Journal of environmental quality最新文献

{"title":"Biochar captures ammonium and nitrate in easily extractable and strongly retained form without stimulating greenhouse gas emissions during composting","authors":"Franziska Busch,&nbsp;Otávio dos Anjos Leal,&nbsp;Nina Siebers,&nbsp;Nicolas Brüggemann","doi":"10.1002/jeq2.20634","DOIUrl":"10.1002/jeq2.20634","url":null,"abstract":"<p>During composting of organic waste, nitrogen is lost through gaseous forms and ion leaching. Biochar has been shown to capture mineral nitrogen (N_min: NH₄⁺ and NO₃⁻) from compost, which we hypothesize reduces N₂O formation. However, associating N_min captured by biochar with the dynamics of N₂O and other greenhouse gas (GHG) emissions during composting remains unstudied and was the aim of this work. We composted (outdoor for 148 days) together kitchen scraps (43.3% dw, where dw is dry weight), horse manure (40.9% dw), and wheat (<i>Triticum aestivum</i> L) straw (15.8% dw) without (Control) or with biochar (Bc, 15% compost dw). The biochar consisted of hardwood and softwood pieces pyrolyzed at 680°C and exhibited 60% of particles with 4–8 mm. We monitored compost GHG (CO₂, CH₄, N₂O) emissions, N_min content in compost and biochar particles (sequential extractions), and biochar surface transformations (SEM-EDX and ¹³C-NMR spectroscopy) along composting. Biochar did not significantly reduce or increase GHG emissions and N_min content (mg kg⁻¹) in compost. However, the final NO₃⁻ amount (g compost pile⁻¹) in the Bc treatment was significantly higher (54%) compared to the Control, indicating lower NO₃⁻ losses. Despite the high aromaticity and minimal contribution of carboxyl C to the biochar structure, biochar retained NH₄⁺, mainly in easily extractable form (55%), in the first 2 weeks of composting and mainly in strongly retained form (75%) in the final compost. The NO₃⁻ content in biochar increased continuously during composting. In the final compost, the NO₃⁻ content extracted from biochar was 164 (37%, easily extractable), 80 (19%, moderately extractable), and 194 mg NO₃⁻–N kg⁻¹ (44%, strongly retained). Although N_min retention in biochar was not accompanied by lower N₂O emissions, contradicting our hypothesis, we demonstrated the efficacy of biochar to recover N_min from organic waste without stimulating GHG emissions.</p>","PeriodicalId":15732,"journal":{"name":"Journal of environmental quality","volume":"53 6","pages":"1099-1115"},"PeriodicalIF":2.2,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jeq2.20634","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142391005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The LTAR Grazing Land Common Experiment at Platte River High Plains Aquifer","authors":"M. Khorchani,&nbsp;M. Schmer,&nbsp;A. Freidenreich,&nbsp;T. Awada,&nbsp;G. Birru,&nbsp;S. Christofferson,&nbsp;R. Drijber,&nbsp;G. Erickson,&nbsp;V. Jin,&nbsp;R. McDermott,&nbsp;A. Suyker,&nbsp;A. Watson,&nbsp;B. Woodbury,&nbsp;Y. Xiong,&nbsp;J. Hiller,&nbsp;X. Sun,&nbsp;L. Li","doi":"10.1002/jeq2.20629","DOIUrl":"10.1002/jeq2.20629","url":null,"abstract":"<p>The Long-Term Agroecosystem Research (LTAR) network of the United States Department of Agriculture (USDA) consists presently of 18 sites within the contiguous United States that are managed by the Agricultural Research Service (ARS) and its partners. The LTAR network focuses on developing national strategies for more efficient, resilient, and profitable agricultural production systems, improved environmental quality, and enhanced rural prosperity. The Platte River High Plains Aquifer (PRHPA) LTAR site is managed jointly by the University of Nebraska-Lincoln (UNL) and USDA-ARS and is one of the LTAR sites that conduct research on both integrated cropping and grazing systems. The PRHPA region encompasses multiple land resource areas and diverse agricultural production systems. The PRHPA sites, predominantly located in eastern Nebraska, are designated as an integrated system focused specifically on the region's dominant production practices of row crop (corn and soybean), managed pastures, and beef cattle production. Here, we focus on C₃ cool-season smooth bromegrass (<i>Bromus inermis</i> Leyss.) pasture grazing systems under prevailing and alternative management practices for the region. The sites evaluate continuous and rotational grazing with and without pasture fertilization (prevailing practices). In an additional treatment, cattle are supplemented with dry distillers grains plus solubles, while manure supplies fertilization (alternative practice). Main measurements at the site evaluate plant and animal productivity, forage quality, greenhouse gas fluxes, and soil physical, chemical, and biological properties. This paper describes the regional characteristics of the PRHPA site, ongoing LTAR research related to pasture and livestock production, stakeholder engagement, and future research plans.