Open Access Publications - Department of Plant and Soil Sciences

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Open access publications by faculty, postdocs, and graduate students in the Department of Plant and Soil Sciences.

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The influence of urban and agricultural landscape contexts on forest diversity and structure across ecoregions
(Ecosphere, 2025-02-25) Schmit, John Paul; Johnson, Lea R.; Baker, Matthew; Darling, Lindsay; Fahey, Robert; Locke, Dexter H.; Morzillo, Anita T.; Sonti, Nancy F.; Trammell, Tara L. E.; Aronson, Myla F. J.; Johnson, Michelle L.
Forest patches in urban landscapes make outsized contributions to biodiversity, ecosystem function, and human health and well-being. However, urbanization can alter environmental conditions that underpin forest health. Most studies of forest health in urban landscapes have focused on few forest patches across a single metropolitan region, and synthesis is needed to understand broader patterns. We assessed variation among measures of forest health across land cover gradients and ecoregions by determining (1) whether the degree of urban, agricultural, and forested land surrounding a forest patch was reflected in differences in tree community composition, diversity, and structure and (2) whether these differences were consistent across ecoregions. We synthesized data from 17 observational studies (3334 plots) and remotely sensed land cover (1-km buffer) across four metropolitan regions (Baltimore–Washington DC, Chicago, New York City, and Philadelphia) spanning five ecoregions of the eastern deciduous forest of North America. Land cover surrounding forest patches differed among ecoregions, and forests were surrounded by heterogeneous land cover even in the most urbanized areas. Patterns of tree species composition and forest structure reflected landscape context. Forest patches surrounded by high canopy cover had greater or equal tree species diversity, density, basal area, and diversity of tree sizes relative to patches surrounded by highly agricultural or highly impervious landscapes. In contrast, there was little difference in structure and diversity between forests in highly agricultural and impervious settings. Tree species composition varied among ecoregions, yet tree community assemblages of forests in intensively urbanized areas were consistently distinct from those of forests in other contexts. Forest patches in the most urban and most agricultural landscapes shared predominantly native species communities and were characterized by low tree species diversity, basal area, and size class diversity, as well as high non-native tree abundance, highlighting commonalities among these intensive anthropogenic landscapes. These results point to both common challenges to forest health and common opportunities for forest stewardship in urban and agricultural landscapes.
Sustainability Nexus AID: soil health
(Sustainability Nexus Forum, 2025-02-02) Shokri, Nima; Aminzadeh, Milad; Flury, Markus; Jin, Yan; Matin, Mir A.; Panagos, Panos; Razavi, Bahar S.; Robinson, David A.; Smith, Pete; Todd-Brown, Katherine; Toth, Gergely; Zarei, Azin; Madani, Kaveh
The Sustainability Nexus Analytics, Informatics, and Data (AID) Programme of the United Nations University (UNU), aims to provide information, data, computational, and analytical tools to support the sustainable management and long-term security of natural resources using a nexus approach. This paper introduces the Soil Health Module of the Sustainability Nexus AID Programme. Healthy soil is crucial for life on Earth, and it is essential for ecosystem services and functioning, access to clean water, socioeconomic structure, biodiversity, and food security for the growing population of the world. Healthy soils contribute to mitigating the effects of climate change and reduce the consequences of extreme events such as flooding and drought. Healthy soils influence the hydrologic cycle by regulating transpiration, water infiltration, and soil water evaporation affecting land–atmosphere interactions. The Soil Health Module of the UNU Sustainability Nexus AID Programme aims to evolve into the ultimate focal point, supporting a diverse array of stakeholders with state-of-the-art data and tools that are essential for soil health monitoring and projection. This paper discusses the importance of adopting a nexus approach for ensuring soil health, explores the AID tools currently at our disposal for quantifying and predicting soil health, and concludes with recommendations for future effort and direction within the Sustainability Nexus AID Programme concerning soil health.
