POSTER SESSION 4th Annual Meeting July 16, 2019 Hyatt Regency • Sacramento, California USA POSTER SESSION 4:00 p.m. to 6:00 p.m., Tuesday, July 16

presenter: Guihua Chen describe, and illustrate by a limited example, the concepts and assessment of soil’s capacity POSTER 1 measured through its capability, and condition as contributors to an overall soil security framework. The links to other notions such as threats to soil and soil functions are made. California Healthy Soils Program: Promoting Adoption 1 1 2 of Conservation Agricultural Management Practices on Authors: Alex McBratney , Damien Field , Cristine Morgan California Agricultural Lands Affiliations: 1) The University of Sydney, School of Life and Environmental Sciences & Sydney Research Description: Institute of Agriculture, NSW, Australia; 2) Soil Health Institute California is the national leader in agricultural production and exports. Among 100 million acres of California land, about 40% is used for agriculture. Conventional management practices presenter: Alex McBratney and intensive production systems may result in soil degradation such as loss of soil organic POSTER 4 matter and biodiversity, nutrient depletion, and salinity. Healthy soils are crucial to support agricultural production, increase resilience to natural disasters such as drought and pests, Tea-Bag Index: A Method for Promoting Soil Health and and maintain sustainability in the long term. Healthy soils also play a key role in mitigating Security in Schools greenhouse gas (GHGs) emissions through carbon sequestration. Research Description: California Department of Food and Agriculture leads the Healthy Soils Program (HSP) that Soil organic matter (SOM) is critical for soil health. However, the SOM quality is variable stems from California Healthy Soils Initiative (HSI), a collaboration of state agencies and and indicates its potential for long-term storage. This quality can be defined as a balance departments that promotes the development of healthy soils on California’s farms and between the rate of SOM formation and its stabilization and these both are controlled by ranchlands. The program has two components: Incentives Program and Demonstration Projects the soil environment. The tea bag index (TBI) method makes estimates of the breakdown of a that aim to build soil organic carbon and reduce atmospheric GHGs by (1) providing financial newly introduced organic substrate which is a function of biological and chemical activity and incentives to California growers and ranchers for implementing conservation management physical condition. By using two substrates (two kinds of tea leaves) with different degrees practices that sequester carbon, reduce GHGs and improve soil health, (2) funding on-farm of recalcitrance an assessment of the soil’s SOM stabilization (S) and rate of decomposition demonstration projects that showcase conservation management practices that mitigate GHG (k) can be made in a few weeks. The k and S values have shown to be meaningful indicators emissions and increase soil health, and (3) creating a platform promoting widespread adoption to characterize and compare carbon decomposition dynamics between different soil types and of conservation management practices throughout the state. conditions. The simplicity and cost-effectiveness of the method make it suitable for educational In 2017, the program received $7.5 million from California Climate Investments to fund purposes. We have been using the method as a way of introducing High School students 100 projects on about 7,200 acres of agricultural lands to implement various conservation to the soil, soil functioning, condition, health and security. We have engaged approximately management practices to improve soil health. The estimated reduction in atmospheric GHGs 2,000 students for applying TBI alongside field decomposition experiments. They are providing from implementing these projects is around 14,300 MT CO2 equivalent per year. The program a contribution in comparing decomposition rates and stabilization between different soil will continue funding more agricultural lands to improve statewide soil health. ecosystems leading to new insights into the health and quality of those Australian soils. The poster outlines the method, rollout and some early results, as well as an assessment of the Author: Guihua Chen impacts on High School students into the concepts of soil health and security. Affiliation: California Department of Food and Agriculture Authors: Alex McBratney, Vanessa Pino Affiliations: The University of Sydney, School of Life and Environmental Sciences & Sydney presenter: William Salas Institute of Agriculture, NSW, Australia POSTER 2

Mapping the Adoption of Conservation Practices and presenter: Jae E. Yang Associated Soil Health Outcomes Across The Corn Belt POSTER 5 Research Description: Integrated Web-GIS Portal System for Management of Soil Management decisions made by growers - including those around tillage, cover cropping, and Ecosystem Services and Threats crop rotations - can affect soil health and environmental outcomes. In this project, we map Research Description: changes in adoption rates of no-till, cover cropping, and crop rotations across Land Resource Region M (the corn belt) between 2005 and 2017, and then use a modeling approach to Soil health is one of the key components of the ecosystem services that provide various investigate soil health and environmental outcomes associated with changes in these adoption benefits to humanity and environment. The sustainable soil management should consider the rates. The Operational Tillage Information System (OpTIS), a satellite-based system for ways how to enhance the soil ecosystem services and how to minimize the soil threats. We mapping tillage practices and cover cropping, is combined with DeNitrification DeComposition have developed the WEB GIS-based portal system as a tool for soil management by integrating (DNDC), a soil biogeochemical model, to extract and combine details of practice adoption and both ecosystem services and soil erosion (threats). The system uses various big datasets such associated outcomes region-by-region through time. Preliminary results indicate significant as those that give soil properties, climate, hydrology, topography, and land uses. Through the increases in cover crop adoption in many areas in the corn belt and suggest beneficial soil portal system, soil health (quality) and erosion can be predicted, and soil ecosystem services health outcomes. can be assessed based on soil function indicators, such as biomass production, groundwater recharge, biodiversity and organic carbon storage. Both soil ecosystem services and soil Authors: William A. Salas1, Stephen C. Hagen1, Ian R. Cooke2, Justin Fisk1, Peter Ingraham1, erosion are integrated to designate the priority areas for soil conservation. Soil conservation Grace Delgado2, David Gustafson3, Pipa Elias4 planning can be formulated using the specific best management practices (BMP) at designated Affiliations: 1) Applied Geosolutions, 2) Dagan, Inc., 3) CTIC, 4) TNC areas, followed by the assessment of BMP effects on soil erosion and ecosystem services. The system suggests the framework for policy makers to develop a strategy and policy for soil conservation to enhance soil ecosystem services and minimize soil threats. We will presenter: Alex McBratney also introduce in this poster presentation about the recent research projects to advance the POSTER 3 prediction technology for monitoring the changes of soil ecosystem services and threats. On Soil Capability, Capacity and Condition Authors: Jae Yang, K.J. Lim, S.C. Kim, H.S. Kim and S.P. Lee Research Description: Affiliation: Department of Biological Environment, Kangwon National University, Chuncheon, There are several approaches to what soil can do functionally for humanity and/or the Korea ecosystem. Sometimes this is called soil capability, sometimes soil quality or soil health. We

2 POSTER SESSION 4:00 p.m. to 6:00 p.m., Tuesday, July 16

presenter: Jennifer Moore-Kucera Authors: Katherine A. Dynarski1,2, Deborah Bossio2, Kate M. Scow1 POSTER 6 Affiliations: 1) UC Davis Department of Land, Air, and Water Resources, 2) The Nature Agricultural Policy and Practices to Support USCA Conservancy States’ Climate Mitigation Goals

Research Description: presenter: Eric Bendfeldt The US Climate Alliance (USCA) is comprised of 24 member states, who have each committed POSTER 8 to implementing policies to advance the goals of the Paris Agreement and reduce greenhouse Promotion and Adoption of Soil Health in Virginia: The gas (GHG) emissions by at least 26-28 percent below 2005 levels by 2025. As part of their Power of a Simple Demonstration and Story participation in the USCA, states are investigating opportunities to reduce GHG emissions and sequester carbon through their natural and working lands, of which agriculture plays a key Research Description: role. Alliance states have requested more information on a number of agricultural policy and Soil is a foundational resource for farming, natural resource conservation, and health in the practice topics including: what agricultural policies and programs exist in USCA states (and at 21st century, particularly in relation to Virginia’s water quality improvement and restoration the federal level) to reduce GHGs and sequester carbon; how have states been successful in efforts in the Chesapeake Bay region. Finding common ground can often be difficult within the implementing and financing these programs and policies; which agricultural practices have the farming community when people come from diverse backgrounds, have specific philosophic greatest potential for large scale reductions; and what are the most effective approaches to perspectives or passionate viewpoints on how soils are to be managed. An educational need estimate the agriculture offset potential in their states. for Extension educators, USDA professionals, and mentor farmer-leaders was identified to Objective: Our goals are to 1) synthesize a policy analysis for each member state; increase peer-to-peer learning and training around core soil health principles through simple and 2) identify priority agriculture practices that reduce GHG and sequester carbon. classroom and on-farm demonstrations, case studies, and testimonials of innovative farmers. Collectively, the most effective policies and programs to accelerate adoption of those A key educational strategy collaboratively used by Virginia Cooperative Extension, Virginia practices will be identified and presented to states through an interactive website. USDA-NRCS, and collaborators of an emerging Virginia Soil Health Coalition was to use the Approach: Research and compile data on state policy programs and policies, conduct power of a simple demonstration (i.e., slake test, rainfall simulation, side by side on-farm interviews with state agricultural teams, and synthesize research literature on agricultural field test, etc.) or a simple story in a farmer’s own words to encourage the adoption of soil practices and systems targeting offensive (mitigation) and defensive (adaptation) strategies. health principles and help people find common ground in Virginia. From December 2015 to July 2017, face-to-face soil health instruction reached over 1,500 people including Extension/ Results: To date, 20 of the 24 member state policy profiles have been completed and 10 USDA professionals and mentor farmer-leaders. On-farm rainfall simulator demonstrations state team interviews have been conducted. Initial results have identified several programs were part of this instruction. A rainfall simulator demonstration was conducted as part of the that specifically support carbon sequestration and/or reduce GHG emissions in agriculture; Shenandoah Valley Produce Auction’s Season-End Members Meeting in October 2016 and multiple programs address co-benefits such as improved water quality and on-farm energy reached 120 farmers and their families -- women, youth, and children who are also stewards generation. Additionally, every state profile shows some sort of farmland preservation policy. of farmland and market and family gardens. Educational programming and outreach included The presentation will highlight these and additional existing and proposed policies and 23 training events, which accounted for 45+ hours of soil health instruction. The story and programs from USCA states and provide an overview of key agronomic practices targeting testimonial-based educational outreach method using 11 short videos and technical clips climate mitigation, resiliency, and farm and ranch land viability. We aim to inspire discussion resulted in 16,484 online views. These simple demonstrations and stories also resulted in and dialogue on how best to advance state and federal efforts to combat and adapt to climate cooperating farmers changing cropping rotations, gaining an understanding of different change, and ensure agriculture realizes its potential as an essential and significant element no-till farming options (e.g., rolling and crimping cover crops), minimizing soil disturbance, of these efforts. peers finding common ground, and more peer-to-peer conversations on how to build soil The US Climate Alliance (USCA) is comprised of 24 member states, who have each committed health. Virginia Cooperative Extension, Virginia USDA-NRCS, and educational collaborators to implementing policies to advance the goals of the Paris Agreement and reduce greenhouse continue to recognize the power of a simple demonstration or a simple story for encouraging gas (GHG) emissions by at least 26-28 percent below 2005 levels by 2025. the adoption of core soil health principles in their educational programming and an integral Authors: Jennifer Moore-Kucera1, Jimmy Daukas1, Thayer Tomlinson2, Anna Harmon2 outreach method for complementing ongoing soil health research. Affiliations: 1) American Farmland Trust, 2) Coalition on Agricultural Greenhouse Gases Authors: Eric S. Bendfeldt, Chris Lawrence, Wade Thomason, Ph.D., Kim Niewolny, Ph.D. Affiliations: Virginia Tech, Virginia Cooperative Extension and Virginia USDA-Natural Resources Conservation Service Research presenter: Katherine Dynarski POSTER 7 presenter: R. Shange Dynamic Stability: Building Soil Carbon for Soil Health POSTER 9 and Climate Change Mitigation Research Description: Integrated Research and Extension in the Alabama Black Belt in Relation to Soil Health Response to Land Use Increasing carbon (C) sequestration in agricultural soils is a “win-win” pathway for mitigating Management climate change, because management practices that promote C sequestration are also proposed to improve food security and reduce chemical fertilizer needs through restoration Research Description: of soil organic matter. However, uncertainty surrounding the permanence of intentionally Tuskegee University Cooperative Extension Program has had the objective of communicating sequestered C in agricultural soils presents a significant barrier to wide-scale investment in updated scientific information that promoted soil health. As researchers utilize updated soil C sequestration projects. This uncertainty is due to both a currently evolving scientific methods in molecular biology and biochemistry for soil health research, the Extension program understanding of how (and for how long) C is stored in soils and a mismatch in definitions seeks to communicate those results in such a way that may help current stakeholders. The and ideas about soil C permanence between soil scientists and policymakers. To harmonize studies presented here are those that show the collaboration between Research and Extension these two sectors and provide a way forward for long-term C sequestration in agricultural in soil health to further that mission. Studies utilized molecular and biochemical methods in soils, we synthesized the scientific literature focused on the permanence of soil C. We show addition to traditional soil methods to assess differences in soil health between pastures, that enhancing long-term C sequestration while building soil health relies on robust below- forest, and cropland as well as within each land use type. Results revealed that the molecular ground biological C cycling and microbial processing of organic matter. The most effective and biochemical methods were good indicators of soil health, and also provided more management strategies for building soil C are therefore those that support and maintain the information regarding the ecology of the ecosystem. Demonstrations, field days, and one-on- dynamic soil ecosystem. one consultations have been effective in sharing the results and recommendations with land

