Progress 01/01/22 to 12/31/23
Outputs
Target Audience:Target audiences for this project included scientists, farmers, and other agricultural professionals.All target audiences were reached through a variety of extension and outreach activities, as well as conferences where PD Elmquist presented project results. We reached over 170farmers and other agricultural professionals through extension efforts related to this project. PD Elmquist shard relevant results with producers and agricultural professionals at 5 field days, 5 workshops, and 3 symposia targeted to growers and agricultural professionals.Fact sheets that included project results and take-home messages complemented the field day presentations and were distributed to all attendees.Results wereshared during two 1.5 hr-long courses titled "Macrofauna & Soil Health: Getting to know our belowground partners in PNW wheat systems" at the 2022 Washington State University Wheat Academy. Each session included a breakout period where attendees interacted with and observed live soil arthropod communities, engaged with researchers, and asked questions. Throughout the duration of the project, PD Elmquist communicated research findings to the scientific/research community. Findings were communicated during the Soil Ecology Society national meeting (2022-oral presentation), the Entomological Society of America national meeting (2022-invited oral presentation), and thePacific Branch of the Entomological Society of America meeting (2023-poster). Project findings were also presented during PD Elmquist's public dissertation defense to researchers and extension professionals. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?PD Elmquist engaged in several training activities to develop new interdisciplinary research skills in soil science and soil ecology. Members of the advisory committee assisted Elmquist in the training activities. PD Elmquist learned how to prepare plant and soil samples for elemental and nutrient analyses, respectively. This involved learning and developing proficiency in sample preparation followed by analysis using an Elementar CNS analyzer. By the conclusion of the training, PD Elmquist was able to operate the analytical equipment independently. PD Elmquist also learned how to process and analyze the data resulting from these analyses. PD Elmquist was trained in how to extract and analyze plant tissues for various phytohormones. One the main training goals of this proposal was for PD Elmquist to gain new analytical research skills.PD Elmquist learned and gained proficiency in three new analytical methods that helped him accomplishproject objectives. In addition to his own training, PD Elmquist advised and trained three undergraduate research assistants during the project. PD Elmquist trained undergraduate research assistants to quantify and characterize soil arthropods, manage data, establish greenhouse experiments,and contribute to general lab maintenance. One undergraduate research assistant has proceeded on to graduate school in the agricultural sciences. This project has resulted in an increase in undergraduates gaining research experience at the University of Idaho.Additionally, PD Elmquist has received instruction, guidance, and review for writing professional-quality scientific research articles from his advisory committee.This project has provided several professional development opportunities for PD Elmquist. Elmquist presented Obj 1. resultsengaged in interdisciplinary networking at the 2022 Soil Ecology Society meeting. Elmquist also attended the 2022 national meeting of the Entomological Society of America where he gave an invited presentation in the program symposium "What Lies Beneath: The Art and Science of Soil Arthropods". Elmquist participated in informal discussions and networking with other researchers studying soil arthropod ecology. Elmquist attended and presented at the 2023 Pacific Branch of theEntomological Society of America meeting. Elmquist gave 13extension presentations to diverse audiencesduring the life of the projectthat helped his professional development. The advisory committee was instrumental in facilitating and supporting these professional development opportunities. Finally, these professional development opportuities facilitated the hiring of PD Elmquist as the Conservation Cropping Outreach Extension Specialist for the University of Wisconsin-Madison after the completion of his PhD.There, he is directly applying the skills and techniques developed under this project to conduct research and educate growers and agricultural professionals on soil ecology and soil health. How have the results been disseminated to communities of interest?Over 170farmers and other agricultural professionals learned about project findings through extension efforts related to this project. PD Elmquist shard relevant results with producers and agricultural professionals at 5 field days, 5 workshops, and 3 symposia targeted to growers and agricultural professionals.Throughout the duration of the project, PD Elmquist communicated research findings to the scientific/research community. Findings were communicated during the Soil Ecology Society national meeting (2022-oral presentation), the Entomological Society of America national meeting (2022-invited oral presentation), and thePacific Branch of the Entomological Society of America meeting (2023-poster). Project findings were also presented during PD Elmquist's public dissertation defense to researchers and extension professionals. Relevant citations are listed in the publications section. