Brief Summary of Minutes of Annual Meeting

Activities:

* Planned meeting and field visit planned in Laramie, WY was cancelled due to COVID-19.

Business meeting minutes

- Twenty participants.

- State report presentations: Arkansas, Indiana, Kentucky, Maryland, Michigan, Nebraska, North Dakota, Ohio, Oregon, Texas, Tennessee, Utah, Wyoming, and Wisconsin.

- Updates by NIFA Representative: new program areas, funding opportunities, and updates in AFRI and NIFA.  

- Discussion about a new project on phenological development, David Hannaway, Kim Cassida and Jeff Volenec.

- Committee is in good standing and is perceived to be a productive committee.

- Discussions on the collaborative submitted SAS proposal led by Valentin Picasso.

- Next meeting tentative location: Laramie, WY (since travel was not permitted in 2021). Host: Wyoming- Anowar Islam.

- Goujie Wang incoming chair: 2021; Valentin Picasso incoming secretary.

Arkansas

During 2020-2021, two agroforestry-related projects were continued: 1) assessment of annual and perennial forages in thinned pine tree plantations and 2) establishment of perennial forages in a thinned native hardwood forest. Forages were selected based on previous research and experience from participating landowners. We continued a NIFA-funded project on the effects of tannin-containing silage diets on sheep intake and soil quality parameters and ammonia emissions after the application on native warm-season grasses of collected urine and feces resulting from this study. Plots were established in a native grass (big bluestem, indiangrass, and little bluestem) pasture to which sheep urine and feces were applied to test for leaching, ammonia emissions, and various soil biochemical and physical parameters. This study was concluded in early fall of 2020 and a full data analysis is under way.

Quantified best management practice effects on soil health. A series of experiments set out to identify long-term (>15 years) conservation practices influence on soil quality, as understanding the impacts of long-term agricultural practices on soil quality is key for sustaining agroecosystem productivity.  Researchers at the Fayetteville, AR; Booneville, AR; and Lincoln, NE units and University of Arkansas and the Federal Rural University in Lavras, Brazil used the Soil Management Assessment Framework to quantify soil health in grassland, cropping, and agroforestry systems. Researchers found that practices such as animal manure applications, non-tillage, crop rotations, and rotational grazing improved soil quality relative to business-as-usual practices (e.g. monocropping, tilled, and inorganic fertilizer management). Soil health improvements corresponded to increased carbon storage, primary productivity, and water quality improvements, which underlines the benefits of conservation soil management in diverse circular systems.

Identified alternative management practices to ensure long-term sustainable use of poultry litter. Broiler (meat chicken) production in the southeastern US is a leading enterprise totaling $31.7 billion USD in agricultural receipts, with about half of the production occurring in four southeastern states.  The use of by-products from poultry production, or poultry litter, has the potential to close nutrient loops, as by-products are re-applied the following season to marginal soils. Although, conventional application methods entail spreading poultry litter on the soil surface, which can result in up to 60% of nutrients being lost to the air, soil, and water. In efforts to improve management options that aid in nutrient sustainability and improve crop yield, an ARS research team developed an implement for subsurface applications of poultry litter in conservation tillage systems. This ‘Subsurfer’ lowers nutrient runoff and ammonia emissions by 90%. This practice was compared to poultry litter surface applications in small watersheds. Researchers found that the ARS Subsurfer reduced nutrient losses in runoff by 66% and improved crop yields by 39%. Therefore, subsurface incorporation of poultry litter relative to surface applications of poultry litter can enhance soil and water conservation and improve crop yields.

Identified practices that minimize the spread of antibiotic resistant gene movement in the environment. Veterinary pharmaceutical usage is an essential component of treating infections in poultry and bovine production.  Manure from treated animals, which is an abundant source of valuable nutrients, may also contain antimicrobial resistant (AMR) bacteria.  The existence of AMR bacteria in soil and water is a significant public health concern. According to the Organisation for Economic Cooperation and Development, 2.4 million people will die from infections with resistant microorganisms in the next 30 years, costing up to 3.5 billion USD per year.  Yet the fate and transport pathways from animals to the environment is poorly understood in the largest U.S. land-use category, or grasslands.  A series of studies tracked the movement of AMR bacteria following animal manure (cow and poultry) land applications. After 14-years of continuous management, AMR bacteria were greatest under continuous grazing (relative to conservation best management practices), suggesting continuous cattle manure deposition may increase AMR gene presence. In general, AMR genes increased downslope, suggesting potential lateral movement and accumulation based on landscape position. Researchers found that poultry litter had lower abundance of AMR bacteria relative to cattle manure. Adoption of conservation pasture best management such as riparian buffer strips improves water quality while disrupting AMR bacteria movement, which will contribute positively to disease management. 

Developed a method for rapidly quantifying spatial overlaps and gaps for precision agriculture tools in pastures. Scientists from Fayetteville and Booneville, Arkansas and University of Arkansas research partners developed an automated method for rapid determination of spatial coverage of precision agriculture technologies, such as auto-guided tractors and other self-propelled machinery that reduce over-application of on-farm nutrients and inputs by 10-20%. It is estimated that auto-guided tractors reduce on-farm inputs by as much as 20% and can save producers $10.8-13.5 million annually by improving gains in equipment efficiency and enhancing yields. Moreover, producers can also reduce the over-application of fertilizers and herbicides, which reduces the negative environmental footprint of crop production and avoids unintentional input costs to the producer. Currently, roughly half of large-scale row crop producers are using tractor guidance, however, 82% of the total farms in the US are small farms but are largely not adopting these cost and environmental saving technologies. Therefore, this team: 1) developed a method to calculate overlaps and gaps, and 2) quantified overall gains by tractor guidance systems. Field research was conducted using fertilizer (inorganic and poultry litter) and sprayer applications with and without tractor guidance. USDA-ARS researchers developed a novel automated method for quantifying overlaps and gaps and proposes a new method for calculating spatial coverage efficiency. Results suggests that tractor guidance systems reduce overlaps (up to 6% of the total field area) and gaps (up to 16%) during field operations and improves the average overall efficiency by 8%.  Hence, tractor guidance systems likely result in reduced input-use and shorter in-field operation time leading to improved economic and environmental savings. Our approach to estimate tractor guidance efficiency on small farms using actual field research is novel and may aid in adoption of tractor guidance, thus potentially improving efficiency gains on 82% of US farms.

Kentucky

During 2020, faculty from University of Kentucky published data from forage and alfalfa variety trials, a number of scientific studies, and trained numerous undergraduate and graduate students. Outreach activities were dramatically impacted by the COVID-19 pandemic and shifted to primarily online, though some traditional activities continued in a reduced capacity or altered fashion (e.g., farm visits, interactions with producer and commodity groups, farm visits, etc.). We collected data on the third version of our climate change study, focused on red clover and alfalfa, and we continued work in collaboration with USDA-ARS-FAPRU evaluating the effects of biochanin A (an isoflavone produced by red clover) supplementation on ruminant microbes and resulting N use efficiency and N excreta to the environment, as well as excreta effects on greenhouse gas emissions from soils.

Maryland

Dragonflies and damselflies (Odonata) as beneficial predators in alfalfa (Medicago sativa).

Margaret E. Hartman and William O. Lamp. 

Dragonflies and damselflies are opportunistic predators as adults. However, the potential for adult dragonflies as biological control agents in alfalfa (Medicago sativa) has been understudied. The primary goal of this study is to compare richness and abundance of assemblages of adult species of dragonflies and damselflies among farms and crops. Visual encounter surveys were conducted at three University of Maryland farms during the 2020 and 2021 field seasons. We hope to highlight the importance of adult dragonflies as generalist natural enemies in alfalfa by first determining their richness and abundance in agroecosystems. Odonata provide humans with ecosystem services in several ways, with one primary contribution being their ability to eat large quantities of arthropods often considered pest species. Predatory insects used as biological control in agriculture are an alternative to chemical pesticides and can indirectly improve soil and water quality by reducing chemical inputs into the environment. The primary goal of this study is to compare richness and abundance of assemblages of adult species of dragonflies and damselflies among farms and crops. Thirty-minute visual encounter surveys (VES) of adult odonates in alfalfa were conducted at three University of Maryland farms in central and western Maryland during the summer 2020 and summer 2021 field seasons. During the VES, the number of novel dragonfly and damselfly encounters were recorded. Crop height, cloud cover, temperature, wind speed, time, behavior at time of sighting and sex were recorded. The behavior of the dragonfly can be described as flying, perching, foraging, aggression or tandem flying. A total of 16 species of Odonata were identified in alfalfa during the 2020 and 2021 summer seasons. Of these, 14 were Anisoptera and 2 were Zygoptera. The family Libellulidae comprised 11 of the total 16 species in alfalfa. The most abundant species in alfalfa between both field seasons were all libellulids and included Tramea lacerata, Libellula luctosa and Plathemis lydia. During sampling events, anywhere from 0 to 15 odonates were detected with an average abundance of 3. This was significantly less than average abundance in both corn and soy fields (P < 0.0001). Perching and flying behavior varied among species, and thus foraging tactics were varied. Tramea lacerata were observed exclusively foraging about ten feet above the crop canopy, eating on the wing and perching on tall structures. They were never observed perched on the ground. Conversely, Plathemis lydia were observed flying low to the ground and directly above the crop canopy. P. lydia were observed perching over 70% of the time, but foraging behavior was rarely observed. Species in alfalfa primarily flew low in the vegetation and favored high perches, such as sticky trap rods. Additionally, many odonate observations were made along the edge of the alfalfa, corn and soy, where plant structure, height and complexity changed dramatically. The height of the alfalfa was noted during odonate visual encounter surveys and it varied from 3 cm to 58 cm throughout the growing season. There was no clear trend between odonate abundance and alfalfa canopy height, but several other variables need to be investigated such as temperature and sex. This study provides a first examination of the importance of adult dragonflies as generalist predators of agricultural pests. We can begin to inform farmers of the importance of dragonflies as natural enemies, and identify ways to encourage dragonfly communities in agroecosystems to enhance conservation biological control and thus lessen reliance on pesticides.

