Source: UNIV OF MINNESOTA submitted to
ENHANCING SOIL HEALTH IN US POTATO PRODUCTION SYSTEMS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
EXTENDED
Funding Source
Reporting Frequency
Annual
Accession No.
1016514
Grant No.
2018-51181-28704
Project No.
MIN-25-G26
Proposal No.
2018-03309
Multistate No.
(N/A)
Program Code
SCRI
Project Start Date
Sep 1, 2018
Project End Date
Aug 31, 2022
Grant Year
2019
Project Director
Rosen, C.
Recipient Organization
UNIV OF MINNESOTA
(N/A)
ST PAUL,MN 55108
Performing Department
Soil, Water, and Climate
Non Technical Summary
Critical Need and Rationale: In the U.S., potatoes are grown on over 1 million acres in 30 states with a farm-gate value of approximately $4 billion. The top nine producing states (Idaho, Washington, Oregon, North Dakota, Minnesota, Wisconsin, Michigan, Maine and Colorado) comprise four major U.S. growing regions (Pacific Northwest, Upper Midwest, Northeast, and Southwest). Soil health is a term used to identify the condition of a soil to function as a vital living ecosystem that sustains plants, animals and humans. A major focus of soil health is on maintaining and enhancing soil organic matter and a beneficial soil microbial community. Soilborne diseases in potato production represent a major challenge to the potato industry often requiring fumigation for their control. Increasing evidence exists that incorporating practices to improve soil health may be a sustainable option for mitigating the effects of soilborne diseases. However, enhancing soil health in potato cropping systems is a challenge because of the significant soil disturbance that occurs during potato planting and harvest, lack of organic residue associated with potato vines, difficulty in establishing a cover crop following harvest in some regions, and the need to rely on fumigation to control diseases. This project will address significant knowledge gaps related to the complex relationships among factors affecting soil health and potato soilborne diseases. Our studies will consider the entire potato cropping system, including potato cultivar, rotation crops, biological control options, and cover crops to identify management practices that enhance soil health and reduce soilborne diseases and to identify indicators of soil health associated with those practices across the major U.S. potato production areas. The overall result will be to enhance environmental quality and to sustain the economic viability of potato operations in the U.S.Methods, Approaches and Expected Accomplishments: This project involves a team of 24 collaborators consisting of soil scientists, plant pathologists, potato agronomists, and social scientists. Field experiments with defined potato rotations will be established to evaluate the effects of potato cultivar, fumigation, crop rotation, cover crops, green manures, microbial inoculants, and nutrient amendments on biological, chemical and physical soil health indicators, as well as on potato health and yields. Next generation sequencing DNA analysis will be used to identify soil microbial communities associated with practices that enhance soil health. An on-farm network of sites throughout major commercial potato production areas will be established to evaluate spatial variability of soil health indicators and plant health/productivity data. This information will be used to develop a soil health assessment and soilborne pathogen risk-advisory tool for precision management of potato. The next step will be to identify factors affecting adoption of practices and technologies that improve soil health in potato production systems. Monetary and non-monetary informational requirements necessary for potato growers to adopt recommended soil enhancement practices will be identified and a model to identify optimal crop rotations with potatoes will be developed. The information generated will be used to develop state, regional and national extension programs in potato soil health that will lead to greater adoption of sustainable management practices. By the end of this project, our vision is to develop two regional manuals on potato soil health (Northwest/Southwest and Midwest/East) that provide soil health information appropriate for each region.
Animal Health Component
0%
Research Effort Categories
Basic
50%
Applied
50%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1021310106050%
2050110116050%
Goals / Objectives
The major goal of this project is to establish physical, chemical, and biological indicators of soil health for sustainable potato production. The specific objectives for this project are as follows:1) Enhance potato health, productivity, and quality via management-based optimization of soil microbiomes and physicochemical characteristics.2) Determine on-farm soil health-based indicators associated with potato crop health, yield and quality.3) Identify the incentives, impediments, and determinants of adopting practices and technologies that encourage practices to improve soil health in potato production.4) Facilitate adoption of soil health best management practice systems by the potato industry.
Project Methods
Objective 1: Soil microbiome data and soil physicochemical data will be collected to generate regional and continental-scale data on the relationships between potato cultivar, crop rotation, soil fumigation, cover crops or green manures, microbial inoculants, and nutrient amendments, and soil microbiomes, soil physicochemical characteristics, potato health, and tuber yields. This work will provide a systematic foundation of data for evaluating key soil correlates of potato yield and health thus identifying critical targets for crop management. The proposed research will provide benchmark measurements for defining `soil health' in potato production systems, empower researchers to more effectively quantify the effects of diverse management strategies on soil health, and enable growers to engage in data-driven soil health management. The core experimental design will consist of two coordinated experimental field plots representing 3-year (experiment 1) and 2-year (experiment 2) potato rotations to be established at a long-term agricultural research site in every state. Experiments 1 & 2 will be established separately to accommodate differences in irrigation requirements for potato and rotational crops. Each experiment will consist of 6 treatments that will each be replicated 5 times in a randomized complete block design. Rotation crops and sequences will be optimized to each region. Within each of the two field experiments in every state, the six treatments will include: (i) a control planted to standard Russet Burbank; (ii) a control planted to region-specific preferred potato cultivar; and four treatments to be determined by each state's investigators with input from growers. Treatments are expected to include one or more of the following: alternative crop rotation sequences; microbial inoculants; green manure or cover crop treatments; fumigation; or nutrient amendments. Soil biotic characteristics to be analyzed include: organic matter (%), active carbon, soil respiration, and autoclave citrate extractable protein. Soil physical characteristics measured will include texture, wet aggregate stability, and compaction with a penetrometer. Soil chemical properties measured using standard soil testing procedures. Microbial community composition in every soil sample will be characterized by sequencing of prokaryotic 16S-V4 and fungal ITS2 rRNA gene regions.Objective 2: We will employ GIS-based spatial analyses and geostatistics to evaluate measurements from geo-referenced field sampling points with the goal of evaluating the consistency of relationships in space among biological, chemical, physical soil assessments and plant health/productivity data. This work seeks to determine the feasibility of subfield management and aid in identifying locations in the field where plant protection is most needed (e.g., pathogen hot spots). It is our intent to create a database and pipeline that would integrate subfield biological, chemical, and physical soil measurements and allow for visualization of the data using a suite of spatial analysis tools. These tools will provide the foundation to be ported to a web-based graphical user interface (GUI). An on-farm