Seasonal Variation and Key Controls of Groundwater Ammonium Concentrations in Hypoxic/Anoxic Riparian Sediments
(Journal of Geophysical Research: Biogeosciences, 2025-01-30) Sena, Matthew G.; Peipoch, Marc; Joshi, Bisesh; Rahman, Md. Moklesur; Peck, Erin; Gold, Arthur J.; Kan, Jinjun; Inamdar, Shreeram
The seasonal controls of hydrology, temperature, hypoxia, and biogeochemical conditions for groundwater ammonium–N (NH4+) concentrations are not well understood. Here we investigated these controls for riparian groundwaters located upstream of two milldams over a period of 4 years. Groundwater chemistry was sampled monthly while groundwater elevations, hydraulic gradients, and temperatures were recorded sub-hourly. Distinct seasonal patterns for NH4+ were observed which differed among the wells. For wells that displayed a strong seasonal pattern, NH4+ concentrations increased through the summer and peaked in October–November. These elevated concentrations were attributed to ammonification, suppression of nitrification, and/or dissimilatory nitrate reduction to ammonium (DNRA). These processes were driven by high groundwater temperatures, low hydraulic gradients (or long residence times), hypoxic/anoxic groundwater conditions, and increased availability of dissolved organic carbon as an electron donor. In contrast, NH4+ concentrations decreased in the riparian groundwater from January to April during cool and wet conditions. A groundwater well with elevated total dissolved iron (TdFe) concentrations had elevated NH4+ concentrations but displayed a muted seasonal response. In addition to hydrologic controls, we attributed this response to additional NH4+ contribution from Fe-driven autotrophic DNRA and/or ammonification linked to dissimilatory Fe reduction. Understanding the temporal patterns and factors controlling NH4+ in riparian groundwaters is important for making appropriate watershed management decisions and implementing appropriate best management practices. Plain Language Summary Wetland or riparian soils and groundwaters depleted of oxygen can accumulate ammonium–N (NH4+), a toxic pollutant at high concentrations. NH4+ can be produced and removed via microbial processes that are influenced by seasonal factors such as: temperature, groundwater levels, dissolved oxygen, organic carbon, nitrate, and dissolved iron. In this study, we studied monthly grab samples of riparian groundwater collected upstream of milldams over a period of 4 years. We evaluated the data, identified three main seasons, and generated relationships between physical and chemical factors and NH4+ over time. The main findings from this study show that NH4+: (a) peaks in October and November when water is warm, stagnant, and high in organic carbon, (b) decreases from January – April when temperatures cooled and lowered microbial production, and (c) elevated iron groundwater concentrations can dampen these seasonal trends. Results from this study can help to improve the timing of milldam removal practices and for the management of wetlands that remove nitrogen from the terrestrial environment. Key Points - Groundwater ammonium–N concentrations peaked following warm water temperatures, low hydraulic gradients, and high dissolved organic carbon (DOC) - Ammonium concentrations were likely driven by seasonal changes in ammonification, nitrification, and dissimilatory nitrate reduction to ammonium (DNRA) - Hydrologic conditions and elevated dissolved iron (Fe) concentrations likely shaped the seasonal ammonium patterns
A tool to measure maize root system stiffness that enables a comprehensive understanding of plant mechanics and lodging
(Journal of Experimental Botany, 2025-01-24) Hostetler, Ashley N.; Reneau, Jonathan W.; Cristiano, Joseph; Weldekidan, Teclemariam; Kermani, Taran A.; Kim, Therese T.; Sparks, Erin E.
Plant mechanical failure, known as lodging, has detrimental impacts on the quality and quantity of maize yields. Failure can occur at stalks (stalk lodging) or at roots (root lodging). While previous research has focused on proxy measures for stalk stiffness, stalk strength, and root strength, there is a need to quantify the root system stiffness, which quantifies the force–displacement relationship. Here, we report a tool to quantify the root system stiffness of maize hybrids grown in different conditions. The results show that maize hybrids with a higher root system stiffness have a greater susceptibility to root lodging. This result is consistent with expected mechanical behavior, since higher root system stiffness values mean that the plant reaches the failure strength at lower displacements compared with a plant with lower root system stiffness. Collectively, this study describes the first tool to measure root system stiffness and enables a comprehensive understanding of the integrated plant mechanics and lodging.