Colonization and development of natural enemies in alfalfa cultivars neighboring soybean: A landscape complexity approach to enhance biological control. Darsy Smith and William O. Lamp.

Conservation biological control (CBC) is the implementation of practices to facilitate the reproduction and survival of natural enemies in a cropping system. Different than other types of biological control, CBC seeks to enhance natural enemy populations by managing habitats. The ecosystems provided by natural enemies in these habitats include suppression of pest populations, pollination, and prevention of secondary pest outbreaks. Despite the diversity of natural enemies in cropping system may be well documented little is known about best management practices to enhance their reproduction. A common practice in cropping systems is the selection of the cultivar which offer options to control potato leafhopper (PLH: Empoasca fabae: Hemiptera: Cicadellidae). It is unknow if alfalfa PLH resistant cultivar enhance natural enemy reproduction when comparing to PLH susceptible cultivar. To test this question our objectives are to compare the colonization, reproduction, and development time of lady beetles in two alfalfa cultivars and determine the survivorship of lady beetles after harvest. We started conducting a randomized block design experiment at the Western Maryland Research and Education Center in Keedysville, Maryland mid-April 2021. Each block includes: 1) PLH resistant alfalfa cultivar, 2) PLH susceptible alfalfa cultivar, and 3) soybean. The samples were collected on a weekly basis to measure absolute densities from sweep samples, sticky traps, and foliar samples. A total of 7 species of Coccinellidae were collected from both alfalfa cultivars and 3 of them are currently in pending for id confirmation. The Simpson’s Index of Diversity for sweep samples from PLH resistant cultivar was 0.21 while for PLH susceptible cultivar was 0.71. The predominant species in both cultivars was Coccinella septempunctata. From the almost three months of sampling in two occasions 1 larva of coccinellid was observed and 2 adults of C. septempunctata We observed no survival of lady beetles after the harvest on May 12 and the harvest on June 16. The diversity of coccinellids in cropping systems may be potentially increased by selecting the PLH susceptible cultivar. Overall, these preliminary results suggest that the selection of the cultivar may play a role in coccinellids success in cropping systems despite their low abundance comparing to alfalfa pest. Further research is needed to understand how the selection of the cultivar impacts lady beetle development.

Diversity of natural enemy assemblages in drainage ditches and adjacent crops.  Alireza Shokoohi and W. Lamp.

Agricultural drainage ditches, which are common structures on farms along Maryland’s Eastern Shore, are typically using to provide hydrological control for croplands located above high-water tables. Recently, drainage ditches have begun to receive attention as potential sources of beneficial arthropods for adjacent croplands, such as natural enemies of agricultural pests. Spiders, the most abundant generalist predators in agroecosystems, have been previously been supported as abundant and diverse natural enemies living in drainage ditches in Maryland. This report focuses on spiders, but additional sampling is underway for carabid beetles, parasitic hymenopterans, and other generalist predators. To better understand to what extent spiders in drainage ditches colonize crops growing in adjacent croplands, we investigated the following research objectives: (1) to assess how spider assemblages in drainage ditches and their neighboring croplands change throughout the soybean growing season, (2) to determine what spiders colonize croplands from drainage ditches, and (3) to identify what environmental conditions influence spider assemblages and colonization between drainage ditches and croplands. We implemented an experimental design during the 2018 and 2019 soybean growing seasons on a private organic farm, where spiders were collected from drainage ditches and their adjacent soybean fields at specific distances leading into the field from the ditch via foliar sweep netting and pitfall trapping. During the preliminary 2018 growing season, one drainage ditch on our organic farm was selected to collect spiders from to test our experimental design. During the next soybean growing season in 2019, this methodology was expanded upon to include three drainage ditches and assess environmental data such as prey abundance, ground-level temperature and humidity, and plant assemblage metrics. We found that drainage ditches possess spider species that migrate to soybean fields as the growing season progresses, as soybean fields begin to offer comparable prey availability as drainage ditches later in the growing season. Spider diversity and abundance in drainage ditches was significantly higher than in-field diversity and abundance early in the growing season (p<0.05). As the soybean growing season progressed, spider assemblages in ditches and soybean fields became more similar in diversity and abundance. Linear regression analysis comparing prey abundance and spider abundance across drainage ditches and their adjacent croplands found that prey abundance has a positive significant association with spider abundance in these habitats.  Drainage ditches were found to simplify in their plant diversity as the growing season progresses, and thus provide less prey abundance for spiders over time, while soybean fields increased in prey abundance as they grew.

A Forage-Based Educational Needs Assessment for Livestock and Forage Producers in Maryland.

Amanda Grev and Sarah Potts

The objective of this project was to collect and formally document information on the educational needs, preferences, and challenges for livestock and forage producers in Maryland. To accomplish this, a needs assessment survey was conducted online during April/May 2020. The survey was open to all livestock and forage producers and consisted of 36 questions designed to collect information on educational preferences, production and management practices, and forage-related challenges/successes. The survey was completed by 159 respondents spanning the dairy, beef, small ruminant, equine, and forage production industries. The majority of respondents were male (59%), were 35 to 64 years old (70%), and had been involved in the industry for more than 11 years (61%). Rank-type questions were analyzed on a scale of 1 to 4, with 1 indicating no value/interest and 4 indicating a high value/interest. Private consultants (3.42) and regional sales representatives (3.09) received the highest rating as sources for forage-related information. The most preferred formats for receiving information included internet webpages (2.87), half-day sessions (2.85), and newsletters (2.83). Respondents showed the greatest interest in education on extending the grazing season (3.36), weed control (3.36), and improving soil organic matter (3.30). When asked to identify limitations to improving forage production, a lack of time/labor (2.44), high fertilizer costs (2.27), and dependence on hay (2.25) were listed as most limiting. The results of this assessment will be used to help Extension educators generate more effective forage-related educational programming to better meet the needs of the agricultural community in Maryland.

Effect of Energy Supplementation on Growth, Health, and Carcass Traits of Pasture-Raised Lambs.

Amanda Grev, Susan Schoenian, Jeff Semler, and Dahlia O’Brien

Energy is often the most limiting nutrient in pasture diets. The effect of energy supplementation on the growth, health, and carcass traits of pasture-raised lambs was investigated. Seventy-nine Katahdin ram lambs were delivered to the Western Maryland Research & Education Center on June 15, 2020. After an 11-d acclimation period, lambs were allocated to two treatment groups based on age, weight, birth type, and FEC. Lambs in the PASTURE group (n=40) rotationally grazed 2 ha of high quality, mixed pasture for 102 d. Lambs in the SUPPL group (n=39) grazed similar pastures and were hand-fed a daily energy supplement (450 g of whole barley). The groups were handled bi-weekly to determine body weights, FAMACHA©, BCS, and dag scores. Individual fecal samples were collected upon arrival and at two additional time points. Lambs were ultrasound scanned on Sept 25 to determine carcass traits. Data was analyzed using the MIXED procedure of SAS, with statistical significance set at P ≤ 0.05. ADG varied considerably among weigh periods. Standard deviations were typically quite large, indicating wide variation in individual performance. Overall, the SUPPL lambs had higher ADG (p< 0.01), more backfat (p< 0.03), and higher BCS (p< 0.01) than the PASTURE lambs. There were no statistical differences in starting weight, ending weight, and loin depth. While internal parasites were not a problem during the study (only one lamb had a FAMACHA© score >4), PASTURE lambs had lower FEC (p< 0.05) on August 17 (240 ± 81 vs. 468 ± 80 epg). The value of additional gain (0.9 kg) would not have covered the cost of feed; however, four lambs were removed from the PASTURE group (due to death or failure to thrive) whereas only two lambs were removed from the SUPPL group. The study is currently being repeated in 2021 with similar lambs and protocol.