network of sites throughout commercial potato production areas in ID, WA, OR, ND, MN, WI, MI, ME and CO will be established. In each production area, potato fields with varying levels of disease pressure or inoculum, based on grower cooperator reporting or pre-plant quantification, will be selected for sampling. Potato fields with high and low disease pressure and productivity in previous years will be selected for sampling. Management history, (e.g., length of rotation, cultural practices, variety, vine-kill, conventional fumigated, non-fumigated, history of cover crops such as mustard and radish types or soil amendments added) and the range of soil types, environments, and production types typical of each state will be considered when selecting field sites for sampling. When possible, fields with similar attributes (e.g. high/low disease) in different U.S. production areas will be included. All pertinent metadata for each field (e.g., crop and planting history, length of rotation and chemical use, etc.) will be collected. Soil health measurements analogous to Objective 1 will be used in this objective to study soil health in potato production systems at the national, regional, farm and field level. Field sites throughout commercial potato production areas in participating states will be identified and sampled. Specifically, up to four field sites will be sampled from each of the nine states on an annual basis over a four-year period.Objective 3: The crop rotation, cover crops, fertilizer, and inoculant practices outlined in the above objectives may provide significant benefits through improved soil health, water retention, pest reductions, and increased yields. However, they may also increase economic costs, particularly in the short term. Therefore, understanding the physical benefits of healthy soils alone is insufficient to promote better on-farm practices; we must also understand the incentives and impediments that prevent individuals and businesses from adopting such practices. Despite the potential benefits of soil enhancement strategies, many growers will desire additional information, education, and surety that adopting new practices will lead to improved outcomes. Our intent is to assist growers by providing risk and economic information for soil enhancement strategies. Existing enterprise budgets will be modified based on information garnered in Objectives 1 and 2 (Core Field Experiments). These modifications will account for additional costs imposed by the proposed soil enhancement practices and rotations to evaluate the financial feasibility of each activity (or in the case of the rotation experiments, of the entire rotation versus current practice). This analysis will require a thorough collection and evaluation of regional crop and enterprise budgets, including any significant capital investments required to plant or harvest under the experimental cropping practices. The experimental design will randomize the information each participant observes when making a hypothetical decision to adopt a new practice. Once a sufficient understanding of soil enhancement practices has been achieved, information from the core field experiments will be used to estimate the total benefits (in net present value) of each practice, and all reasonable permutations of each practice for a given producer. The model will also allow for random shocks in output price and weather, to provide sensitivity to each production choice. Choice variables in the model will include the presence and level of particular soil enhancement strategies and cropping choices. These choices will affect the state variables of interests--specifically pathogen buildup, weed populations, and nutrient availability--which have a direct effect on yield and pest outbreaks.Objective 4: The team assembled for this proposal includes plant pathologists and soil scientists. In the context of soil health (and more specifically soil health measurements), pathogenic microorganisms have not traditionally been considered in these assessments. Plant pathologists think about soil health in terms of reducing pathogens, while soil scientists think about soil health in terms of increasing soil organic matter, enhancing soil biology and improving physical structure. Here, we seek to combine both a plant pathology vision for soil health with the traditional soil science approach to develop state, regional, and national extension programming in Potato Soil Health. A three-tiered approach (state, regional, and national programming) will be taken to achieve the extension objectives. The structure will be a bottom-up approach where state extension programming supports regional programming and regional programming supports national programming.

Progress 09/01/20 to 08/31/21

Outputs
Target Audience:The following target audiences were reached: Potato growers; Potato agronomists; Potato processors; Potato industry personnel; Extension educators; Scientific community working with potato production. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Colorado State University researchers incorporated data from the Potato Soil Health Project into two undergraduate courses, in units exploring sustainable agricultural practices. Two undergraduate students in Agricultural Biology have been trained in wet lab skills, data management and analysis, and soil processing under this project. Researchers have presented to growers and the general public through conferences, research board meetings, and informal research discussions. At the University of Maine, a Ph.D. student and an M.S. student have been supported by the grant as key personnel in the project. They have given presentations on the project at Extension meetings. The University of Minnesota provided 100% support to a postdoctoral student for DNA sequence analysis for the whole project in Objectives 1 and 2 until the end of May 2021. This postdoc also hosted a series of five monthly meetings between January and May 2021 to train other researchers on the project in analyzing microbiome data. A replacement is currently being sought. A second postdoc has received 100% support under the project since March 2021. He is assisting with DNA sequence analysis and is analyzing Objective 2 data for the full project. In addition, support staff have contributed to field plot establishment in Objectives 1 and 2, plot maintenance in Objective 1, soil sample collection, harvest, and tuber sorting and grading. North Dakota State University provided 100% support to one postdoctoral student responsible for both fieldwork logistics and data analysis. Two other postdoctoral students and four undergraduates have contributed to the project and gained experience in diverse field and laboratory techniques. Support staff have contributed to soil sampling, penetrometer measurements, and tuber harvest, sorting, and grading. Oregon State supported and trained one postdoctoral student through January 2021, when she obtained a position in industry. A new postdoctoral student is being sought. A graduate student research assistant supports field and laboratory work for this project, including field experimentation, sampling, and data collection and analysis. Two graduate students are being trained through this project at the University of Wisconsin - Madison, one in soil science and one in plant pathology. A master's student at Washington State supported by this grant will present a poster online at the American Phytopathological Society Annual Meeting - Plant Health - in August 2021. How have the results been disseminated to communities of interest?Results have been shared on our project website (https://potatosoilhealth.cfans.umn.edu), including Extension factsheets, progress updates, and minutes of group and stakeholder meetings. Factsheets and announcements are also shared through the project Twitter account (@SpudSoilHealth). Nine Extension factsheets have been produced and shared through these outlets. On January 5, 2021, a poster and virtual booth were presented at the Potato Expo, a grower's conference that was held online this year. A webinar was presented on February 16, 2021. It was hosted by Spudman, a trade journal for potato growers, and it was the most successful webinar hosted by this publication to date, with over 200 