoroalkyl substances (PFAS) via Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) promises unprecedented insights into the "fluorinome", i.e., the complete set of organofluorine compounds in a given sample. In this study, we present a Python-based workflow developed in parallel with a carefully constructed PFAS formula database comprising ∼ 20 million entries to facilitate the assignment of chemical formulas to ultrahigh-resolution mass spectra. PFAS assignments based on the analysis of complex aqueous film-forming foam (AFFF) on the world's highest-resolving 21 tesla FT-ICR MS were compared to quadrupole time-of-flight (QTOF) MS data, validating 22 common and discovering 19 previously undetected PFAS classes. We then explored the viability of ultrahigh-resolution FT-ICR MS analysis for forensic profiling purposes on PFAS-impacted groundwater samples, identifying bis-perfluoroalkyl sulfonimides (bis-FASIs) as long-suspected ingredients of electrochemical fluorination AFFFs. While our newly developed workflow may also be used for other types of high-resolution mass spectrometers such as QTOF and Orbitrap, this work leverages the unique ultrahigh-resolving power, sub-ppm mass measurement accuracy, and high dynamic range of 21 tesla FT-ICR mass spectrometry to maximize information from complex contaminant mixtures in environmental samples.
Agrobacterium-mediated Cuscuta campestris transformation as a tool for understanding plant-plant interactions
Adhikari, Supral; Mudalige, Asha; Phillips, Lydia; Lee, Hyeyoung; Bernal-Galeano, Vivian; Gruszewski, Hope; Westwood, James H.; Park, So-Yon (Wiley, 2025-02)
Cuscuta campestris, a stem parasitic plant, has served as a valuable model plant for the exploration of plant–plant interactions and molecular trafficking. However, a major barrier to C. campestris research is that a method to generate stable transgenic plants has not yet been developed. Here, we describe the development of a Cuscuta transformation protocol using various reporter genes (GFP, GUS, or RUBY) and morphogenic genes (CcWUS2 and CcGRF/GIF), leading to a robust protocol for Agrobacterium-mediated C. campestris transformation. The stably transformed and regenerated RUBY C. campestris plants produced haustoria, the signature organ of parasitic plants, and these were functional in forming host attachments. The locations of T-DNA integration in the parasite genome were confirmed through TAIL-PCR. Transformed C. campestris also produced flowers and viable transgenic seeds exhibiting betalain pigment, providing proof of germline transmission of the RUBY transgene. Furthermore, RUBY is not only a useful selectable marker for the Agrobacterium-mediated transformation, but may also provide insight into the movement of molecules from C. campestris to the host during parasitism. Thus, the protocol for transformation of C. campestris reported here overcomes a major obstacle to Cuscuta research and opens new possibilities for studying parasitic plants and their interactions with hosts.
Effects of Clipping Heifer Hair Coats on Vaginal Temperatures and Performance of Fall-Born Heifers Stocked on Toxic Endophyte-Infected Tall Fescue During the Summer
Beard, Christopher T.; Swecker, William S.; Abaye, Ozzie; Pent, Gabriel J. (MDPI, 2025-11-12)
Achieving satisfactory levels of weight gain for developing replacement beef heifers is challenging when utilizing toxic endophyte-infected tall fescue (Schedonorus arundinaceus) as the primary forage. This is due to the intensifying impact of ergot alkaloids produced by the fungal endophyte on heifer heat stress in the summer. The purpose of this trial was to determine if clipping hair coats would reduce heat stress impacts experienced by fall-born heifers stocked on toxic endophyte-infected tall fescue. Heifers were randomly assigned to a control cohort and a clipped cohort. The heifers in the clipped treatment group were sheared along the body of the heifer. Vaginal temperature loggers were used to record core temperatures every ten minutes during several sampling periods. Hair coats on clipped heifers resembled hair coats of the control heifers by the conclusion of the 16-week trial. Average daily gains of the clipped heifers exceeded the average daily gains of the control heifers only in the first four-week period. There were no differences in seasonal average daily gain or pregnancy rates. Clipped heifers had cooler core temperatures by 0.2–0.3 °C in the morning compared to the control heifers. Clipping hair coats of heifers only provided short-term relief for cattle stocked on toxic endophyte-infected tall fescue.