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Agricultural sustainability can be achieved through greater reliance on biodiversity and ecosystem services, including from soils and their biota. Soil arthropods are a key component of soil biodiversity and affect soil health and plant performance through their interactions with plants and soil microbes. However, research on these effects of soil arthropods has focused on a few organisms within natural systems, largely neglecting agroecosystems and arthropod community-level effects. Given the potential for soil arthropod communities to internally regulate soil processes that contribute to agricultural sustainability, this project aims to assess how communities of soil arthropods induce changes in plant growth, performance, and resistance to aboveground herbivores and identify the mechanisms (e.g. plant hormones) mediating these effects in crop plants.Objective 1: Determine how soil arthropod communities derived directly from agroecosystem soils influence the growth and performance of winter wheat. Reporting for objective 1 is described extensively in the previous progress report, except for data on microbial communities.Microbial biomass was calculated based on PLFAs (nmol g-1 soil) and PLFA biomarkers wereused to evaluate the coarse functional group composition of the microbial community (gram-positive and negative bacteria, non-arbuscular mycorrhizal fungi, and arbuscular mycorrhizal fungi). Microbial community biomass and composition were not significantly affected by soil arthropod communities or rotation treatment. Furthermore, microbial biomass was not significantly affected by our Berlese Funnel extraction methods (i.e., microbial biomass in the pre- and post-extracted soils did not differ). Ultimately our findings show thatsoil arthropod communities may help plants defend against herbivores aboveground by facilitating induction of plant hormones related to growth and defense while offsetting costs by increasing soil nutrients and modifying plant growth.This study has changed and advanced our knowledge of the community-level effects of field-collected soil arthropods on plant growth and above-belowground interactions and calls for the consideration of community-level effects in future studies investigating how to optimize above-belowground interactions to improve plant production and protection strategies. These findings have been published in peer-reviewed journal and as a chapter of PD Elmquist's PhD dissertation.Objective 2: Examine how manipulating soil arthropod community structure influences crop growth and resistance to aboveground herbivores across multiple feeding guilds. Beneficial soil organisms, such as Collembola, may moderate harmful effects of crop pests by enhancing plant performance or resistance. Obj. 2 investigated thehypothesis that soil Collembola from two different functional groups can reduce the consequences of herbivore (Hessian fly (HF), Mayetiola destructor) attack for wheat, either by providing resources to resistant plants that make up for the costs of induced resistance or by providing resources to susceptible/intermediately-resistant plants that allow plants to initiate new growth and thereby survive the effects of being attacked by Hessian fly. Here, we quantifiedthe impact of soil Collembola functional groups-either alone or in combination-on growth of and biomass allocation by susceptible, intermediately-resistant, and resistant wheat lines in the absence and presence of HF and determined if Collembola influenced HF fitness outcomes. This study is the first to evaluate how soil arthropods affect plant-insect interactions with a gall-inducing aboveground herbivore, expanding our knowledge of above-belowground interactions between soil arthropods and herbivores.1) Major activities completed: Wheat growth and HF devlopment was measured in a greenhouse conetainer microcosm study usinga factorial design, with three wheat lines (one susceptible to HF (var. Melba), one of intermediate resistance (Var. Jefferson), and one resistant to HF (var. Kelse)), two levels of HF infestation (present +HF, absent -HF), and four levels of Collembola treatment (density of 16 Collembola individuals/microcosm): 1) control, 2) eudaphic Onychiuridae, 3) hemiedaphic Isotomidae, and 4) a combination of both functional groups Onychiuridae+Isotomidae. There were six replicates of each unique treatment combinations for a total of 144 individual conetainer microcosms. HF were allowed to oviposit on each wheatXcollembolatreatment combinationafter 10 days growth and the experiment was concluded 24 days after infestation.2) Data collected: Dried root and shoot biomass; root architecture variables (length, surface area, volume, diameter, tips, and forks); plant height 24 hrs after infestation; plant height at end of experiment; # plant leaves;# HF eggs laid; # HF pupae; # HF adults; pupal biomass; adult biomass; # of Collembola at end of experiment. 