viewers. Researchers from the project gave presentations on soil health as it pertains to soil characteristics, soil microbes, and potato farm economics. We held a stakeholder meeting (virtually) on March 4, 2021, to provide project stakeholders with a progress report and solicit their input on future directions. Research teams participating in Objective 1 contributed soil and tuber samples to the Real Food Campaign to assist with their research on the linkages between soil health and crop nutrient density (https://bionutrient.org/site/real-food-campaign). Traditional methods of disseminating results, such as industry and academic conferences, grower workshops, and field days have been greatly inhibited by the COVID-19 pandemic during this reporting period; lathough participants have been involved with virtual conference and more recently in person field days asindicated in the products and output section. What do you plan to do during the next reporting period to accomplish the goals?Objective 1. Soil samples will be collected and penetrometer readings taken in all experimental plots in late summer through fall 2021 and spring and summer 2022. The 2021 samples will be taken after rotation crop harvest and prior to any application of chemical fumigants or planting of biofumigant crops. The spring 2022 samples will be taken before any fertilizer applications (and before planting), and the summer samples will be taken 60 days after planting. All samples will be analyzed for soil physical and chemical characteristics, and DNA will be extracted for microbiome sequence analysis. In addition, the fall 2021 and spring 2022 samples will be analyzed for the population densities of Verticillium propagules and 16 nematode taxa. All experimental treatments, including compost or manure applications, fumigant applications, and rotation crops, cover crops, green manure crops, and biofumigant crops, will have been fully applied by the time potatoes are planted in all plots in spring 2022, the fourth and final year of fieldwork. By the end of the next reporting period, the potato crop will have been harvested from a portion of the experimental sites, particularly in the western states. Microbiome DNA sequencing and processing will continue. We anticipate that sequencing will speed up in the next year as demand for COVID-19 testing wanes and sequencing for research projects becomes a higher priority at the University of Minnesota Genomics Center. A new postdoctoral student is being hired at Minnesota to work on processing the raw sequence data, distributing the processed data to project researchers, and analyzing the whole-project microbiome results for Objective 1. Analysis of 2019 and 2020 soil and harvest data will continue, and analysis of microbiome results will expand substantially as researchers explore and familiarize themselves with the data. Cynthia Gleason and colleagues will further analyze the 2019 nematode data to compare community indices such as phylogenetic diversity among the experimental treatments used. They will continue processing of 2020 and 2021 samples. Objective 2. Researchers in participating states will collect harvest samples in the 23 sites used in 2021, sorting and grading the tubers and measuring specific gravity and the prevalence of disqualifying hollow heart, severe scab, and vascular browning in a representative subset of tubers from the harvest sample. In 2022, researchers will survey a mixture of new and revisited grower field sites, collecting soil samples and penetrometer readings at planting and 60 days after and tuber samples shortly before the grower-determined harvest date, as in previous years. Soil physical and chemical characteristics will be measured at both sampling times, while aggregate stability and populations of Verticillium propagules and nematodes will only be measured in spring. In sites that have not been surveyed previously, soil texture will be measured in the spring samples. Processing of 2019 microbial sequence data will be completed, as will sequencing and processing of 2020 sequence data. An initial spatial statistical analyses of the 2019 and 2020 data for the whole project will be complete by the end of the reporting period, and analysis of the 2021 data will have begun. Objective 3. The discrete choice experiment to identify the attributes of growing practices that are most and least amenable for growers will be completed. A sensitivity analysis to model effects of soil health management decisions on farm economics will be parameterized based on field results from years 1 and 2. Researchers will attend two annual meetings (held by the Potato Association of America and the National Potato Council) to discuss results and elicit feedback. Objective 4. A final factsheet will be completed by the end of the next reporting period, if not by the end of the current one. After that, work will begin on a larger soil health practices manual for potato growers. This manual will focus on irrigated cropping systems and will be structured around the timing of soil health interventions (rotations, pre-season, in-season, harvest/postharvest) and highlight a dozen or so specific practices that be applicable across regions but allow for addendums as needed for specific practices within states or regions. The manual will promote the why, how, when, what and how much for each section discussed and our current outline is projecting around 10 chapters for the manual. Development will begin in the fall of 2021, and draft will be completed by summer or fall of 2022.

Impacts
What was accomplished under these goals? Objective 1. Potato plots in the two-year rotation plots were surveyed for percentage green cover remaining shortly before vine kill. Green cover is strongly related to the severity of potato early dying, which is caused by Verticillium fungi. Potatoes were harvested from the two-year rotation plots in all states participating in Objective 1 (CO, ID, ME, MI, MN, ND, OR, and WI). For russet potatoes, marketable yield was divided into U.S. No. 1 and U.S. No. 2 grades, and yields of 0-4-oz., 4-6-oz., 6-10-oz., 10-14-oz., and over-14-oz. tubers were determined for each plot. Other kinds of potatoes were sorted and graded according to standards described below, in the accomplishments of individual participating states. A representative 50-tuber subsample was taken for each plot and used to measure tuber specific gravity and the prevalence of disqualifying hollow heart, vascular discoloration (a symptom of Verticillium infection), and severe scab damage. The first rotation crop was harvested from the three-year rotation crops. Soil samples were collected from these plots in late summer to fall (depending on the site) and analyzed for soil chemical and physical characteristics, and soil penetrometer readings were taken. DNA was extracted from these samples for sequencing analysis to assess the microbiome in each plot. In 2021 to date, rotation crops have been planted in all experimental plots. Treatments have been applied to plots as planned. Soil samples in all plots will be taken in late summer to fall and have already been collected in Idaho. Researchers participating in this objective also contributed tuber and soil samples to the Real Food Campaign to advance their research into the linkages between soil health and crop nutrient density. Research groups received their processed 2019 Objective 1 microbiome sequencing results in November 2000. Sequencing is also complete on the 2020 samples, and those sequences are now being processed. Effects of treatments are beginning to emerge in some locations. Researchers at the University of Idaho have found that compost applications and green manures result in statistically significant increases in soil phosphorus. Those at the University of Minnesota found that fall fumigation with metam sodium resulted in 15% higher total yields and 18% higher marketable yields in Russet Burbank potatoes across 2019 and 2020, while in Russet Norkotah, applying turkey manure increased total and marketable yield by 10% across 2019 and 2020. Cynthia Gleason of Washington State University, Inga Zasada of the USDA, Ken Frost of Oregon State University, and Ann MacGuidwin of the University of Wisconsin - Madison continue to collaborate on the nematode