3 POSTER SESSION 4:00 p.m. to 6:00 p.m., Tuesday, July 16

managers and landowners. As a result, more direct methods are being developed to enhance corn cropping. We examine field-level rotational complexity and its drivers in the Central discussion of updated scientific information with land managers and landowners. U.S., including soil inherent quality, distance to grain elevators, distance to biofuel plants, Authors: R.Shange, R.O. Ankumah, A. Kumi, S. Karki, D. Stone, S. McKoy, A. Howard and precipitation, using the USDA’s cropland data layer to define a metric of crop rotational complexity at a resolution of 150 x 150m. We find a significant negative correlation (p < 0.01) Affiliations: Tuskegee University between inherent soil quality (operationalized as SSURGO’s NCCPI) and rotational complexity using generalized additive mixed models to account for spatial autocorrelation in the data. presenter: Dianna Bagnall High-quality soils in the region may become increasingly degraded, as declines in rotational complexity are more prevalent in soils with the highest inherent quality, likely due to their POSTER 10 ability to tolerate the degradative effects of corn monocultures in the short term. Supporting Investigating Soil Health and Stakeholder Motivations in soil health requires a shift from defining indicators to tackling the structural factors that the Texas Blackland Prairies undermine farmers’ ability to apply all principles of soil health management. Research Description: Authors: Yvonne Socolar, Benjamin R Goldstein, Perry de Valpine, Timothy M Bowles In Texas’ Brazos River watershed, poor soil management causes nutrient leaching from Affiliations: Department of Environmental Science, Policy, and Management, University of farmland, sedimentation, and increased runoff. Conservation practices such as no-till can help, California, Berkeley but adoption rates are low. A transdisciplinary team that integrates soil science, hydrology, economics, and sociology is combing field measurement, modeling, and socio-economic analyses to develop protocols to measure soil processes, value soil ecosystem services, and presenter: Zahangir Kabir develop communication strategies with stakeholders to incentivize improved soil management. POSTER 12 This shows how improved soil heath can benefit dryland farmers who depend on capture and storage of rainfall for their existence, and down-stream stakeholders in the region. Expanding Soil Health Practices Across California Landscapes In both soil and social science, the team is working from the ground up by taking measurements directly in farmers’ fields and conducting interviews that let farmer’s needs and language drive Research Description: potential solutions. The team’s research works and findings include: The four soil health principles: i) minimize soil disturbance, ii) maximize diversity, iii) maximize Soils and Hydrology presence of living roots and iv) maximize soil cover plants and residues can be generally used in all production systems to improve how soils function. However, the specific practices chosen • Novel aggregate stability and soil structure measurements quantified differences in soil to implement the principles must be adapted to each production system, climate, ecosystem, function between conventional tillage and no-till. This forms the foundation for including and soil to effectively build and maintain healthy, functioning soil. This poster is designed soil structure and the effects of tillage in hydrology models. to help people in the field of soil conservation visualize plant communities and ecosystems • Hydrology models allow changes in management practices to be translated to a metric in different landscapes across a generalized cross-section of California’s diverse landscapes, that is clearly and directly valuable to land managers soil water. including annual and perennial crops, rangelands and forests. This is an interactive poster Understanding drivers of no-till adoption where the attendees of the conference will be invited to add their ideas in five categories: i) natural processes, ii) opportunities, iii) human factors, iv) barriers and v) tools that are involved • Interviews with farmers led to a model for the decision to adopt no-till. Survey data, in the field of soil health in a specific area of interest. We propose that this concept can be which is currently being collected, will distinguish which soil, social, and economic drivers useful for visualizing the range of soil heath practices or issues across diverse landscapes, of no-till adoption are most motivating to farmers. at many scales and settings. This visualization tool can be implemented using cross-sections Impact of soil health on down-stream stakeholders of other states, or any land area. It helps to initiate conversations around soil health, engage • Economic models indicate anglers have a positive willingness to pay for water quality a broad audience and allows individuals to interact at their own pace. Information gathered related to soil health, opening up opportunities for stakeholder support of soil health can then be used to guide further local or regional soil health efforts such as management adoption. decisions, regional strategic planning and prioritization, identifying training opportunities, or addressing of knowledge gaps in the field. • An upcoming survey will quantify the economic value that farmers place on improvements in soil health indictors such as organic matter, compaction, and infiltration. Authors: Zahangir Kabir, Jennifer Wood, Steve Hill This ongoing work is enhancing dialogue among farmers, watershed stakeholders, and Affiliations: USDA-NRCS scientists and quantifying the advantages of soil health for both producers and society. Authors: Dianna K. Bagnall1, Cristine L.S. Morgan1,5, Richard T. Woodward2, Wm. Alex presenter: Wendiam Sawadgo 3 4 2 4 McIntosh , Srinivasulu Ale , Michael Black , and Sayantan Samanta POSTER 13 Affiliations: 1) Department of Soil and Crop Sciences, Texas A&M University, 2) Department What Drives Landowners’ Conservation Decisions? of Agricultural Economics, Texas A&M University, 3) Department of Sociology, Texas A&M Evidence from Iowa University, 4) Department of Biological and Agricultural Engineering, Texas A&M University, 5) Soil Health Institute Research Description: Conservation practices such as no-till, cover crops, buffer strips, and sediment basins have been shown to have both on- and off-farm benefits; however, conventional wisdom suggests presenter: Yvonne Socolar adoption of conservation practices may be subdued on rented land, since the tenant may POSTER 11 undertake the costs but not reap the benefits of using the conservation practice. This is A Novel High-Resolution Spatial Analysis of Crop problematic in Iowa, where 53 percent of the state’s farmland is leased. In this study, we Temporal Diversity and Its Landscape Determinants in use data from the Iowa Farmland Ownership and Tenure Survey, a statistically representative the Central U.S.: Tradeoffs Between Soil Quality and Soil dataset of the state’s farmland, to statistically analyze how land tenure and landowner Health characteristics affect statewide conservation-practice adoption and gauge landowners’ willingness to incentivize tenants to plant cover crops. We find that land tenure may be a Research Description: potential barrier to the use of cover crops, buffer strips, and sediment basins, but not for no- Crop rotation is a fundamental practice of sustainable agricultural systems and an NRCS soil till. Moreover, over one-third of landowners state that they would be willing to encourage health principle. Yet analyses at the county level show declines in rotational complexity across their tenant to use cover crops by paying for part of the planting costs. The results of the the Central U.S. as agricultural policy and economics push farmers toward more frequent study suggest that reaching out to both landowners and farm operators may be necessary to

4 POSTER SESSION 4:00 p.m. to 6:00 p.m., Tuesday, July 16

increase the state’s conservation-practice acreage. winter wheat – summer fallow system (WW-SF) due its limited rainfall, and the potential to Authors: Wendiam Sawadgo, Wendong Zhang, Alejandro Plastina store soil water in the fallow year. Soil organic matter (SOM) is central in soil health dynamics, and generally, healthy soils have more SOM than less health soil. The WW-SF is slowly losing Affiliations: Department of Economics, Iowa State University SOM even as tillage is reduced. Several long-term studies have compared crop rotation and intensity, and tillage frequency at two locations: Columbia Basin Agricultural Research Center presenter: Bill Robertson (CBARC), Pendleton, and Sherman Station, Moro, Oregon. POSTER 14 Authors: Stephen Machado and Mary Corp Evaluation of Economics and Sustainability of Cotton Affiliation: Oregon State University as Influenced by Practices to Improve Soil Health Research Description: presenter: Haly Neely Practices that lead to improved soil health can have widespread positive impacts at many POSTER 17 levels. The objective of this study was to evaluate the impact of greatly reducing tillage and Improve Outreach to Improve Soils: Combining Data, utilizing cereal rye cover crops on sustainability and profitability of cotton. The University Economics, and Communication to Improve Soil Health of Arkansas Cotton Research Verification Sustainability program has conducted research Across the South Central United States along with Discovery Farms in two fields in Southeast Arkansas in 2015-2017. Each field was composed of two irrigation sets allowing for evaluation of farmer standard practices on one Research Description: side using full tillage with no cover to that of a modified production system no-till with a cover Management practices, such as leaving the soil fallow and conventional tillage, threaten on the other side. All fields were monitored for inputs and entered into the Field to Market soil health and agriculture’s long-term sustainability. Cover crops and conservation tillage Fieldprint Calculator and used to calculate expenses and profitability. Yield on the no-till with contribute to soil health but producers face obstacles to implementation including: concerns cover increased 9.30% and was $0.05 per pound cheaper to produce than Farmer Standard over water availability and nutrient cycling, lack of identified suitable crops or cropping systems, tillage with no-cover in 2015-2017. The metrics from the Fieldprint Calculator all favored uncertainties about grain yield and biomass production, questions about on-farm economics no-till with cover. Soil conservation or erosion was reduced by 77.85% and greenhouse gas and long-term economic risk, and/or a lack of knowledge on implementing a new management emissions decreased by 11.48%. The use of practices to improve soil health in this study strategy. The objectives of this study are: 1) use research trials and on-farm demonstrations resulted in both improved profitability and sustainability. of double-cropping systems under multiple tillage methods to collect quantitative data Authors: Bill Robertson, Amanda Free, Mike Daniels, Breana Watkins on the impact of soil health management practices on soil properties and cropping system productivity; 2) use the data from research and on-farm trials, perform economic analyses Affiliations: University of Arkansas System Division of Ag Cooperative Extension Service on the effect of increasing diversity and reducing tillage on on-farm profitability and the potential for reducing long-term economic risk; and 3) develop communication messages based on producers’ preferences that are most effective in increasing implementation rates presenter: D. Huggins of soil health management practices, and evaluate their impact through producer feedback. POSTER 15 This whole-picture approach addresses the majority of the identified obstacles producers p-Nitrophenol Enzyme Activity Across Varying face when implementing soil health management practices. We are also using an innovative Managements Within Selective Precipitation double-cropping system for both research trials and on-farm demonstrations. This project will Climosequence in Semi-Arid Palouse Soils serve as a model for other regions to fine-tune their outreach efforts to encourage soil health management practices. Deliverables include soil property and crop production data, detailed Research Description: economic analyses, and communication messages and modules. We expect this project will The Palouse region of Eastern Washington and Northwestern Idaho is recognized for its vast increase implementation of soil health management practices and therefore improve soil skies and rolling hills of wheat, with grassland patches, but the soil is what really drives its health across the region. unique beauty and productivity. This study is a part of a NRCS-funded project evaluating Authors: Haly Neely1, Clark Neely1, Katie Lewis1, Jamie Foster1, Josh Lofton2, Josh Copes3, effects of agricultural management on soil health, with a defined set of in-field and laboratory Mark Welch1, Holli Leggette-Archer1 methodologies. Fall soil sampling was across a defined precipitation gradient and included a grassland site for native reference and recently harvested wheat fields, practicing either Affiliations: 1) Texas A&M University, 2) Oklahoma State University, 3) Louisiana State conventional tillage or no-till management methods. This experiment focused on soil enzymes, University a biological indicator of soil health. Enzymes are essential to the phosphorus, carbon, nitrogen and sulfur cycles, which control availability of macronutrients for uptake by plant roots and presenter: Kristen Veum sustenance for other living soil organisms. Enzymes in the soil are responsible for the rate POSTER 18 at which decomposition occurs and also stimulate microbial activity. Also included are some standard analyses that show the biogeochemical productivity and health of these Palouse Soil Health after 25 Years of Conservation Management soils, such as organic matter, soil pH, moisture content, and relative carbon and nitrogen on Claypan Soils present across varying management. Research Description: Authors: Huggins, D. Madsen, I. Naasko, K. Pan, W. Reganold, J. Sullivan, T. Tao, H. Due to the vulnerability of the Central Claypan Region, monitoring and assessment of soil Affiliation: Washington State University health is critical. The objectives of this study were (1) to compare soil health after 25 years of continuous management under 12 different perennial vegetation and annual cropping systems typically employed in this region, (2) to evaluate the sensitivity and utility of multiple soil health presenter: Mary Corp indicators across these management systems, and (3) to examine relationships among multiple POSTER 16 soil health indicators. Annual cropping systems included corn-soybean rotations with variable Small Grains Cropping System Improves Soil Health in tillage and cover crop management. Perennial vegetation systems included permanent cool- Eastern Oregon and warm-season grasses and working grasslands (i.e., hay production). Multiple biological, physical, and chemical soil health indicators were measured, including phospholipid fatty acid Research Description: profiles for microbial community structure, total organic carbon and nitrogen, β-glucosidase Soil health is vital for sustainable agricultural production and environmental quality in eastern and β-glucosaminidase enzyme activities, total protein, respiration, mineralizable nitrogen, Oregon wheat focused rain-fed system. The semi-arid region predominantly uses a traditional active carbon, pH, extractable P and K, bulk density, aggregate stability, and particle size.