Beaver Versus Human: The Big Differences in Small Dams
(WIREs: Water, 2025-03-27) Wohl, Ellen; Inamdar, Shreeram
As beavers (Castor spp.) are reintroduced to streams in the northern hemisphere and nature-based and process-based river restoration emphasizes human-built analogues for beaver dams, it is reasonable to ask how beaver dams and ponds compare to different types of small dams constructed by humans for diverse purposes. We use published research as a basis for comparing the effects of beaver dams and four types of human dams—beaver dam analogues, earthen embankments perpendicular to flow that are used to create stock ponds, check dams, and mill dams. We compare these dams with respect to water balance and three-dimensional hydrologic connectivity, sediment, particulate organic matter and carbon, nutrients, habitat, and biota. These assessments inform us in ranking small dams from generally most beneficial with respect to providing ecosystem services (beaver meadows with multiple dams) to least beneficial (mill dams), recognizing that beaver meadows may not be beneficial at some sites for infrastructure and human property within the river corridor, and mill dams may be beneficial at some sites where they impede upstream migration by invasive species or provide lentic habitat in the river corridor. This comparison among dam types highlights the need for research on the cumulative effects of multiple small dams along a river corridor and across a river catchment, as well as identifying gaps in our understanding of the effects of specific types of dams, including the effects of stock ponds and check dams on carbon and nutrient dynamics. Graphical Abstract available at: https://doi.org/10.1002/wat2.70019 Illustration of the net benefits and costs of different types of dams considered in this paper. The types of dams are ordered by relative benefit from left to right, with the most beneficial on the left. The number of + symbols under benefits and − symbols under costs indicate the likely magnitude of the effect, from + for small effect to +++ for substantial effect. The inset photo for the earthen embankment is a Google Earth view (with scale bar) for a stock pond in Wyoming.
Connecting the past with restoration futures: integrating legacy thinking into environmental decision making
(Environmental Research Letters, 2025-02-18) Basu, Nandita B.; Meter, K. J. Van; Bennett, Elena; Bernhardt, Emily; Inamdar, Shreeram; McCrackin, Michelle
"If you want to understand today you have to search yesterday." Pearl S. Buck, American novelist (1892‒1973) The interplay of human activities with landscapes over years, decades, and centuries creates lasting legacies that shape the intricate narrative of our environmental and ecological present. In this Environmental Research Letters focus issue on landscape legacies, we invited contributors to explore the many legacies of human activity that have developed over decades of agricultural intensification, resource extraction, and urbanization, and to address how these legacies are affecting water quality and ecosystem function. This invitation led to the creation of a unique volume of articles exploring a wide variety of legacies, from the accumulation of phosphorus in lake sediments to the long-term effects of mountaintop mining, from the legacy of effects of beaver loss across the continental United States to the effects of legacy pollution on landowner investments in water quality. These articles, both individually and together, challenge us to face the long-term legacy effects of agricultural intensification, resource extraction, and urban development, and to assess current decision-making about resource use as we connect present behavior with future environmental and ecosystem outcomes. In addition, from these articles, four important actions emerge as keys to environmental systems analysis and restoration: (1) characterization and quantification of legacies; (2) take the long view; (3) celebrate success; and (4) evaluate conservation goals with a legacy lens.
Crop and Weed Management Practices of Snap Bean (Phaseolus vulgaris) Production Fields in the United States
(HortScience, 2025-01-31) Pavlovic, Pavle; Colquhoun, Jed B.; Korres, Nicholas E.; Liu, Rui; Lowry, Carolyn J.; Peachey, Ed; Scott, Barbara; Sosnoskie, Lynn M.; VanGessel, Mark J.; Williams, Martin M. II
Agronomic and weed management practices employed by growers in the production of snap bean (Phaseolus vulgaris) for the processing industry are poorly characterized. To address this knowledge gap, records of agronomic and weed management practices from 358 snap bean fields were obtained from collaborating processors. These fields encompassed three production regions in the United States: the Northwest (NW), Midwest (MW), and Northeast (NE). The obtained records were formatted to be more suitable for presentation or analysis. Forty cultivars were used across all three regions, primarily of green round podded type (∼90% of all fields). However, it was common for only relatively few cultivars to be widespread in each region. Seeding rates were substantially higher (by more than 100,000 plants/ha on average) in the NW region. Crop row widths were also narrower in the NW region compared with other regions. Planting and harvest occurred across a wide range of dates in all three production regions, with the NW having a delay of ∼10 days. The most common crop in rotation with snap bean was usually some type of corn, although the NW region had more variability in crop rotation. Spring tillage and irrigation were commonly used practices across all regions. Weed management was dominated by the use of interrow cultivation and a narrow spectrum of preemergence and postemergence herbicides. However, interrow cultivation was not used as much in the NW compared with the other two regions. Snap bean grown in the NW production region showed a departure in agronomic and weed management practices compared with the MW and NE production regions.
