SYNERGISTIC RESPONSE OF SOIL FUNCTION AND BIODIVERSITY TO MULTIPLE SOIL HEALTH MANAGEMENT PRACTICES

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: ACTIVE
• Funding Source: AFRI COMPETITIVE GRANT
• Reporting Frequency: Annual
• Accession No.: 1027664
• Grant No.: 2022-67020-36110
• Cumulative Award Amt.: $749,832.00
• Proposal No.: 2021-09118
• Project Start Date: Oct 1, 2021
• Project End Date: Sep 30, 2026
• Grant Year: 2022
• Program Code: [A1401]- Foundational Program: Soil Health

Recipient Organization
UNIV OF IDAHO
875 PERIMETER DRIVE
MOSCOW,ID 83844-9803

Performing Department
Soils and Water Systems

Non Technical Summary
Historically management of agricultural soils has resulted in depletion of soil biodiversity and inefficiencies in biogeochemical cycles. Soil health management strategies have often combated these negative effects, but stakeholders are hungry for information regarding potential synergies between management practices. Here we propose to improve the potential of soil health management and identify its implication for soil function and diversity by addressing the following integrated research (RO) objectives:•RO1. Determine the interactive effects of cover crop diversity, intercropping, compost addition, and livestock-crop integration on agroecosystem C and nitrogen (N) cycling.•RO2. Determine the interactive effects of cover crop diversity, intercropping, compost addition, and livestock-crop integration on microbial community composition, diversity, and function.•RO3. Determine whether multiple soil health management practices influence soil resistance/resilience to global change factors (i.e., warming, precipitation, and salinity regimes).To realize RO1 and RO2, we will pair a common garden experiment with a stable isotope pulse-chase, while simultaneously quantifying the composition, diversity and function of soil microbial communities, enabling for a better understanding of how soil health management practices interact. We will then expose soils to an array of global change factors, using a microcosm approach, to address RO3. Together the results of these objectives will illustrate synergies between soil health management practices, and how these practices impact soil biogeochemistry and microbial communities. Additionally, this work will provide critical links between soil health metrics and soil microbial community composition and function while also highlighting the resistance/resilience of these communities to global change.

Animal Health Component

50%

Research Effort Categories

Basic

50%

Applied

50%

Developmental

0%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
102	0199	1000	50%
102	4099	1070	50%

Knowledge Area
102 - Soil, Plant, Water, Nutrient Relationships;

Subject Of Investigation
4099 - Microorganisms, general/other; 0199 - Soil and land, general;

Field Of Science
1070 - Ecology; 1000 - Biochemistry and biophysics;