community analysis. They evaluated soil samples from four treatments from the three-year rotation plots in the Objective 1 fields in Colorado, Idaho, Oregon, and Wisconsin, using both morphological data and sequencing data to create a nematode reference library that can be used to identify nematode taxa based on 18S rDNA sequences. Objective 2. In 2020, due to COVID-19-related restrictions on fieldwork and travel by some institutions, researchers from some Colorado and Wisconsin were unable to participate in this objective as planned. Researchers from Idaho, North Dakota, and Oregon were able to participate, while no fieldwork in Objective 2 was scheduled for 2020 in Minnesota. Four grower fields were used in each participating state. Soil samples were taken in these fields during the previous reporting period. Yield samples were collected from at least ten feet of row shortly before the grower intended to harvest, from the same 20 locations per field used for soil sampling. For russet potatoes, marketable yield was graded into U.S. No. 1 and U.S. No. 2 tubers. Yield was determined for tubers in the following size classes: 0-4 oz., 4-6 oz., 6-10 oz., 10-14 oz., and over 14 oz. Fifty representative tubers from each sampling location were assessed for specific gravity and the prevalence of disqualifying hollow heart, vascular discoloration (a symptom of Verticillium wilt), and severe scab damage. In 2021, researchers from six states (Colorado, Idaho, Minnesota, North Dakota, Oregon, and Wisconsin) are participating in field research under Objective 2, working in 23 grower fields. Soil samples were collected from grower fields and soil penetrometer readings taken at planting time and 60 days after. Samples taken at planting were analyzed for texture unless texture (which is very stable over time) had already been measured in 2019. All samples taken at planting were analyzed for a suite of physical and chemical properties, Verticillium propagules, and 16 nematode taxa (including Pratylenchus, which interacts with Verticllium to cause potato early dying), and DNA was extracted from each sample for microbiome analysis. Samples taken 60 days after planting were analyzed for physical and chemical properties, and DNA was extracted for microbiome analysis. Researchers in Idaho have found that potato yield is negatively related to population densities of Verticillium and positively related to soil organic matter content and microbial respiration rates, indicating that managing for soil health and pathogen suppression may be beneficial to yield and farm economics in potato cropping systems. In contrast, Minnesota researchers found that the yield of U.S. No. 1 tubers was negatively related to soil organic matter in one field. However, this was partly explained by low yield and high organic matter in a low, wet area in the field, underscoring the need for caution in interpreting apparent relationships in the data. Microbial DNA samples from 2020 have been sequenced, but have not yet been processed. Samples from 2021 are awaiting sequencing, which has been delayed due to the University of Minnesota Genomics Center's involvement with COVID-19 testing, which receives higher priority. In May 2020, the co-director in charge of Objective 2 (Noah Rosenzweig) left his academic institution and the project. As a result, Michigan State University has withdrawn from participation in this objective. Project director Carl Rosen has directed activity for this objective, but a researcher with experience in GIS and microbiome research was still needed to bring work on this project to a successful conclusion. In March of this year, a postdoctoral scholar, Touqeer Abbas, was hired for this purpose. Objective 3. More than any other objective in this study, Objective 3 has been impacted by COVID-19, because much of the work depends on direct contact with potato growers at meetings, and remote substitutes for this contact have not been entirely sufficient. Nevertheless, the researchers working on this objective have persevered and made progress. They have completed a thorough survey of enterprise budgets, white, and academic papers and summarized the results of that work. They also used a discrete choice experiment survey to elicit farmer preferences for soil health practices and presented the preliminary results at the project's February 2021 webinar (described below) hosted by Spudman, a trade publication. Objective 4. During the reporting period, a total of nine factsheets on topics related to soil health management in potato cropping systems were released and published on the project website (https://potatosoilhealth.cfans.umn.edu) and Twitter account (@SpudSoilHealth). The Objective 4 team presented a virtual "booth" at Potato Expo 2021 (which was conducted online) in December 2020 providing an update on the project to potato growers. On January 5, 2021, Deana Knuteson and Bryn Evin hosted an open Q & A session on the booth, to positive participant feedback. On February 16, 2021, the project presented an hour-long webinar to potato growers on soil health in potato cropping systems, with talks on soils, microbes, and economics. Over 200 participants viewed the webinar.

Publications

  • Type: Other Status: Published Year Published: 2021 Citation: Binzen Fuller, Kate (Montana State), Alex Maas and Chris McIntosh (University of Idaho), and Deana Knuteson (UW-Madison). Basics of Potato Economics. Potato Soil Health Factsheet. July, 2021. https://drive.google.com/file/d/1givtblIJrVtj4lPEWnJ1u9PmgVWQzf10/view
  • Type: Other Status: Published Year Published: 2021 Citation: Evin, Bryn and Kenneth Frost (Oregon State University), Linda Kinkel (University of Minnesota), Ann MacGuidwin, Deana Knuteson, and Amanda Gevens (UW-Madison), Bob Larkin (USDA). What are disease suppressive soils? Potato Soil Health Factsheet. Feb 2021. https://drive.google.com/file/d/13dRbsgODWUKLfNc3dcgOEpbIsTZ-owBf/view
  • Type: Other Status: Published Year Published: 2021 Citation: Evin, Bryn and Kenneth Frost (Oregon State University), Deana Knuteson and Matthew Ruark (University of Wisconsin), and Andrew Robinson (North Dakota State University/University of Minnesota). Improving soil with cover cropping in potato production. Potato Soil Health Factsheet, November, 2020. https://drive.google.com/file/d/1WmZH9W8HwOn1W7pSXQgr-pJu7NeKdYZ3/view
  • Type: Other Status: Published Year Published: 2021 Citation: Evin, Bryn and Kenneth Frost (Oregon State University), Andrew Robinson (North Dakota State University), Deana Knuteson, Amanda Gevens and Ann MacGuidwin (UW-Madison), Jianjun Hao (University of Maine). A Brief Overview of Soil-borne Pathogens & Pests in Potato Production Systems. Potato Soil Health Factsheet, November, 2020. https://drive.google.com/file/d/1N8rX9lOKJUxuvLu6-c_wd_0zoJpNEjvR/view
  • Type: Other Status: Published Year Published: 2021 Citation: Evin, Bryn (Oregon State University), Linda Kinkle and Marian Bolton (University of MN), Deana Knuteson (UW-Madison) and Jianjun Hau (University of Maine). What are Beneficial Soil Microbes?. Potato Soil Health Factsheet, March, 2021 https://drive.google.com/file/d/1CZ1dMrGjX6EYgPFF3WZROVI2tS44liH5/view
  • Type: Other Status: Published Year Published: 2021 Citation: Evin, Bryn, and Deana Knuteson. January 5, 2021. What is a potato soil health cropping system? Update from the SCRI Potato Soil Health Project. Potato Expo 2021. Virtual conference. Potato_Soil_Health_Potato_Expo_2021_poster_final_2020_12_09.pdf - Google Drive
  • Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: Ge, T., J. Hao. Diversified bacteria associated with blackleg and soft rot of potato in Northeastern America. Annual Maine Potato Conference, online, January 11, 2021
  • Type: Theses/Dissertations Status: Published Year Published: 2021 Citation: Li, Kedi 2021. Determining effects of managements on potato early dying and soil microbiome and assessing risk of fungicide resistance in Verticillium dahliae. M.S. thesis. University of Maine NIFA FUNDING ACKNOWLEDGED
  • Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Rawal, A. and M.D. Ruark. 2020. Differences in the modern russet potato varieties at limiting and non-limiting nitrogen conditions: Above ground biomass and yield. 2020 ASA-SSSA-CSSA Annual Meeting, Virtual.