Effects of Nitrogen and Sulfur Fertility on Triticale Forage Protein Concentrations and Dairy Cow Performance. Amanda Grev, Sarah Potts, and Jeff Semler

Winter forages like triticale can provide environmental benefits through increased nutrient retention and soil erosion control while also producing a high-yielding and high quality forage crop for livestock. Triticale can also serve as a good source of protein, potentially making it a more economical alternative to other feed ingredients such as soybean meal and allowing livestock producers to meet the nutritional needs of their animals while reducing overall feed expenses. The objectives of this study are to compare varying nitrogen fertility rates with and without sulfur on triticale forage to determine if using a higher fertilization rate will the increase the value of the forage through increased protein concentrations, as well as the resulting implications of incorporating that forage into the ration for lactating dairy cattle. The research will be completed in three main parts, including an initial field trial to assess soil nutrient status, forage quality, and forage yield under varying nitrogen and sulfur fertility treatments, followed by a feeding study to assess dairy cow production and performance when fed the resulting forage, and then finally an economic analysis to assess the effectiveness of the system. In the fall of 2020, triticale forage plots were established at two locations in Maryland. Fertility treatments included the following: CON (0 lb N, 0 lb S), SUL (0 lb N, 15 lb S), NLOW (50 lb N, 0 lb S), NSLOW (50 lb N, 15 lb S), NMED (100 lb N, 0 lb S), NSMED (100 lb N, 15 lb S), NHIGH (150 lb N, 0 lb S), and NSHIGH (150 lb N, 15 lb S). Treatments were applied to the established triticale plots in a randomized complete block design with 4 replicates at each location in March 2021. Plots were mechanically harvested in April 2021 and weighed to determine yield, and forage samples were collected to determine forage nutritive value. At both locations, yields for the fertility treatments were similar but were increased compared to the CON and SUL control treatments. Crude protein concentrations were lowest for the CON and SUL treatments and increased with increasing fertility, with the NHIGH and NSHIGH treatments containing the greatest amount of protein. Neutral detergent fiber and total digestible nutrients did not differ between treatments. These initial results indicate that fertility can influence forage protein concentrations. The feeding study portion of this project will begin in fall 2021, and the study will be repeated in 2022.

Michigan

Developing  a Grass Maturity Index.  Michigan joined a collaborative industry-driven project to develop a maturity index rating system for perennial forage grasses. This effort aims to identify reference grass varieties with a consistent ranking of maturity dates across environments. These reference varieties will ultimately be used to issue industry-standard maturity group rankings to released varieties. Preliminary data from three states (OR, IA, KY) were analyzed. Two Michigan sites were established in 2020/21. Key Outcomes and other accomplishments realized: Pearson rank correlation indicated stable ranking of varieties across locations. 

Performance of Reduced Lignin Alfalfa. Two trials were established in 2017 to evaluate the relationship of harvest maturity to forage quality across conventionally-bred high-quality or yield and GMO reduced-lignin (HVX) alfalfa varieties. Yield and forage quality data were collected from 2018 to 2021. One trial had locations in six states (MI, WI, KS, OH, CA, UT) while the other had locations in southern and northern Michigan. Key Outcomes and other accomplishments realized:  Second generation and commercially available HVX alfalfa varieties have similar yield and usually better fiber digestibility compared to standard high quality varieties, but some conventionally-bred varieties have comparable fiber digestibility. 

Identifying factors to optimize establishment of alfalfa interseeded in corn. A four-state experiment (Wisconsin, Michigan, Pennsylvania, and Idaho) funded by NIFA-AFRP was conducted in 2018 and 2019 to evaluate management option to improve establishment of alfalfa in silage corn. A follow-up trial was funded from Project GREEEN  in 2019. Summary statistics and discussion of results: Data collection is ongoing in 2019 and results will be evaluated at the end of the growing season. Key Outcomes and other accomplishments realized: Final results from this trial are reported from the Wisconsin state report. 

Commercial Variety Testing. Michigan State University conducted variety trials on alfalfa, red clover, orchardgrass, fescues, perennial and Italian ryegrass, timothy, Kentucky bluegrass, and cover crops. Key Outcomes and other accomplishments realized: These data were distributed to farmers, industry and made available to other researchers for “big data” analysis.

North Dakota

Alfalfa-corn intercropping: It is a good option for farmers that grow corn silage and alfalfa. In 2020, experiments with corn-alfalfa intercropping at 60 and 30” row spacing were conducted. Results indicate corn at 60” has about 18% lower yield than corn at 30 inches without alfalfa. With alfalfa intercropping the reduction was only 11% and establishment of alfalfa at 60-inch corn was better than at 30”. Alfalfa and corn roots were separately analyzed for their AM colonization. Compared with Prosper, the AM colonization of alfalfa was consistently higher at Hickson (~55% to 60% in Hickson, and ~30% to 40% in Prosper), but the AM colonization in the plots in which alfalfa was planted alone did not differ from the plots in which alfalfa was planted with corn. While the alfalfa colonization in Hickson was higher than in Prosper, the AM colonization of corn did not differ at both sites, and was with ~25% to 35% relatively low. The spacing between the corn rows (30 or 60”) or the intercropping with alfalfa did not affect the AM colonization of the corn plants.

K fertilization and its impact on yield, quality, and winter hardiness of alfalfa Two separate sites were established for this study. The two locations differ in their clay mineralogy and their smectite-to-illite ratio. With a smectite to illite ratio greater than 3.5, the soil at Milnor immobilizes potassium, while the soil at Lisbon with a smectite to illite ratio less than 3.5, allows potassium to be more mobile. The three alfalfa varieties Presteez RR, Stratica RR, and L-450 RR were used for this study. Each of the varieties has a different fall dormancy score. Three different K treatments were applied: 0, 168, and 336 kg K₂O ha^-1 in single- and split-application. Half of the experimental units were stressed by harvesting mid-September, while the other half was non-stressed by harvesting in October. Soil K was higher with a split-application, compared with a single-application of K at the same rate. Total seasonal forage yield was significantly lower when no K was applied. Stressed alfalfa had lower root protein in both years and starch was lower in Milnor 2019 and Lisbon 2020 compared with the non-stressed treatment. We also analyzed the arbuscular mycorrhizal (AM) colonization of the roots. Independent of the location (Lisbon and Milnor), the K fertilization, and the variety, the plants showed a similar mycorrhizal colonization rate of 50 to 60% in 2019. Compared with 2019, the AM colonization in 2020 of the different varieties increased particularly in Lisbon. While the AM colonization at Milnor did not differ, the AM colonization of the varieties L-450RR and Stratica increased at high K fertilization rates and the colonization rate of Presteez at low K fertilization rates and reached up to 75%.

Identify AM fungal communities and Rhizobia in alfalfa populations in North Dakota and South Dakota In 2021, alfalfa roots were sampled at 30 locations in North Dakota and 22 locations in South Dakota between May 25-29. Samples for this experiment were taken from different sites in North Dakota (Fargo, Hickson, Milnor, Lisbon, Carrington, Sykeston, Williston, Charbon Township, Watford City, Dunn Center, Dickinson, Richardton, Mott, Hettinger, SD National Grasslands, New Leipzig, Strasburg, Linton, Napoleon, Alkaline Lake, REC Streeter) that were planted between 1988 (Napoleon) and 2020 (Hickson) and differ in their management practices. The samples in South Dakota were taken from Beresford, Tyndall, Mt. Vernon, Baltic, Madison, Wilmot, Clark, Ipswitch, Selby, Timber Lake, Buffalo, Newell, Spearfish, Oelrichs, Long Valley, Colome, Pierre, Ree Heights, and Brookings).  Soil samples were taken at each site and N-NO₃, P, K, organic matter, pH, and electrical conductivity were evaluated. Samples are currently being prepared for AMF colonization analysis and metagenome analysis.

Perennial grasses winter-hardiness evaluation:

Twenty perennial forage grasses from different species and varieties were planted in 2020 in Prosper and Fargo. Forage yield differences in the seeding year between varieties of the same species were not significant. The large significant difference between the variety Esquire and the other two cultivars of perennial ryegrass can likely be attributed to ‘Esquire’ having higher incidence of leaf rust early in the seeding year.