Keywords

carbon

cover crops

grazing

intercropping

metagenomics

microbial communities

stable isotopes

Goals / Objectives
We seek to understand how multiple soil health management practices enacted individually or in combination influence agroecosystem biogeochemical processes, microbial community structure and function, and response to multiple global change factors. The objectives of this project directly address the Soil Health program area priorities a and c. Specifically, the research objectives of this project will "advance scientific understanding of soil physical and biogeochemical processes and interactions." While the research objectives proposed here are of a fundamental nature, the involvement of the stakeholder advisory group will provide links to the human and economic dimensions of this project. This proposed research will also "lead to strategies to improve overall soil health and the resilience and sustainability of agricultural production systems and ecosystem services." That is, this research will examine the interaction between multiple management practices and their effects on soil health (RO1 and RO2), and through the proposed laboratory-based experiment (RO3) we will identify how these management practices effect the resistance/resilience of soils to global environmental change. Furthermore, the research proposed here will provide an "evaluation of the effects of management practices on soil microbial community's function and their contribution to healthy soils and sustainable agroecosystems." Specifically, the proposed research will assess the effect of multiple management practices on soil microbial community composition and diversity - determined via amplicon sequencing and PLFA analysis, microbial biomass, and microbial function - determined via shotgun metagenomics and extracellular enzyme activity. The proposed research will also determine if change in these microbial characteristics contribute to greater microbial C-use efficiency and/or the resistance/resilience of these communities when faced with global change phenomena. Specifics of each research objective is described below:RO1. Determine the interactive effects of cover crop diversity, intercropping, compost addition, and livestock-crop integration on agroecosystem C and nitrogen (N) cycling. Often research has focused on one or two soil health management practices at a time when considering elemental cycling and belowground biodiversity (but see Carrera et al. 2007). Understanding the synergistic effects of multiple management practices has been identified as a major need by our stakeholder advisory group. Additionally, the effect of cover crop diversity on elemental cycling is largely unknown in agroecosystems. Here we will examine how increasing cover crop diversity (from 0 to 12 species) in combination with intercropping, compost additions, and simulated grazing affect elemental cycling.RO2. Determine the interactive effects of cover crop diversity, intercropping, compost addition, and livestock-crop integration on microbial community composition, diversity, and function. Understanding the response of microbial communities to multiple soil health management practices may provide rapid insight into the efficacy of these practices. Additionally, there is increasing demand from stakeholders for microbial community metrics that are relevant and relatable to soil health (Fierer et al. 2021). Here we will examine the response of microbial community diversity, composition, and function to multiple soil health management practices. We will also examine how these community metrics related to other soil health indexes and whether the soil microbial community is indicative of a soil's response to global change (see RO3, below).RO3. Determine whether multiple management practices influence soil resistance/resilience to global change factors (i.e. warming, precipitation, and salinity regimes). In the future, agricultural systems are likely to face a range of perturbations from increasing temperature to drought to salinity, but the effect of multiple management practices on soil resistance/resilience is largely unknown. Using a lab-based microcosm study we will examine how soils exposed to multiple years of various management practices will respond to warming, drought, and salinity.Long-term goalsTogether the results of these objectives will create a clear picture of the potential interactive effects of multiple soil health management practices on soil biodiversity and agroecosystem biogeochemical cycles and productivity. This research will demonstrate the potential effect such practices have on sustainable agriculture and the ability of agroecosystems to sequester C and promote microbial diversity and function, as well as the resistance and resilience of these systems to multiple global change factors, thus leading to wider adoption of the practices we investigate. This research will lead to the identification of soil microbial metrics that can be used to assess the success soil health management techniques. Furthermore, this research may lead to novel insights regarding the integration of multiple management practices beyond those proposed here and will drive future on-farm research. Ultimately, our long-term goal is to understand the interactive effects of management practices on the sustainability and resilience of agroecosystems.