A global open-source dataset of monthly irrigated and rainfed cropped areas (MIRCA-OS) for the 21st century
(Scientific Data, 2025-02-04) Kebede, Endalkachew Abebe; Oluoch, Kevin Ong’are; Siebert, Stefan; Mehta, Piyush; Hartman, Sarah; Jägermeyr, Jonas; Ray, Deepak; Ali, Tariq; Brauman, Kate A.; Deng, Qinyu; Xie, Wei; Davis, Kyle Frankel
Crop production is among the most extensive human activities on the planet – with critical importance for global food security, land use, environmental burden, and climate. Yet despite the key role that croplands play in global land use and Earth systems, there remains little understanding of how spatial patterns of global crop cultivation have recently evolved and which crops have contributed most to these changes. Here we construct a new data library of subnational crop-specific irrigated and rainfed harvested area statistics and combine it with global gridded land cover products to develop a global gridded (5-arcminute) irrigated and rainfed cropped area (MIRCA-OS) dataset for the years 2000 to 2015 for 23 crop classes. These global data products support critical insights into the spatially detailed patterns of irrigated and rainfed cropland change since the start of the century and provide an improved foundation for a wide array of global assessments spanning agriculture, water resource management, land use change, climate impact, and sustainable development.
Swapping rice for alternative cereals can reduce climate-induced production losses and increase farmer incomes in India
(Nature Communications, 2025-03-02) Wei, Dongyang; Castro, Leslie Guadalupe; Chhatre, Ashwini; Tuninetti, Marta; Davis, Kyle Frankel
The rising homogeneity of global crop supply has increased vulnerability to climatic and economic disruptions. While substantial work has examined yield variations in relation to climate variability, little is known about the influence of harvested area on production stability. To investigate this, here we take the example of monsoon cereal production in India, which has steadily shifted towards climate-sensitive rice and away from alternative cereals (finger millet, maize, pearl millet, and sorghum). We find that variations in harvested area are significantly associated with current and past price fluctuations for all cereals except rice. This suggests that farmer decisions based on economic factors may exercise great influence in determining variations in harvested area. We also show that optimized allocations of harvested area can reduce climate-induced production loss by 11% or improve farmer net profit by 11% while maintaining calorie production and cropland area. Such improvements would be possible by reducing harvested areas dedicated to rice and increasing areas allocated to alternative cereals. Our findings show that strategies using harvested area to address cereal yield fluctuations and improve farm profits could complement ongoing efforts to improve alternative cereal yields and stabilize cereal production.
Deepening water scarcity in breadbasket nations
(Nature Communications, 2025-01-28) Deng, Qinyu; Sharretts, Tyler; Ali, Tariq; Ao, Yufei Zoe; Chiarelli, Davide Danilo; Demeke, Betelhem; Marston, Landon; Mehta, Piyush; Mekonnen, Mesfin; Rulli, Maria Cristina; Tuninetti, Marta; Xie, Wei; Davis, Kyle Frankel
Water is crucial for meeting sustainability targets, but its unsustainable use threatens human wellbeing and the environment. Past assessments of water scarcity (i.e., water demand in exceedance of availability) have often been spatially coarse and temporally limited, reducing their utility for targeting interventions. Here we perform a detailed monthly sub-basin assessment of the evolution of blue (i.e., surface and ground) water scarcity (years 1980-2015) for the world’s three most populous countries – China, India, and the USA. Disaggregating by specific crops and sectors, we find that blue water demand rose by 60% (China), 71% (India), and 27% (USA), dominated by irrigation for a few key crops (alfalfa, maize, rice, wheat). We also find that unsustainable demand during peak months of use has increased by 101% (China), 82% (India), and 49% (USA) and that 32% (China), 61% (India), and 27% (US) of sub-basins experience at least 4 months of scarcity. These findings demonstrate that rising water demands are disproportionately being met by water resources in already stressed regions and provide a basis for targeting potential solutions that better balance the water needs of humanity and nature.