In the first production year, winter survival was much greater in Fargo than in Prosper across species and varieties.  There were not great differences among varieties within a same crop.  Meadow and smooth brome had the highest survival of all grasses. Perennial ryegrass survival was less than 10% with not clear significant differences among varieties. Intermediate wheatgrass varieties had the greatest yield in the first cut of 2021 ranging between 4,500 and 6000 lbs/acre

Life cycle assessment (LCA) of integrated cropping systems for food, feed, and energy: Treatments with intersseeded cover crops (camelina, field pennycress and rye) had (a) lower eutrophication potential and water soil erosion, and (b) lower GWP if the cover crop was not fertilized with nitrogen. Winter camelina and pennycress were more effective than rye in reducing soil losses, while the three cover crops provided similar results for eutrophication potential. The results for the SOC variation were mixed, but the sequence with rye had the best performance in all locations.  The results of this study suggest that the introduction of winter camelina and field pennycress as winter-hardy cover crops has a strong potential for reducing the environmental impacts of the maize-soybean rotation in the U.S. upper Midwest. However, a better field management of nitrogen fertilization and crop residues of these cover crops in a relay-cropping system is needed to make them a viable and sustainable agricultural practice.

Ohio

A rotational stocking strategy to maintain pasture sward heights that optimize sheep and forage responses. (Verhoff, Sulc, Chiavegato, and Barker)
An experiment was established in May 2021 in a tall fescue dominant pasture to compare animal and forage sward productivity under (i) “rotatinuous” (RN) stocking management in which lambs graze off 30% of the sward height and (ii) traditional rotational stocking management (RT) in which lambs graze off 60% of the sward height. The goal is to have pre-grazing height of the rotatinuous treatment near the optimal height for maximizing sheep instantaneous intake on tall fescue, as reported by Szymczak et al. (2020), Studies have demonstrated that pasture structure limits forage intake (consumption) of animals on pasture, indicating that management strategies can be designed to maximize bite mass and forage intake per unit of grazing time that promote both high animal production and landscape and ecosystem. Previous studies with diverse forage species have shown that forage intake on pasture begins to decline rapidly in cattle after 40% of the initial sward height is removed and in sheep after 30% of the initial sward height is removed. Therefore, we hypothesize that a rotational stocking management system based on only 30% sward height (lenient pasture utilization) removal should increase lamb intake and weight gain compared with the traditional approach of a removing 60 to 70% of the sward height (high pasture utilization).

Ecology of running buffalo clover. (Barker)
The Ohio State University has collaborated with the Ohio Department of Natural Resources (ODNR) and Great Parks of Hamilton County (City of Cincinnati) to collect and propagate running buffalo clover (RBC) (Trifolium stoloniferum) plants from natural sites in Ohio. Running buffalo clover is a federally protected, endangered legume species. Studies to date have found RBC has high shade tolerance, readily propagates by stolons, and has excellent nutritive value. Its potential as a forage species in native pastures is not known, however, insufficient plant material is available for the conduct of research studies. This study has procured up to 25 RBC stolons from each of twelve sites in Ohio, and successfully cloned approx 1000 plantlets from these stolons. Of these, 750 plants served as a resource for replanting back into natural areas (especially for small populations having <50 plants). Another 250 plants will be a resource for genetic analysis in 2019. The plants will also be used for seed increase in 2019.

Soil carbon inputs and storage in flooded pasture fields of Southern Ohio. (Chiavegato et al.)

An experiment was established in May 2020 in Jackson, OH to evaluate above and below ground inputs of organic carbon and soil carbon storage in different forage species combinations, under flooding-prone and non-flooding prone pastures, and in a non-flooding prone hayfield. The treatments in flood prone and non-flood prone grazed plots were composed of: i) control (dominated by tall fescue, orchard grass and red and white clover); ii) winter cover-crops, rye and oat; iii) a cool-season species mixture established by drilling in tall fescue, Kentucky bluegrass, orchard grass, red and white clover; and iv) cool-season + warm-season mixed pasture. The hayfield was dominanted by tall fescue with random lesser amounts of clover and orchardgrass. Aboveground dry matter mass is being monitored throughout the 2021 growing season and roots were collected in mid-summer 2021 and will be collected again in late fall 2021 to determine carbon inputs. A preliminary analysis of the soil carbon stocks (0-100 cm depth) showed higher values in the grazed pastures (average of 112.2 Mg C ha^-1) relative to hayfield (102.1 Mg C ha^-1). This difference occurred mainly due to increased C content in the first 20 cm of soil in grazed plots (30.4 vs 23.2 g dm^-3 in the hayfield). Flooded grazed plots had decreased C storage (0-100 cm) of 8.8%, mainly due to reduced C contents on the 0-20 cm soil depth. The aboveground dry matter in mid-summer was 20% lower in the flood prone area compared with the non-flood prone pasture, and probably this lower productivity is leading to reduced carbon inputs, and therefore, reduced carbon storage in flood prone soils.

Effect of recurring, short-term flooding on soil, pasture and environmental characteristics of grazed and hay pastures. (Chiavegato et al.)

A two-scenario project has been established at two different locations in Ohio, southern (Jackson, OH – Scenario 1) and northwestern (Jenera, OH – Scenario 2). In Scenario 1, flood-prone and non-flooded grazed and hay pastures are composed of tall fescue, with random occurrence of red clover, and orchard grass. Three treatments were identified for that scenario at the farm in 2019: flood and non-flood prone pastures for grazing and non-flood prone hay field. In Scenario 2, hayfields and croplands will be monitored at a commercial partnering farm in the Western Lake Erie Watershed region. Croplands are predominantly on flat landscapes and the establishment of forage cover on the environmentally sensitive areas is encouraged through the Ohio Working Lands Buffer Program administered by the Ohio Department of Agriculture and local Soil and Water Districts. Forage areas were established in 2019 under this program, and farmers can harvest and remove forage. Three treatments were identified for this scenario: three levels of flood prone hay fields (non-flood, low flood and high flood prone). The specific objectives are to monitor GHG emissions from soils, soil C, N and organic matter content, pasture diversity, and forage quality and quantity in both scenarios. We hypothesize that flood-prone pastures for grazing and for hay will have lower forage quality and higher GHG emissions in comparison with non-flood prone pastures for grazing and for hay, due to increased water content in the soil.

Native warm season grasses to enhance pasture resilience to climate change (Chiavegato et al.)

This project will focus on identifying best management practices (BMPs) to establish native warm-season grasses (NWSG) in pastures at four different locations in Ohio: Jackson, Caldwell, Flushing, and Georgetown. The objective of this study is to assess morphogenic and structural characteristics of NWSG species when there are different plant establishment strategies. This proposal has extension and research objectives. The extension objective is to determine the best management practices for establishment of the warm‐season grass species tested. The outcomes are extension publications and field days to communicate the BMPs and show the demonstration plots. Four NWSG will be tested, switchgrass, indiangrass, big bluestem, and eastern gamagrass, using conventional and non-chemical practices for stand establishment. Big bluestem and indiangrass will be planted in mixtures which is the conventional practice of most beef producers. Switchgrass and Indiangrass will be planted individually. The non-chemical practices will be used to address organic producer needs. Three treatments will be tested, with different strategies of summer and winter cover crops in rotation with the NWSG.

Comparing the environmental tradeoffs and synergies of alternative modes of integrating livestock into cash grain cropping systems (Jackson-Smith et al.)

The project’s goal to identify pathways to improve the performance of integrated crop‐livestock systems, document opportunities and barriers to the expansion of the most promising approaches, and to develop recommendations for public and private interventions that can accelerate their use. To achieve these goals, we will pursue five interrelated objectives: 1) Quantify the diverse environmental outcomes associated with each approach to livestock‐crop integration under working farm conditions; 2) Assess the animal welfare and human health risks and benefits associated with more widespread use of manure and greater integration of livestock in cash grain cropping systems; 3) Develop whole farm models to quantify the socioeconomic, health/welfare and environmental tradeoffs and synergies associated with each approach to livestock crop integration; 4) Identify the social, technical, economic, and institutional constraints that limit adoption of each approach on regional livestock and cash grain farms, and 5) Use a participatory on‐farm approach throughout to better integrate research and extension/outreach activities. We will collaboratively develop recommendations for public policies and private supply chain programs to incentivize the most economically and environmentally beneficial approaches to livestock‐crop integration.

Oregon

Collaborative Efforts: Oregon State University Extension and Research faculty working together through a “Forage and Livestock Systems” Extension (and Research and Teaching) Working Group. The mission of this working group is to increase collaboration on planning and execution of high priority projects and contributing to the many integrated scientific disciplines involved in sustainable forage-livestock systems.