  • Type: Other Status: Published Year Published: 2020 Citation: Ruark, Matt, Deana Knuteson, Amber Moore, Bryn Evin, Carl Rosen. Soil Health Indicators for Potato Cropping Systems. Potato Soil Health Factsheet, November, 2020. https://drive.google.com/file/d/1hpuXFIL2EOGdvdpWUAeVV4hHfegdL4zo/view
  • Type: Websites Status: Published Year Published: 2021 Citation: Potato Soil Health Website. Updated, 2021. https://potatosoilhealth.cfans.umn.edu.
  • Type: Other Status: Published Year Published: 2021 Citation: Gleason, Cynthia (Washington State University), Ann MacGuidwin and Deana Knuteson (UW-Madison). Nematodes for Soil Health. Potato Soil Health Factsheet. May, 2021. https://drive.google.com/file/d/1dDmxt5pCZ7PA0zdNhSK2k5GqXALkMjZE/view
  • Type: Other Status: Published Year Published: 2020 Citation: Knuteson, Deana and Amanda Gevens (UW-Madison), Bryn Evin and Kenneth Frost, (Oregon State University), and Andrew Robinson (North Dakota State University/University of Minnesota). Fumigation in potato production systems. Potato Soil Health Factsheet. Dec 2020. https://drive.google.com/file/d/1L_2Fjpu3FZ7dIf3CpMSScgYWkpE8Llkz/view
  • Type: Other Status: Published Year Published: 2021 Citation: Knuteson, Deana and Matthew Ruark (University of WI-Madison), Amber Moore (Oregon State University), Carl Rosen (University of MN), Kurt Steinke (MI State University). Potato Soil Fertility Basics. Potato Soil Health Factsheet. April, 2021. https://drive.google.com/file/d/13Xba36PPda_VBdJDZFTR4Ph3d3uy3dlT/view


Progress 09/01/19 to 08/31/20

Outputs
Target Audience:The following target audiences were reached: Potato growers; Potato agronomists; Potato processors; Potato industry personnel; Extension educators, Scientific community Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The University of Maine provides 100% support to a PhD student for experiment design, soil and yield sampling, sample processing, and data analyses. Michigan State University provides 50% support to one graduate student. This student maintains the Objective 1 study site, collecting and processing soil samples per the project schedule and applying pesticides as needed to maintain crop health. The University of Minnesota provides 100% support to a postdoc for DNA sequence analysis for the full project in Objectives 1 and 2. She also participates in experimental design, soil and yield sampling, and sample processing in Objective 1. In April, they hired a master's student to work hourly for up to 14 hours per week performing GIS analysis of the Minnesota data in Objective 2. In addition, graduate student and support staff at the University of Minnesota have contributed to field plot establishment, soil sample collection, harvest, and tuber grading, as well as development of analytical pipelines for sequence data analyses. North Dakota State University fully supports one PhD student on the grant. She manages and participates in all activities for Objectives 1 and 2 except planting and harvesting of the Objective 1 plots and maintaining the project budget. She helped selected 2019 fields for Objective 2 and selected the 2020 fields. She regularly provides state updates for group conference calls and stakeholder meetings. Oregon State University has one postdoctoral scholar and one graduate student are working on this project. The postdoc was hired in January 2020 and is responsible for support of the extension and outreach objectives related to the project for the Western U.S. She is participating in field days and grower education events, developing extension documents, as well as, a soil health manual for the Western U.S. She is also contributing to the ongoing field and laboratory studies, soil sampling, and data analyses. A graduate research assistant was hired to support the field and laboratory work related to this project, including the field experimentation, sampling, and collection and analyses of generated data. At Washington State University, a Master's student supported by the grant is assisting Cynthia Gleason with genetic and morphological nematode community analysis. The University of Wisconsin - Madison provided 100% support to one postdoc responsible for extension and outreach activities in the Eastern U.S. She helped develop two extension documents and began literature review work for a soil health manual for the Eastern U.S. She worked on the project from January 2019 to February 2020. In August 2020, a replacement postdoc was hired at 50% support. In addition, each state has employed undergraduate students to assist with fieldwork and data collection in more limited capacities. How have the results been disseminated to communities of interest?We continue to develop the project website (https://potatosoilhealth.cfans.umn.edu/), which provides access to the minutes of our group and stakeholder meetings as well as PDFs of some of the presentations given over the course of the project. Individual state researchers have been involved with grower workshops, academic and professional conferences, and field days. These presentations have been documented in the "products" section of this report. Finally, we have held three stakeholder/advisory committee meetings since our last progress report: one at the Potato Association of America meeting in Winnipeg, MB, on July 31, 2019; one at the Potato Expo in Las Vegas, NV, on January 15, 2020; and one at the International Hotel at the Minneapolis-St. Paul airport on March 13, 2020. What do you plan to do during the next reporting period to accomplish the goals?In Objectives 1 and 2, the remaining yield samples will be collected and sorted by size and grade, and 50-tuber subsamples will be assessed for disease symptoms and quality. In Objective 1, cover crops will be planted after harvest in designated treatments, and rotation crops will be planted in all plots (both two-year and three-year rotations) in 2021. In Objective 2, fields on two-year rotations that were initially sampled in 2019 will be re-sampled on the same grids in 2021. New grower fields will also be sampled, and states that were unable to sample grower fields in 2020 due to COVID-19-related research restrictions will compensate by adding more fields in 2021 and 2022 than originally planned, provided the restrictions are lifted by then. Analysis of the 2019 data is still underway. Soil physical, chemical, and health data were not complete until February of this year, and we have only recently received microbiome data. In 2020, our main soil analysis vendor has been turning samples around much more quickly, and our contract with the University of Minnesota Genomics Center is now in place, which should result in much faster turnaround of microbiome data in future years.