Cropland expansion links climate extremes and diets in Nigeria
(Science Advances, 2025-01-10) Khan, Bhoktear; Mehta, Piyush; Wei, Dongyang; Ali, Hanan Abou; Adeluyi, Oluseun; Alabi, Tunrayo; Olayide, Olawale; Uponi, John; Davis, Kyle Frankel
Climate change threatens smallholder agriculture and food security in the Global South. While cropland expansion is often used to counter adverse climate effects despite ecological trade-offs, the benefits for diets and nutrition remain unclear. This study quantitatively examines relationships between climate anomalies, forest loss from cropland expansion, and dietary outcomes in Nigeria, Africa’s most populous country. Combining high-resolution data on forest cover and climate variables within random forest and panel regression models, we find that 25 to 31% of annual forest loss is linked to climate variability. Using georeferenced household survey data, we then find that changes in forest cover have a significant positive association with changes in child diet diversity—a key proxy of nutritional adequacy—while cropland expansion does not, suggesting that such forest conversions may be an ineffective climate adaptation strategy for improving nutrition. Our findings highlight the potential of nutrition-sensitive climate adaptation to enhance yields, promote nutritious cropping choices, and protect remaining forests.
Potassium Sulfate Supplementation with Elevated Electrical Conductivity Was Unproductive for Hydroponic Strawberry at the Original Yamazaki Nutrient Solution Nitrogen Level
(HortScience, 2025-01-08) Ries, Jonathan; Meng, Qingwu; Park, Yujin
The production of strawberries (Fragaria ×ananassa) in hydroponic systems has been increasing. In hydroponic systems, precise nutrient management is crucial for optimal plant growth and fruit production. Among essential elements, potassium (K) is a key nutrient that affects fruit yield and quality in fruiting crops. The objective of this study was to investigate whether increasing the K concentration in the Yamazaki strawberry nutrient solution could enhance plant growth, fruit yield, and fruit quality in hydroponic strawberries. Bare-root plants of strawberry ‘Monterey’ and ‘San Andreas’ were planted in a deep water culture hydroponic system and grown with initial K concentrations of 117, 194, 271, and 348 mg·L−1 under the same initial nitrogen concentration of 77 mg·L−1. As the K concentration increased from 117 to 348 mg·L−1, the nutrient solution electrical conductivity increased from 1.0 to 1.9 dS·m−1. The experiment was conducted inside an indoor vertical farm at a 23 °C air temperature with an extended photon flux density (400–750 nm) of 350 µmol·m−2·s−1 under an 18-hour photoperiod. Increasing the K concentration from 117 to 348 mg·L−1 had minimal effects on plant growth characteristics of both cultivars, although root dry mass of ‘Monterey’ increased linearly with increasing K. Increasing the K concentration from 117 to 348 mg·L−1 did not affect the total fruit number or total fruit fresh mass of ‘Monterey’, but for ‘San Andreas’, it reduced the total fruit number by 34% and total fruit fresh mass by 45%. Additionally, increasing the K concentration from 117 to 348 mg·L−1 reduced the individual fruit mass, fruit length, and fruit diameter and increased titratable acidity in both cultivars. These results indicate that increasing the K concentration in the Yamazaki strawberry nutrient solution did not benefit plant growth, fruit yield, or fruit quality of the hydroponically grown strawberries ‘Monterey’ or ‘San Andreas’.
Improving future agricultural sustainability by optimizing crop distributions in China
(PNAS Nexus, 2025-01-07) Guan, Qi; Tang, Jing; Davis, Kyle Frankel; Kong, Mengxiang; Feng, Lian; Shi, Kun; Schurgers, Guy
Improving agricultural sustainability is a global challenge, particularly for China's high-input and low-efficiency cropping systems with environmental tradeoffs. Although national strategies have been implemented to achieve Sustainable Development Goals in agriculture, the potential contributions of crop switching as a promising solution under varying future climate change are still under-explored. Here, we optimize cropping patterns spatially with the targets of enhancing agriculture production, reducing environmental burdens, and achieving sustainable fertilization across different climate scenarios. Compared with current cropping patterns, the optimal crop distributions under different climate scenarios consistently suggest allocating the planting areas of maize and rapeseed to the other crops (rice, wheat, soybean, peanut, and potato). Such crop switching can consequently increase crop production by 14.1%, with accompanying reductions in environmental impacts (8.2% for leached nitrogen and 24.0% for irrigation water use) across three representative Shared Socio-economic Pathways from 2020 to 2100. The sustainable fertilization rates vary from 148–173 kg N ha−1 in 2030 to 213–253 kg N ha−1 in 2070, significantly smaller than the current rate (305 kg N ha−1). These outcomes highlight large potential benefits of crop switching and fertilizer management for improving China's future agricultural sustainability.