Cryosols
Galbraith, John M.; Balks, Megan; Broll, Gabriele; Kabala, Cezary; Lupachev, Alexey; Unc, Adrian (ISRIC, 2024)
This text is a contribution to the WRB Documentation Centre that illustrates the Reference Soil Groups (RSG) and all their principal qualifiers (PQ) in the World Reference Base for Soil Resources (IUSS Working Group WRB, 2022). These lecture notes deal with the RSG of Cryosols. It provides the soil forming factors and the main characteristics of this RSG and reviews its classification at RSG and qualifier level. Examples of fully documented Cryosols with their principal qualifiers derived from expert sources are given in the “Typifying pedons” accompanying document . The “Historical review” accompanying document describes the changes in the evolving classification criteria for Cryosols since the FAO/Unesco Legend of the Soil Map of the World. The WRB soil classification system will benefit from a core set of documented occurrences of Reference Soil Groups with their principal qualifiers as illustrated here. However, not all principal qualifiers could be documented and a call for contributions is made to fill the gaps in the present Cryosol collection.
Portable X-ray fluorescence as a tool for urban soil contamination analysis: accuracy, precision, and practicality
Jenkins, Eriell M.; Galbraith, John M.; Paltseva, Anna A. (Copernicus, 2025-08-13)
Urban agriculture has become an essential component of urban sustainability, but it often faces the challenge of soil contamination with heavy metal(loid)s like lead (Pb), arsenic (As), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), and zinc (Zn). Traditional laboratory methods for detecting these contaminants, such as atomic absorption spectroscopy and other inductively coupled plasma techniques, are accurate but can be costly and time-consuming and require extensive sample preparation. Portable X-ray fluorescence (PXRF) presents a promising alternative, offering rapid, in situ analysis with minimal sample preparation. The study reviews literature on PXRF analyzers to determine their accuracy and precision in analyzing heavy metal(loid)s in urban soils, with the goal of optimizing sampling, reducing laboratory costs and time, and identifying priority metal contamination hotspots. A literature review was conducted using Web of Science and Google Scholar, focusing on studies that validated PXRF measurements with alternate laboratory methods or certified reference materials (CRMs). This study reviews 84 publications to evaluate the accuracy and precision of PXRF in analyzing heavy metal(loid)s in urban soils. The review covers instrument types, action methods, testing conditions, and sample preparation techniques. Results show that, when properly calibrated, particularly with CRMs, PXRF can achieve reliable accuracy. Ex situ measurements tend to be more precise due to controlled conditions, although in situ measurements offer practical advantages in urban settings. Portable XRF emerges as a viable method for assessing urban soil contamination by balancing accuracy and practicality. Future research should focus on optimizing sample preparation and calibration to further enhance PXRF reliability in urban environments, ultimately strengthening PXRF methodologies and supporting extension efforts through improved, accessible soil-testing tools, facilitating healthier urban soils, safer urban food production, and enhanced community well-being.
Determining Aroma Compounds and Their Relation to Consumer Acceptability in United States Edamame
Miller, Rebekah J.; Duncan, Susan E.; Carneiro, Renata; Lahne, Jacob; Kuhar, Thomas P.; Zhang, Bo; Yin, Yun (American Chemical Society, 2025-06-06)
Edamame is a highly nutritious crop with significant economic value, but its consumption in the United States depends predominantly on imported products. Efforts in domestic edamame breeding aim to develop varieties that satisfy both agronomic performance and consumer expectations. Aroma profiles of 10 genotypes grown in 2019 across 4 U.S. locations were analyzed using solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry. Sixteen aroma compounds were identified across edamame genotypes and growing locations. Significant differences in individual aroma concentrations were observed (p < 0.05) across genotypes and growing locations. The compounds 1-octen-3-ol, hexanal, and octanal consistently exhibited the highest odor activity values in all samples. The relationship between aroma compound profiles and previously published consumer acceptability was also examined. Correlation analysis revealed limited strong associations (>|0.5|) between aroma compounds and sensory attributes, with only one compound, 1-octanol, showing a strong correlation with overall consumer liking. No individual aroma compounds were found to strongly associated with consumer liking or disliking.