3) Summary statistics and discussion of results:At the end of the experiment, wheat varietal and HF infestation had an interactive effect on plant height and leaf number, with a strong reduction in height and leaf numberobserved in infested susceptible plants. Collembola treatment and HF infestation also had an interactive effect on plant height, with greater plant height in the Collembola treatments relative to the control only in the absence of HF.Collembola treatment and HF infestation also had an interactive effect on number of leaves, with a reduction in leaf number in the +Onych+Iso Collembola treatment in the presence of HF.Collembola treatment and HF infestation also had an interactive effect on shoot biomass, with greater biomass in the Collembola treatments relative to the control on noninfested plants. Infested plants had reduced shoot biomass in the Onych+Iso Collembola treatment. All root architectural variables, except root diameter,were impacted by wheat varietal and Collembola treatments. Infestation status did not affect root architectural variables.Female HF laid an average of 25.59±2.47 eggs per plant (range = 0-89). Neither wheat varietal nor Collembola treatment affected the number of eggs laid on wheat plants. Number of HF pupae were lowest on wheat grown in the control Collembola treatment soil, but the effect was not statistically sigificant.No HF survived to the pupal stage on resistant wheat plants. 2.17±1.16 puparia were recovered from the Jeffersonplants and 11.04±1.79 puparia were recovered from the Melba plants. Adult HF emergence was lowest on wheat grown in soils with thecombination of both Collembola functional groups. 0.89±0.50 adults emerged from the Jeffersonplants and 4.13±1.37 adults emerged from the Melba plants. Adult and pupal biomass were lowest for wheat plants grown in the control Collembola treatment soil, but the effect was not statistically sigificant. Abundance of Onychiuridae+Isotomidae was affected by a varietalXHFinteraction. In the presence of Hessian fly, Onych+Iso abundance was greater on the susceptible varietal compared to the resistant varietal with intermediate in between. In conclusion, under our experimental conditions, Collembola did not significantly impact HF densities or fitness, but did affect wheat plant biomass and root architecture, and therefore may play a role in wheat tolerance to HF in non-resistant and intermediate-resistantplants. We observed that HF infestation on the susceptible wheat varietal increased the abundance of Collembola, suggesting above-belowground bidirectional interactions between Collembola and HF.4) Key outcomes: Coupled with the results from Obj. 1, this research has changed and advanced our knowledge around the impacts ofsoil arthropods on plant-insect interactions between different herbivore guilds aboveground (e.g., piercing-sucking and gall-forming), and suggests that soil arthropods can enable crops, such as wheat, to grow well and defend better simultaneously.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2024
Citation:
Elmquist, D.C., Adhikari, S.A., Popova, I., Eigenbrode, S.D. 2024. Soil arthropod communities collected from agricultural soils influence wheat growth and modify phytohormone responses to aboveground herbivory in a microcosm experiment. Appl. Soil Ecol. 194: 105197 https://doi.org/10.1016/j.apsoil.2023.105197
- Type:
Journal Articles
Status:
Published
Year Published:
2023
Citation:
Elmquist, D.C., Eigenbrode, S.D. 2023. Going belowground: Burying anthropomorphic biases on gustation and olfaction. Front. Ecol. Evol. 11: 1231042. doi.org/10.3389/fevo.2023.1231042
- Type:
Journal Articles
Status:
Under Review
Year Published:
2024
Citation:
Elmquist, D.C., Sone, B.M., Strickland, M.S., Eigenbrode, S.D. In review. Cover crops influence soil arthropod communities, decomposition rates, and plant productivity in a subsequent cash crop.
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2023
Citation:
Elmquist, D.C. 2023. Soil Arthropod Ecology in Diversified Agroecosystems. University of Idaho.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2023
Citation:
Elmquist, D.C., Adhikari, S., Popova, I., Eigenbrode, S.D. Interactions between aboveground herbivores and belowground soil arthropod communities impact wheat growth and phytohormones. Poster presentation. Pacific Branch of the Entomological Society of America. Seattle, WA. 2023.