Searching for consistent postemergence weed control in progressively inconsistent weather
(Weed Science, 2024-11-18) Landau, Christopher; Bradley, Kevin; Burns, Erin; Dobbels, Anthony; Essman, Alyssa; Flessner, Michael; Gage, Karla; Hager, Aaron; Jhala, Amit; Johnson, Paul O.; Johnson, William; Lancaster, Sarah; Lingenfelter, Dwight; Loux, Mark; Miller, Eric; Owen, Micheal; Sarangi, Debalin; Sikkema, Peter; Sprague, Christy; VanGessel, Mark; Werle, Rodrigo; Young, Bryan; Williams, Martin, II
Foliar applied postemergence herbicides are a critical component of corn and soybean weed management programs in North America. Rainfall and air temperature around the time of application may affect the efficacy of herbicides applied postemergence in corn or soybean production fields. However, previous research utilized a limited number of site-years and may not capture the range of rainfall and air temperatures that these herbicides are exposed to throughout North America. The objective of this research was to model the probability of achieving successful weed control (≥85%) with commonly applied postemergence herbicides across a broad range of environments. A large database of over 10,000 individual herbicide evaluation field trials conducted throughout North America was used in this study. The database was filtered to include only trials with a single postemergence application of fomesafen, glyphosate, mesotrione, or fomesafen + glyphosate. Waterhemp (Amaranthus tuburculatus (Moq.) J. D. Sauer), morningglory species (Ipomoea spp.), and giant foxtail (Setaria faberi Herrm.) were the weeds of focus. Separate random forest models were created for each weed species by herbicide combination. The probability of successful weed control deteriorated when the average air temperature within the first ten d after application was <19 or >25 C for most of the herbicide by weed species models. Additionally, dryer conditions prior to postemergence herbicide application reduced the probability of successful control for several of the herbicide by weed species models. As air temperatures increase and rainfall becomes more variable, weed control with many of the commonly used postemergence herbicides is likely to become less reliable.
Weed Communities of Snap Bean Fields in the United States
(Weed Science, 2024-11-15) Pavlovic, Pavle; Colquhoun, Jed B.; Korres, Nicholas E.; Liu, Rui; Lowry, Carolyn J.; Peachey, Ed; Scott, Barbara; Sosnoskie, Lynn M.; VanGessel, Mark J.; Williams, Martin M., II
Weeds are one of the greatest challenges to snap bean production. Anecdotal observation posits certain species frequently escape the weed management system by the time of crop harvest, hereafter called residual weeds. The objectives of this work were to 1) quantify the residual weed community in snap bean (Phaseolus vulgaris L.) grown for processing across the major growing regions in the U.S., and 2) investigate linkages between the density of residual weeds and their contributions to weed canopy cover. In surveys of 358 fields across the Northwest (NW), Midwest (MW), and Northeast (NE), residual weeds were observed in 95% of the fields. While a total of 109 species or species-group were identified, one to three species dominated the residual weed community of individual fields in most cases. It was not uncommon to have >10 weeds m-2 with a weed canopy covering >5% of the field’s surface area. Some of the most abundant and problematic species or species-group escaping control included amaranth species (such as smooth pigweed (Amaranthus hybridus L.), Palmer amaranth (Amaranthus palmeri S. Watson), redroot pigweed (Amaranthus retroflexus L.), and waterhemp [Amaranthus tuberculatus (Moq.) J. D. Sauer]), common lambsquarters (Chenopodium album L.), large crabgrass [Digitaria sanguinalis (L.) Scop.], and ivyleaf morningglory (Ipomoea hederacea Jacq.). Emerging threats include hophornbeam copperleaf (Acalypha ostryifolia Riddell) in the MW and sharppoint fluvellin [Kickxia elatine (L.) Dumort.] in the NW. Beyond crop losses due to weed interference, the weed canopy at harvest poses a risk to contaminating snap bean products with foreign material. Random forest modeling predicts the residual weed canopy is dominated by common lambsquarters, large crabgrass, carpetweed (Mollugo verticillata L.), I. hederacea, amaranth species, and A. ostryifolia. This is the first quantitative report on the weed community escaping control in U.S. snap bean production.