Does fall manure injection cause differential growth and forage nutritive value in small grains?
Hilfiker, Derek R.; Maguire, Rory O.; Ferreira, Gonzalo; Thomason, Wade E.; Stewart, Ryan D. (Wiley, 2024-05-01)
Producers utilizing fall manure injection have reported increased growth and greenness in small grains growing on the injection band compared to small grains growing between injection bands. To determine how producers utilizing fall manure injection in small grains should manage potential differential growth, 24 sites under fall manure injection were established. Soil samples were taken in-band and between-band 1 month after manure application and at silage harvest for soil NO3-N. Small grain growth stage was assessed 1 month after planting and at silage harvest, while dry matter (DM) yield and forage nutritive value parameters were assessed at silage harvest. Soil NO3-N was elevated in-band compared to between-band 1 month after manure application (p < 0.05); however, this did not persist until silage harvest. No differences in growth stage were observed 1 month after planting in 2021; however, growth stage means were consistently elevated in-band in 2022, likely due to earlier planting dates in 2022 compared to 2021. Growth stage at harvest was the same in-band and between-band at each site. Small grain DM yield was only increased in-band compared to between-band in three of 24 sites. Two of the three sites planted with wheat (Triticum aestivum L.) showed significantly increased DM yield in-band, suggesting DM yield response could be species dependent. No consistent differences in forage nutritive value parameters were observed. As no consistent differences in small grain DM yield and forage nutritive value were found at harvest, we recommend no changes to management practices for producers utilizing fall manure injection in small grains.
Persistence and relocation of dislodgable herbicide residue from simulated rainfall following glyphosate treatment to dormant zoysiagrass turf
Godara, Navdeep; Craft, Jordan M.; Goncalves, Clebson G.; Askew, Shawn D. (Wiley, 2025-01-01)
The severity of herbicide injury to dormant zoysiagrass (Zoysia spp.) increases with increasing green leaves at treatment time, but injury also occurs following treatment to fully dormant zoysiagrass, especially when treatment precedes rapid shoot emergence. Research was conducted to determine the persistence of radio-labeled glyphosate or glufosinate on dormant zoysiagrass leaves, to assess how simulated raindrop quantity affects relocation of glyphosate plus colorant to subcanopy areas, and to evaluate the response of post-dormant zoysiagrass to glyphosate dislodged and relocated from dormant leaves via simulated rainfall, dew, or disturbance during post-dormancy growth. When dormant zoysiagrass leaves were treated with C-14-glufosinate or C-14-glyphosate, 69% and 57%, respectively, of the herbicides were water extractable for 21 days. Increasing the number of simulated raindrops 0.5 cm(-2) from 1 to 20 removed >95% of the applied colorant from treated dormant zoysiagrass leaves, with concomitant relocation of residue to underlying filter paper. Maximum exposure of a single subtending green shoot occurred at five simulated raindrops 0.5 cm(-2), which would approximate a rainfall of 3.35 mm. Subsequently, glyphosate applied to dormant zoysiagrass plugs followed by 3 mm simulated rainfall or dew and wiping 7-9 days later, when turf had reached 15% green cover, reduced zoysiagrass clipping biomass by 35% and 72%, respectively. Glyphosate applied to dormant zoysiagrass can dislodge and injure newly developing green shoots during transition. This injury can be mitigated by irrigating 1 day after glyphosate treatment to dormant turf or ensuring that the first irrigation or rainfall following treatment is at least 12 mm.
