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Pollinator declines and expectations for more sustainable agriculture, including pasture-based enterprises, bring attention to strategies to enhance the habitat value of grazing lands. We evaluated native warm-season grass (NWSG) pastures with (FORB) and without (CONT) interseeded native forbs in 2021–2023. An analysis was conducted using R with the significance set at p ≤ 0.05. The grass appeared to be weakened predominantly by grazing management practices. Forb density and mass had an inverse relationship in seasons two and three. Total forage mass declined in response to increased grazing days and weakened stands. The forage nutritive compositions differed, with more stable, season-long crude protein and lower fiber concentrations in late-season FORB, which supported higher bodyweight gains and season-long average daily gain. Black-eyed Susan (Rudbeckia hirta; BESU), lanceleaf coreopsis (Coreopsis lanceolata; LCOR), and showy ticktrefoil (Desmodium canadensis; STTF) were the most abundant forbs, and BESU, LCOR, and purple coneflower (Echinacea purpurea; PURC) produced long flowering windows. Cattle grazed STTF, cup plant (Silphium perfoliatum; CUPP), and oxeye sunflower (Helopsis helianthoides) the most. Under continuous stocking, a blend of BESU, LCOR, PURC, STTF, and CUPP produced acceptable cattle gains and provided pollinator resources, suggesting that this model may be a viable means to enhance the sustainability of pastures.

Edible food production is a growing area of horticultural interest that can engage multiple generations of rural to urban residents with varying levels of experience. Residential or community garden food production can provide many benefits, including the production of healthy produce, establishment of community or social connections, and increased physical activity. Regardless of experience, food gardeners are interested in growing crops and cultivars well-suited to their region and which provide both productivity and crop quality. This means that cultivar selection is a common question for gardeners. However, formal cultivar evaluation is relatively rare in the non-commercial food production sector due to the number of cultivars, the challenges of replicated trial management, and the scarcity of public researchers focused on consumer horticulture. This limits the information available to support new gardeners, which lowers the chances of overall success including high-quality harvests. Such crop and variety selection questions are common for Extension personnel in the United States as well as many others who work with gardeners. Even with this high level of interest, funding for consumer garden trials is limited and the cost of replicated trials across various geographical sites is high. To fill this gap in research and address the need for high-quality data to support education, University of Tennessee Extension and research faculty have developed a citizen science approach called the Home Garden Variety Trial (HGVT) program. The HGVT is a collaborative effort between Extension and research faculty and educators, who select trials, provide seeds, and compile data, and citizen scientists around the state, who conduct the trials using their usual gardening practices in their own home or community gardens. Beginning in 2017, the collaborators have conducted five years of research involving over 450 individual gardeners in more than half of the counties in Tennessee. The HGVT is a novel and effective tool to introduce gardeners to new crops and cultivars while providing previously unavailable data to researchers. Together, researchers and home gardeners collect and compile data that supports residential and community food production success while engaging new and experienced gardeners in participatory science research.

Winter oilseed Brassica plants have several documented allelochemicals; however, most literature revolves around the application of seed meal to fields, or the use of aerial parts of the plant. It is not clear if these chemicals interact with the surrounding environment to the same extent if the winter oilseeds are harvested as a cash crop in the spring. To determine this, we conducted a preliminary study bioassay using water extractable compounds from canola (Brassica napus L.) and pennycress (Thlaspi arvense L.) roots diluted to 25 and 50% (v/v). These four extracts, as well as deionized water for control, were used to irrigate plates with the seeds of soybean (Glycine max L.), Palmer amaranth [Amaranthus palmeri (S.) Watson], and mare's tail (Erigeron canadensis). We measured germination percent per plate and seedling radicle and hypocotyl lengths after 8 days of treatment. Mare's tail germination was lowered by 40% on day 4 by 50% pennycress extracts, and root length was stunted by both canola and pennycress extracts by 3–5 mm. Palmer amaranth root length was stunted by 10–15 mm by both species’ extracts, as well as shoots lengthened by 5–10 mm. Extract treatments did not affect soybean germination or growth. These interactions indicate potential for allelopathic interactions in the field following harvest of dual cropped winter oilseed and herbicide‐resistant weeds and warrant further study into the topic. Core Ideas Water extractable allelochemicals in winter oilseed roots impact herbicide resistant weed germination and growth. Canola and pennycress root extract lowered the germination and root length of herbicide‐resistant mare's tail. Canola and pennycress root extract shortened roots and lengthened shoots of Palmer amaranth. Canola and pennycress root extract did not affect soybean germination and growth.