5 POSTER SESSION 4:00 p.m. to 6:00 p.m., Tuesday, July 16

Results of this study are expected to demonstrate the strong influence of vegetative cover potential to increase water and nitrogen use efficiency, improve soil microbial properties and and living roots on surface soil health, and emphasize the importance of diversified cropping soil structure, reduce leaching potential, store carbon, and decrease the overall environmental systems that reduce soil disturbance and maximize soil cover. footprint of agricultural productions – all whilst maintaining or improving yields. Perennial Authors: Kristen Veum, Newell Kitchen, Ken Sudduth cropping systems present large opportunities to improve soil health, yet past research has predominately focused on annual cropping systems. In addition, production-maximizing Affiliation: USDA-ARS strategies have resulted in perennial orchard systems with highly degraded soils and an undefined potential for soil health management to support soil services. We aim to address the presenter: P. Mubvumba knowledge gaps about the relationships between perennial management practices, soil health, and soil service potential by fostering an active collaboration between researchers across POSTER 19 the University of California system and almond growers. The almond industry, in particular, Soil Health Indicators in Long-Term Conservation has made significant strides towards more sustainable productions like improving water use Systems in Semi-Arid Regions of Texas efficiency, yet orchards frequently exhibit extremely compacted and degraded soils that result Research Description: in decreased infiltration and water storage. We are using an on-farm survey approach in 15 almond orchards that represent a gradient of management practices, from bare soil to fully As interest in soil health management continues to increase, so does the need for consistent, ecologically intensified systems, that are currently used by almond growers in Yolo county. replicable, scientifically sound indicators and associated data that will allow for the Analyses of soil and tree samples as well as management history will allow us to create assessment of how agricultural management practices are affecting soil health over time. benchmarks of soil health and outreach material to help guide soil management decision- In semi-arid regions of Texas, research has shown that soil organic C, a standard soil health making. As orchards become more ubiquitous across California’s agricultural landscape, indicator, has shown little or no change over the long-term while other soil properties have there is a critical need to reconsider orchard floors as living and dynamic ecosystems. Soil been greatly impacted in the short-term. As part of the NRCS coordinated project Dynamic health management practices, as well as the principles that shift our perspectives about the Soil Properties for Soil Health Assessment, we evaluated the effects of various long-term importance of soil in agricultural productions, will be an invaluable tool for ensuring that management practices on soil properties and soil function. Three management practices were orchard systems can support environmental health and provide sustainably and productively quantified on a Pullman clay loam soil: 1) native grassland; 2) no-till row cropping; and 3) into the future. conventional tillage row cropping. Soil physical, chemical, and biological properties were quantified for each scenario. Initial results have shown mixed results among various measured Authors: Krista Marshall1, Katherine Jarvis-Shean4, Timothy Bowles2, Jorge Rodrigues3, properties. We have also found that time of year can have a profound effect on biological Amanda Hodson5, Amélie C.M. Gaudin1 components. We will provide complete details during our presentation. Affiliations: 1) Department of Plant Sciences, University of California – Davis, 2) Department Authors: P. Mubvumba1, P.B. DeLaune1, K.L Lewis, R.L. Baumhardt2 of Environmental Science, Policy, and Management, University of California – Berkeley, 3) Department of Land, Air, and Water Resources, University of California – Davis, 4) University Affiliations: 1) Texas A&M AgriLife Research, 2) USDA-ARS of California Agriculture and Natural Resources, Cooperative Extension, 5) Department of Entomology and Nematology, University of California – Davis presenter: Nathan Jones POSTER 20 presenter: Skye Wills Dynamic Soil Properties: Biopsies of the Soil in Beadle POSTER 22 County, SD Dynamic Soil Properties for Soil Health Assessment: Research Description: Coordinating a National Project Dynamic Soil Properties (DSPs) are information on physical, chemical, and biological soil Research Description: properties gathered from various contrasting side-by-side management situations, e.g., no-till and tilled cropland, minimal and intensively grazed rangeland, etc., to enable an Producers and land managers need guidance on using quantitative and qualitative field and understanding of the impacts the management systems can have on soil properties across laboratory metrics to assess soil health. The NRCS soil survey provides limited interpretations South Dakota. The DSPs therefore aids in making better informed decisions regarding these of soil properties as they relate to soil health but doesn’t provide reference or benchmarks long-term management practices. In Beadle County SD, Houdek soil, fine-loamy glacial till, for most soil health metrics. Concurrent efforts by NRCS and other groups recommended was evaluated under two conventional till and two no-till systems. The no-till systems had a set of laboratory methods to standardize procedures across the United States. To bridge cover crops incorporated into the cropping system, while one conventional tilled site had soil health assessment and soil survey products, the Soil and Plant Science Division of manure added. Overall, there were visual differences between the DSP locations when NRCS is coordinating a project called Dynamic Soil Properties for Soil Health Assessment comparing a no-till that had cover crops in the rotation vs a conventionally tilled field. In as part of a broader Science of Soil Health Initiative. The project consists of nine individual the conventional till site with manure applications, the manure played a role in DSPs. When cooperative agreements with common protocols and procedures. The projects combine manure was added to the conventionally tilled site, the DSPs were similar to the no-till sites field assessment, laboratory techniques and characterizations for locally important soils with cover crops. Re-evaluations of these sites after 10 years would further provide better and land management systems. Results to date, including difficulties in replicating study understanding of the influence that manure and cover crops can have on DSPs. design, standardizing laboratory protocols, and database development will be discussed. The data will be incorporated into soil survey databases and products with the ultimate goal of Authors: Nathan Jones, Carrie Werkmeister, Kent Vlieger, Andy Oxford, Matti Osterman, Jeff enhanced soil health information that can be used to make interpretations and management Hemenway recommendations. Affiliation: USDA-NRCS Authors: Skye Wills, Michael Robotham Affiliation: USDA-NRCS, Soil and Plant Science Division presenter: Krista Marshall POSTER 21 Managing for Soil Health: Targets and Soil Service Potential in Almond Orchards Research Description: Healthy soils support and regulate the essential functions that ultimately control the provisional capacity of our agroecosystems. Incorporating soil health into management has the