Impacts
What was accomplished under these goals? Accomplishments for each objective over the past year are as follows: Objective 1. In 2019, after our previous REEport was submitted, soil samples were collected and penetrometer readings made 60 days after planting from each plot under three-year rotation. The soil samples were submitted for soil physical, chemical, and health analyses, and DNA was extracted from each sample for microbiome analysis. Tubers were harvested from each of these plots, and total yield marketable yield divided into U.S. No. 1 and No. 2, and yields of 0-4-oz, 4-6-oz, 6-10-oz, 10-14-oz, and over-14-oz were determined for each plot. A representative 50-tuber subsample of marketable yield was collected from each plot and analyzed for specific gravity, the prevalence of hollow heart, severe scab damage, and vascular browning (indicative of Verticillium infection). Soil samples and penetrometer readings were also collected from the plots under two-year rotation in the late summer and fall. These were submitted for physical, chemical, health, and nematode community analyses, and DNA was extracted for microbiome analysis. In 2020 to date, the two-year rotation plots have been planted in all states participating in Objective 1 (Colorado, Idaho, Maine, Michigan, Minnesota, North Dakota, Oregon, and Wisconsin). Soil samples were collected before planting and 60 days after planting. These samples have been submitted for soil physical, chemical, and health analysis, and DNA has been extracted from each sample for microbiome analysis. Treatments to be applied before planting, such as soil fumigation and manure application, were conducted as planned. In Oregon, the two-year rotation plots have been harvested, yield samples have been collected and sorted by size and grade, and 50-tuber subsamples have been taken for tuber disease and quality assessments. In the three-year rotation plots, the first of two years of rotation crops have been established and all planned rotation-year treatments to date have been applied. No soil samples are scheduled this year for the three-year rotation plots. Cynthia Gleason of Washington State University, Inga Zasada of the USDA, Ken Frost of Oregon State University, and Ann MacGuidwin of the University of Wisconsin - Madison are collaborating on nematode community analysis of soil samples in potato cropping systems in conjunction with the Potato Soil Health Project. In 2019, they obtained 70 core samples from Potato Soil Health Project fields in Idaho, Washington, Oregon, Colorado, and Wisconsin. The samples were divided into two parts, half for nematode morphological analysis and half for DNA sequence analysis. The goal is to compare molecular and metabarcoding methods for nematode community analysis and incorporate nematode community data into the larger soil health SCRI dataset to improve soil health assessment. Subsequently, a total of 1,665 DNA samples were submitted to the University of Minnesota Genomics Center for characterization of bacterial (16S) and fungal (ITS) sequences. Though COVID shutdowns delayed sample processing, sequencing data were received in mid-August of 2020. In 2019, a total of 555 samples, from trials in 8 different states were collected at each time point over the growing season; pre-planting, 60-days and harvest. . Objective 2. In 2019, all of the sampling plots in grower's fields that were sampled for pre-planting soil characteristics were again sampled for soil characteristics 60 days later. Like the spring samples covered in the previous REEport, the 60-day samples were sent to be analyzed for soil physical, chemical, and health characteristics, although their nematode communities were not assessed. DNA was extracted from the soil samples and, along with the DNA extracted from the pre-planting soil samples and the Objective 1 samples from 2019, sent to the University of Minnesota Genomics Center for 16S and 18S sequence analysis. Yield samples were collected by hand from 10 feet of row in the center of each plot shortly before each grower's scheduled harvest. Tubers from these samples were sorted by size and grade, and a representative subsample of 50 tubers (or as many marketable tubers as were available) was assessed for specific gravity, hollow heart, scab, and the presence of vascular discoloration, a symptom of verticillium wilt. In total, 28 grower fields were sampled in 2019 from Colorado (4), Idaho (2), Michigan (6), Minnesota (4), North Dakota (4), Oregon (4), and Wisconsin (4). All data from the 2019 season have now been collected, and analyses have begun. State PIs have analyzed their data for non-spatial correlations, and the University of Minnesota has begun work on spatially informed correlation analyses and multi-site analyses. Due to COVID-19-related restrictions on fieldwork, some of the project PIs were unable to conduct research in growers' fields in 2020. PIs in Idaho, Oregon, and North Dakota were able to conduct fieldwork related to this objective in this year, while those in Colorado, Michigan, and Wisconsin were not. No fieldwork in Objective 2 was planned in Minnesota in 2020. In each participating grower's field, sampling grids were established, soil samples were collected, and penetrometer readings were taken before planting and 60 days after planting. Soil from each sampling time was sent for physical, chemical, and health analysis, and DNA was extracted from each sample. In addition, a portion of the pre-planting samples was sent for nematode community analysis. Objective 3. Chris McIntosh and Alex Maas (University of Idaho) worked with Kate Fuller (Montana State University) to design a choice experiment survey with which to elicit perceived benefits and costs of practices to benefit soil health. They are continuing to develop a decision support and budgeting tool that incorporates soil health dynamics in calculating net present value returns from rotation crops and other practices to promote soil health. Objective 4. Oregon State University hired a postdoctoral scholar, Bryn Evin, in January 2020 to support outreach and extension activities related to the grant for the Western U.S. She is participating in developing extension documents, as well as a soil health manual for the Western U.S. At the University of Wisconsin - Madison, postdoctoral scholar Michelle Marks helped develop the first two of a planned series of factsheets for the public, one on the soil microbiome and one on the definition of healthy soil. She started drafting a review paper on existing potato early dying (PED) management strategies in the Upper Midwest and assembled a list of existing extension materials on potato soil health, scab, and PED for eventual inclusion in the website. She also launched and managed the project's Twitter page (with the handle @SpudSoilHealth); Bryn Evin has taken over curation of this page. Finally, Dr. Marks and Dr. Matt Ruark put together a survey to determine what types of information potato growers are interested in receiving as part of the project, how they would like to receive it; Dr. Ruark tested this survey on growers at the Wisconsin Potato and Vegetable Growers Association meeting in Steven's Point, WI, in early February 2020. The survey had 69 respondents and the results were published in the June edition of the Badger Common'Tater (trade publication of the Wisconsin Potato and Vegetable Growers Association, https://issuu.com/bctater/docs/620_standard. These results are being used to determine future extension needs for the project. Dr. Marks left the project in late February. In early August, Deana Knuteson was hired to fill the role of project extension specialist for the Eastern U.S.