Weather and glufosinate efficacy; a retrospective analysis looking forward to the changing climate
(Weed Science, 2025-01-08) Landau, Christopher; Bradley, Kevin; Burns, Erin; DeWerff, Ryan; Dobbels, Anthony; Essman, Alyssa; Flessner, Michael; Gage, Karla; Hager, Aaron; Jhala, Amit; Johnson, Paul O.; Johnson, William; Lancaster, Sarah; Lingenfelter, Dwight; Loux, Mark; Miller, Eric; Owen, Micheal; Sarangi, Debalin; Sikkema, Peter; Sprague, Christy; VanGessel, Mark; Werle, Rodrigo; Young, Bryan; Williams II, Martin
Foliar-applied postemergence applications of glufosinate are often applied to glufosinate-resistant crops to provide nonselective weed control without significant crop injury. Rainfall, air temperature, solar radiation, and relative humidity near the time of application have been reported to affect glufosinate efficacy. However, previous research may have not captured the full range of weather variability to which glufosinate may be exposed to prior to or following application. Additionally, climate models suggest more extreme weather will become the norm, further expanding this weather range glufosinate can be exposed to. The objective of this research was to quantify the probability of successful weed control (efficacy ≥85%) with glufosinate applied to some key weed species across a broad range of weather conditions. A database of >10,000 North American herbicide evaluation trials was used in this study. The database was filtered to include treatments with a single POST application of glufosinate applied to waterhemp (Amaranthus tuburculatus (Moq.) J. D. Sauer), morningglory species (Ipomoea spp.), and/or giant foxtail (Setaria faberi Herm.) <15cm in height. These species were chosen because they are well represented in the database and listed as common and troublesome weed species in both corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] (Van Wychen 2020, 2022). Individual random forest models were created. Low rainfall (≤20 mm) over the five days prior to glufosinate application was detrimental to the probability of successful control of A. tuburculatus and S. faberi. Lower relative humidity (≤70%) and solar radiation (≤23 MJ m-1 day-1) the day of application reduced the probability of successful weed control in most cases. Additionally, the probability of successful control decreased for all species when average air temperature over the first five days after application was ≤25C. As climate continues to change and become more variable, the risk of unacceptable control of several common species with glufosinate is likely to increase.
Drawdown of soil phosphorus by crop removal: A meta-analysis of 56 fields with interrupted fertilization
(Agricultural & Environmental Letters, 2025-01-03) Gatiboni, Luke; Shober, Amy L.; Fiorellino, Nicole; Osmond, Deanna; Mosesso, Lauren R.
Phosphorus (P) is an essential nutrient applied as fertilizer in agricultural fields. However, excessive fertilization leads to P build up in soils, increasing its potential to cause environmental pollution. The objective of this study was to evaluate the average P drawdown rate of 56 sites with drawdown management presented in 14 publications. Soil test P (STP) results were converted to Mehlich-3 equivalent and resampling analysis was used to compare the annual drawdown rate in fields grouped by four initial STP classes. The STP was reduced by 4.3%–8.2% per year, depending on the initial STP class. It took from 8.4 to 15.9 years to reduce the STP by half. The resulting equations from this meta-analysis can be used by landowners to estimate the time needed for STP drawdown by cropping without additional P to achieve the desired STP concentration. Core Ideas - Cropping without phosphorus (P) fertilization is one of the few options to reduce soil test P (STP). - A meta-analysis of the annual P drawdown rate was performed using 56 sites presented in 14 publications. - Fields were grouped into four initial STP classes based on Mehlich-3 STP equivalent. - The STP was reduced from 4.3% to 8.2% per year in fields with high and low initial STP. - The time needed to reduce the STP by half varied from 8.4 to 15.9 years depending on the initial STP. Graphical Abstract available at: https://doi.org/10.1002/ael2.70007 Abbreviations ICP inductively coupled plasma optical emission spectroscopy IPNI International Plant Nutrition Institute STP soil test phosphorus STPi initial soil test phosphorus
Evaluation of soil properties and bulk δ15N to assess decadal changes in floodplain denitrification following restoration
(Restoration Ecology, 2024-10-29) Galella, Joseph G.; Rahman, Md. Moklesur; Yaculak, Alexis M.; Peipoch, Marc; Kan, Jinjun; Sena, Matthew; Joshi, Bisesh; Kaushal, Sujay S.; Inamdar, Shreeram