</p>","PeriodicalId":15732,"journal":{"name":"Journal of environmental quality","volume":"53 6","pages":"948-956"},"PeriodicalIF":2.2,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jeq2.20629","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142391015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Machine learning reveals dynamic controls of soil nitrous oxide emissions from diverse long-term cropping systems","authors":"Jashanjeet Kaur Dhaliwal,&nbsp;Dinesh Panday,&nbsp;G. Philip Robertson,&nbsp;Debasish Saha","doi":"10.1002/jeq2.20637","DOIUrl":"10.1002/jeq2.20637","url":null,"abstract":"<p>Soil nitrous oxide (N₂O) emissions exhibit high variability in intensively managed cropping systems, which challenges our ability to understand their complex interactions with controlling factors. We leveraged 17 years (2003–2019) of measurements at the Kellogg Biological Station Long-Term Ecological Research (LTER)/Long-Term Agroecosystem Research (LTAR) site to better understand the controls of N₂O emissions in four corn–soybean–winter wheat rotations employing conventional, no-till, reduced input, and biologically based/organic inputs. We used a random forest machine learning model to predict daily N₂O fluxes, trained separately for each system with 70% of observations, using variables such as crop species, daily air temperature, cumulative 2-day precipitation, water-filled pore space, and soil nitrate and ammonium concentrations. The model explained 29%–42% of daily N₂O flux variability in the test data, with greater predictability for the corn phase in each system. The long-term rotations showed different controlling factors and threshold conditions influencing N₂O emissions. In the conventional system, the model identified ammonium (&gt;15 kg N ha⁻¹) and daily air temperature (&gt;23°C) as the most influential variables; in the no-till system, climate variables such as precipitation and air temperature were important variables. In low-input and organic systems, where red clover (<i>Trifolium repens</i> L.; before corn) and cereal rye (<i>Secale cereale</i> L.; before soybean) cover crops were integrated, nitrate was the predominant predictor of N₂O emissions, followed by precipitation and air temperature. In low-input and biologically based systems, red clover residues increased soil nitrogen availability to influence N₂O emissions. Long-term data facilitated machine learning for predicting N₂O emissions in response to differential controls and threshold responses to management, environmental, and biogeochemical drivers.</p>","PeriodicalId":15732,"journal":{"name":"Journal of environmental quality","volume":"54 1","pages":"132-146"},"PeriodicalIF":2.2,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11718152/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142391014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of Minnesota Phosphorus Loss Index performance.","authors":"Heidi Reitmeier, Lindsay Pease, Peyton Loss, Tim Radatz","doi":"10.1002/jeq2.20635","DOIUrl":"https://doi.org/10.1002/jeq2.20635","url":null,"abstract":"<p><p>Supported by the National Phosphorus (P) Research Project led by Dr. Andrew Sharpley, Minnesota developed its statewide P-Index, the Minnesota P Loss Index (MNPI), to manage critical source areas of agricultural P. The MNPI has remained unchanged since its last revision in 2006. The overall goal of this study was to critically evaluate the MNPI to determine, in the parlance of Sharpley, if the MNPI remains \"directionally and magnitudinally correct.\" Observed P loss from 67 site-years of annual edge-of-field data was compared with MNPI-predicted P loss. Our assessment indicates that MNPI performance is directionally correct: it correctly ranks fields that are more at risk than others. The MNPI performed better in years with high-intensity rainfall events. Averaging MNPI assessment across multiple years of data input, along with minor adjustments to the calculation algorithm, improved the robustness of MNPI estimates. Continued re-evaluation of the MNPI will ensure that this important tool for nutrient management is properly evaluating P loss potential. This study reflects Dr. Sharpley's decades-long effort to improve and revise P indices so that they reflect advances in the science and management of agricultural P.