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Progress 01/01/22 to 12/31/22
Outputs
Target Audience:Target audiences for this project include scientists, farmers, and other agricultural professionals. We reached all our target audiences through a variety of extension and outreach activities, as well as conferences where PD Elmquist presented project results. We reached over 130farmers and othre agricultural professionals through extension efforts related to this project in 2022. PD Elmquist shared relevant results with producers and agricultural professionals at the Northern Idaho Collaborative Field Day in Nez Pearce Co., ID (50 participants) and the Prairie Area Crop and Conservation Tour, Lewis Co., ID (30 participants),the Genesee Area Crop Tour in Latah Co., ID (12 participants), and the Farmington Field Day in Whitman Co., WA (10 participants). Fact sheets that included project results and take-home messages complemented the field day presentations and were distributed to all attendees. Results were also shared during two 1.5 hr-long courses titled "Macrofauna & Soil Health: Getting to know our belowground partners in PNW wheat systems" at the 2022 Washington State University Wheat Academy.Each session included a breakout period where attendees interacted with and observed live soil arthropod communities, engaged with researchers, and asked questions. There was a total of 30 attendees (57 total registered for the academy). We will continue to work with regional producers and stakeholders to promote recognition of soil arthropods as vital regulators of soil processes in agroecosystems. PD Elmquist presented preliminary results to soil scientists, soil ecologists, entomologists and other researchprofessionals at the 2022 Soil Ecology Society during a 20-min oral presentation and Q&A period. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Training Activities As outlined in the proposal, PD Elmquist engaged in several training activities to develop new interdisciplinary research skills in soil science and soil ecology. Members of the advisory committee assisted Elmquist in the training activities. PD Elmquist learned how to prepare plant and soil samples for elemental and nutrient analyses, respectively. This involved learning and developing proficiency in sample preparation followed by analysis using an Elementar CNS analyzer. By the conclusion of the training, PD Elmquist was able to operate the analytical equipment independently. PD Elmquist also learned how to process and analyze the data resulting from these analyses. PD Elmquist was trained inhow to extract and analyze plant tissues for various phytohormones. Sample preparation involves a multi-step extraction process, followed by analysis with LC-MS. One the main training goals of this proposal was for PD Elmquist to gain new analytical research skills. In 2022, PD Elmquist learned and gained proficiencyin three new analytical methods that will assist him in accomplishing project objectives. Additionally, these analytical skills help tomake PD Elmquist a more well-rounded researcher and improves his capacity for comprehensively addressing future problems in agriculture. In addition to his own training, PD Elmquist advised and trained two undergraduate research assistants during 2022. PD Elmquist trained undergraduate research assistants to quantify and characterize soil arthropods, manage data, and contribute to general lab maintenance. One undergraduate research assistant is assisting with basic data analysis, and the other will be conducting their own independent research project in agricultural sciences. One undergraduate research assistant has applied to graduate school in the agricultural sciences. This project has resulted in an increase in undergraduates gaining research experience at the University of Idaho. Professional Development This project has provided several professional development opportunities for PD Elmquist. Elmquist presented preliminary project results (Objective 1) and engaged in interdisciplinary networking at the 2022 Soil Ecology Society meeting. Elmquist also attended the 2022 national meeting of the Entomological Society of America where he gave an invited presentation in the program symposium "What Lies Beneath: The Art and Science of Soil Arthropods". Elmquist participated in informal discussions and networking with other researchers studying soil arthropod ecology. Furthermore, PD Elmquist gave several extension presentations (described below) that helped his professional development. The advisory committee was instrumental in facilitating and supporting these professional development opportunities. How have the results been disseminated to communities of interest?We disseminated preliminary project results to over 130 farmers and agricultural professionals through our outreach efforts in 2022. We expect these efforts will lead to an increase in producer/stakeholder knowledge about soil arthropods and their contributions