U.S. cereal rye winter cover crop growth database
Huddell, Alexandria; Thapa, Resham; Marcillo, Guillermo; Ackroyd, Victoria; Bagavathiannan, Muthukumar; Balkcom, Kipling; Bradley, Kevin; Darby, Heather; Reiter, Mark S.; Haymaker, Joseph; Flessner, Michael L.; Wolters, Bethany; Ketterings, Quirine; Kladivko, Eileen; Miller, Jarrod; VanGessel, Mark; Mirsky, Steven (Nature Portfolio, 2024-02-13)
Winter cover crop performance metrics (i.e., vegetative biomass quantity and quality) affect ecosystem services provisions, but they vary widely due to differences in agronomic practices, soil properties, and climate. Cereal rye (Secale cereale) is the most common winter cover crop in the United States due to its winter hardiness, low seed cost, and high biomass production. We compiled data on cereal rye winter cover crop performance metrics, agronomic practices, and soil properties across the eastern half of the United States. The dataset includes a total of 5,695 cereal rye biomass observations across 208 site-years between 2001–2022 and encompasses a wide range of agronomic, soils, and climate conditions. Cereal rye biomass values had a mean of 3,428 kg ha⁻¹, a median of 2,458 kg ha⁻¹, and a standard deviation of 3,163 kg ha⁻¹. The data can be used for empirical analyses, to calibrate, validate, and evaluate process-based models, and to develop decision support tools for management and policy decisions.
High-resolution surface and rootzone soil moisture over US cropland: A novel framework assimilating multi-source remote sensing data, machine learning, and the Layered Green and Ampt Infiltration with Redistribution model
Cai, Shuohao; Xu, Yijia; Yang, Zhengwei; Crow, Wade; Zhang, Zhou; Reberg-Horton, Chris; Schomberg, Harry; Mirsky, Steven; Seehaver, Sarah; Park, Dara; Treadwell, Danielle; Haymaker, Joseph; Reiter, Mark S.; Flessner, Michael L.; Sias, Cynthia; Tomlinson, Peter; Huang, Jingyi (Elsevier, 2026-03-01)
Accurate and high spatiotemporal resolution soil moisture (SM) monitoring in cropland is important for water resource management, drought forecasting, and nutrient transport estimation at the field scale for sustainable crop production. Although recent research has applied machine learning (ML) to downscale coarse-resolution satellite SM products, most of this past work has focused only on surface SM estimation, and the performance of rootzone SM products has not been intensively evaluated in cropland. This study introduces a novel framework that integrates multi-source satellite-based ML models with the Layered Green and Ampt Infiltration with Redistribution (LGAR) model to produce high-resolution (100 m, hourly) SM products for both the surface layer (0–5 cm) and rootzone (0–100 cm) across cropland in the contiguous United States (CONUS). First, six ML models were trained using multiple high-resolution remote sensing datasets (Sentinel-1, Sentinel-2, and Landsat) to predict surface and rootzone SM. These ML predictions were then assimilated into the LGAR model using the ensemble Kalman filter (EnKF). The framework was developed and validated using an eight-fold cross-validation scheme with in-situ data from 431 cropland sites across CONUS, sourced from three networks (SCAN, USCRN, and PSA). The 100-m hourly SM data from this framework surpasses existing products (9-km SMAP L4, SMAP-based 1-km thermal hydraulic disaggregation of SM product) in spatial and temporal resolution and captures rootzone SM that is not available in the SMAP-HydroBlocks SM product. It achieves good performance, with median bias-corrected root mean squared error (ubRMSE) of 0.053 m3/m3 and median Kling-Gupta efficiency (KGE) of 0.379 in the surface layer, and median ubRMSE of 0.027 m3/m3 and median KGE of 0.302 in the rootzone. While the framework demonstrates strong performance, its accuracy varies across climatic regimes, with surface SM performing better in non-humid areas (median KGE = 0.375 versus median KGE = 0.416) and rootzone SM in humid regions (median KGE = 0.313 versus median KGE = 0.127). This high-resolution cropland SM product can potentially benefit multiple agricultural applications, such as irrigation management and nutrient leaching estimation, and provide valuable insights to support farmers and land managers in decision-making processes.