The “Oregon Forages” website (https://forages.oregonstate.edu/oregon) is developing and presenting comprehensive content of forage and livestock topics and segments devoted to the interrelationships among soil, water, plant, animal, and human health and the economic and social implications of sustainable agricultural systems. This site simplifies the search for information by county agents and specialists, farmers and ranchers, and agricultural agency personnel and builds stronger linkages among research, outreach, and classroom and eCampus teaching efforts. Progress to date includes developing the organizational outline of 19 topic areas, numerous sub-topics, and content authors. Initial drafts have been completed for many of the sections and a review process is being developed. This review process is necessary for ensuring “scholarly accomplishments” credit for authors. This past year has used funding from the Extension Program Leader to the Forage Work Group to develop nearly-completed drafts for 11 annual forage fact sheets and initial drafts for numerous other species. A uniform template has been developed and extensive content has been developed. Key components of the template include: Description and Uses, Identification, Cultivar Types, Suitability Zones, Suitability Maps (based on quantitative tolerances and GIS gridded data), Seasonal Production Profiles, Phenological Development (Bloom time for legumes), Establishment and Management, Quality and Antiquality, Image Gallery, Resources, Authors, Reviewers, and Funding Support. Internal and external reviews have been solicited, received, and incorporated.     The primary challenges remaining for completion of these fact sheets include the Seasonal Production Profiles and Phenological Development graphics based on photo-thermal time. This information has not been developed to date, despite hundreds of years of location-based experimentation.

    Research: PI and Project Descriptions

Serkan Ates: Evaluation of novel forage species, especially legumes and other forbs, to diversify forage production and extend the grazing season for dairy and sheep grazing systems.

David Hannaway: Modeling and mapping of forage species suitability leading to improved species and cultivar selection.

Guojie Wang: Evaluation of forage species for increased water use efficiency and seasonal forage production to develop systems that balance agricultural production needs for irrigation water with ecological needs for ecosystems services including wildlife and fish habitat.

Ruijun Qin: Evaluating the effect of the intercropping of alfalfa and grass on the hay production, quality, and economy under two water regimes.

Tennessee

Emergency seeding of cool-season annuals into perennial grass after fall drought. (Nave Oakes and Bates): Spring establishment of cool-season annual grasses into poorly producing orchardgrass (Dactylis glomerata L) (OG) swards may improve forage production and nutritive value in southeastern U.S following a fall drought. Annual ryegrass (Lolium multiflorum Lam.) (AR) and forage oats (Avena sativa L.) (FO) were seeded into an OG sward during two consecutive years in Middle Tennessee. An experiment was carried out with randomized complete block design consisting of two forage species combinations (OG+AR, OG+FO), three interseeding dates and the presence (+) or absence (-) of a burndown herbicide treatment (BD), as well as a control treatment of OG monoculture. In 2017, after a warm and wet winter, the OG was able to produce sufficient forage mass (FM) without significant reduction in nutritive value. Forage oats with BD treatment was more productive than AR, yet showed lower crude protein (CP) and higher fiber content. In 2018, OG had approximately 2600 lb ac-1 less FM than in 2017, suggesting that recurrent fall drought with unfavorable winter conditions resulted in long-term damage to the perennial sward. Meanwhile, treatments without BD did not show higher FM in the beginning of the season. Burndown treatment in general increased FM and nutritive value. Adequate productivity of drought-damaged OG swards is possible in the Mid-South by interseeding annual grass forages.

Forage species selection for transitional organic production. (Nave Oakes)
Despite the vast production markets for forage and organic products nationally, limited work has been done to develop organic forage programs, especially for the Southeastern U.S. and similar regions globally. The present study seeks to evaluate several forage species and mixtures for optimizing forage production and nutritive value under low-input organic conditions. This study was conducted at the Middle Tennessee AgResearch and Education Center, in Spring Hill, TN, U.S. The forage treatments consisted of 1) monoculture tall fescue (Schedonorus arundinaceus (Schreb.) Dumort.), 2) monoculture bermudagrass (Cynodon dactlyon (L.) Pers.), 3) tall fescue and alfalfa (Medicago sativa L.) mixture, 4) bermudagrass and alfalfa mixture, and 5) an annual rotation of winter wheat [Triticum aestivum L.] mixed with winter pea [Pisum sativum L.] followed by sorghum-sudangrass [Sorghum bicolor (L.) Moench x S. sudanese (Piper) Stapf.] mixed with cowpea [Vigna unguiculata (L.) Walp.] mixture). Perennial treatments were established during the 2017-2018 growing season. Monthly production measurements occurred in the 2019 and 2020 growing seasons. Botanical composition fluctuated as a consequence of establishment dynamics and weed competition. Weed competition ranged from 200 to 800 g kg-1 in the perennial swards, and variably affected forage quantity and quality. Nutritive value was sufficient for most livestock operations across treatments, with average crude protein of all treatments remaining ~150 g kg-1 across two growing seasons. The annual rotation was the highest-yielding treatment, producing more than 6000 kg ha-1, though tall fescue and tall fescue-alfalfa produced (~4000 kg ha-1) without associated establishment concern. For transitioning organic producers, the annual rotation, tall fescue, or tall fescue mixed with alfalfa treatments might best serve their operations contingent on weed competition and establishment concerns.  

Comparisons of alfalfa mix with tall fescue and bermudagrass on forage accumulation, botanical composition, and nutritive value. (Nave Oakes and Bates)

To utilize alfalfa (Medicago sativa L.), alone or in mixture with grasses, defoliation management practices must be evaluated to assess their performance. The objective was to determine forage accumulation (FA) and nutritive value of alfalfa monoculture (ALF) and in mixtures with tall fescue [ATF; Lolium arundinaceum (Schreb.) Darbyish)] or bermudagrass [ABG; Cynodon dactylon (L.) Pers] subjected to four harvest intervals (clipped every 21, 28, 35, and 42-d). The study was conducted in Crossville, TN and Charleston, OH during 2016 and 2017 growing seasons, and in Salisbury, NC during 2017 and 2018 growing seasons. Harvest intervals of 35-d or greater showed optimal FA, with greatest productivity in spring. In summer, the plot productivity of ATF was not different than ABG. The ATF mixture was superior to ABG in FA for the entire season. Although tall fescue can be very competitive with alfalfa in mixtures, it results in greater FA while reducing weed competition. Botanical composition indicated greater weed infestation in ALF than mixtures. Growing alfalfa-grass mixtures can increase sward CP compared with grass monocultures (average of 128 g kg^-1 for ATF and 161 g kg^-1 for ABG). We conclude that harvest intervals of 35-d or greater should be adopted to provide greater FA, and treatments ALF and ATF resulted in superior FA compared with ABG in the southern USA.

Texas

During 2019-2020, faculty from Texas A&M University, AgriLife Research and Extension (Bell, Foster, Kimura, Malinowski, Muir, Olson, Redmon, and Rouquette) published data on variety of basic forage-agronomy research topics. Outreach activities included the delivery of our findings during in-service training sessions, field days, and through various extension publications. Faculty at Texas A&M AgriLife Research, Texas A&M University-Kingsville, Texas Native Seed, Texas A&M University, and Tarleton State University continue the working group focused on domesticating and promoting native grassland grasses and forbs for wider use in rangeland revegetation, cultivated pasture, ornamental horticulture, wildlife habitat and feed, and bioenergy.

Utah

Improving forage and bioenergy crops for better adaptation, resilience, and flexibility (Hatch 2019-2022). Earl Creech. Selection of late-heading orchardgrass to improve yield and nutritive value in grass-alfalfa mixtures; the use of companion seeding oats as an aid to alfalfa establishment; evaluation of management practices to avoid injury from freezing temperatures to glyphosate-resistant alfalfa; evaluation of the performance of dairy cattle breeds on various pasture grasses (tall fescue, orchardgrass, meadow brome, and perennial ryegrass) grown in mixtures with birdsfoot trefoil. Multi-year trials of reduced lignin alfalfa were completed, and new variety trials of alfalfa and timothy were established including a 43-entry alfalfa trial on a saline location.

Economic and environmental sustainability of heifer development strategies in pasture-based organic dairy systems (NIFA Grant 2017-51300-26866; 2017-2021 for $999,404). Isom, S. C.; Miller, RH, L.; Young, AL, J..; Peel, MI, .; Waldron, BL, .; Creech, J., EA.; Rood, KE, .; Feuz, DI, M.; Heleba, DE, .; and Thornton-Kurth, KA. Treatments were tall fescue, meadow bromegrass, orchardgrass, and high-carbohydrate perennial ryegrass planted in pastures as monocultures and mixtures with birdsfoot trefoil and rotationally grazed by peri-pubertal Jersey heifers. Factors to be determined include forage production and dry matter intake (BFT mixtures had greater herbage intake than grass monocultures in the order MB+BFT, OG+BFT, OG, MB, PR+BFT, TF+BFT, PR, TF). Heifers grazing grass-BFT mixture pastures had better growth and development compared to heifers grazing grass monocultures. Mixed pastures with BFT may be a sustainable alternative to feeding a TMR for adequate growth of dairy heifers. The economic evaluation has not been completed and one Extension fact sheet has been published and the project has a presence on eOrganic.