6 POSTER SESSION 4:00 p.m. to 6:00 p.m., Tuesday, July 16

presenter: Sarah E. Hetrick growers to monitor soil health and the impact of management. POSTER 23 Authors: Doug Miller, Daniel Davidson Diving Deep: A Soil-Sensing Probe for Clay, Carbon, and Affiliations: 1) MidWest Bio-Tech, 2) Woods End Laboratories Bulk Density Measurement Research Description: presenter: Bradley Crookston As demands for fine resolution soil mapping increases, there is a growing need for improved POSTER 26 instrumentation for sensing changes throughout soils both horizontally (across the surface) Relationships Among Soil Health Assessments, and vertically (towards the Earth’s center). A VisNIR Penetrometer is a vertical, diving Indicators, Management, Environment and Yield proximal sensor that is being developed to sense changes with soil depth with minimal soil Research Description: disturbance. By utilizing many pre-existing national spectral libraries of dried ground soils, locally-collected soil spectra in addition to previously collected intact and moist soil spectra, Soil health assessments (SHAs) estimate a soil’s health by scoring various combinations of soil the VisNIR Penetrometer has the ability to sense fine resolution changes in clay content, biological, chemical, and physical attributes and aggregate them into a single unitless score in organic carbon content, and bulk density content. With improved and continued modeling, the order to guide farmers in decision-making that would improve soil health. Several SHAs exist, VISNIR Penetrometer has the potential to aid in soil mapping efforts by providing rapid and but there are few large-scale evaluations of their ability to predict relationships among soil cost-effective soil profile characterization. health indicators and crop yield. The objectives of this study were to: 1) determine correlations Authors: Sarah E. Hetrick1, Cristine L. S. Morgan2, Jason P. Ackerson3, Nuwan K. Wijewardane4, among four SHA scoring models and between scoring models and crop yield and 2) evaluate Yufeng Ge4 relationships among site management, environment, soil health indicators and yield. Soil health indicators were tested, and scores were calculated at Soil Health Partnership sites Affiliations: 1) Texas A&M University, 2) Soil Health Institute, 3) Purdue University, 4) University across the Midwest. Results suggest that aggregated scores alone are not strong predictors of Nebraska-Lincoln of yield, however, site parameters in addition to soil health indicators were found to improve yield simulation. presenter: J. McEntire Authors: Bradley Crookston, Matt Yost, Jack Cornell, Kristen Veum POSTER 24 Affiliations: Utah State University; Soil Health Partnership; USDA-ARS Making Precision Agriculture a Reality through Machine Learning presenter: Verónica Acosta-Martínez Research Description: POSTER 27 The AR1K Smart Farm Consortium manages a highly instrumented one-thousand-acre field Simultaneous Determination of ß-glucosidase, lab in Arkansas (https://ar1k.org). We aim to dramatically enhance the sustainability of ß-glucosaminidase, Acid Phosphomonoesterase, and industrial agriculture by helping farmers to reduce their reliance on chemical inputs, and to Arylsulfatase in a Soil Sample for a Biogeochemical transform managed lands into engines for improving soil health. We use a densely integrated Cycling Index network of in situ and remote sensors, along with extensive soil testing data to discover Research Description: the limiting factors for yield meter-by-meter. We map response surfaces associated with macro and micronutrients, as well as other aspects of soil chemistry, to optimize return-on- Four enzymes activities (EAs) have been targeted as soil health indicators for their important investment and reduce risks. In year three of our consortium, we have developed a third-wave role in C (ß-glucosidase), N (ß-glucosaminidase), P (acid phosphomonoesterase) and S AI framework for inference and mechanistic analysis that has revealed nonlinear dependence (arylsulfatase) cycling. Although these EAs can be measured in air-dried soil following the of yield on high-order functions of soil nutrient levels and chemistry. Our models validate on same approach (detection of released p-nitrophenol after 1hr incubation at 37C), the current held-out data, and are aware of their own competencies — enabling uncertainty quantification protocol is time consuming as each EA is measured independently. Thus, we developed an and therefore actuarial analysis in surrogate models. These technologies are now sufficiently approach for simultaneous determination of the four EAs in the same soil sample. Soils with mature and data-type-agnostic to apply to far less instrumented field sites. We discuss the a wide range in organic C (4–44 g C kg-1 soil) were used to provide an approach that can be insights obtained and methods developed in the first two years of our consortium. used across regions. Our combined assay that will be referred to as “CNPS activity”, showed positive significant (p < 0.001) correlations with the sum of the individual EAs (r = 0.97) and Authors: Ben Brown, Jay McEntire, John McEntire with soil organic C (r = 0.94) and total nitrogen (r = 0.93). The CNPS activity distinguished Affiliation: AR1K.org, Arva Intelligence, Lawrence Berkeley National Laboratory among diverse agroecosystems similarly to the sum of the individual EAs for Minnesota soils (corn-soybean = grass < rotation), and for Texas soils (continuous cotton < grass < Conservation Reserve Program). The combined assay for CNPS activity will reduce time, resources and presenter: Daniel Davidson chemical waste than assaying the EAs individually, while generating a single index of soil POSTER 25 organic matter dynamics and biogeochemical cycling potential across regions. Evaluating Soil Health of Different Landscapes Using Commercially Authors: Verónica Acosta-Martínez1, Lumarie Pérez-Guzmán1, and Jane M.F. Johnson2 Available Soil Health Methods Affiliations: 1) USDA-ARS, Cropping Systems Research Laboratory, Wind Erosion and Water Research Description: Conservation Unit, Lubbock, Texas, 2) USDA-ARS, North Central Soil Conservation Research Describing soil health can be a challenge and selecting the right tools to measure health Laboratory can be confusing. The objective was to understand what soil health measurements best characterized the health of different fields based on differences in landscape, production presenter: Sean Bloszies history and management. The approach was to select six fields that differed in history and tilth and included cool-season pasture, permanent grassland, alfalfa, and three cropped fields POSTER 28 that differed visually in tilth. Measurements included the Solvita soil respiration, soil labile A Comparison of Soil Health Indicators and Water amino-nitrogen (SLAN) mineralization, microaggregate stability, Haney Soil Health Test and Quality Measurements in the Mississippi Watershed associated score, and phospholipid fatty acid (PLFA) test. Results showed that each of the above tests ranked fields similarly in soil health. In addition, tests suggest why some fields Research Description: were healthier than others and why long-term management practices play a key role. The The Mississippi River and Gulf of Mexico suffer from multiple contaminants lost from high findings suggest that a short list of soil health measurements can effectively be used by input row crop fields to tile drainage, ditches, and streams. While much work has been

7 POSTER SESSION 4:00 p.m. to 6:00 p.m., Tuesday, July 16

done to understand the impact of specific practices on such losses, the links between soil Authors: Stacy M. Zuber1, Eileen J. Kladivko2 health and water quality have received less attention. We analyzed soil samples from four Affiliations: 1) University of Missouri-Columbia, 2) Purdue University paired field water quality monitoring experiments in the Mississippi River Basin for chemical, biological, and physical properties including total carbon (TC), potentially mineralizable N presenter: Matt Yost (PMN) field saturated hydraulic conductivity (Kf), and compaction index. These experiments were established to test for the effects of planting cover crops, reducing tillage, or perennial POSTER 31 rotation, all practices that have been shown to enhance soil health. Differences were found Soil Health Indicators Aid Maize Nitrogen Management between fields’ soils in terms of TC, fK , and compaction index, and between field’s edge of field dissolved reactive phosphorus (DRP) drain tile loads and drain tile discharge depth. In Research Description: Caraway, Arkansas, higher compaction index was not met by a difference in any of the runoff Few soil health indicators or tests have been directly utilized for management decisions. A parameters, but abandoning cover crop planting did increase NO -N loads. In Ft. Recovery, OH, 3 prominent and recent example is using soil biological tests for estimating soil N availability transitioning to alfalfa from a corn-soy rotation decreased runoff depth, runoff total N loads, and subsequently corn fertilizer N recommendations. One objective of this research was to and runoff DRP loads. Total carbon and drain tile discharge depth were also higher in the field evaluate relationships between the Soil Health Nutrient Tool (SHNT), also known as the Soil where alfalfa was planted during the treatment phase. This study documents the importance Health Tool or Haney test, and the economically optimum N rate (EONR) for corn grain yield at of management impacts in determining nutrient and runoff losses. Differences in soil variables 17 sites in eight Midwest US states in 2016. Another was to explore whether the abundance were not consistently matched by differences in edge of field losses. and diversity of soil microorganism genetics could help predict corn N need at 3 sites in Author: Sean Bloszies Missouri. Results indicated that rapid soil respiration were well correlated to EONR, but that Affiliation: Soil Health Institute soil genetics provided few clues for improving corn N management. Therefore, soil biological properties could help improve N stewardship. Authors: Matt Yost1, Newell Kitchen2, Brad Geary3, Kristen Veum2 presenter: Gloria Ambrowiak Affiliations: 1) Utah State University, 2) USDA-ARS, 3) Brigham Young University POSTER 29 Building a Soil Health Database for Oregon presenter: Radomir Schmidt Research Description: POSTER 32 We have created a database that contains soil health data for over 300 samples from Functional Differences in Soil Microbial Community agricultural regions in Oregon. Soil health information is most valuable when evaluated across Composition Under Organic and Conventional time intervals and between growing regions or management systems. We chose the software Management Microsoft Access as the user interface with our repository of soil health datasets. Soil health data were arranged such that each individual data set contained the three elements: (i) soil Research Description: data; (ii) site information (geographic) and (iii) management information. Rules for scoring and Linking soil management outcomes to microbial community function is fundamental to efforts binning were added and the database was designed using SQL and VBA languages such that aimed at refining farming systems to promote healthy soils. In order to study temporal and these rules can be dynamically modified. Currently, the database can perform queries based management-induced changes in microbial communities over the course of a growing season, on soil texture, geographic location, and management history. While our data repository is we used high-throughput 16S rRNA gene sequencing to analyze samples from organic and still of limited size, we are already able to run queries that reveal important trends in soil conventionally-managed tomato (Solanum lycopersicum) plots at the Russell Ranch long term health indicators, for instance we can easily investigate relationships between indicators research facility in Davis, CA. We used the Faprotax package to assign functional traits to of soil health (organic matter content of the soil, available water holding capacity, etc.) and the resulting sequence data. Long-term organic management fostered microbial communities management information. With sufficient data, scoring rules and functions can be investigated with greater resistance to seasonal disturbances, as well as potentially greater resistance and optimized for maximum resolution, thereby enabling robust health assessments in regions to intracellular and extracellular parasites and pathogens. Soil microbial communities also as diverse as the green Willamette Valley and semiarid Central Oregon. differed in the relative representation of specific groups involved in carbon and nitrogen Authors: Gloria Ambrowiak, Drew Childs, Markus Kleber cycling: organically managed soils were enriched for total chemoheterotrophs, including fermenters, chitinolytic and cellulolytic microbes, as well as ureolyitic and nitrate reducing Affiliation: Oregon State University organisms, while conventional soils were enriched for hydrocarbon degraders and nitrifiers. These functional differences advance our understanding of the microbial underpinnings of carbon storage dynamics central to healthy soil management. presenter: Stacy M. Zuber POSTER 30 Authors: Radomir Schmidt, Evan Dumas, Kelly Gravuer, Kate Scow Trends and Relationships among Soil Health Indicators Affiliation: LAWR Department, University of California, Davis from On-Farm Research in Indiana Research Description: presenter: Janina Milkereit Currently available commercial soil health tests are comprised of many different soil health POSTER 33 indicators. With the cost of many of these tests being relatively high, it is important to Optimizing Soil Carbon Management in California understand the relationships among these measurements and the possible redundancies Almonds using Organic Amendments as well as to assess changes in these tests over time under a new conservation cropping Research Description: practice. The objective of this study was to use commercial soil health tests to evaluate soil health improvements from the use of cover crops at 11 sites across Indiana. The tests included Organic amendments such as compost, biochar and food waste hydrolysate may increase soil phospholipid fatty acids (PLFA), Cornell Comprehensive Assessment of Soil Health and the health and soil organic matter but may also come at the cost of high greenhouse gas emissions Haney Soil Health Nutrient Tool, which were measured over a four-year period. We found incurred during decomposition. This study examines which organic amendments best build that, in general, most of the soil health parameters increased over the time frame in no-till soil carbon pools, stimulate soil food webs, and support plant growth while minimizing systems with and without cover crops. However, they did not increase to a greater degree with greenhouse gas emissions. In a first-year almond orchard, treatments included compost (4.46, the addition of cover crops to the long-term no-till systems. There were strong relationships 22.3 and 44.6 tons/acre), biochar (4.46, 22.3 and 44.6 tons/acre), fertilizer (82 lbs N/acre), among several soil health indicators, particularly those relating to soil carbon and the size of food hydrolysate (25, 40, and 50 gallons per acre) and untreated controls. Treatments were the microbial community as measured by PLFA. arranged in a randomized complete block design and each of the 11 treatments was replicated