to soil health and sustainable agriculture and an increase in the use of agricultural practices that promote soil biodiversity and ecosystem services. PD Elmquist shared relevant results with producers and agricultural professionals at the Northern Idaho Collaborative Field Day in Nez Pearce Co., ID (50 participants) and the Prairie Area Crop and Conservation Tour, Lewis Co., ID (30 participants),the Genesee Area Crop Tour in Latah Co., ID (12 participants), and the Farmington Field Day in Whitman Co., WA (10 participants). Fact sheets that included project results and take-home messages complemented the field day presentations and were distributed to all attendees. Results were also shared during two 1.5 hr-long courses titled "Macrofauna & Soil Health: Getting to know our belowground partners in PNW wheat systems" at the 2022 Washington State University Wheat Academy.Each session included a breakout period where attendees interacted with and observed live soil arthropod communities, engaged with researchers, and asked questions. There was a total of 30 attendees (57 total registered for the academy). PD Elmquist presented preliminary results to soil scientists, soil ecologists, entomologists, and other researchprofessionals at the 2022 Soil Ecology Society during a 20-min oral presentation and Q&A period. This conference was an ideal venue to present research that is at the intersection of entomology and soil ecology. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Project Impact: Year 1 Agricultural sustainability can be achieved through greater reliance on biodiversity and ecosystem services, including from soils and their biota. Soil arthropods are a key component of soil biodiversity and affect soil health and plant performance through their interactions with plants and soil microbes. However, research on these effects of soil arthropods has focused on a few organisms within natural systems, largely neglecting agroecosystems and arthropod community-level effects. Given the potential for soil arthropod communities to internally regulate soil processes that contribute to agricultural sustainability, this project aims to assess how communities of soil arthropods induce changes in plant growth, performance, and resistance to aboveground herbivores and identify the mechanisms (e.g. plant hormones) mediating these effects in crop plants. In the first year of the project, PD Elmquist investigatedthe effects of soil arthropod communities from wheat-based systems on wheat plant growth and above-belowground interactions. He measured nutrient cycling and wheat growth in a greenhouse study using field-collected agricultural soils with and without their soil arthropod communities. PD Elmquist also assessed soil arthropod effects on aboveground plant compounds involved in defense, thecolony growth of an aphid that feeds on wheat, and the interactions among these factors.Wheat plants grown in soil with arthropod communities had 58% more aboveground wheat biomass and altered root architecture compared to control wheat plants grown in soil without arthropod. Soils with arthropod communities had more than double the amount of crop-available nitrogen compared to controls. This study also showedthat soil arthropod communities influence the production of wheat plant hormones and that the presence of soil arthropod communities modifies the production of defense-related compounds in response to aphid herbivory. These results suggest cropping practices that conserve and promote soil arthropod communities in agricultural soils can augment the internal regulation of soil processes to increase crop growth and resistance to aphid herbivores.This research is changing our knowledge of how soil arthropod communities contribute to sustainable crop production and performance. Objective 1: Determine how soil arthropod communities derived directly from agroecosystem soils influence the growth and performance of winter wheat 1) Major activities completed/experiments conducted The experiments to investigate Objective 1 were completed during this reporting period. Nutrient cycling and wheat growth was measured in a greenhouse microcosm study using field-collected agricultural soils from two rotational schemes with and without their soil arthropod communities. We also assessed the effects on above-ground phytohormones and colony growth of an aphid (Metopolophium festucae cerealium) and the interactions among these factors. 