Employing forage legumes to improve the sustainability of ruminant production (Hatch 2017-2022). Jennifer MacAdam. 1. In a column study of two legumes, a grass and a non-legume forb that was carried out in the greenhouse through 10 harvests, equivalent to approximately three years of field growth, we demonstrated that the two legumes reduced total soil nitrogen concentration while the grass and forb increased total soil nitrogen. This was due to a far greater investment in roots by the grass and the forb. 2. In a study of long-chain fatty acids from four beef diets (two legume pastures, a grass pasture and a feedlot concentrate diet, we demonstrated that the subcutaneous fat of cattle grazing one of the legumes, birdsfoot trefoil, had elevated omega-3 fatty acid concentration relative to cattle on the feedlot diets or the other pasture diets. Grass pastures resulted in the greatest ratio of acetic to propionic acid (A:P), followed by birdsfoot trefoil pastures, with the lowest A:P in cattle fed a feedlot diet. A greater A:P is associated with reduced methane emissions. 3. In a field study of alfalfa and meadow bromegrass, it was demonstrated that alfalfa accumulates between 35 and 45% of dry matter as non-fiber carbohydrate, including 25% of dry matter as pectins, while pectins comprise about 7% of grass dry matter.

Management and environmental factors affecting nitrogen cycling and use efficiency in forage-based livestock production systems (Hatch 2019-2024). Rhonda Miller. Treatments were tall fescue, meadow bromegrass, orchardgrass, and high-carbohydrate perennial ryegrass planted in pastures as monocultures and mixtures with birdsfoot trefoil and rotationally grazed by Jersey heifers. The dairy impact of pasture production on nitrogen cycling in response to grazing grass-legume mixtures will be evaluated. Soil samples from 2016-2018 have been analyzed for nitrate, ammonia, and phosphorus. All leachate samples have been analyzed from 2016, 2017 and 2018 for nitrate. Urine samples have been analyzed for urea for all three years. Fecal samples have been run for total nitrogen and total carbon for all three years, but still need to be analyzed for ammonia.

Chemical diversity in rangelands and pasturelands: a sustainable tool to enhance livestock production and ecological health while minimizing environmental impacts (Hatch 2017-2022). Juan Villalba. The invasive weed medusahead (Taeniatherum caput-medusae (L.) Nevski) was managed by grazing and herbicide applications, and intake of and preference for medusahead treated with glyphosate by livestock was evaluated, as well as the influence of the potassium salt present in glyphosate on selection of this grass. Non-treated medusahead was consumed to a greater extent than glyphosate-treated medusahead by lambs (P < 0.05) but in a two-way choice, all lambs tended to consume more medusahead treated at a high rate of glyphosate (P = 0.052). In a study with angus-cross steers of medusahead-infested pastures, medusahead defoliation declined to a greater extent in the glyphosate-treated plots than in the rest of the treatments (P = 0.022). Only small improvements in nutritional composition (reduced fiber contents and increased fiber digestibility) were observed in glyphosate-treated medusahead relative to the control. Both sheep and cattle showed increments in the use of medusahead. A combined herbicide-grazing treatment shows promise as a practical tool to reduce medusahead. In another study, pairs of heifers grazed 7 treatments: monocultures of birdsfoot trefoil, sainfoin and alalfa and all possible 2- and 3-way choices among strips of these legumes during two 15-d periods in 2 consecutive years. Average daily gains of heifers grazing tanniferous legumes (1.05 kg/d) were 40% greater (p b 0.10) than that of heifers grazing alfalfa during the first year. Heifers grazing the 3-way choice had greater intakes and gain than those grazing legume monocultures, suggesting a nutritional synergism among legumes. The average methane emissions for legume monocultures was greater than for 2- and 3-way choices. For heifers grazing sainfoin and birdsfoot trefoil compared with alfalfa, blood urea N was less but fecal N concentrations were. Combining the two tanniferous legumes (sainfoin and birdsfoot trefoil) led to the greatest declines in urinary N and urea-N concentrations, suggesting that different types of tannins in different legumes result in associative effects that enhance N economy. Heifers grazing 3-way choice treatments partitioned less N into urine and retained more N than heifers grazing legume monocultures. Heifers grazing the 3-way choice gained more BW than the average gains observed for animals grazing in all legume monocultures or 2-way choices, suggesting a synergism among pasture species for the treatment with the highest diversity. Spatial segregation of forage species into patches has the potential to enhance animal performance without influencing foraging behavior. The incorporation of a diverse array of chemicals into the diet, like the ingestion of different types and concentrations of condensed tannins or soluble carbohydrates may promote synergisms that benefit animal nutrition and health.

Wisconsin

The resilience of alfalfa to variable environments grant reached its final year and we are writing the publications documenting the different resilience of alfalfa cultivars to drought and cold stress. Results from this project informed the development of the RESILIENCE CAP.

Christine C. Nieman, Kenneth P. Coffey, Elizabeth B. Kegley, P. Hornsby, J. Hollenback, Dirk Philipp. 20XX. Supplementation of different sources and heating of dried distillers grains for lactating beef cows consuming bermudagrass hay. Submitted (J. Anim. Sci.)

Niyigena, V., Coffey, K. P., Coblentz, W. K., Philipp, D., Althaber, C., Diaz Gomez, J., Rhein, R. T., Pruden, M. C. 20XX. Intake, digestibility rumen fermentation and nitrogen balance in sheep offered alfalfa and tall fescue-mixtures harvested and ensiled after a killing frost. Submitted (Anim. Feed Sci. Technol.)

Niyigena, Valens, Ashworth, Amanda J, Nieman, Christine, Acharya, Mohan, Coffey, Ken, Philipp, Dirk, Meadors, Lillian, Sauer, Tom. 20XX. Factors affecting sugar accumulation and fluxes in warm- and cool-season forages grown in a silvopastoral system. Submitted (Crop Sci.)

Amanda J. Ashworth, Tulsi Kharel, Phillip R. Owens, Taylor C. Adams, Dirk Philipp, Andrew L. Thomas, and Tom Sauer. 20XX. Determining how spatially variable landscape attributes impact preferential grazing in silvopasture systems. Submitted (Nature Communications)

A.J. Ashworth, T.C. Adams, T.P. Kharel, D. Philipp, P. Owens, and T. Sauer. 20XX. Forage Root Decomposition in Silvopastoral Systems Influenced by Soil Moisture, Grazing, Fertilization, and Grass Species. Submitted (Archives of Agronomy and Soil Science).

Niyigena, K. P. Coffey, W. K. Coblentz, D. Philipp, R. T. Rhein, J. D. Caldwell, and B. C. Shanks. 20XX. Nitrogen balance and blood urea nitrogen by gestating sheep offered alfalfa silage wrapped with or without an enhanced oxygen barrier plastic after time delays up to three days. Submitted (Small Ruminant Research).

Rocateli, A.C., A.J. Ashworth, C.P. West, K.R. Brye, M. Popp, and J.R. Kiniry. 2020.  Simulating switchgrass biomass productivity using ALMANAC. I. Calibration of soil water. Agronomy Journal. 112: 183– 193. doi: 10.1002/agj2.20054

Ashworth, A.J., K. V. Knapp, F.L. Allen, and A.M. Saxton. 2020. Comparing yield trial locations based on their elicited expressions of genetic variance among soybean cultivars. Crop Sci. 60:1313–1324.  doi:10.1002/csc2.20066

Ashworth, A.J., P.R. Owens, and F.L. Allen. 2020. Long-term cropping systems management influences soil strength and nutrient cycling. Geoderma. 361. 114062, doi:org/10.1016/j.geoderma.2019.114062

Anderson, K., P.A. Moore, Jr., C. Pilon, J. Martin, D.H. Pote, P.R. Owens, A.J. Ashworth, D. Miller, and P. DeLaune. 2020.  Long-term study on the effects of buffer strips and grazing management on phosphorus runoff from pastures. J. Environ. Qual. 49: 85– 96. doi:10.1002/jeq2.20010

Acharya, M., B.S. Howell, J. Burke, A.J. Ashworth, and R.W. Rorie. 2020. Relationship of anti-mullerian hormone to reproductive traits in katahdin ewes bred in late spring or fall. Advances in Reproductive Sciences. 8: 48-56. doi: 10.4236/arsci.2020.81005

Ashworth, A.J., D.H. Pote, D.B. Watts, and T.R. Way. 2020. Effect of seeding distance from subsurface banded poultry litter on corn yield and leaf greenness. Agronomy Journal. 112:1679–1689. doi: 10.1002/agj2.20186

Ashworth, A.J., P.A. Moore, Jr., R. King, J.L. Douglas, D.H. Pote, and A.A. Jacobs. 2020. Switchgrass nitrogen fertility response and nutrient cycling in a hay system. Agronomy Journal. 112:1963–1971. doi:10.1002/agj2.20156. 2020

Amorim, H.C.S., A.J. Ashworth, B.J. Wienhold, M.S. Savin, F.L. Allen, A.M. Saxton, P.R. Owens, and N. Curi. 2020. Soil quality indices based on long-term conservation cropping systems management. Agrosystems, Geosciences & Environment. 3:e20036. doi.org/10.1002/agg2.20036

Anderson, K., P.A. Moore, Jr., and J. Martin, and A.J. Ashworth. 2020. Effect of a new manure amendment on ammonia emissions from poultry litter. Atmosphere. 11, 225. doi:10.3390/atmos11030257

Kharel, T.P., A.J. Ashworth, A. Shew, M. Popp, and P.R. Owens. 2020. Tractor guidance improves production efficiency by reducing overlaps and gaps. Agricultural & Environmental Letters. 5:e20012. doi.org/10.1002/ael2.20012

Kharel, T.P., A.J. Ashworth, P.R. Owens, and M. Buser. 2020. Spatially and temporally disparate data in systems agriculture: issues and prospective solutions. Agronomy Journal. 112:4498–4510. doi.org/10.1002/agj2.20285

Amorim, H.C.S., A.J. Ashworth, P.A. Moore, Jr., B.J. Wienhold, M.S. Savin, P.R. Owens, S. Jagadamma; T. Carvalho, and S. Xu. 2020. Soil quality indices following long-term conservation pasture management practices. Agriculture, Ecosystems and Environment. 301.