8 POSTER SESSION 4:00 p.m. to 6:00 p.m., Tuesday, July 16

6 times. Our study shows that in the short term, biochar had the best soil carbon balance with presenter: Sally Landefeld fewest emissions caused and greatest soil carbon contents. Food waste hydrolysate showed POSTER 36 promising effects by stimulating greater microbial biomass, potentially contributing to the formation of stable carbon pools in soils. Effects of Soil Organic Amendments on Soil Chemistry and Nutrients (2) Authors: Janina Milkereit, Amanda K. Hodson Research Description: Affiliation: University of California, Davis Globally, soil organic matter (SOM) sequesters more carbon than all vegetation and the atmosphere combined. However, depletion of SOM due to agricultural and land management presenter: A.J. Hodson practices has depleted SOM and, consequently, soil nutrient quality. Here, we investigate the POSTER 34 effects of two types of biosolid and two types of compost soil amendments on soil chemistry and nutrient quality, in comparison with synthetic NPK fertilizer at three sites in western Influence of Recycled Olive Waste Products on Washington. These preliminary results indicate clear differences in soil chemistry based on Nematode Bioindicators and Soil Nitrogen Availability both site and soil amendment type, and that each type of soil amendment may be a valuable, Research Description: highly renewable, inexpensive method to return unique nutrients to depleted soils. Further The use of olive waste products as soil amendments can improve soil health by restoring research on individual organic matter soil amendments as well as combinations is necessary soil organic matter pools, providing nutrients, and supporting soil biological communities. The to further characterize the value and potential of these renewable, natural, and safe fertilizers. abundance of certain nematode feeding guilds provide insights into resource availability and Author: Toby Una, Norah Kates, Sally Landefeld, Sally Brown, David Butman food web complexity, making them useful bioindicators of soil health. We measured free- Affiliations: University of Washington, National Science Foundation living nematode communities and nitrogen availability in a completely randomized incubation experiment evaluating two different olive pomace composts (8 tons/acre) and raw olive pomace (8 tons/acre), comparing them to fertilizer (270 lbs N/acre) and untreated controls. presenter: Erin Manaigo Nematode community composition significantly differed between soil amendment treatments, POSTER 37 and raw olive pomace increased numbers of bacterial and fungal feeding nematodes, Compost, Biochar, and Basalt: Combining Technologies to Catalyze suggesting nutrient processing. While fertilizer treatments had higher nitrogen availability in Negative Emissions in Agriculture the beginning of the study, organic amendments exceeded nitrogen availability from fertilizer after 12 weeks, suggesting overall benefits of olive waste amendments for soil health and Research Description: nutrient availability. The Working Lands Center, California Collaborative for Climate Change Solutions, and the John Authors: Hodson, A.K., Milkereit, J. Muir Institute have put together a team of scientists, tribes, and stakeholders to take on the challenge reducing agriculture’s contribution to greenhouse gas emissions while producing Affiliation: Department of Entomology and Nematology, University of California, Davis co-benefits for growers and soil health. We will deploy a suite of soil amendments to decipher potential pathways to sustain GHG emissions reductions, while improving crop yields and presenter: Sally Landefeld soil health indicators. Beginning fall 2019, we will apply biochar, compost, and enhanced POSTER 35 weathering of basalt, singularly and in combination (compost+biochar, biochar+basalt, compost+basalt, compost+biochar+basalt) to 6-acre plots in 3 land management regimes: Effects of Organic Soil Amendments on Soil Chemistry cropland, rangeland, and almond orchard. This project aims to further our understanding of and Nutrients (I) (1) soil health impacts of these amendment technologies alone and in combination, (2) their Research Description: CO2 drawdown potential, and their ramifications in California’s Cap and Trade Market, and (4) evaluate the lifecycle of each amendment technology in terms of CO2 emissions equivalent Organic soil amendments present an effective method to increase soil organic carbon (SOC) from mine or production, through transport, application, and harvest. while replenishing critical soil nutrients, thereby improving soil chemical properties and overall soil health while reducing synthetic chemical inputs that are harmful to ecosystem balance Authors: Erin Manaigo1; Ben Houlton1; Whendee Silver2 and human health. Biosolids and food waste composts are highly renewable, available, and Affiliations: 1) UC Davis, 2) UC Berkeley economic forms of organic soil amendments, are safe to use for food production, and have UC Merced, UC Davis John Muir Institute of the Environment, Working Lands Innovation the capacity to fortify soils with a full suite of macro- and micronutrients required for optimal Center, California Collaborative for Climate Change Solutions soil health and crop production. This analysis explores the effect of two types of biosolid soil amendments (TAGRO, GroCo) and two types of composted food waste soil amendments

(vermicompost, bokashi) on soil chemical properties. Site, use of treatment, and treatment type presenter: Hana You each significantly affect various aspects of soil chemistry. TAGRO biosolids show the potential to greatly increase SOC and N while reducing soil nitrogen oxides (NOx). GroCo biosolids effect POSTER 38 negligible to minor improvements in all soil chemical properties. Composts show the potential Impact of Soil Organic Amendments on Soil Biological to greatly improve overall nutrient richness in soils, especially micronutrient richness, while and Chemical Properties and Plant Growth reducing NOx. Pre-existing differences between three sites, as opposed to soil treatment Research Description: effects, may be an underlying cause of some results observed herein. This field trial will be followed by two additional seasons in order to verify these preliminary results. As increased concerns of sustainable management, demand of organic amendments has been increased. Organic amendment can provide nutrients for plant growth but also enhance Author: Sally Landefeld soil fertility while minimizing negative environmental effects. The main purpose of this study Affiliation: University of Washington, National Science Foundation is to evaluate whether the liquid organic amendment enhances soil organic matter (SOM) decomposition and changes plant available nitrogen releasing pattern. 3 fertilizer treatments, a liquid organic amendment (LOA) derived from food waste, a synthetic fertilizer (SF) has equivalent NPK with LOA, and an unfertilized control (UC), were applied in the presence and absence of tomato plants pots and SOM decomposition, plant available nitrogen and leaf gas exchange were measured every week for 6 weeks. SOM decomposition was greater in LOA treatment compared with SF treatment but the difference was not statistically significant and we also found that plants additionally stimulate SOM decomposition. It is likely that organic

9 POSTER SESSION 4:00 p.m. to 6:00 p.m., Tuesday, July 16

amendments have more diverse effect on soil biological and chemical properties by modulating presenter: Matt Fryer decomposition and mineralization process. POSTER 41 Authors: Hana You, Astrid Volder The Impact of Cover Crop Termination Timing on Soil Affiliations: University of California, Davis Health and Lint Yield of Cotton Research Description: presenter: Chelsea J. Carey Utilization of cover crops and reducing tillage are two practices that can have a significant POSTER 39 impact toward improving soil health. Cover crops possibly providing a "green bridge" for pest to cross over into the cash crop and the difficulty of obtaining an acceptable stand in the cover Assessing the Effects of a Microbial Inoculant and residue are concerns for most growers. The objective of this study was to investigate the Biostimulant on Rangeland Soil Microbial and Plant affects of cereal rye cover crop termination timing on cereal rye root production and residue Community Dynamics in California management at planting. A replicated field study was utilized to evaluate five termination Research Description: timings of cereal rye: 1) early-boot, 2) mid-boot, 3) late-boot, 4) full panicle exertion, and In California, as elsewhere, rangeland management is increasingly focused on promoting soil 5) anthesis. Termination timing did influence above ground biomass, root mass, and depth health. While the definition of a healthy rangeland soil depends on the context, microbial of rooting with greater quantities being produced as termination was delayed. Cereal rye communities invariably play a central albeit underexplored role in maintaining and promoting terminated at planting did produce the greatest levels of above-ground biomass and root mass healthy conditions. In 2018-19, we initiated and sampled from a well-replicated controlled ratings . However, the treatment yielded significantly less than the termination timing two field experiment at TomKat Ranch (Pescadero, California) with the goal of understanding the weeks prior to planting. It is possible to terminate cereal rye two weeks prior to planting cotton combined effects of microbial inoculants and biostimulants (humic acids) on soil microbial to achieve benefits associated with a cover crop while avoiding pest issues from the existence composition/activity and forage production/quality. We found that while total and active of a “green bridge”. bacteria and fungi remained generally unaffected within the first year of implementation, Authors: Matt Fryer, Bill Robertson, Amanda Free, Cheyenne Manuel some aboveground parameters responded positively. In addition to characterizing total and active bacteria and fungi, we used DNA amplicon sequencing to explore finer-level changes Affiliations: University of Arkansas System Division of Agriculture Cooperative Extension in microbial community composition, the results of which will also be discussed. This work Service offers new insights into the ability of these innovative management practices to influence soil microbial and plant community dynamics in California’s Mediterranean-type rangeland systems, with possible implications for soil and rangeland health. presenter: Kade D. Flynn Authors: Chelsea J. Carey1, Hayley Strohm2, Ford Smith2, Mark Biaggi2 POSTER 42 Affiliations: 1) Point Blue Conservation Science, 2) TomKat Ranch SLAKES: A Smartphone Application for Aggregate Stability

presenter: Tsz Fai Wong Research Description: POSTER 40 Measurements of soil condition that can be simply implemented by farm mangers or scientists Effects of Compost Application on Soil Carbon and are ideal for quantifying and comparing soil condition. Quantified soil condition ratings can Greenhouse Gas Emissions in Wine Grape Production inform managers and scientists on effective soil management practices and identify regions where poor soil condition is jeopardizing the environment and soil productivity. However, many Research Description: current methods for quantifying a rating of soil health are complicated, time consuming, and Compost is commonly used as an organic amendment in cropping systems such as vineyards, require specialized equipment-especially the measure of aggregate stability. SLAKES is a and has been shown to be beneficial to carbon (C) sequestration and soil health improvement. new application that runs on an Android smartphone and uses the built-in camera along with As perennial crops, grapevines have a larger potential for carbon (C) sequestration than image recognition software to quantify aggregate stability through a simple experiment. The most crops. Yet, there is a lack of clear correlation between compost application rate, the experiment requires three pea-sized soil aggregates, a petri dish of water, and an Android magnitude of C sequestration, and its environmental tradeoff in the form of greenhouse gas smartphone running the SLAKES application. The application takes ten minutes to produce an (GHG) emissions. In this study, we investigated the effects of compost application rate on soil C on-screen rating of aggregate stability, which is obtained from a non-linear Gompertz function sequestration and GHG emissions at J. Lohr Vineyards and Wines, Paso Robles, CA. The effects that is fit to the dissolution data, and a downloadable text file of the aggregate dissolution of four compost application rates (0, 2, 4 and 6 tons acre-1 year-1) on soil total C at depths of over time. SLAKES, along with the Cornell Wet Aggregate Stability Test, was used on seven 0-6” and 6-12” of two functional locations (tractor row and vine row) were assessed, as well conventional, seven no-till, and eight perennial fields in agricultural production to determine as cumulative and management-induced GHG emissions. Compost treatments were applied to whether the application showed sensitivity to different management practices. All 22 sites the entire plot area between harvest and first precipitation event in fall. We hypothesized that were on Vertisols, Typic Haplusterts. Instances where aggregate dissolution data contained soil total C as well as C sequestration would increase with increasing compost application an initial cluster of negative values were corrected, and the Gompertz function was refit to rates. We also expected that no significant difference in cumulative GHG emissions would be each data set. These results showed higher significant separation of means between each observed between treatments. Our preliminary data suggested that the effects of the applied management type than the Cornell method, which was only able to differentiate between rates on soil C sequestration and cumulative GHG emissions were minimal after the first year conventional tillage and perennial managements at a much lower significance. Interestingly, of compost application. More sensitive indicators such as permanganate oxidizable carbon the standard deviation of SLAKES Slaking Index increased non-linearly from perennial, to (POXC), mineralizable C, aggregate fractionation, and concentrations of mineral nitrogen no tillage to conventional tillage. SLAKES proved to be a legitimate method for quantifying (NH4+ and NO3-) are currently being measured to investigate early signs of changes in soil C aggregate stability based on slaking. With this simplified aggregate stability measurement dynamics and GHG emissions. method, rating and quantifying soil health is viable for anyone with a portable electronic device Authors: Tsz Fai Wong1, Jenna Janz Merrilees1, Mia E. Falcone1, Geovan Rich1, Craig Stubler1, and much less tedious than traditional lab-based methods.​ Cristina Lazcano1,2, Charlotte Decock1 Authors: Kade D. Flynn, Dianna K. Bagnall, Cristine L.S. Morgan Affiliations: 1) Natural Resources Management and Environmental Sciences, California Affiliations: Texas A&M University Polytechnic State University, 2) Department of Land, Air and Water Resources, University of California, Davis