Project Methods
To assess the interactive effects of soil health management techniques on and C and N cycling (RO1), we will conduct a 4-year experiment that couples a common garden approach with stable-isotope pulse-tracking techniques. This experiment will consist of the following 4 management treatments:Cover crop diversity: Cover crop treatments will represent a continuum of species diversity, consisting of 0 (i.e. fallow), 1, 6, and 12 species combinations. Each treatment will be replicated 6 times and cover crops will be planted each fall, following recommended seeding rates, during the normal fallow period for crop production in the region.Intercropping: Intercropping will include two treatments (i.e. with or without intercropping). Intercropping will consist of spring pea (P. sativum) planted at a 1:1 basis with wheat (cultivar 'Alturas'). Intercropping will occur each spring, during the normal crop production period in the region. N fertilization will be applied based on a soil test at 0-60 cm depth at planting following the production guidelines for dryland cereal crops in Idaho.Compost addition: Compost additions will include two treatments (i.e. with or without compost). Subplots receiving compost will be amended using compost at an equivalent rate of 2.2-2.3 metric tons ha-1 each spring prior to the planting of spring wheat.Simulated livestock integration: Livestock integration will include two treatments (i.e. with or without simulated grazing). Simulated grazing will occur during the cover cropping regimes, likely during early spring of each experiment year.Treatments will be combined in a fully crossed, randomized block, split-plot design implemented at the USDA-NRCS Plant Materials Center (Pullman, WA). During the growing season, all plots will be planted with the same crop to maintain consistency, and spring pea (the intercropped species). Crops will be rotated annually using crops of interest to our stakeholder group.To assess the effect of multiple management practices on agroecosystem C and N cycling, we will conduct a stable isotope pulse-chase experiment in the fall and spring of the second and third years. Both C and N are added at low amounts in order to reduce disturbance. We will destructively harvest 0.20 m2 samples to 10 cm depth from each plot and determine the amount of 13C and 15N, using isotope ratio mass spectrometry, in the following pools: aboveground plant biomass, belowground plant biomass, dissolved organic matter, soil organic matter, and microbial biomass. We will also monitor evolution of 13CO2 across the one-week pulse-chase.We will monitor multiple edaphic characteristics associated with this experiment seasonally for 3 years. These include microbial biomass, microbial C-use efficiency, C and N mineralization, pH, and C and N in both DOM and SOM. We will also use the permanganate oxidizable carbon (POX-C) assay described in the NRCS Soil Health Technical Notes. This is a commonly used and simple assay to assess microbially available carbon.To assess the effect of multiple soil health management practices on soil microbes (RO2), we will determine soil microbial community (i.e., prokaryotes and fungi) composition, phospholipid fatty acid (PLFA) profiles, and extracellular enzyme activity during the fall (i.e., during cover cropping) and spring (i.e., during spring wheat production) each year; functional metagenomes will be determined during the fall of the second and fourth years of the experiment. We will determine soil microbial community composition and diversity via a high-throughput DNA sequencing approach.To assess the functional attributes of soil microbial communities, we will construct soil metagenomes. DNA from the soil will be extracted and purified, and shotgun metagenomics analyses will be conducted. After quality control, sequence data will be uploaded to MG-RAST for downstream analyses (i.e., assignment of genes to subsystem categories). This will enable us to assess the prevalence of genes related to specific microbial processes, from C, N, and P metabolism to pathogenicity.Extracellular enzymes are the link between microbial community structure and function, sounderstanding how soil health management practices affect enzyme activity is vital to understanding their potential impact on biogeochemical processes. We will assess extracellular enzyme activity by determining the activity of hydrolytic enzymes.Phospholipid fatty acids are important components of cellular membranes that are used as biomarkers are used to identify major groups within a microbial community. This method is widely used to assess soil health and it is currently recommended by the NRCS. With this method we can capture Gram negative bacteria, Gram-positive bacteria, anaeorobic bacteria, actinobacteria, methanotrophes, Archaea, Eurkaryotes, fungi, and arbuscular mycorrihizae fungi.To assess resistance/resilience of soils to global change factors (RO3), we will conduct a lab-based microcosm experiment. For this experiment, we will source soil from the field experiment at the end of the second year. However, to reduce sample number we will only assess treatments from 4 blocks. This reduces the number of overall samples within the experiment and will ensure tractability (i.e. 4 cover crop treatments × 2 intercropping treatments × 2 compost treatments × 2 grazing treatments × 4 blocks = 128 soil samples).Each of the soil samples, after sieving and homogenization, will be subjected to a factorial combination of three global change factors (warming, drought, and salinity). Each of these global change factors, and their combination represent perturbations likely to be experienced by producers in the region. In fact, downscaled climate models project drier and warmer summers for most of the Inland Pacific Northwest, including Idaho, with effects on agriculture. This will result in 1,280 experimental units (128 soil samples × 10 global change treatments [3 factors × 3 factors + control]). Each experimental unit will consist of 15g of dry weight equivalent soil housed in 50ml conical tubes (note: replication is at the field scale; i.e. n=4).While we expect that these three global change factors are of relevance to local stakeholders, we will also assess the factors that stakeholders identify as important to consider in the future. If a particular factor not represented above is deemed of vital interest by stakeholders, then we would incorporate it into this experiment, or potentially conduct a second experiment including that factor.The experiment will be run for 6 weeks during which time we will monitor soil respiration. At the end of 6 weeks, microcosms will be destructively harvested and both microbial community composition, and extracellular enzyme activity will be determined. Microbial community composition and enzyme activity will be determined. To gauge the degree that soil health management practices mediate the effects of global change factors on soil communities and processes, we will calculate the effect size of each global change treatment.