Elevated Soybean Seed Oil Phenotype Associated with a Single Nucleotide Polymorphism in GmNFR1α
Patibandla, Sri Veda; Carrero-Colón, Militza; Song, Qijian; Qin, Quilin; Clevinger, Elizabeth; Zhu, Hongyan; Maroof, M. A. Saghai; Hudson, Karen (MDPI, 2025-12-03)
Soybean seed composition, particularly the oil and protein content of the seed, has been a longstanding focus of research due to the economic and nutritional importance of these components for both feed and industrial applications. Through forward genetic screening of a mutagenized population derived from the soybean cultivar Williams-82, a mutant line designated PID 17238 was identified for high seed oil content. This phenotype is associated with a decrease in levels of protein with respect to Williams-82. The phenotype was mapped to chromosome 2 to a region near Satt459. Fine mapping and whole-genome resequencing were used to identify the causative mutation. Analysis of the resequencing data within the candidate region uncovered 55 sequence variants. Glyma.02G270800 contained a single nucleotide polymorphism (SNP) within the coding sequence. Glyma.02G270800 encodes a lysin motif (LysM) receptor-like kinase previously reported in the literature as GmNFR1α. Importantly, this locus is allelic to the well-characterized rj1 locus, a recessive mutation known to cause a non-nodulating phenotype in soybean. Nodulation in soybeans, which enables nitrogen fixation, is crucial for protein synthesis in seeds, and the lack of nodulation may explain the lower protein content in PID 17238.
Long-term effects of cover crops and no-tillage on soil health in the Virginia Coastal Plain
Haymaker, Joseph; Stewart, Ryan D.; Wolters, Bethany; Stephenson, Stephen Kurt; Balkcom, Kipling; Reiter, Mark S. (Elsevier, 2025-10-03)
After centuries of conventional tillage practices, sandy loam Coastal Plain soils have been heavily degraded, resulting in severely depleted soil organic carbon (SOC) stocks. This study examined impacts on soil health when transitioning from intensive tillage in vegetable production to no-till (NT) corn (Zea mays L.) and soybean (Glycine max (L.) Merr.) production with cover crops (CC). A long-term cropping system experiment, established in 2014, assessed twelve different crop rotations, including a conventionally tilled (CT) fallow control and various CC treatments, ranging from monocultures to a perennial mixture with corn planted every third year. After nine years, CC treatments increased near-surface SOC concentrations (8.4–10.5 g kg⁻¹at 0–5 cm) and SOC stocks (4.6–7.3 Mg ha⁻¹) compared to fallow controls (6.4–6.9 g kg⁻¹; 4.6–5.2 Mg ha⁻¹). Soil organic carbon gains were most pronounced in the surface 5 cm and had a positive relationship with cumulative C inputs (R²= 0.38). Cover crops reduced bulk density by up to 11 %, and SOC stocks were still significantly greater than fallow treatments as SOC concentration gains offset the lower bulk density. Treatments with hairy vetch (Vicia villosa Roth L.) or legume-dominant CC mixes lowered soil pH compared to fallow or grass-based CC treatments, potentially increasing the need for lime applications. Adoption of NT alone, without CCs, did not deliver similar soil health benefits. These results highlight the importance of integrating CCs into crop rotations to enhance SOC and improve soil physical properties in degraded Coastal Plain soils.