Publications

  • Type: Other Status: Published Year Published: 2020 Citation: Marks, M., M. Ruark, R. Lankau, L. Kinkel, and K. Frost. What is the microbiome? NIFA Enhancing Soil Health in U.S. Potato Production Systems Extension Publication. https://potatosoilhealth.cfans.umn.edu/education
  • Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Evin, B., E. Smith, J. Stemke, V. Killman, A. Moore, and K. Frost. 2020. Defining and manipulating soil health in potato production systems. Poster. Annual Potato Association of America Meeting. Online July 20-22, 2020
  • Type: Websites Status: Published Year Published: 2020 Citation: https://potatosoilhealth.cfans.umn.edu/
  • Type: Other Status: Published Year Published: 2019 Citation: Jahn, C. J. and J. E. Stewart. Soil Health in Potato. CPAC Newsletter, 2019
  • Type: Other Status: Published Year Published: 2019 Citation: Keller, Denise. October 14, 2019. Improving Soil Health. Potato Country. September/October 2019. https://potatocountry.com/2019/10/14/improving-soil-health/#:~:text=The%20project%20aims%20to%20enhance,biological%2C%20chemical%20and%20physical%20characteristics.&text=The%20expectation%20is%20to%20see,%2Dyear%20rotation%2C%20Moore%20explained.
  • Type: Other Status: Published Year Published: 2019 Citation: Pinkerton, Rachal. December 12, 2019. Potato soil health research underway. Columbia Basin Herald. https://columbiabasinherald.com/news/2019/dec/12/potato-soil-health-research-underway/
  • Type: Other Status: Published Year Published: 2020 Citation: Tekip, Alex. July 1, 2020. Health soil for healthy potatoes. Futures. Summer 2020. https://www.canr.msu.edu/news/healthy-soil-for-healthy-potatoes
  • Type: Other Status: Published Year Published: 2020 Citation: Marks, M., M. Ruark, K. Steinke, and K. Frost. 2020. What makes healthy soils? USDA NIFA Enhancing Soil Health in U.S. Potato Production Systems Extension Publication. https://potatosoilhealth.cfans.umn.edu/education
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Delventhal, K.D., X. Li, V. Skillman, D. R. Leopold, P.E. Busby, and K. E. Frost. 2019. Tare soil microbiome of seed potato (Solanum tuberosum) varies by geographic location and seed growing operation. Phytopathology 109(Suppl. 10): S2.152.
  • Type: Journal Articles Status: Awaiting Publication Year Published: 2020 Citation: Fuller, K. B., C. McIntosh, and N. Zidack. 2020. Valuing disease prevention in a vegetatively propagated annual crop: Benefits from the Montana seed potato certification program. Plant Disease. In press. https://doi.org/10.1094/PDIS-03-19-0443-SR
  • Type: Journal Articles Status: Under Review Year Published: 2021 Citation: Crants, J., C. Rosen , L. Kinkel, JP Dundore-Arias, A. Robinson, and N. Gudmestad. Potato nitrogen response and soil microbial activity as affected by fumigation. Under review.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Hao, J.J. Managing Plant Microbe Interactions in Soil to Promote Sustainable Agriculture. W3147 Annual Meeting, Puyallup, WA. Dec. 6, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Li,K., Y. Wang, S.B. Johnson, R. Larkin, A. Smart, J. Hao. Efficacy and resistance risk of Aprovia and Elatus in controlling Verticillium dahliae. Annual Meeting of Northeastern Division of American Phytopathological Society. Northampton, MA, Mar. 11-13, 2020


Progress 09/01/18 to 08/31/19

Outputs
Target Audience:The following target audiences were reached: Potato growers; Potato agronomists; Potato processors; Potato industry personnel; Extension educators, Scientific community Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Each state has hired undergraduate students, graduate students and/or postdoctoral research associates to assist with this project. All of these individuals will have the opportunity to participate in the research or outreach activities. Some will also participate in professional meetings once the results from the objectives are obtained. How have the results been disseminated to communities of interest?One of our first activities was to develop a website for the project. The URL for the website is: http://potatosoilhealth.cfans.umn.edu/. This website provides access to the minutes of our group and stakeholder meetings as well as PDFs of some the presentations given over the course of the project. More importantly, individual states have been involved with grower workshops to discuss the project objectives and anticipated outcomes. All of these presentations have been documented in the "products" section of this report. Finally, we have held two stakeholder/advisory committee meetings, one at the Potato Expo in Austin TX on January 10, 2019, and one at the Minneapolis-St. Paul airport hotel on March 7, 2019. We received useful feedback on treatments for our experiments in objective 1 as well as on approaches for the other objectives. What do you plan to do during the next reporting period to accomplish the goals?For objectives 1 and 2, our immediate plans are to take soil samples from the experimental plots and commercial grower fields at approximately 60 days post planting. These samples will be sent to the labs for soil health and disease measurements. At the end of the growing season, yield and quality measurements will be made. Soil samples will also be collected in the late summer to obtain initial soil health measurements and disease assessment for plots to be established in 2020. For objective 3, a protocol for yield and quality measurements will be finalized to enable an economic analysis of the data. For objective 4, the PDs, Co-PDs, Co-PIs, and stakeholders will have the opportunity to meet at the Potato Association of America meeting in July 2019 to provide an update on the research and obtain more feedback for future years. A soil health extension specialist will be hired for the Pacific Northwest area to assist with outreach and extension programming in that area of the U.S. In the Midwest/East a conference call is scheduled this June to formulate a detailed extension plan to disseminate soil health information to stakeholders in the region.