Progress 10/01/24 to 09/30/25

Outputs
Target Audience:The target audience for this project include farmers (both conventional and regenerative), researchers, and soil health professionals. Results have been disseminated via scientific meetings, small group meetings, and field days. Specifically, sevenpresentations have presented the results of this research. These include presentations made at the Ecological Society of America, the Soil Science Society of America, and the International Association for Food Protection meeting. Results have also been shared with stakeholders via conversations. Finally, this research has also resulted in one MS thesis. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The project has supported the training of three graduate students, and one post-doctoral fellow. These participants have received training in setting up field experiments, sample collection, and sample analysis. Graduate students and the post-doctoral fellow have also presented at regional, national, and international meetings. Graduate students and the post-doctoral fellow are also receiving training on scientific writing and are currently composing manuscripts, and dissertations related to this work. One student completer his MS thesis during this period. One PhD student, due in part to his work on this project received the2025 Tribal Agricultural Fellowship. How have the results been disseminated to communities of interest?Results have been disseminated via scientific meetings, small group meetings, and field days. Specifically, sevenpresentations have presented the results of this research. These include presentations made at the Ecological Society of America, the Soil Science Society of America, and the International Association for Food Protection meeting. Results have also been shared with stakeholders via conversations. Finally, this research has also resulted in one MS thesis. What do you plan to do during the next reporting period to accomplish the goals?We will continue to maintain the experimental site and collect samples. We will conduct a field-based pulse chase experiment in the next period and will complete assessments of soil microbial communities. We will begin preparation of manuscripts associated with this project, with the goal of submitting at least two before project completion. Students will complete or be near to completing thier dissertations.

Impacts
What was accomplished under these goals? RO1. We have collected data for the third year of this project on soil and plant metrics. We have also conducted initial analyses of this data. Briefly, we have found that increasing cover crop diversity leads to increased aboveground biomass, and this is postively related to POXC. Suggesting that increased cover crop diversity may lead to increased active soil carbon. Additionally of thirty-one plant (cash and cover crop) and soil variables assessed, we note that cover crop diversity and compost amendments tend to drive these responses. We note that soil respiration increases with both increasing cover crop diversity, and the addition of compost; active microbial biomass increases with compost but no other soil health management strategie has an effect on this variable; cash crop ground cover (%) tends to decrease with increasing cover crop diversity; and belowground cover crop biomass was affected by an interaction between all soil health management strategies. These results indicate that not all plant or soil response variables will respond similarly to soil health managementstrategies. RO2. Analyses and data collection of PLFAs, 16S and ITS amplicons, and metagenomes are being conducted. Intial analyses of 16S amplicons (i.e., bacterial community composition) indicate that compost amendments have a strong effect on community composition, and tend to weaken the effect of cover crop diversity. Additionally, bacterial community composition appears to also be influenced by intercropping and simulated grazing. Interestingly, preliminary data indicates that the abundance of stress adapted genera decrease in the presence of soil health management strategies. RO3. Results from this work were presented in one MS thesis, and are now being further analyzed for publication.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2025 Citation: Strickland, M.S. 2025. Interactions between the soil resistome and climate change. CFS Annual Meeting. Atlanta, GA, USA.
• Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Otero-Jim�nez, V., Strickland, M.S. 2024. Curious Minds: cover crops, potatoes, and soil health. Potato Conference. Pocatello, ID, USA.
• Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Strickland, M.S. 2024. Peering deeper: Exploring soil's hidden half. Palouse Prairie Foundation, Moscow, ID, USA.
• Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Strickland, M.S. 2024. The Biogeography of the Soil Resistome under Global Change  Bacterial Antibiotic Resistance. International Association for Food Protection. Long Beach, CA, USA.
• Type: Conference Papers and Presentations Status: Published Year Published: 2025 Citation: Otero-Jim�nez, V. 2025. Medium C:N ratio cover crop treatment improved soil health in the first-year study. ESA Annual Meeting. Baltimore, MD, USA.
• Type: Conference Papers and Presentations Status: Published Year Published: 2025 Citation: Otero-Jim�nez, V. 2025. Optimizing stoichiometry in Cover Crops to Boost Soil Health and Enhance Carbon Sequestration. ISAID Annual Meeting. Boise, ID, USA.
• Type: Conference Papers and Presentations Status: Published Year Published: 2025 Citation: Otero-Jim�nez, V. 2025. Managing cover crop stoichiometry to improve carbon sequestration and soil health. SSSA Annual Meeting. San Antonio, TX, USA.
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2025 Citation: Otero-Jim�nez, V. 2025.Cover crops, compost, and mowing practices improve soil health. SSSA Annual Meeting. Salt Lake City, UT, USA.
• Type: Theses/Dissertations Status: Published Year Published: 2025 Citation: Connor Daugherty. 2025. Exploring the Influence of Regenerative Agricultural Practices on Soil Health. University of Idaho, Moscow, ID, USA.
• Type: Conference Papers and Presentations Status: Published Year Published: 2025 Citation: Otero Jim�nez, V., Schott, L., Stricklaand, M.S. 2025. Optimizing stoichiometry in Cover Crops to Boost Soil Health and Enhance Carbon Sequestration. Waste to Worth Conference, Boise, ID, USA.