107060. doi.org/10.1016/j.agee.2020.107060

Kharel, T.P., P.R. Owens, and A.J. Ashworth. 2020. Tractor path overlap is influenced by field shape and terrain attributes. Agricultural & Environmental Letters. 5:e20027. doi.org/10.1002/ael2.20027

Xu, S., S. Jagadamma, A.J. Ashworth, S. Surendra, P.R. Owens, and P.A. Moore, Jr. 2020. Long-term effects of pasture management and fenced riparian buffers on soil organic carbon content and aggregation. Geoderma. 382, 114666, doi.org/10.1016/j.geoderma.2020.114666.

Ashworth, A.J., K. V. Knapp, F.L. Allen, and A.M. Saxton. 2020. Comparison of discriminatory effects of corn yield test locations based on their genetic variation expression among hybrids. Crop Sci. 60: 3166–3174. doi.org/10.1002/csc2.20298

Gelley, C.H., A.J. Ashworth, P.D. Keyser, R. Nave-Oakes, and J. Reinhart. 2020. Water-use efficiency of forage crops in the Southeastern United States. Agronomy. 10: 9, 1377; doi.org/10.3390/agronomy10091377

Yang, Y., A.J. Ashworth, J. DeBruyn, L.M. Durso, M. Savin, K. Cook, P.A. Moore, Jr., and P.R. Owens. 2020. Antimicrobial resistant gene prevalence in soils due to animal manure deposition and long-term pasture management. PeerJ 8:e10258. doi.org/10.7717/peerj.10258

Amorim, H.C.S., A.J. Ashworth, K.R. Brye, B.J. Wienhold, M.C. Savin, P.R. Owens, and S.H. G. Silva. 2021. Soil quality indices as affected by long-term burning, irrigation, tillage, and fertility management. Soil Science Society of America J. 85:379–395. doi:10.1002/saj2.20188

Ashworth, A.J., P.A. Moore, D.H. Pote, P.R. Owens, J. Martin, and K. Anderson. 2021. Conservation management practices reduce non-point source pollution from grazed pastures. Heliyon. 7, e06238. doi.org/10.1016/j.heliyon.2021.e06238.

Gurmessa, B., A.J. Ashworth, Y. Yang, K. Adhikari, M. Savin, P.R. Owens, T. Sauer, E.F. Pedretti, S. Cocco, and G. Corti. 2021. Soil bacterial diversity based on management and topography in a silvopastoral system. Applied Soil Ecology. 163, 103918. doi.org/10.1016/j.apsoil.2021.103918

Niyigena, V., A.J. Ashworth, C. Nieman, M. Achara, K.P. Coffey, D. Philipp, L. Meadors, and T.J. Sauer. 2021. Factors affecting sugar accumulation and fluxes in warm- and cool-season forages grown in a silvopastoral system. Agronomy. 11, 354. doi.org/10.3390/agronomy11020354

Gurmessa, B., A.J. Ashworth, Y. Yang, M. Savin, P.A. Moore Jr., S. Ricke, G. Corti. E.F. Pedretti, and S. Cocco. 2021.Variations in bacterial community structure and antimicrobial resistance gene abundance in cattle manure and poultry litter. Environmental Research. 97, 111011. doi.org/10.1016/j.envres.2021.111011

Acharya, M., A.J. Ashworth, Y. Yang, J.M. Burke, J.A. Lee, and R. Sharma-Acharya. 2021. Soil microbial diversity in organic and non-organic pasture systems. PeerJ 9:e11184. doi.org/10.7717/peerj.11184

Zhou, V., J.A. Larson, V.R. Sykes, A.J. Ashworth, and F.L. Allen. 2021. Crop rotation, cover crop, and poultry litter effects on no-tillage cotton profitability. Agronomy Journal. 113: 2648– 2663. doi.org/10.1002/agj2.20661

Yang, Y., A.J. Ashworth, L.M. Durso, M. Savin, J. DeBruyn, K. Cook, P.A. Moore, Jr., and P.R. Owens. 2021. Do long-term conservation pasture management practices influence microbial diversity and antimicrobial resistant genes in runoff? Frontiers in Microbiology. 12, 617066.  doi.org/10.3389/fmicb.2021.617066

Popp, M.P., A.J. Ashworth, and C.P. West. 2021. Simulating the feasibility of dual use switchgrass. Energies. 14, 2422. doi.org/10.3390/en14092422

Anderson, K., P.A. Moore, Jr., J. Martin, and A.J. Ashworth. 2021. Evaluation of a novel poultry litter amendment on greenhouse gas emissions. Atmosphere. 12, 563. doi.org/10.3390/atmos12050563

Adams, T.C., A.J. Ashworth, and T. Sauer. 2021. Soil CO2 evolution is driven by forage species, soil moisture, grazing pressure, poultry litter fertilization, and seasonality in silvopastures. Agrosystems, Geosciences & Environment. 4:e20179. doi.org/10.1002/agg2.20179

Richwine, J.D., P.D. Keyser, D.W. Hancock, and A.J. Ashworth. Using a browntop millet companion crop to aid native grass establishment. Agronomy Journal. 1−12. doi: 10.1002/agj2.20739

• Friesen, G.M.A., R. Smith, D.J. Cattani, and A.T. Phan. 2020. Characterizing genetically diverse blue grama [Bouteloua gracilis (Willd. ex Kunth) Lag. ex Griffiths] seed sources. Can. J. Botany 98:11. https://doi.org/10.1139/cjb-2020-0029
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Avanesyan, A., and W. Lamp.  2020.  Use of molecular gut content analysis to decipher the range of food plants of the invasive spotted lanternfly, Lycorma delicatula.  Insects 11, 215. 

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Avanesyan, A., N. Illahi, and W. Lamp.  2021.  Detecting ingested host plant DNA in potato leafhopper, Empoasca fabae: potential use of molecular markers for gut content analysis.  Journal of Economic Entomology 114: 472-475. doi: 10.1093/jee/toaa247

Eckert, R., H. Halvorson, K. Kuehn, and W. Lamp.  2020.  Macroinvertebrate community patterns in relation to leaf-associated periphyton under contrasting light and nutrient conditions in headwater streams.  Freshwater Biology 65: 1270-1287. DOI: 10.1111/fwb.13473

Eckert, R., W. Lamp, and G. Marbach-Ad.  2021. Jigsaw dissection activity enhances student ability to relate morphology and ecology in aquatic insects.  Journal of Biological Education (in press)

Thompson, M., and W. Lamp.  2021.  Herbivory enhances legume-rhizobia symbioses function, increasing aboveground allocation of biologically fixed nitrogen, but only in soils without additional nitrate.  Plant Soil https://doi.org/10.1007/s11104-021-04999-6.