10 POSTER SESSION 4:00 p.m. to 6:00 p.m., Tuesday, July 16

presenter: Mattie Schmitt presenter: Daoyuan Wang POSTER 43 POSTER 45 Factors Affecting Establishment of Cover Crops Interseeded into Corn Impacts of Dairy Manure on Soil Structure, Carbon Prior to Harvest Dynamics, and Water Characteristics in a Corn-Wheat Research Description: System Cover crops can be an effective management tool to protect the soil during fallow periods Research Description: from wind and water erosion. In the Northern Plains there is a short period for cover crops Excessive land application of dairy manure on lands surrounding dairy farms can result in to establish after cash crop harvest. Therefore, interseeding cover crops into the cash crop negative environmental consequences, including nitrate leaching. In a field trial at the Russell gives them more time to grow and develop. Research was conducted to quantify the impacts Ranch Sustainable Agricultural Research Facility at UC Davis we are studying the optimal of planting method and timing on cover crop establishment and development; and the effect utilization of solid dairy manure by comparing impacts of solid dairy manure amendment of cover crop growth on corn (Zea mays L.) yield. Cover crops (camelina, radish, and rye) were (mineral fertilizer (-M), 50% manure (Mixed), and 100% manure (+M)) on a corn/wheat rotation planted at two different timings (V7 and R4 corn growth stage) using two different methods system. The average mean weight diameter of soil water stable aggregates significantly (hoe and broadcast) in corn plots that remained until harvest and in plots where corn was increased by 32% (Mixed) and 46% (+M), respectively, after manure applications. The bulk removed at the time of cover crop planting. The interseeding of cover crops had no effect on carbon content in the top 15 cm soil increased by 10% (Mixed) and 16% (+M). Both carbon and corn grain yield. Reduced light from the corn canopy significantly reduced cover crop biomass nitrogen in macroaggregates increased in +M treatment by 31% and 30%, respectively. Carbon and ground cover compared to cover crop growth with no corn. Light intensity was a main (C) stable isotopic analysis revealed that 16% and 22% of C in macro- and microaggregates, contributing factor to the establishment and development of interseeded cover crops. Rye respectively, was derived from manure in +M treatment, however, only 1% of manure-C and camelina established and grew better than radish when intercropped. There were fewer was detected either aggregate size in the system receiving the lower amount of manure surviving plants at the time of corn harvest when cover crops were planted early (V7) compared (mixed). This indicated that +M treatment significantly altered soil C dynamics and enhanced to late (R4). In the spring, the gravimetric water content was not significantly reduced when sequestration and physical protection of soil C after three manure amendments. Each manure camelina, radish, and rye were intercropped. The radish plots where the corn was removed, application significantly increased soil microbial biomass C (MBC) by 40% (Mixed) and 60% contained similar amounts of gravimetric water compared to the cover crops interseeded in (+M) relative to the -M. However, increases were temporary and MBC declined to previous corn. Rye and camelina significantly reduced the gravimetric water content in the spring when levels by 30 days. Soil dissolved organic C remained elevated throughout the entire growing grown without corn. Survival and growth of interseeded cover crops was minimal due to light seasons in +M treatment. Properties reflecting water dynamics--soil water retention capacity intensity which limited their ability to draw down moisture in the spring. and infiltration rates surprisingly showed no changes after 3 applications of manure. Manure Authors: Mattie Schmitt, Dr. Joel Ransom application increased soil plant available N for 45 days while it did not impact corn and wheat yield and quality. Thus, multiple dairy manure amendments can increase soil aggregation Affiliation: North Dakota State University and associated C sequestration by improving physical protection for soil organic matter. Meanwhile, solid dairy manure amendment partly (Mixed) or entirely replaced (+M) synthetic presenter: Kalyn Diederich mineral N inputs without tradeoff in crop yield and quality. POSTER 44 Authors: Daoyuan Wang, Jordan M. Sayre, Daniel Geisseler, Amelie CM Gaudin, Jorge L.M. Rodrigues and Kate M. Scow Enhancing Farm Resilience Underground: Can Perennial Grains Provide Soil Ecosystem Services in the Affiliation: Department of Land, Air and Water Resources, University of California, Davis Mediterranean Climate of California? Research Description: presenter: Katherine Naasko The growing interest in perennial grain agriculture in large stems from agricultural stakeholders POSTER 46 wanting to improve soil health, protect freshwater supplies, reduce input costs, and mitigate Soil Enzyme Activities Vary Greatly Across Tillage Intensities and global climate change. In recent studies conducted in the Midwest, the novel perennial grain Precipitation Gradient in Semi-Arid Palouse Soils crop known as Kernza (Thinopyrum intermedium) has shown the ability to decrease nitrate Research Description: leaching, increase labile soil carbon and sequester more carbon in its biomass than its annual wheat counterpart. The objective of this study is to investigate if Kernza is a viable agronomic Enzymes are key biological indicators of soil health, as they provide insight into metabolic crop for the Mediterranean climate of California, while also expanding on existing knowledge processes, microbial activity and biogeochemical productivity of soil. Specialized enzymes concerning Kernza’s potential to sequester carbon and improve soil ecosystem services. This drive decomposition processes, carbon cycling and nutrient cycles of nitrogen, sulfur and study takes place at UC-Davis Russell Ranch Sustainable Agriculture Facility, a long-term phosphorus, and therefore influence availability of these nutrients for uptake by plant roots research trial in Davis, California that is comprised primarily of Yolo silt loam. To account for and other living soil organisms. Enzymes facilitate important ecosystem services that allow agronomic challenges specific to the region (i.e., groundwater contamination and limited water for agricultural sustainability and optimal management in terms of nutrient and water supply. supply), we implemented a split-plot randomized complete block design with plant species Authors: Katherine Naasko1, Haiying Tao1, William Pan1, John Reganold1, Tarah Sullivan1, Isaac (annual wheat and Kernza) and tillage (till and no-till annual wheat) as a whole plot treatment, Madsen1, David Huggins2 irrigation as a subplot treatment, and nitrogen fertilization (0-150 kg N/ha) as a sub-sub plot treatment. We present our first year of findings comparing Kernza and annual wheat yields, soil Affiliations: 1) Washington State University, 2) USDA-ARS health metrics and stable soil carbon stock accumulation as part of a four-year experiment that will investigate whether observed improvements in soil health and soil carbon stocks are due presenter: Marisol Montes to a lack of tillage or due to the deep rooting structure of Kernza. Furthermore, we will explore how these potential soil improvements are affected by irrigation and nitrogen gradients across POSTER 47 crop type and tillage treatments. The Relationship between Aboveground Diversity and Authors: Kalyn Diederich, Kate Scow, Mark Lundy AMF on Agroecosystems Affiliation: University of California, Davis Research Description: Arbuscular mycorrhizal fungi (AMF) have the potential to benefit agroecosystems most notably through their role in promoting the host plant’s growth, development, and pathogenic resistance. Yet, little is known about how agricultural landscapes effect the colonization of AMF, more so, through a range of farm management practices. AMF associate with more than 70% of

11 POSTER SESSION 4:00 p.m. to 6:00 p.m., Tuesday, July 16

vascular plants, including major crops. Still, while AMF is not plant host-specific, mycorrhizal 45 cm). Microbial biomass C was also significantly higher at shallow depths (0-15 cm) and associations are also not random. It is suggested that AMF colonization is influenced by host showed enrichment in multiple distinct functional groups including arbuscular mycorrhizal plants, soil chemical and physical properties. Thus, in agroecosystems, a relationship between fungi, actinomycetes, and saprophytic fungi. Grazed plots had higher bioavailable-P content, managed aboveground diversity (e.g. crop diversity) and AMF colonization is expected. In this despite lower phosphatase enzyme activity, and NH4+, NO3-, and leucine aminopeptidase study, we examined how AMF colonization vary between high plant diversity (i.e. polycultures; and urease enzyme activity were all higher in grazed plots. Our results support that ISVS has >20 crop types) and low plant diversity (i.e. monocultures; 1 crop type) across 20 eggplant substantial potential to increase soil C storage and improve important ecosystem synergies farms in 2017 and 2018. We used microscopy techniques on plant roots to determine the such as microbial functioning and biogeochemical cycling. proportion of AMF colonization. Our recent analyses demonstrate that AMF colonization Authors: Kelsey M. Brewer, Amelie C. M. Gaudin correlates with greater crop diversity across the farm. Together, this research shows how diversifying farm management practices at the field-scale could foster potential beneficial soil Affiliation: University of California, Davis ecosystem functions via crop plant symbiosis with AMF on agroecosystems and for farmers. presenter: Daniel Rath Authors: Aidee Guzman, Marisol Montes, Leke Hutchins, Anne Kakouridis, Gisel DeLaCerda, Claire Kremen, Tim Bowles, Mary Firestone POSTER 50 Affiliations: University of California, Berkeley 25 Years and Counting: Long Term Impacts of Compost, Cover Cropping and Mineral Fertilizer on Soil Carbon, Nitrogen, and Microbial Biomass presenter: Jenna Janz Merrilees Research Description: POSTER 48 Most research into human agricultural impacts on soil health are focused only on the top 15 cm The Effects of Herbaceous Cover Crop Management of the soil and run only for 2-3 years. Considering that organic matter accumulation may take Through Tillage and Grazing on Soil C and Greenhouse centuries and affect soils down to the bedrock, there would appear to be a serious gap in our Emissions in Wine Grape Production understanding of how soils gain carbon and maintain microbial communities. We can bridge Research Description: this temporal gap through long term research experiments that track how an entire soil profile changes over decades, allowing us to measure practices that may have a tiny additive impact, Cover crops are beneficial for soil health as they increase soil organic matter, but they may but large cumulative impacts. This study uses the context of a >25yr research experiment to also increase soil greenhouse gas (GHG) emissions such as CO2, N2O, and CH4 depending measure the impact of organic, cover cropped and conventional farming practices on carbon, on the management strategy used. This study aims to determine soil GHG emissions and C nitrogen, microbial biomass and soil structure. We measure total and water-soluble carbon sequestration under the influence of tillage and animal grazing activities within a vineyard on the central coast of California in Paso Robles. We hypothesized that tillage would increase and nitrogen pools, and combine that with measurements of soil structure, microbial biomass short-term CO2 emissions, and grazing would increase soil N inputs from urine and manure, carbon and nitrogen to determine how amendments applied to the topsoil can change soil along with N2O and CH4 outputs. Additionally, we hypothesized that both reduced tillage and conditions up to 1 m deep. Our results indicate that dissolved organic carbon (DOC) from grazing would increase long-term soil C. The effects of cover crop management through tilling compost addition may have a major impact on carbon storage below the plough layer, but that or grazing was evaluated in a field experiment using a factorial design, with four treatments more resistant carbon from cover crops may not be as easily transported and sequestered that (tilled + grazed, tilled + non-grazed, non-tilled + grazed, non-tilled + non-grazed) and four deep. These results may indicate that carbon storage models need to take the subsoil layers replicates per treatment. Treatments were applied to 9.7 by 14.6-meter plots in May and into account when predicting rates of carbon storage, and that rates of C sequestration under November 2018 (tillage and grazing), and March-May 2019 (tillage and grazing). At each plot, cover cropping may not be as high as predicted. CO2, N2O and CH4 emissions were determined following each management event, along with Author: Daniel Rath major irrigation and precipitation events, using static chambers installed in vine and tractor Affiliation: University of California, Davis rows. Soil bulk density, organic matter (SOM), permanganate oxidizable carbon (POXC), soil NO3-N and NH4-N were also determined after each event. Opposite to what we expected, CO2 presenter: Juliana Wu and N2O emissions right after tilling were lower than in non-tilled soils. Grazing increased/ decreased GHG emissions as compared to non-grazed soils. There was an interaction between POSTER 51 grazing and tilling on N2O, but not CO2. Spatial variability existed in the case of both GHGs. The Effect of Cover Crop Root Interactions on Soil Health Results of this research are essential to design best management strategies that will support and Fe Availability in Organic Pears soil health in vineyards, in particular to the best of our knowledge no research to date has Research Description: studied the direct effects of grazing on GHG emissions in a vineyard system. The incorporation of cover crop mixes in organic orchard production can increase the Authors: Jenna Janz Merrilees1, Tsz Fai Wong1, Mia E Falcone1, Geovan Rich1, Craig Stubler1, Bwalya Malama1, Charlotte Decock1, Cristina Lazcano1 sustainability and carbon sequestration potential of agricultural systems in order to address climate change. We initiated a field study March 2018 in Kelseyville, CA with cereal-legume Affiliations: 1) Natural Resources Management and Environmental Sciences, California cover crop mixes in an organic pear orchard and our objectives were to (i) elucidate changes Polytechnic State University 2) Department of Land, Air and Water Resources, University of in iron Fe cycling, (ii) determine pear root growth response, and (iii) quantify changes in soil California, Davis health parameters. Samples of cover crop biomass, pear leaves, alleyway soil, and roots were collected at three time points throughout the season to determine changes in pear leaf Fe, chlorosis, soil pH, soil organic matter, soil respiration, and specific root length in response to presenter: Kelsey M. Brewer the cover crop treatment. The cover crop treatments resulted in significant decreases in soil POSTER 49 pH and increased Fe availability compared to the mechanically managed control, however Soil Organic Carbon and Biogeochemical Dynamics of after cover crop termination there was no longer a significant effect on pH but the effect on Integrated Sheep-Vineyard Systems in The California soil Fe persisted. The increase in soil Fe did not result in significant increases in pear leaf Fe Coastal Foothills or decreases in pear leaf chlorosis. These findings suggest that cereal-legume cover crops can Research Description: be utilized as a sustainable management practice to increase soil Fe availability in orchards susceptible to iron chlorosis but further research is required to better understand Fe-uptake in Quantification of carbon sequestration and soil health impacts from livestock integration into organic orchard systems. perennial cropping systems remain unclear. We conducted a study of three long term (10+ years) ISVS plots to assess soil health shifts from sheep-vineyard integration. SOC stocks were Authors: Juliana Wu, Rachel Elkins, Astrid Volder significantly higher at multiple ISVS plots for each depth zone (0-15 cm, 15-30 cm, and 30- Affiliation: Department of Plant Sciences, University of California, Davis