Impacts
What was accomplished under these goals? Because this is a field based project and we are in the first year, there are no results to report yet; however, significant progress has been made in setting up field experiments and initiating outreach activities including stakeholder engagement. A project manager, Dr. James Crants, was hired in October 2018. One of our first major activities was to develop a website for the project, which can be accessed at the following URL - http://potatosoilhealth.cfans.umn.edu/. This website is updated on regular basis. Accomplishments for each objective are as follows: Objective 1. The PI's in each state (CO, ID, ME, MI, MN, ND, OR, WI) designed an experiment with six treatments in two-year rotations and six in three-year rotations. One of the six treatments in each rotation has been planted with Russet Burbank grown using conventional methods for the region as a control treatment for comparison with the same treatment in other states. The other five treatments use cultivars commonly grown in the state in question and test soil health management techniques of interest to growers in that state. The effects of each treatment are being measured in terms of soil physicochemical characteristics (e.g., nutrient concentrations, organic matter content, pH), soil health characteristics (e.g., aggregate stability, 24-hour CO2 release, protein N, penetrometer readings), Verticillium and nematode population assessments, and soil microbiome analysis, as well as plant health and crop yield and quality. Samples were taken before or within one week after planting. Objective 2. All participating states have identified participating grower fields for 2019, placed grid points within each field, and collected soil samples at each grid point for the same measurements listed in objective 1. Most have shipped the soil samples to vendors for analysis. Maine is not participating in this objective. However, researchers in Maine will be performing parallel sampling and analysis in an existing long-term potato research plot established over 10 years ago. Data from this study will be used as a baseline for comparison with the commercial fields. Objective 3. An informal, interactive pilot survey was conducted at a workshop at the 2018 Montana Seed Potato Seminar. Eighty-five participants, most of them seed potato growers and most from Montana, were provided with electronic clickers with which to respond to 23 questions about their soil health management practices and their reasons for adopting or not adopting practices. The questions touched on crop rotation, cover crops, leaving crop residues in place, reduced tillage, and soil amendments. Objective 4. The regional extension manager for the Midwest/East region, Michelle Marks, was hired in January 2019. She has been reviewing and summarizing the existing literature on soil health in potato cropping systems. At the state level, multiple project PIs have given presentations or led workshops related to this project since work began. A list of these presentations and workshops, a list of project hires, and the slides from a subset of the presentations can be found at http://potatosoilhealth.cfans.umn.edu/education.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Rosen, C. et al. (2019) The Soil Health Initiative: Enhancing Soil Health in Potato Cropping Systems MN Area II Potato Growers Workshop, Duelm, MN, Feb. 26, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Rosen, C. et al., 2019. The Soil Health Initiative: Enhancing Soil Health in Potato Cropping Systems , Northern Plains Potato growers research reporting session, Grand Forks, ND, Feb. 19, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Rosen, C. 2019. Enhancing Soil Health in Potato Cropping Systems: The SCRI Kickoff. Potato Expo. Austin, TX January , 9, 2019. http://potatosoilhealth.cfans.umn.edu/sites/g/files/pua5841/f/media/potato_expo_2019_ppt_soil_health_final.pdf
  • Type: Websites Status: Published Year Published: 2019 Citation: http://potatosoilhealth.cfans.umn.edu/
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Gudmestad, N. 2019. Potato Soil Health. McCain Foods Annual Grower Meeting. Plover, WI. February 28, 2019.
  • Type: Other Status: Published Year Published: 2018 Citation: Stunz, S. 2018. Digging in on Soil Health. Spudman. Vol. 56, #8. 32-34. http://potatosoilhealth.cfans.umn.edu/
  • Type: Other Status: Published Year Published: 2019 Citation: Manning, A. 2019. Potato pathogens meet their match through $8 million research initiative. https://agsci.source.colostate.edu/potato-pathogens-to-meet-their-match-through-8-million-multistate-research-initiative/
  • Type: Other Status: Published Year Published: 2019 Citation: Erlich, S. 2019. Always Learning: Elevating potato research in Colorado and throughout the world. Potato Grower Magazine. March issue. https://www.potatogrower.com/2019/03/always-learning
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Thornton, M. 2019. Recent advances in management of the potato early die complex. Syngenta potato partners, San Antonio TX. November 14, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Thornton, M. 2019. What are the alternatives to fumigation? Univ. of Idaho Storage and Agronomy Advisory Committee. Twin Falls, ID Dec. 6, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Thornton, M. 2019. Soil Health Workshop. Idaho Potato Conference. Pocatello, ID. January 31, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Marks, M., 2019. Potato Soil Health National Project: An Introduction & Overview. Wisconsin Seed Potato Improvement Association, Inc. Antigo, WI, January 30, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Ruark, M., 2019. Launching the USDA-SCRI potato soil health project. UW Extension & WPVGA Grower Conference. Stevens Point, WI. February, 5, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: MacGuidwin, A. 2019. Improving soil health with cover crops. UW Extension & WPVGA Grower Conference. Stevens Point, WI. February, 5, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Ruark, M., 2019. Other biological indicators of soil health. UW Extension & WPVGA Grower Conference. Stevens Point, WI. February, 5, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Lankau, R. 2019. Microbiome-based prediction of potato soilbourne disease and yield. UW Extension & WPVGA Grower Conference. Stevens Point, WI. February, 5, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Frost, K. 2018. Introduction and update to the potato soil health USDA SCRI CAP project. National Potato Council Summer Meeting. Leavenworth, WA. July 19, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Rosenzweig, N. 2018. Enhancing Soil Health in U.S. Potato Production Systems (Project Overview. Washington State University Extension Building Soils for Better Potato Crops. Big Bend Community College, ATEC Building, Moses Lake, WA. May 18, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Rosenzweig, N., L. Kinkel, and L. Tiemann. 2019. A national perspective on soil health in potato production systems. Michigan Potato Industry Commission Winter Potato Conference. Grand Rapids, MI. February, 14, 2019.