Subsidy-stress responses of ecosystem functions along experimental freshwater salinity gradients
DeVilbiss, Stephen E.; Badgley, Brian D.; Hotchkiss, Erin R.; Steele, Meredith K. (Springer, 2024-05-01)
Human activity is increasing salt concentrations in freshwaters worldwide, but effects of freshwater salinity gradients on biogeochemical cycling are less understood than in saline, brackish, or marine environments. Using controlled microcosm experiments, we characterized (1) short-term (one to five days) biogeochemical responses and (2) water column metabolism along a freshwater salinity gradient of multiple salt types. After one day, microcosms were oxic (4.48-7.40 mg O2 L-1) but became hypoxic (1.20-3.31 mg L-1) by day five. After one day in oxic conditions, microbial respiration in magnesium-, sodium-, and sea salt-based salinity treatments showed a subsidy-stress response, with respiration increasing by over 100% as salinity increased from 30 to 350-800 mu S cm-1. Conversely, respiration consistently increased along a calcium-based salinity gradient, peaking at 1500 mu S cm-1. By day five, an inverse subsidy-stress response was observed with elevated respiration at upper or lower ends of the gradient except for the magnesium treatment, which had the lowest respiration at the highest salinity. Calcium- and magnesium-based salinity treatments also caused considerable changes in phosphorus concentrations and C:P and N:P. In a separate experiment, microbial respiration and water column primary production also displayed subsidy-stress responses, but imbalances in effect sizes caused consistently declining net community production with increasing salinity. Collectively, our results establish that short-term exposure to different salt ion concentrations can enhance freshwater biogeochemical cycling at relatively low concentrations and alter resource stoichiometry. Furthermore, the nature of effects of freshwater salinization may also change with oxygen availability.
Using hyperspectral signatures for predicting foliar nitrogen and calcium content of tissue cultured little-leaf mockorange (Philadelphus microphyllus A. Gray) shoots
Khajehyar, Razieh; Vahidi, Milad; Tripepi, Robert (Springer, 2024-06-01)
Determining foliar mineral status of tissue cultured shoots can be costly and time consuming, yet hyperspectral signatures might be useful for determining mineral contents of these shoots. In this study, hyperspectral signatures were acquired from tissue cultured little-leaf mockorange (Philadelphus microphillus) shoots to determine the feasibility of using this technology to predict foliar nitrogen and calcium contents. After using a spectroradiometer to take hyperspectral images for determining foliar N and Ca contents, the correlation between the hyperspectral bands, vegetation indices, and hyperspectral features were calculated from the spectra. Features with high correlations were selected to develop the models via different regression methods including linear, random forest (RF), and support vector machines. The results showed that non-linear regression models developed through machine learning techniques, including RF methods and support vector machines provided satisfactory prediction models with high R-2 values (%N by RF with R-2 = 0.72, and %Ca by RF with R-2 = 0.99), that can estimate nitrogen and calcium content of little-leaf mockorange shoots grown in vitro. Overall, the RF regression method provided the most accurate and satisfactory models for both foliar N and Ca estimation of little-leaf mockorange shoots grown in tissue culture.
PFAS fate using lysimeters during degraded soil reclamation using biosolids
Peter, Lynda; Modiri-Gharehveran, Mahsa; Alvarez-Campos, Odiney; Evanylo, Gregory K.; Lee, Linda S. (Wiley, 2025-01-01)
Carbon- and nutrient-rich biosolids are used in agriculture and land reclamation. However, per- and polyfluoroalkyl substances (PFAS) typically present in biosolids raise concerns of PFAS leaching to groundwater and plant uptake. Here, we investigated PFAS persistence and leaching from biosolids applied to a site constructed artificially to mimic degraded soils. Treatments included biosolids and biosolids blended with mulch applied at different rates to attain either one and five times the agronomic N rate for vegetable crops and a control treatment with synthetic urea and triple superphosphate fertilizer. Leachates were collected for a 2-year period from 15-cm depth zero-tension drainage lysimeters. Soils were analyzed post biosolids application. PFAS were quantified using isotope-dilution, solid-phase extraction and liquid chromatography tandem mass spectrometry. Leachate profiles exemplified an initial high total PFAS concentration, followed by a sharp decline and subsequent small fluctuations attributed to pre-existing soil conditions and rainfall patterns. Quantifiable PFAS in leachate were proportional to biosolids application rates. Short-chain perfluoroalkyl acids (CF2 < 6) were dominant in leachate, while the percentage of longer chains homologues was higher in soils. A 43% biosolids blend with mulch resulted in 21% lower PFAS leachate concentrations even with the blend application rate being 1.5 times higher than biosolids due to the blend's lower N-content. The blending effect was more pronounced for long-chain perfluoroalkyl sulfonic acids that have a greater retention by soils and the air-water interface. Biosolids blending as a pragmatic strategy for reducing PFAS leachate concentrations may aid in the sustainable beneficial reuse of biosolids.