Dual-use cover crops as forage for livestock could offer ecological and economic benefits when incorporated into rotations with corn (Zea mays L.) and soybean (Glycine max (L.) Merr) in the Mid-South USA; however, information on implementation and impact is limited. A factorial of sixteen cool-season species and a no-cover control by two management systems (forage harvest and residue left in the field) was repeated under two cover crop planting/termination timings: long-season (Oct. through May; corn/cover-crop/soybean) and short-season (Nov. through Apr.; soybean/cover-crop/corn), two locations (Spring Hill and Knoxville, TN), and two growing seasons (2017/2018 and 2018/2019). Data were analyzed using a mixed model ANOVA (SAS 9.4.). The forage biomass did not differ by species within the short-season (415 to 1583 kg ha−1) but did in the long-season (475 to 4282 kg ha−1). Within the long-season, crimson clover (Trifolium incarnatum L.) and winter pea (Pisum sativum subsp. arvense (L.)) had crude protein and acid detergent fiber values within the range for prime forage and were among the highest biomasses. The forage harvest did not negatively affect soil properties or succeeding crop yield and quality. If appropriate species are selected, cover crops within a corn/cover-crop/soybean rotation can provide quality forage, without reducing the short term ecological benefits.

Winter cover crops can improve the soil’s moisture-holding capacity, reduce soil water evaporation, and mitigate water-induced soil erosion; however, economic studies show mixed results on cover crop impacts on profits. One way to potentially increase the profits from planting cover crops is to harvest the cover crop for hay. The objective of this study was to determine the profitability of planting and harvesting cover crops when planting corn (Zea mays) or soybean (Glycine max (L.) Merr.) as a cash crop. We determined the difference in net returns among 15 cover crop species when planted before corn and soybeans. We then calculated the breakeven hay price if the cover crop was harvested. Data were collected from an experiment in Tennessee, from 2017 to 2019, at two locations. There was no difference in net returns across cover crop treatments for both corn and soybeans, thus indicating that planting a cover crop does not reduce profits. The breakeven prices for harvesting cover crops suggest that this system would not likely be profitable for corn but might be profitable if planting soybeans, depending on labor availability and local demand for hay.

Cover crops (CCs) have shown great potential for suppressing annual weeds within agronomic cropping systems across the United States. However, the weed suppressive potential of CCs may be moderated by environmental and management factors that are specific to certain geographic areas and their associated characteristics. This may be particularly true within the U.S. Southeast, where higher mean annual temperature and precipitation generate favorable conditions for both CC and weed growth. To understand the effects of this regional context on CCs and weeds, a meta-analysis examining paired comparisons of weed biomass and/or weed density under CC and bare ground conditions from studies conducted within the Southeast was conducted. Data were identified and extracted from 28 journal articles in which weed biomass and/or weed density were measured along with cash crop yield data, if they were provided. Fourteen studies provided 142 comparisons for weed biomass; 23 studies provided 139 comparisons for weed density; and 22 studies, pooled over both weed response variables, provided 144 comparisons for cash crop yield. CCs had a negative effect on weed density (P = 0.0016) but no effect on either weed biomass (P = 0.16) or cash crop yield (P = 0.88). The mean relative reduction in weed density under CCs was 44%. Subsequent analyses indicated that CC biomass was the key factor associated with this reduction. Weed density suppression was linearly related to CC biomass; a 50% decrease in weed density was associated with 6,600 kg ha–1 of CC biomass. Edaphic, geographic, and other management factors had no bearing on this suppressive effect. This highlights the importance of generating adequate CC biomass if weed suppression is the primary objective of CC use and the potential for CCs to reduce weed density over diverse soil, climate, and farm management conditions.

PurposeHeavy metal contamination in soil and crop grain due to long-term poultry litter (PL) application is largely unknown under no-till production and subtropical climate. The objective of this study was to assess the accumulation of heavy metals in soil profile and corn and soybean grains after 15-year poultry litter application under no-tillage in the Mid-south region of the United States.Materials and methodsLong-term field experiments initiated in 2002 with or without PL application as a N source involving monocultures of corn and soybean under no-tillage at Milan and Spring Hill in Tennessee, USA, were selected for this study in 2017. Available and/or total contents of arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), copper (Cu), and zinc (Zn) in soil were measured in soil and corn and soybean grains. Contamination indices including contamination factor (CF), degree of contamination (DC), pollution load index (PLI), and geo-accumulation index (Igeo) were calculated.Results and discussionLong-term application of PL did not increase the total content of As, Cd, Cr, or Pb in the surface 0–15 cm soil relative to no PL application. However, total and available contents of Zn were increased by 11–17% and 2.2–5.6 times respectively, in the surface soil due to PL application. 1.7 times of total Cu and 1.7–2.1 times of available Cu were accumulated in surface soil after long-term PL application. Only total Zn content was increased by 7–17% in corn and soybean grains due to PL application.ConclusionsLong-term application of PL does not pose risk of As, Pb, Cd, or Cr contamination to soil or crop grains but enhanced total and available contents of Zn and Cu in surface soil and total Zn content in crop grains under no-till production and subtropical climate. Enhanced total Zn content in corn and soybean grains is beneficial for animal and human health.