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presenter: Leah L. R. Renwick in two rangeland ecosystems (Northern mixed-grass prairie (NMGP) and shortgrass steppe POSTER 52 (SGS)). Available water holding capacity was measured by comparing gravimetric moisture content difference between pressures of 10kPa and 1500kPA to calculate available water Do Crop Rotation Complexity and No-Till Improve holding capacity. Field-saturated hydraulic conductivity was measured using a 20cm diameter Corn Drought Resistance by Increasing Soil Water tension infiltrometer. Results were partially reflective of prior studies, with lower infiltration Conservation? rates occurring in heavily grazed treatments. Decreased soil water infiltration could be a Research Description: result of soil compaction and sealing by animal trampling, and reduced litter cover. Available water holding capacity had inverse relationships to grazing intensity between the two sites, Higher complexity and perennialization of corn-soy rotations increases corn yield and yield illustrating the complexity of ecosystem response to grazing. Soil/water relationships are stability, particularly in hot and dry years. Soil health indicators such as soil organic carbon, difficult to generalize in rangeland systems; climate, moisture regime, species composition, aggregation, and bulk density often improve with increasing rotation complexity, prompting the surface cover, and plant condition affect interactions of grazing, soil water infiltration, and hypothesis that related soil hydraulic properties such as higher water infiltration and retention available water holding capacity. drive rotation benefits under drought. We conducted a drought simulation experiment using rainout shelters at a long-term crop rotation and no-till trial to test the impact of rotation Authors: Bryce Lidtka, J. Derek Scasta, Peter Stahl, and Kristie Maczko complexity and no-till on yield losses under drought and the underlying mechanisms, including Affiliations: University of Wyoming and Sustainable Rangelands Roundtable crop physiological acclimation and shifts in soil moisture dynamics. We found that rotation complexity buffered maize against yield loss due to imposed drought relative to irrigated presenter: William Brinton control conditions, while no-till had no significant effect. We will present results on whether higher soil water infiltration and/or retention drive higher drought resistance. Our study POSTER 55 highlights the functional significance of one soil health building management practice— Seasonal Effects of Organic Tillage Compared to No-Till rotation complexity—for crop productivity under stressful rainfall conditions and explore one with Respect of Soil Health Parameters proposed mechanism to explain this phenomenon. Research Description: 1 2 1 Authors: Leah L. R. Renwick , Bill Deen , Amélie C. M. Gaudin Tillage is a large topic of discussion in soil health communities with an increased focus on Affiliations: 1) Department of Plant Sciences, University of California Davis, 2) Department of organic farming practices which are viewed as tillage-intensive. Many believe that soil Plant Agriculture, University of Guelph, Ontario, Canada cultivation stimulates soil C loss by accelerating the oxidation of soil C by microbial activity, therefore differences in soil cultivation should be readily observable in measurable changes during the season in carbon and associated quality factors. We established replicated plots presenter: Sarah Light in winter wheat and performed weekly analyses through the entire growing season. We POSTER 53 compared organic mechanical tillage, organic broad-forking to No-Till and Bare Fallow plots. Soil temperature was not influenced by tillage all season, and moisture increased with tillage. How Do Cover Crops and Reduced Disturbance Tillage Microbial respiration showed significant differences and correlated to plant cover but not Affect Soil Function in California’s Central Valley? strictly to tillage mode. Water stable aggregates were greatest in organic broad-forked plots. Research Description: Overall, the results do not support a general conclusion of tillage damage to soil health, rather point to a complex set of interacting mechanisms controlling the appearance of soil health Despite the known benefits to soil health of reducing soil disturbance and adding cover crops to traits related to management. The presence of plant roots and thus the effects of tillage or NT crop production systems, there is very little use of these practices in annual cropping systems on plant population appeared to be a primary factor determining whether soil analyses will in California’s Central Valley. We evaluated soil hydraulic indicators of soil health after 18 lead to a conclusion of observable effects due to management. years of standard tillage with and without cover crops and no-tillage with and without cover crops in a common annual crop rotation in Five Points, CA. Water retention and unsaturated Authors: WIlliam Brinton, Jeremiah Vallotton, Daniel Davidson hydraulic conductivities were measured on samples from 0 – 5 and 20 – 25 cm depths using Affiliations: Woods End Laboratories, Memorial University of Newfoundland the HYPROP instrument and saturated hydraulic conductivity was measured using the KSAT instrument. Aggregate stability was assessed on surface samples using the NRCS stability presenter: Vesh R. Thapa class scoring system. Saturated hydraulic conductivity of the top 5 cm was not statistically significant (P<0.1) among the treatments although cover crops, regardless of tillage, increased POSTER 56 conductivity. Below 20 cm, there was a difference (p<0.1) between the no-tillage and cover crop Soil Microbial Properties As Indicator Of Soil Health In systems and the standard tillage no cover crop systems. The combination of these treatments Limited-Irrigation Crop Rotation In Semiarid Eastern almost doubled conductivity. Aggregate stability scores for the no-tillage systems were 4.65 New Mexico + 0.05 versus 4.43 + 0.03 for standard tillage. Findings from additional determinations and the Research Description: functional significance of these results are discussed. Microbial community size and structure play a crucial role in soil organic matter and nutrient Authors: Sarah Light1, Samuel Araya2, Teamrat Ghezzehei2, Robert Roy3, Jeff Mitchell4 cycling, and greatly influence soil health and resilience. This study investigated soil microbial Affiliations: 1) University of California Agriculture and Natural Resources Sutter County, 2) community structure and enzyme activities under diverse cover crops in a limited-irrigation University of California, Merced, 3) USDA-NRCS, 4) University of California, Davis winter wheat (Triticum aestivum)-sorghum (Sorghum bicolor)-fallow rotation. The study had a randomized complete block design with eight treatments and three replications. The treatments were fallow, pea (Pisum sativum), oat (Avena sativa), canola (Brassica napus L.), pea + oat presenter: Kristie Maczko (POM), pea + canola (PCM), pea + oat + canola (POCM), and six species mixture (SSM) of pea, POSTER 54 oat, canola, hairy vetch (Vicia villosa), forage radish (Raphanus sativus L.) and barley (Hordeum Soil Water Relationships Vary Across Rangeland vulgare L.) cover crops. Soil samples (0-15 cm) were analyzed for soil microbial community Ecosystems and Grazing Management size, structure, and functions. Community size for soil fungi was 47.8 nmole g-1 soil under oat, which was similar to SSM and significantly greater than 33.9 nmole g-1 soil under fallow. Research Description: The arbuscular mycorrhizal fungi had 83.9% greater community size under oat than fallow. Precipitation is a primary limiting factor for plant and animal production, and physical Averaged across cover cropping treatments, community size increased by 101%, 24.6%, properties of the soil environment strongly influence the rate and amount of water entering and 25.8% for protozoa, soil fungi, and gram-negative bacteria, respectively, in 2018 than the soil profile. Researchers evaluated differences among stocking rates (excluded, light, in 2017. These changes were associated with 47.4% alkaline phosphatase enzyme activity. moderate, and heavy) influence on soil water infiltration and available water holding capacity The combined enzyme activity (acid phosphatase, β-glucosidase and β-glucosaminidase)