</p>","PeriodicalId":15732,"journal":{"name":"Journal of environmental quality","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142391006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Watershed-scale spatial prediction of agricultural land phosphorus mass balance and soil phosphorus metrics: A bottom-up approach","authors":"Finn A. Bondeson,&nbsp;Joshua W. Faulkner,&nbsp;Tiffany L. Chin,&nbsp;Andrew W. Schroth,&nbsp;Michael Winchell,&nbsp;Aubert Michaud,&nbsp;Mohamed Niang,&nbsp;Eric D. Roy","doi":"10.1002/jeq2.20633","DOIUrl":"10.1002/jeq2.20633","url":null,"abstract":"<p>Analysis of nutrient balance at the watershed scale, including for phosphorus (P), is typically accomplished using aggregate input datasets, resulting in an inability to capture the variability of P status across the study region. This study presents a set of methods to predict and visualize partial P mass balance, soil P saturation ratio (PSR), and soil test P for agricultural parcels across a watershed in the Lake Champlain Basin (Vermont, USA) using granular, field-level data. K-means cluster analyses were used to group agricultural parcels by soil texture, average slope, and crop type. Using a set of parcels accounting for ∼21% of the watershed's agricultural land and having known soil test and nutrient management parameters, predictions of partial P mass balance, PSR, and soil test P for agricultural land across the watershed were made by cluster, incorporating uncertainty. This resulted in an average partial P balance of 5.5 ± 0.2 kg P ha⁻¹ year⁻¹ and an average PSR of 0.0399 ± 0.0002. Furthermore, approximately 30% of agricultural land had predicted soil test P values above optimum levels. Results were used to visualize areas with high P loss potential. Such data and visualizations can inform watershed P modeling and assist practitioners in nutrient management decision making. These techniques can also serve as a framework for bottom-up modeling of nutrient mass balance and soil metrics in other regions.</p>","PeriodicalId":15732,"journal":{"name":"Journal of environmental quality","volume":"53 6","pages":"1152-1163"},"PeriodicalIF":2.2,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jeq2.20633","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142380988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"From wastewater to feed: Understanding per- and polyfluoroalkyl substances occurrence in wastewater-irrigated crops","authors":"Kelly Kosiarski,&nbsp;Charles (Zeke) Usner,&nbsp;Heather E. Preisendanz","doi":"10.1002/jeq2.20630","DOIUrl":"10.1002/jeq2.20630","url":null,"abstract":"<p>Reusing treated wastewater for irrigation is a sustainable way to recycle nutrients and reduce freshwater use. However, wastewater irrigation inadvertently introduces per- and polyfluoroalkyl substances (PFAS) into agroecosystems, causing concerns regarding potential adverse effects to ecosystem, animal, and human health. Therefore, a better understanding of the pathways by which PFAS accumulate in forage crops is needed. A greenhouse study was conducted to (1) quantify the contribution of root uptake versus foliar sorption of PFAS in corn (<i>Zea mays</i>) and orchard grass (<i>Dactylis glomerata</i>), (2) assess effects of PFAS-impacted wastewater irrigation on plant health, and (3) determine the potential implications for bioaccumulation. The greenhouse study was composed of four treatments for each forage crop to isolate the relative contribution of two uptake pathways. Results suggested that foliar sorption was an unlikely contributor to PFAS concentrations observed in crop tissue. Root uptake was identified as the predominant uptake pathway. PFAS were detected more frequently in orchard grass samples compared to corn silage samples. Additionally, corn exhibited a lower uptake of long-chain PFAS compared to grass. Overall, no plant health effects on growth attributable to PFAS concentrations were observed. Forage data suggest cattle exposure to PFAS would be largely short-chain PFAS or long-chain “replacement” compounds (&gt;50%). However, cattle may still be exposed to potentially harmful long-chain PFAS; levels in the forage crops exceeded the tolerable weekly intake set by the European Food Safety Authority. This study provides insights on PFAS entry into the food chain and potential implications for livestock and human health.