On-farm large plot comparison of Bt and non-Bt corn hybrids for Helicoverpa zea (Lepidoptera: Noctuidae) feeding, yield, and economic return
Alsdorf, Alexis; Reisig, Dominic; Ferraro, Gregory; Malone, Sean; Mott, Joshua; Schardong, Igor; Taylor, Sally; Rejesus, Roderick (Oxford University Press, 2025-11-16)
Helicoverpa zea (Bodie) is a widespread damaging pest in the US that has evolved varying levels of resistance to Cry toxins in corn and cotton. To delay resistance evolution to this pest and others targeted by Bt corn, growers in the southern United States are required to plant at least 20% of their corn area with non-Bt corn. However, growers are reluctant to do this. Multiple small-plot research studies show timely planted non-Bt and Bt corn hybrids yield equally; however, growers often think non-Bt hybrids yield less than Bt hybrids. In response, we compared non-Bt and Bt hybrids using grower-owned planting and harvesting equipment. Growers planted 5 corn hybrids as strip plots (Bt-P1197YHR, DKC65-99, non-Bt-P1197LR, DKC67-70, and DKC65-93) in 2022 at 27 locations and 4 hybrids (excluding DKC65-93) in 2023 at 28 locations throughout North Carolina. When corn reached dent (R5), we measured the area of H. zea injury from each hybrid at each location. We calculated yield and economic net returns at harvest. We separated analyses for Bt trait pyramid and hybrid for both feeding and yield. H. zea feeding was at moderate levels, following predictable patterns. There were no significant differences between Bt and non-Bt hybrids within the 2 companies we compared (Pioneer [P] and Bayer [DKC]) across both years. In general, farm profitability is not statistically different when planting a 20% non-Bt refuge compared to planting 100% Bt corn. Factors other than typical H. zea feeding are more impactful on yield in North Carolina.
Soil health indicators for predicting corn nitrogen requirement in long-term cover cropping
Pokhrel, Sapana; Maguire, Rory O.; Thomason, Wade E.; Stewart, Ryan D.; Flessner, Michael L.; Reiter, Mark S. (Wiley, 2024-09-01)
Efforts to address economic and environmental concerns surrounding nitrogen (N) have motivated attempts to improve estimates of plant-available N in soil. Several soil health indicators, including CO2 burst, permanganate oxidizable carbon (C) (POXC), and autoclaved-citrate extractable (ACE) soil protein, assess labile C and N, and therefore may help to estimate soil N mineralization in long-term cover cropping systems (>3 years). This study evaluated the relationship of CO2 burst, POXC, ACE-soil protein, and pre-sidedress nitrate test (PSNT) with agronomic optimum N rate (AONR) in corn (Zea mays L.). The study also looked at relationship between other soil test and corn yield parameters, relative yield (RY) and yield without N sidedress at 25 long-term cover crop sites across Virginia. Results showed relatively weak correlations between AONR and CO2 burst, POXC, ACE-soil protein, and NO3-N (r = 0.00 to -0.48), which indicates that these soil health tests may not reliably predict soil N availability and corn yield. Corn yield with zero-sidedress N rate had a negative relationship with cover crop C:N ratio (r = -0.66) and a positive relationship with cover crop N content (r = 0.59), and NO3-N at pre-planting (r = 0.54) and sidedress (PSNT) (r = 0.63). The PSNT showed a better relationship (r = 0.65) compared to 72-h CO2 burst (r = 0.48) with RY. Soil health indicators (CO2 burst, POXC and ACE-soil protein) resulted in a poor or no relationship with AONR. Our results indicate that the PSNT was a more reliable indicator of the sidedress N rate in corn.