Progress 10/01/23 to 09/30/24

Outputs
Target Audience:The target audience during this period were stakeholders, including farmers and agroindustry, and the scientific community. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The project has supported the training of three graduate students, one undergraduate technician, and one post-doctoral fellow. These participants have received training in setting up field experiments, sample collection, and sample analysis. Graduate students and the post-doctoral fellow have also presented at regional, national, and international meetings. Graduate students and the post-doctoral fellow are also receiving training on scientific writing and are currently composing manuscripts, a thesis, and dissertations related to this work. How have the results been disseminated to communities of interest?Results have been disseminated via scientific meetings, small group meetings, and field days. Specifically, ten presentations have presented the results of this research. These include presentations made at the Ecological Society of America, the Soil Science Society of America, and the USDA PI meeting. Results have also been shared with stakeholders via conversations and during one field day conducted at the USDA Plant Materials Center in Pullman, WA. What do you plan to do during the next reporting period to accomplish the goals?We will continue to maintain the experimental site and collect samples. We will conduct a field-based pulse chase experiment in the next period and will complete assessments of soil microbial communities. We also have planned additional lab experiments examining how differences in cover crop composition impact litter decomposition and continue assessing the resistance/resilience of soil communities sourced from across different agriculture management practices to global change. Finally, one master student thesis will be completed during this next period.