</p>","PeriodicalId":15732,"journal":{"name":"Journal of environmental quality","volume":"54 1","pages":"66-79"},"PeriodicalIF":2.2,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11718136/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142372016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phosphorus lability across diverse agricultural contexts with legacy sources.","authors":"Zachary P Simpson, Joshua Mott, Kyle Elkin, Anthony Buda, Joshua Faulkner, Cathleen Hapeman, Greg McCarty, Maryam Foroughi, W Dean Hively, Kevin King, Will Osterholz, Chad Penn, Mark Williams, Lindsey Witthaus, Martin Locke, Ethan Pawlowski, Brent Dalzell, Gary Feyereisen, Christine Dolph, David Bjorneberg, Kossi Nouwakpo, Christopher W Rogers, Isis Scott, Carl H Bolster, Lisa Duriancik, Peter J A Kleinman","doi":"10.1002/jeq2.20632","DOIUrl":"https://doi.org/10.1002/jeq2.20632","url":null,"abstract":"<p><p>The buffering of phosphorus (P) in the landscape delays management outcomes for water quality. If stored in labile form (readily exchangeable and bioavailable), P may readily pollute waters. We studied labile P and its intensity for >600 soils and sediments across seven study locations in the United States. Stocks of labile P were large enough to sustain high P losses for decades, indicating the transport-limited regime typical of legacy P. Sediments were commonly more P-sorptive than nearby soils. Soils in the top 5 cm had 1.3-3.0 times more labile P than soils at 5-15 cm. Stratification in soil test P and total P was, however, less consistent. As P exchange via sorption processes follows the difference in intensities between soil/sediment surface and solution, we built a model for the equilibrium phosphate concentration at net zero sorption (EPC₀) as a function of labile P (quantity) and buffer capacity. Despite widely varying properties across sites, the model generalized well for all soils and sediments: EPC₀ increased sharply with more labile P and to greater degree when buffer capacity was low or sorption sites were likely more saturated. This quantity-intensity-capacity relationship is central to the P transport models we rely on today. Our data inform the improvement of such P models, which will be necessary to predict the impacts of legacy P. Further, this work reaffirms the position of labile P as a key focus for environmental P management-a view Dr. Sharpley developed in the 1980s with fewer data and resources.</p>","PeriodicalId":15732,"journal":{"name":"Journal of environmental quality","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142347951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The LTAR Cropland Common Experiment at Upper Mississippi River Basin–Morris","authors":"Jane M. F. Johnson,&nbsp;Christina M. Helseth,&nbsp;Sharon Weyers,&nbsp;Thanos Papanicolaou,&nbsp;Dennis Busche","doi":"10.1002/jeq2.20631","DOIUrl":"10.1002/jeq2.20631","url":null,"abstract":"<p>The Upper Mississippi River Basin (UMRB) Long-Term Agroecosystem Research (LTAR) watershed is hydrologically complex, with a notable temperature and precipitation gradient across four locations: Ames, IA; Platteville, WI; Morris, MN; and St. Paul, MN. Each location established LTAR Croplands Common Experiment (CCE) scenarios to fit local climatic and cultural practices. This paper describes the UMRB-Morris location, which was established in 2016 and is the most northern of the sites and contributes to the major watersheds of the UMRB and the Red River of the North. Both on-farm and plot-scale studies are included. The prevailing system is a corn (<i>Zea mays</i> L.)–soybean (<i>Glycine max</i> L.) rotation with annual deep ripping tillage. The signature alternative system is alternative 1, which is a shallow strip-till in a corn–soybean rotation. A second alternative system includes shallow tillage/rotational no-tillage in a corn–soybean–wheat (<i>Triticum aestivum</i> L.) with winter oilseed and cover crops, and it is considered a test ground for future alternative systems. On-farm fields are equipped with eddy covariance towers and include 16 geo-referenced soil core sampling sites for incremental samplings. Each field is sampled annually for crop yield and management data are recorded. Plot-scale versions of the treatments are managed at the Swan Lake Research Farm. On-farm and plot-scale fields are instrumented with Phenocams to capture continuous photographic records. The CCE at UMRB-Morris aims to integrate soil, crop, weather data, and image classification to assess benefits and challenges across different management strategies.