Winter oilseeds are cool season Brassica crops currently being grown in the upper Midwest and North‐West of the United States. They have the potential to function as dual crops when grown in rotation with corn, soybean, and small grains. They provide many of the benefits of typical cover crops over winter, with the added benefit of extra revenue to growers who sell the seeds for uses such as biofuel, industrial products, human consumption, or animal feed. This review gathers current agronomic and industrial use information about canola (Brassica napus L.), camelina [Camelina sativa (L.) Crantz], and pennycress (Thlaspi arvense L.). Currently, most research involving these crops is specific to the Midwest. This review also poses questions regarding how these crops could be adapted to grow in the Mid‐South, with further research being necessary in several areas before promoting adoption in the region. Core Ideas Winter oilseed crops have the potential to address both environmental and economic sustainability issues. Winter oilseed crops provide winter cover, biofuel production, and revenue without interfering with the food supply. Canola production is well established in the United States, and pennycress and camelina production is increasing. Winter oilseeds may have untapped potential within the Mid‐South region of the United States.

Living mulch (LM) production systems are gaining traction as an alternative to the use of annual cover crops in the southeastern United States, warranting research on the viability and functionality of this system. Our objective was to evaluate the benefits of LM in corn silage and grain production and to evaluate the potential of LM grazing during the corn (Zea Mays L.) growing season. The experiment was conducted in Spring Hill, TN in 2020 and 2021 and consisted of two mulch species, white clover (WC) (Trifolium repens L.) and a mixture of crimson clover (Trifolium incarnatum L.) and cereal rye (CCCR) (Secale cereale L.). Cull cows were used for the grazing periods (4 weeks before planting and after the harvest of corn). The study evaluated the botanical composition, mulch mass, nutritive value, corn silage and grain production, and cow average daily weight gain (ADG). The WC treatment had a greater weed control than CCCR. In 2020, when differences in mulch mass were observed, CCCR had greater mass than WC mass due to the weed presence. Meanwhile, in 2021, the mulch mass did not differ between WC and CCCR, with both treatments showing less mass in spring and early summer. Grain production was 30% less than silage in 2020 and 90% less in 2021. The ADG was only observed for WC (0.5 kg−1) paddocks. It was concluded that WC as LM has greater corn production than CCCR treatments. The LM for grazing is a beneficial strategy if feeding costs are greater than $2.22 head day−1. Core Ideas White clover living mulch improves corn production systems. White clover living mulch promotes weed suppression in corn production. White clover enhances the average daily weight gain of cows.

Crop rotations, cover crops, and manures may enhance yields, improve soils, and provide other ecosystem services. However, farmers may be reluctant to adopt the aforementioned practices because of uncertain profits. This study determined the profitability of cotton (Gossypium hirsutum L.) rotated with other crops and also utilizing cover crops and poultry litter (PL). Whole‐block treatments were 10 sequences of no‐tillage cotton, corn (Zea mays L.), and soybean [Glycine max (L.) Merr.] at Milan, TN. Sequences were repeated in 4‐yr cycles called Phases (Phases I, II, III, and IV) starting in 2002 and continuing through 2017 to assess effects of consecutive applications of sequences on cotton net returns (NRs). Split‐block treatments included winter wheat (Triticum aestivum L.), hairy vetch (Vicia villosa L.), PL, and fallow. The ANOVA was used to determine treatment NR differences compared to continuous cotton and fallow for 2002–2017 and for each Phase. Including soybean and corn in rotation with cotton did not positively affect cotton NRs in Phases I, II, and III. Droughts may explain lack of yield and NR response in Phases II and III. However, including soybean and corn in the rotation provided higher cotton NRs in Phase IV (2014–2017). Better weather and improved soils with residue diversity in Phase IV may explain higher yields and NRs of cotton in rotation with other crops. For cover crops and PL, yield benefits and/or N fertilizer savings did not offset input costs, indicating monetary incentives may be needed for famers to include these practices in their cropping system. Core Ideas Cotton rotating with corn and soybean may increase cotton profitability in the longer term. Yield benefits and/or nitrogen fertilizer savings with cover crops did not offset input costs. Poultry litter made similar lint yields to urea as a source of N but high costs impeded profits.