2) Data collected - Soil nitrate and ammonium concentrations (mg N kg-1soil); dried root and shoot biomass, root architecture variables (length, surface area, volume, diameter, tips, and forks); root and shoot nitrogen (%), carbon (%), and C:N;plant hormones involved in growth and defense (chlorogenic acid (CA), salicylic acid (SA), jasmonic acid (JA), methyl salicylate (MeSA), methyl jasmonate (MeJA), abscisic acid (ABA), indole-3-acetic acid (IAA);# aphids, aphid feeding damage; soil arthropod community metrics (abundance, Shannon Diversity, richness, and counts of all taxa) 3) Summary statistics and discussion of results Results The concentrations of soil nitrate and ammonium were affected by soil arthropod communities. Soils with arthropods had higher nitrate concentrations compared to soils without arthropods(+ Arth mean: 62.18± 4.76mg NO3--N kg-1soil, - Arth mean:13.07± 0.62 mg NO3--N kg-1soil).Wheat grown in soils with their soil arthropod communities had lower shoot nitrogen (+ Arth mean: 2.91± 0.09 %,- Arth mean: 3.24± 0.1 %), higher shoot carbon (+ Arth mean: 37.44± 0.32%,- Arth mean: 36.09± 0.54%), and greater shoot C:N ratio (+ Arth mean: 13.21± 0.38%,- Arth mean: 11.36± 0.32%) compared to wheat grown in soils without arthropods.Wheat grown in soils with their soil arthropod communities had significantly higher root nitrogen (+ Arth mean: 1.77± 0.20%,- Arth mean:1.38± 0.05%) and marginally higher root carbon (+ Arth mean: 42.00± 2.40%,- Arth mean:37.54± 0.74%) compared to wheat grown in soils without arthropods. Soil arthropod communities affected shoot biomass, root biomass, and root architecture. Wheat grown in soils with their arthropod communities had greater root biomass (g dry weight) (+ Arth mean: 0.14± 0.01,- Arth mean: 0.06± 0.005) and shoot biomass (g dry weight) (+ Arth mean: 0.38±0.03,- Arth mean:0.24±0.03). Similarly, wheat grown in soils with their arthropod communities had altered root architecture. Wheat grown in soils with arthropods also had greater root diameter, but only in the absence of MFC (Arth x MFC interaction).The number of aphids was greater on wheat plants grown in soils with their arthropod communities (30.50 ± 4.06) compared to wheat grown in soils without arthropods (22.13 ± 3.36). Soil arthropods did not affect aphid damage scores (+ Arth mean: 2.72 ± 0.17, - Arth mean: 2.69 ± 0.16). In the absence of MFC, wheat grown in soils without their arthropod communities had greater concentrations of ABA, MeJA, and MeSA compared to wheat grown in soils with their arthropod communities. Wheat plants grown in soils without arthropods showed no differences in phytohormone concentrations regardless of aphid presence. Wheat grown in soils with their arthropod communities had greater concentrations of ABA, CA, MeJA, MeSA, and SA when aphids werepresent compared to when aphids wereabsent. Discussion This study showed that soil arthropod communities collected from agroecosystem soils modified soil processes and influenced plant chemical and morphological traits. In addition, above-belowground interactions between soil arthropod communities and aphids modified arthropod effects on wheat traits and affected phytohormone concentrations. Overall, our results support the concept that soil arthropod communities benefit plant growth.Perhaps surprisingly, although the arthropod communities from the two rotations differed, there was no evidence that these communities had different effects on wheat plants (no soil arthropod community X rotation interactions).By enabling an induced increase in stress- and defense-related compounds and counterbalancing the costs through enhanced nutrient availability and modifications to root architecture and ensuing nutrient acquisition, soil arthropod communities may enable crops, such as wheat, to respond more efficiently to environmental stressors without compromising growth. 4) Key Outcomes Soil arthropod communities may help plants defend against herbivores aboveground by facilitating induction of plant hormones related to growth and defense while offsetting costs by increasing soil nutrients and modifying plant growth.This study has changed and advanced our knowledge of the community-level effects of field-collected soil arthropods on plant growth and above-belowground interactions and calls for the consideration of community-level effects in future studies investigating how to optimize above-belowground interactions to improve plant production and protection strategies. Objective 2: Examine how manipulating soil arthropod community structure influences crop growth and resistance to aboveground herbivores across multiple feeding guilds Objective 2 is underway during 2023 and will be summarized in the final report.
Publications
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2022
Citation:
Elmquist, D.C., Adhikari, S., Popova, I., Eigenbrode, S.D. 2022. Arthropod communities derived from agroecosystem soils affect wheat growth, phytohormones, and aphid responses. Oral presentation, Soil Ecology Society Biennial Meeting, Richland, WA.
- Type:
Other
Status:
Accepted
Year Published:
2022
Citation:
Elmquist, D.C., Kalh, K., Johnson-Manard, J., Eigenbrode, S.D. 2022. Assessing the Effects of Rotational Diversification on Soil Health Using Arthropods as Bioindicators. In S. Crow, K. Schroeder, D. Finkelnburg, S. Philips, & M. Corp (Eds.), 2022 Dryland Field Day Abstracts: Highlights of Research Progress. University of Idaho Extension.
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