</p>","PeriodicalId":15732,"journal":{"name":"Journal of environmental quality","volume":"53 6","pages":"989-998"},"PeriodicalIF":2.2,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142347952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the biodegradability of hazardous industrial solid waste: Study of key parameters","authors":"M. Auset,&nbsp;L. Margarit,&nbsp;J. Cuadros,&nbsp;L. Fernández-Ruano,&nbsp;M. Claramunt,&nbsp;X. Mundet","doi":"10.1002/jeq2.20624","DOIUrl":"10.1002/jeq2.20624","url":null,"abstract":"<p>The biological stability of solid waste is one of the main problems related to the environmental impact of landfills and their long-term emission potential. Current European legislation (European Landfill Directive, EC/99/31) introduced the need to reduce biodegradable organic compounds deposited in landfills; however, it set neither official parameters nor methods to define the stability of such a waste. In Spain, biodegradability is generally evaluated using the biological oxygen demand/chemical oxygen demand (BOD₅/COD) ratio, measuring it on the leachate, thus not considering the non-soluble fraction and therefore creating false negatives. To solve this problem, the biodegradability of hazardous industrial waste has been determined by measuring its respirometric activity (AT₄). Our results show that the measure of the AT₄ is independent of the enrichment with a microbial inoculum, and a sample size no higher than 20 g could be a reasonable value for a sensitive biodegradability determination. The highest respirometric index is obtained in waste with pH values between 6.5 and 10.5. Furthermore, respirometric biodegradability values are independent of traditional parameters of organic matter characterization such as BOD₅/COD ratio, volatile content, and total and dissolved organic carbon. Consequently, the AT₄ parameter provides new information on the composition and stability of organic matter in hazardous industrial waste. Its incorporation into pre-disposal waste characterization protocols allows to identify waste that exceeds recommended biodegradability thresholds. This approach ensures that only waste meeting specified biodegradability standards is deposited, avoiding landfill emissions and related environmental impacts, and thereby improving the overall effectiveness and sustainability of waste management practices.</p>","PeriodicalId":15732,"journal":{"name":"Journal of environmental quality","volume":"53 6","pages":"1164-1175"},"PeriodicalIF":2.2,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jeq2.20624","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142248538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biochanin A feed supplementation alters dynamics of trace gas emissions from lamb urine-amended soil","authors":"Alayna A. Jacobs,&nbsp;Michael D. Flythe,&nbsp;Donald G. Ely,&nbsp;Leah Munoz,&nbsp;John B. May,&nbsp;Jim A. Nelson,&nbsp;Victoria Stanton,&nbsp;Rebecca K. McGrail,&nbsp;Kent Pham,&nbsp;Rebecca L. McCulley","doi":"10.1002/jeq2.20628","DOIUrl":"10.1002/jeq2.20628","url":null,"abstract":"<p>Sustainable growth in livestock production requires reductions in trace gas emissions on grazing lands. Urine excreta patches are hot spots for accelerated emissions of carbon and nitrogen. Ruminant dietary supplementation with the isoflavone biochanin A (BCA) has been shown to improve cattle weight gain. To determine if BCA supplementation affects urine N excretion and soil trace gas emissions, soil in microcosms was amended with urine from lambs fed 0, 0.45, or 0.90 g BCA day⁻¹. Soil gas emissions were measured over 60 days and analyzed with a linear mixed-effects model with repeated measures. On 2 days during the incubation, BCA addition across doses significantly reduced nitrous oxide emissions by 73% and methane by 98% compared to urine from non-dosed lambs. Cumulative ammonia volatilization was significantly reduced by 33% but cumulative nitrous oxide and methane emissions were not. Alterations in trace gas emissions occurred despite no change in urine N content with BCA feed supplementation. A separate laboratory incubation using urine from a non-supplemented lamb that was exogenously spiked with varying BCA concentrations supported these results: BCA significantly altered ammonia and methane emission dynamics and reduced cumulative nitrous oxide emissions by up to 41%. BCA did not change soil microbial community structure, suggesting alterations to other processes, such as soil enzyme activity, were affecting soil trace gas emissions. Overall, lamb BCA supplementation did not affect urine N but reduced ammonia volatilization, which may contribute to greater sustainability in livestock production systems.</p>","PeriodicalId":15732,"journal":{"name":"Journal of environmental quality","volume":"53 6","pages":"1086-1098"},"PeriodicalIF":2.2,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142248539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}