Stream and floodplain restoration is a popular billion-dollar industry in the United States, with many restorations being conducted to satisfy water pollution regulations and nutrient reduction goals. The long-term efficacy of these restorations is, however, not well studied, and key soil metrics that can be used for performance assessments have not been developed. We evaluated a chronosequence of 12 restoration sites spanning an age range of 0–22 years to assess changes in denitrification rates and associated soil parameters. Restored versus unrestored reaches were compared for denitrification rate and functional gene nosZ, bulk soil δ15N, soil organic carbon (SOC), soil organic matter (SOM), bulk density, and soil moisture. Denitrification, SOM, SOC, and soil moisture were all found to increase with site age at restored sites, with the largest increase for the 10–22 age category. Bulk density decreased with time, with a significant decrease in restored floodplain soils. Bulk soil δ15N was highest immediately after restoration, decreased with restoration age, and was not positively correlated with denitrification. This may reduce its potential as a proxy for denitrification. Overall, this study reveals that selected soil metrics (SOC, SOM, soil moisture, and bulk density) could serve as a valuable proxy for denitrification and could help assess the denitrification effectiveness of floodplain restorations at the decadal time scales. Ideally, the soil metrics should be combined with other short-term assessment measures, such as those for stream and groundwaters, for a robust performance assessment of restored floodplains. Implications for Practice - Soil characteristics have not been routinely used for assessing the long-term effectiveness of stream and floodplain restorations, and guidance is needed for their use. - Soil organic matter, moisture, and bulk density improved over time for restored floodplains and could be used as reliable proxies for denitrification nitrogen removal. - Site-specific differences in restoration design and construction (e.g. soil amendments such as woody debris/chips) could significantly affect the response of soil metrics. - Since soil characteristics change slowly over decadal time scales, restoration assessments should also include quicker, short-term performance measures such as those associated with surface and groundwater quality.
Soil bacterial communities in urban deciduous forests are filtered by site identity, soil chemistry, and shrub presence
(Scientific Reports, 2024-12-30) Wu, Derek Griffin; D’Amico, Vincent; Trammell, Tara Lynn Eckard
Urban forest soils are complex environments subjected to various stressors that alter chemical and microbial properties. To understand soil chemistry and bacterial community patterns in urban forest soils with respect to site identity and multiflora rose (Rosa multiflora) invasion, soils were collected from beneath R. multiflora, native spice bush (Lindera benzoin), and uncovered ground in three forests in Newark, Delaware. High-throughput sequencing was used to analyze bacterial communities with corresponding soil chemical properties. Soil chemistry and operational taxonomic unit (OTU) communities were explained by site rather than by shrub cover type. Unlike other invasive plant studies, R. multiflora had minimal effects on either soil chemistry or bacterial communities. Phylum level bacterial communities were more uniform under shrub cover versus no cover, indicative of a generalized plant effect shaping soil microbiomes. Correlations between bacterial phyla and soil chemistry varied, with some phyla positively or negatively correlating with the same property at different sites. Filters for bacterial communities differ across forest scales, where sites and sampling location primarily correlate with OTU communities yet shrub presence mediates phylum level organization. Forest soil studies should consider location-based differences in bacterial communities and their correlations with soil chemistry before generalizing outcomes for whole macrosystems.
Graft incompatibility between pepper and tomato elicits an immune response and triggers localized cell death
(Horticulture Research, 2024-09-11) Thomas, Hannah Rae; Gevorgyan, Alice; Hermanson, Alexandra; Yanders, Samantha; Erndwein, Lindsay; Norman-Ariztía, Matthew; Sparks, Erin E.; Frank, Margaret H.
Graft compatibility is the capacity of two plants to form cohesive vascular connections. Tomato and pepper are incompatible graft partners; however, the underlying cause of graft rejection between these two species remains unknown. We diagnosed graft incompatibility between tomato and diverse pepper varieties based on weakened biophysical stability, decreased growth, and persistent cell death using viability stains. Transcriptomic analysis of the junction was performed using RNA sequencing, and molecular signatures for incompatible graft response were characterized based on meta-transcriptomic comparisons with other biotic processes. We show that tomato is broadly incompatible with diverse pepper cultivars. These incompatible graft partners activate prolonged transcriptional changes that are highly enriched for defense processes. Amongst these processes was broad nucleotide-binding and leucine-rich repeat receptors (NLR) upregulation and genetic signatures indicative of an immune response. Using transcriptomic datasets for a variety of biotic stress treatments, we identified a significant overlap in the genetic profile of incompatible grafting and plant parasitism. In addition, we found over 1000 genes that are uniquely upregulated in incompatible grafts. Based on NLR overactivity, DNA damage, and prolonged cell death, we hypothesize that tomato and pepper graft incompatibility is characterized by an immune response that triggers cell death which interferes with junction formation.

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