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Wilson-Ounekeo, R. and W. Lamp.  2020.  Perceptions and responses of residents to the nuisance black fly Simulium jenningsi (Diptera: Simuliidae) in the mid-Atlantic United States.  Journal of Medical Entomology 57: 1872–1881, DOI: /10.1093/jme/tjaa129

Wilson-Ounekeo, R., and W. Lamp.  2021.  Environmental and spatial predictors of the distribution patterns of the host-seeking black fly, Simulium jenningsi.  Environmental Entomology (in press)

Yurchak, V., A. Leslie, G.P. Dively, W.O. Lamp, and C.R.R. Hooks.  2021.  Degradation of transgenic Bacillus thuringiensis proteins in corn residue to post-harvest management practices. Transgenic Research https://doi.org/10.1007/s11248-021-00273-8

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Patel, S., C.A. Bartel, A.W. Lenssen, K.J. Moore, and T. Berti. 2021. Stem density, productivity, and weed community dynamics in corn-alfalfa intercropping. Agronomy 2021, 11,1696. https://doi.org/10.3390/agronomy11091696

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Schmitt, M. T. Berti, D. Samarappuli, and J. Ransom. 2021. Factors affecting the establishment and growth of cover crops intersown into maize (Zea mays L.). Agronomy 11: 712. https://doi.org/10.3390/agronomy11040712

Kandel, H. D.P. Samarappuli, K. Johnson, and T. Berti. 2021. Soybean relative maturity, not row spacing affected interseeded cover crops biomass. Agriculture 11 (5): 441 https://doi.org/10.3390/agriculture11050441

Berti, M.T., Lukaschewsky, and D.P. Samarappuli. 2021. Intercropping alfalfa into silage maize can be more profitable than maize silage followed by spring-seeded alfalfa. Agronomy 11(6), 1196; https://doi.org/10.3390/agronomy11061196

Cecchin, A., Pourhashem, G., R.W. Gesch, A.W. Lenssen, S. Patel, Y. Mohammed and T. Berti. 2021. The environmental impact of ecological intensification of a cropping system in the U.S. Upper Midwest. Sustainability 13: 1696. https://doi.org/10.3390/su13041696

Cecchin, A., Pourhashem, G., R.W. Gesch, A.W. Lenssen, S. Patel, Y. Mohamed, and T. Berti. 2021. Environmental trade-offs of relay-cropping winter cover crops within maize and soybean. Agric. Systems 189:103062

Patel, S., A.W. Lenssen, K.J. Moore, Y.A. Mohammed, R.W. Gesch, M.S. Wells, B.L. Johnson, T. Berti, and H.L. Matthees. 2021. Interseeded pennycress and camelina yield and their influence on row crops. Agronomy J. doi: 10.1002/agj2.20655

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Dominschek, R.; Barroso, A.A.M.; Lang, C.R.; Moraes, A; Sulc, R.M.; Schuster, M.Z. (2021). Crop rotations with temporary grassland shifts weed patterns and allows herbicide-free management without crop yield loss. J. of Cleaner Production Volume 306. https://doi.org/10.1016/j.jclepro.2021.127140.

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Lin, S., C.A. Medina, S. Norberg, D. Combs, G.J. Wang, G. Shewmaker, S. Fransen, D. Llewellyn & L.X. Yu. 2021. Genome-wide association studies identifying multiple loci associated with alfalfa forage quality. Frontiers in Plant Science/Plant Breeding 12: 648192. doi: 10.3389/fpls.2021.648192.

Yang, Yungui, Yanyan Lin, Lu Zhao, Xuemei Yang, Ting Guo, and David B. Hannaway. 2021. Influence of ensiling additives on silage quality of several oat cultivars. International Journal of Science 8(2): 23-31. http://www.ijscience.org/download/IJS-8-2-23-31.pdf

Wang, G.J., G. Bobe, S.J. Filley, G.J. Pirelli, M.G. Bohle, T.Z. Davis, G.L. Banuelos & J.A. Hall. 2021. Effects of springtime sodium selenate foliar application and NPKS fertilization on selenium concentrations and selenium species in forages across Oregon. Animal Feed Science and Technology 276: 114944.

Wang, M., R. Gao, M. Franco, D.B. Hannaway, W. Ke, Z. Ding, Z. Yu, X. Guo. 2021. Effect of Mixing Alfalfa with Whole-Plant Corn in Different Proportions on Fermentation Characteristics and Bacterial Community of Silage. Agriculture 11: 174-185. https://doi.org/10.3390/agriculture11020174

Cicek, Harun, Serkan Ates, Gazi Ozcan, Mehmet Tezel, Jennifer G. Kling, Mounir Louhaichi and Gurhan Keles. 2020. Effect of nurse crop and seeding rate on the persistence, productivity and nutritive value of sainfoin in a cereal-based production system. Grass and Forage Science 75: 86-95.

Gultekin, Yunus, Shelby Filley, Mary Smallman, David Hannaway, Serkan Ates. 2020. Pasture production, persistence of legumes and lamb growth in summer-dry hill pastures.  Grass and Forage Science. Article ID: GFS12497. DOI 10.1111/gfs.12497.

Qin, Ruijun, C. Noulas, D. Wysocki, X. Liang, G. Wang and S. Lukas. 2020. Application of plant growth regulators on soft white winter wheat under different nitrogen fertilizer scenarios in irrigated fields. MDPI-Agriculture. DOI: 10.3390/agriculture10070305.

Smith, R.W., M. Webb, D. Kidd and D.B. Hannaway. 2020. Mapping pasture species suitability using fine scale soils and climate data. Crop & Pasture Sci. 70 (12): 1175-1183. https://doi.org/10.1071/.

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Wilson, Randi L., Massimo Bionaz, Jennifer W. MacAdam, Karen A. Beauchemin, Harley D. Naumann, and Serkan Ates. 2020. Milk production, nitrogen utilization, and methane emission of dairy cows grazing grass, forb, and legume-based pastures. Journal of Animal Science. https://doi.org/10.1093/jas/skaa220

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Kubesch, J.O.C., R.L.G. Nave, A.P. Griffith, S. Cui, G.E. Bates, D.M. Butler, and V.R. Pantalone. 2021. Economic outcomes of cool and warm-season swards in transitioning organic swards. Agron. J. (in review).

Kubesch, J.O.C., R.L.G. Nave, S. Cui, G.E. Bates, D.M. Butler, and V. R. Pantalone. 2021. Forage species selections for transitional organic production in the Southeastern United States. Agron. J. (in review)

Xiong, Y.V., R.L.G. Nave, A.P. Griffith, M.P. Quinby, G.E. Bates, and M.D. Corbin. 2021. Emergency seeding of cool-season annuals into perennial grass after fall drought. Crop Forage and Turfgrass Management. (in review)

Quinby, M.P.; R.L.G. Nave; R.M. Sulc; M.S. Castillo; G. E. Bates; D. McIntosh; L. Schneider 2021. Comparison of alfalfa mixed with tall fescue and bermudagrass on forage accumulation, botanical composition, and nutritive value. Crop Sci. https://doi.org/10.1002/csc2.20461

Tilhou, N.W., R.L.G. Nave, S. Jagadamma, N. Eash, and J.T. Mulliniks. 2021. Forage species and summer management impacts on soil labile carbon and nitrogen in winter stockpiled grazing systems. Agrosystems, Geoscience and Environment. doi:10.1002/agg2.20132

Gelley, C.H., Ashworth, A., P. Keyser, L.G. Nave, and J. Rhinehart. 2020. Water-use efficiency of forage crops in the southeastern United States. Agronomy. doi:10.3390/agronomy10091377.

Quinby, M.P., R.L.G. Nave, G.E. Bates, and D. McIntosh. 2020. Harvest interval effects on the persistence and productivity of alfalfa grown as a monoculture or in mixtures in the southeastern United States. Crop Forage and Turfgrass Management. doi.org/10.1002/cft2.20018.

Barbero, R.P., E.B. Malheiros, N.M. Aguilar, E.P. Romanzini, A.C. Ferrari, R.L.G. Nave, J.T. Mulliniks, R.A. Reis. 2020. Supplementation level increasing dry matter intake of beef cattle grazing low herbage height. Journal of Applied Animal Research. doi.org/10.1080/09712119.2020.1715985.

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Zimbric, J.W., D. Stoltenberg, V. Picasso. 2020. Strategies to reduce plant height in dual-use intermediate wheatgrass cropping systems. Agronomy Journal 2021;1−11. DOI:10.1002/agj2.20544

Sakiroglu, M., Dong, C., Hall, M.B., Jungers, J. and Picasso, V. 2020. How does nitrogen and forage harvest affect belowground biomass and non‐structural carbohydrates in dual use Kernza intermediate wheatgrass? Crop Science 2020; 60:2562–2573. DOI:10.1002/csc2.20239

Zimbric, J.W., D.E. Stoltenberg, V.D. Picasso. 2020. Effective weed suppression in dual-use intermediate wheatgrass systems. Agronomy Journal 112:2164-2175. DOI: 10.1002/agj2.20194

Darre, E., E. Llanos, L. Astigarraga, M. Cadenazzi, V. Picasso. 2020. Do pasture-based mixed dairy systems with higher milk production have lower environmental impacts? A Uruguayan case study. New Zealand Journal of Agricultural Research. DOI: 10.1080/00288233.2020.1750433

Siri-Prieto, G., O. Ernst, M. Bustamante, V. Picasso. 2020. Impact of nitrogen and phosphorous on biomass yield, nitrogen efficiency, and nutrient removal of perennial grasses for bioenergy. Biomass and Bioenergy 136: 105526. DOI: 10.1016/j.biombioe.2020.105526