13 POSTER SESSION 4:00 p.m. to 6:00 p.m., Tuesday, July 16

was greatest under SSM (294 PNP g-1 soil h-1), which was significantly greater than enzyme presenter: Lauren Hale activity under fallow (204 PNP g-1 soil h-1) in 2018. First two principal components explained POSTER 59 >80% variation in microbial populations across various cover cropping treatments. Cover cropping during fallow period increased fungal abundance and combined enzyme activities Impact of Soil Microbial Community Diversity Loss on associated with C and N cycling over the time and led to soil health improvements in hot and Carbon and Nitrogen Cycling dry semiarid climate. Research Description: Authors: Vesh R. Thapa1, Rajan Ghimire2, Veronica Acosta-Martinez3, Jon Cotton3 Soil microorganisms are critical drivers of soil organic matter turnover and nitrogen (N) cycling Affiliations: 1) Department of Plant and Environmental Sciences, New Mexico State University, and community diversity is a common metric used to profile soil biological health. However, the 2) Agricultural Science Center, New Mexico State University, 3) USDA-ARS relationships between soil microbial diversity and ecosystem functions are not always linear. Hence, fundamental insights into components of microbial diversity that impact process rates are needed. Objective: To examine biodiversity and function relationships in soil microbial communities in presenter: Patricia Lazicki response to carbon (C) and nitrogen (N) inputs. POSTER 57 Approach: We developed a series of soil microcosms with scaled bacterial/archaeal, fungal, Can Soil Health Assessment be Improved by Adding and eukaryotic biodiversity profiles using size-exclusion and serial dilution techniques. Microbial and Plant Health Indicators? Sequencing of 16S rRNA (bacterial/archaeal), ITS (fungal), and 18S rRNA (eukaryotic) genes was performed to approximate biodiversity of microbial groups. Research Description: Results/ Findings: Functional proxies for soil phosphorus (P), C and N cycling were assayed in For agricultural systems, the definition of soil health as “the capacity of a soil to function” response to nitrate fertilization and plant residue inputs. implies both a healthy microbial community and a well-growing crop; however, microbial and plant indicators are seldom included as part of a soil health assessment. This study’s Significant correlations were revealed between functional proxies related to N and C cycling goal is to use the conventional and organic plots of the 25-year old Russell Ranch farming (nitrification potential, soil NO3-, NH4+, total carbon, % organic matter, and respiration rates) systems experiment to test the hypothesis that including microbial and plant indicators and bacterial/ archaeal and fungal diversity indices, but not eukaryotic taxonomic diversity (R2 provides better information on agroecosystem health than soil health indicators (SHI) alone > 0.15, P < 0.05). Soil P and microbial community substrate use profiles did not correlate with by concurrently measuring microbial membership and plant health indicators. Total soil DNA diversity indices of bacterial/ archaeal, fungal, and/or eukaryotic groups (Linear regression was extracted for microbial community analysis, individual soil health indices were calculated analyses, R2 < 0.15, P > 0.05). Nitrification potential was completely lost in the communities for soil chemical, organic matter, biological, and physical indicators, and plant health indices with the lowest biodiversity. Comparing the biodiversity-function relationships in response to were similarly calculated from chlorophyll fluorescence, leaf nitrogen, and yield. We found inputs, community diversity exhibited the strongest correlations with carbon cycling proxies SHIs diverged strongly between conventional and organic systems. However, neither α- nor β- after the input of plant residues, when soil respiration rates were highest and soil N became microbial community diversity differed significantly between systems and that the relationship limited. Whereas, initial community diversity and diversity of communities assayed after N among soil, microbial and plant health indices was not straightforward, likely due to late- fertilization, had stronger correlations to N cycling proxies. season pathogen pressures. While the project is ongoing, our first-year results demonstrate Conclusion/Implications: In conclusion, soil biodiversity exhibited positive linear correlations the complex interrelationships among soil, microbes and plants, and that SHIs can be more for important ecosystem functions relating to C and N cycling. These correlations were driven accurately interpreted when all three factors are considered. by bacterial/ archaeal and fungal groups, which showed variable associations with functional Authors: Patricia Lazicki, Alonna Wright, Daniel Geisseler, Cleverson Matiolli, Maeli Melotto, proxies. These results highlight the importance of biodiversity to different ecosystem functions Jorge Rodrigues and provide insights into how these relationships shift with varying inputs into soils. Affiliation: University of California, Davis Authors: Lauren Hale1,2, Xishu Zhou1,3, Xue Guo1,4, Colin Bates1, Daniel Curtis1, Linwei Wu1, Daliang Ning1, Gangsheng Wang1, Jizhong Zhou1,4

presenter: Chris Dorich Affiliations: 1) University of Oklahoma, 2) USDA-ARS, 3) Central South University, Hunan China; 4) Tsinghua University, Beijing China POSTER 58 Quantifying Soil Health Improvements presenter: Jing Yan Research Description: POSTER 60 Soils that are drought and flood resilient are important goals for farmers under expected climate change. Further, farmers can potentially help mitigate climate change by sequestering carbon Modeling Rhizosphere Hydrodynamics: How Do Roots within soil. Achieving these goals requires the use of appropriate management practices, Extract Resources in Response to Spatial Heterogeneity which vary on a scenario basis. Personalized quantification tools that can help farmers choose in Soil Water and Nutrient best management practices and predict impacts of these practices before implementation Research Description: are needed to help improve soil health. Using the NRCS pedon characteristic database as well as other global soils datasets, we explored pedotransfer functions and current water While its small volume and narrow region compared to bulk soil, the rhizosphere regulates capacity functions to see if current methods are accurately modeling soils or if methods can be numerous processes that determine physical structure, nutrient distribution, and biodiversity of improved. Management and time series data sets were then examined within this framework soils. One of the most important traits is the hydraulic redistribution, where roots transfer soil to test how management practices actually affected soils over time. moisture from wetter to drier soil layers during night time when transpiration becomes low. Such trait alters the physical property of rhizosphere and eventually affects the soil function Authors: Chris Dorich, Keith Paustian and plant health. Here we present a mathematical model of the plant-trait-facilitated alteration Affiliation: Colorado State University of soil hydrodynamic properties considering both rhizodeposition and hydraulic redistribution. We demonstrate that exudates play an important role in facilitating water and nutrient uptake by providing a built-in water potential gradient within the rhizosphere. Furthermore, through a comparison between modeled results with our recent laboratory findings, we show how exudates regulate the “root communication” during hydraulic redistribution by facilitating the release of water from roots to a very dry rhizosphere. In summary, modeling studies suggest that rhizosphere alteration by rhizodeposition is an actively controlled adaptation mechanism that permits plants to live in resource-heterogeneity conditions.

14 POSTER SESSION 4:00 p.m. to 6:00 p.m., Tuesday, July 16

Authors: Jing Yan, Teamrat Ghezzehei provided. Results from these small-scale, mechanistic studies are used to help interpret plant Affiliation: University of California, Merced and soil nitrogen data from year 1 of one-acre, three-year tomato trials in texturally distinct soils in Fresno and Yolo counties. The overarching objective of this work is to provide data on the impact of biochar on soil nitrogen dynamics and mechanisms behind observed trends, as presenter: Zouheir Massri well as information about the soil and biochar parameters most likely to lead to beneficial POSTER 61 outcomes in field-scale agriculture. 1 1 1 1 1 2 Spectro-Gel Innovative Method for Assessment of Soil Authors: DL Gelardi , WR Horwath , D Geisseler , AT O’Geen , KM Scow , M McGiffen , M 3 1 Microbial Respiration in Field and Lab Conditions Leinfelder-Miles , SJ Parikh Research Description: Affiliations: 1) Department of Land, Air and Water Resources, University of California, Davis, 2) Department of Botany and Plant Science, University of California, Riverside, 3) Cooperative Soil respiration is a complex process that results from several sources of CO2. Measuring Extension San Joaquin County California soil carbon flux (CO2) in the root-soil-microbe interactions “rhizosphere” is a mean to gauge biological soil fertility and gives an insight into the soil health rhizosphere and provides presenter: Marko Divinic feedback on the underground complex, which is vitally important for above ground plant growth. Nowadays, the demand to enhance the reliance on microbial agrochemicals is great, POSTER 63 as a new source of soil fertility-biology amendments, which should support the soil rhizosphere Electromagnetic Exposure of Seeds and Seedlings interactions, a gateway for plants to the uptake of water and nutrients, and to interact with the soil and the plant rhizosphere to potentially manage to increase crop yields. Research Description: USDA promoted the Solvita-Field Test method. However, Solvita despite its simplicity, is Exposure of seeds and seedlings to electromagnetic magnetic field was found to accelerate a commercial product with a selling price that might be a limiting factor to large-scale sprouting and growth of the plant seedlings. Specifically, studies have shown that magnetic deployment and research purposes. In addition, the details of the Solvita method have not field treatment of seeds/seedlings leads to acceleration of plants growth, protein biosynthesis been published. To overcome such high cost in our research fields, we have employed a and root development. We have studied the effect of electromagnetic field (EMF) on the passive sampler which was designed and based on Cornell University as an alkali trap “passive germination and growth rate of soybean (Glycine max) and corn (Zea mays). Both soybean sampler” for measurement the soil microbial respiration activity by capturing the evolved CO2 and corn seeds were grown under optimal conditions and were subjected to continuous (2200 as a waste product of respiration. However, research proved that while having a lot of fine root gauss unit) electromagnetic field. Planted seeds were separately exposed to north (NP) and biomass will likely be of greater respiration, this doesn’t necessarily mean a healthier soil. For south (SP) magnetic poles. The seed germination rate and plant growth under each pole was assessment of soil health, soil microbial respiration was a key parameter for determining soil- measured and compared to control plants that were grown without additional EMF treatment. surface CO2 efflux which continued to be challenging. As known, the majority of soil processes Results of this study indicate that continuous EMF treatment increased seed germination and are intrinsically linked to soil biota, although specific relationships are complex and as yet not plant growth in both crops compared to controls, and that SP outperformed NP treatment. This fully described in all cases, therefore, conditions of certainty that biological indicators are key study confirms the "auxin like" effect of EMF on both dicot and monocot plants and prepossess in monitoring soil health. that primary focus of future biomagnetism studies is placed on the effects of magnetic south pole. Therefore, we were able to improve a gel-based color method defined as the steady rate of CO2 emissions linked to the microbial decomposition of soil organic matter in the rhizosphere. Author: Marko Divinic The method considerably minimized the time for soil preparation, systematic spectrometer Affiliation: Bismarck State College calibration, and laboratory incubation. The color gel is an innovative gel method follows the change in the gel color quantified by measuring the absorbance of the gel at 570 nm using presenter: Cody J. Hatzenbuhler portable spectrophotometer (a spectro-gel) to assess the main efflux of the heterotrophic POSTER 64 respiration and has been newly used, as a replacement for Solvita test which is relatively, an expensive method. The spectro-gel is a microbial indicator tested, evaluated, and confidently Gibberellic Acid Used in North Dakota Cropland used to monitor the impact of microbial agrochemicals (PrimAgro) application in agricultural Research Description: practices on soil biological activities and monitoring of soil health evolution. Gibberellic acid (GA3) has become one of the most frequently used plant growth regulator Authors: Zouheir Massri, Jerry Wilhm, Hudson Potter (PGR) hormone in Asian and South American agriculture. This PGR is known to significantly Affiliations: AgroLiquid affect seed germination and dormancy, regulate abiotic stress in plants, increase stem/leaf growth and flowering in plans, and result in overall improved yields of various crops. Corn and soybeans are an important crop for North Dakota, however, there are no reports on the use of presenter: DL Gelardi PGR potential in relation to these crops in the state or national literature. To better understand POSTER 62 the role of PGRs and their application in agriculture, a pot experiment was carried out to study The Chemical and Physical Retention of Nitrate and Ammonium by effects of GA3 on germination and vegetative growth of the corn (Zea mays) and soybean Biochar across Laboratory and Field Scales (Glycine max). GA3 (50 mg L-1) was mixed with 10% humic acid solution (Biovita Black) and applied as seed treatment, leaving plants with water application as control. On a different set Research Description: of plants, a GA3 (100 mg L-1) was also sprayed on leaves of both crops at the vegetative stage Research shows inconsistent results on the ability of biochar to retain nitrate and ammonium, V3/4. Results of this study indicate that GA3 seed treatment increased plant emergence and either through chemical adsorption or through a physical retardation of the flow of ions in initial corn and soybean root growth, while foliar application of GA3 led to an increase in plant solution. This inconsistency presents a challenge for predicting crop nitrogen use efficiency height, first node height (in soybeans) and stem diameter. Leaf area and dry matter production and for nutrient management in biochar-amended soils. Furthermore, research on biochar- also increased as a result of GA3 foliar application. There was no effect of gibberellin on the mediated soil nitrogen dynamics have limited relevance to real world cropping systems, as number of soybean leaves and number of stem branches. biochar studies are dominated by short-term, laboratory experiments that are difficult to This study suggests that PGRs may have an important role in modern US agriculture, especially extrapolate to field-scale. To quantify the chemical affinity between nitrate or ammonium and in semi-arid and short growing season regions such as North Dakota. biochar, data from batch sorption experiments with seven biochars of diverse feedstock and production temperatures are presented. To investigate the physical retardation of nitrate or Author: Cody J. Hatzenbuhler ammonium flow through the soil profile, nitrogen leaching data from column experiments are Affiliation: Pan-One Institute, BSC, North Dakota State University

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