Transgenerational phenotypic responses to herbicide stress are more rapid than to shade and simulated herbivory in Arabidopsis
Sharma, Gourav; Haak, David; Westwood, James H.; Askew, Shawn; Barney, Jacob N. (Wiley, 2024-09-01)
Weeds in agricultural settings continually adapt to stresses from ecological and anthropogenic sources, in some cases leading to resistant populations. However, consequences of repeated sub-lethal exposure of these stressors on fitness and stress "memory" over generations remain poorly understood. We measured plant performance over a transgenerational experiment with Arabidopsis thaliana where plants were exposed to sub-lethal stress induced by the herbicides glyphosate or trifloxysulfuron, stresses from clipping or shading in either one (G1) or four successive generations (G1-G4), and control plants that never received stress. We found that fourth-generation (G4) plants that had been subjected to three generations of glyphosate or trifloxysulfuron stress produced higher post-stress biomass, seed weight, and rosette area as compared to that produced by plants that experienced stress only in the first generation (G1). By the same measure, clipping and shade were more influential on floral development time (shade) and seed weight (clipping) but did not show responsive phenotypes for vegetative metrics after multiple generations. Overall, we found that plants exhibited more rapid transgenerational vegetative "stress memory" to herbicides while reproductive plasticity was stressor dependent and similar between clipping/shade and anthropogenic stressors. Our study suggests that maternal plant stress memory aids next-generation plants to respond and survive better under the same stressors. We show differential transgenerational phenotypes to different stressors over four generations in Arabidopsis.
Estimates of soil taxonomic change due to near-surface permafrost loss in Alaska
Jelinski, N. A.; Pastick, N. J.; Kholodov, A. L.; Sousa, M. J.; Galbraith, John M. (Wiley, 2024-09-01)
Gelisols (permafrost-affected soils in US Soil Taxonomy) are extensive in Alaska, currently occurring on similar to 45% of the land area of the state. Gelisol taxonomic criteria rely on the presence of near-surface (less than 2 m deep) permafrost, but ongoing climatic and environmental change has the potential to affect the presence of near-surface permafrost across much of Alaska throughout the 21st century. In this study, we utilized scenarios of near-surface permafrost loss and active layer deepening through the 21st century under low (SRES B1, RCP 4.5), mid- (SRES A1B), and high (SRES A2, RCP 8.5) emissions scenarios, in conjunction with the statewide STATSGO soil map, to generate spatially explicit predictions of the susceptibility of Gelisols and Gelisol suborders to taxonomic change in Alaska. We find that 15%-53% of Alaskan Gelisols are susceptible to taxonomic change by mid-century and that 41%-69% of Alaskan Gelisols are susceptible to taxonomic change by the end of the century. The extent of potential change varies between suborders and geographic regions, with Gelisols in Northern Alaska being the most resilient to taxonomic change and Western and Interior Alaskan Gelisols most susceptible to taxonomic change. The Orthel suborder is likely to be highly restricted by the late 21st century, while Histels and Tubels are more likely to be of greater extent. These results should be taken into consideration when designing initial survey and re-mapping efforts in Alaska and suggest that Alaskan Gelisol taxa should be considered threatened soil taxa due to the proportional extent of likely loss. Fifteen to fifty-three percent of Alaskan Gelisols are susceptible to taxonomic change by 2050-2059. forty-one to sixty-nine percent of Alaskan Gelisols are susceptible to taxonomic change by 2090-2099. Extent of taxonomic change is the highest in the Interior and lowest in Northern Alaska. Susceptibility to change differs by land resource region and Gelisol suborder.

Browse

Recent Submissions