Impacts
What was accomplished under these goals? During this period, we planted the second year of cover crop regimes, applied compost, applied the mowing treatments, and planted the third year of the intercrop treatments. Soil samples were taken during cover crop growth before spring planting of the intercrop treatments. These samples have so far been processed for gravimetric water content, water holding capacity, pH, Substrate Induced Respiration, C-mineralization, and N-mineralization, inorganic N (NH4 and NO3) and P (PO4) nutrient analyses, microbial biomass, POXC, and MAOM/POM carbon and nitrogen. Soil samples taken in Spring 2024 are being assessed for the same soil characteristics. DNA has been extracted from these samples and microbial community composition analyses are underway. Additionally, we are assessing how differences in the stoichiometry of cover crops impact soil health and have conducted two studies assessing the resistance/resilience of soils to global change phenomenon. As a component of the resistance/resilience assessment, a lab-based stable isotope pulse-chase experiment was conducted. Results associated with RO1 indicate multiple effects of soil health management strategies on soil properties and function, as well as early indicators of potential effects on cash crop productivity. Specifically, we found that soil respiration increased with increasing cover crop diversity and that compost amendments tended to have the greatest effect on respiration in the six and twelve species treatments. We also found that cover crop biomass was greatest in the six and twelve species treatments, and the mowing treatments tended exhibit the greatest decrease in biomass in these two treatments. Surprisingly when assessing percentage cover of the cash crop, percent cover was greatest in the fallow and single species cover crop treatments compared to the six and twelve species treatments. Assessment of yield this fall will further explore the impact of soil health treatments on the cash crop. Related to RO3, we have found that the response of agricultural soils to individual global change phenomenon (i.e., increasing temperature or drought) are not indicative of the response of these soils to multiple simultaneous global change factors. Additionally, we found that agricultural soils, regardless of their soil health scores, were not resistant to global change factors, but healthier soils tended, on average, to be more resilient. However, the resistance and resilience of soils was largely unrelated to current soil health indexes.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Otero-Jim�nez, V., Sone, B., Strickland, M.S. 2023. Enzyme activities under single species and mixtures of cover crops positively impact soil carbon availability. Ecological Society of America Annual Meeting. Portland, OR, USA.
• Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Otero-Jim�nez, V., Sone, B., Strickland, M.S. 2023. Small bench microplate colorimetric method improve carbon, and phosphorus soil enzymes results. SSSA Annual Meeting. St. Louis, MO, USA.
• Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Otero-Jim�nez, V., Strickland, M.S. 2024. Curious Minds: cover crops, potatoes, and soil health. Potato Conference. Pocatello, ID, USA.
• Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Otero-Jim�nez, V., Strickland, M.S. 2024. An overview of the use of cover crops to increase soil health. Institute of Human Health and the Environment. Moscow, ID, USA.
• Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Otero-Jim�nez, V., Strickland, M.S. 2024. Soil and Human Health. Santa Cruz de la Sierra, Bolivia.
• Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Otero-Jim�nez, V., Sone, B., Strickland, M.S. 2024. Cover crops mixture based on their C:N ratio under different soil and environmental conditions as an alternative to improve carbon sequestration and soil health. Ecological Society of America Annual Meeting. Long Beach, CA, USA.
• Type: Other Status: Other Year Published: 2024 Citation: Edmonds, J., Kayler, Z., Strickland, M., Otero Jimenez, V., Richardson, K., Daughert, C., Owusu Ansah, E. Impact of Various Agriculture Practices on Carbon and Nitrogen Cycling in Idaho. INRA Biogeochemistry of Forest Ecosystems Group, 2024, Nancy, France.
• Type: Other Status: Other Year Published: 2024 Citation: Edmonds, J., Kayler, Z., Strickland, M., Otero Jimenez, V., Richardson, K., Daughert, C., Owusu Ansah, E.Plant functional trait diversity affecting carbon cycling and drought resistance in agroecosystems ranging from the conventional to the sustainable, Gesseler Ecosystem Ecology Group, Swiss Federal Institute for Forest, Snow and Landscape Research, 2024, Zurich, Switzerland.
• Type: Other Status: Other Year Published: 2024 Citation: Edmonds, J., Kayler, Z., Strickland, M., Otero Jimenez, V., Richardson, K., Daughert, C., Owusu Ansah, E. Plant functional trait diversity affecting carbon cycling and drought resistance in agroecosystems ranging from the conventional to the sustainable, Keiluweit Soil Biogeochemistry Group, University of Lausanne, 2024, Lausanne, Switzerland.
• Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Strickland, M.S., Kayler, Z. 2024. Synergistic Response of Soil Function and Biodiversity to Multiple Soil Health Management Practices. USDA Project Director Meeting. Kansas City, MO, USA.

Progress 10/01/22 to 09/30/23

Outputs
Target Audience:The target audience during this period were stakeholders, including farmers and agroindustry, and the scientific community. Changes/Problems:Cover crop growth was less than adequate. We will attempt to remidy this issue by both planiting earlier and increasing planting depth. Because we attempted to increasse the cover crop growth period, this led to failure of the cash crop. We will terminated the cover crop earlier and plant the cash crop earlier as well. What opportunities for training and professional development has the project provided?The project has supported the training of four graduate students and one post-do. These participants have received training in setting up field experiments, sample collection, and sample analysis. One graduate student attended the 2023 Summer School Workshop through the Environmental Molecular Science Laboratory (EMSL) and the Pacific Northwest National Lab in Richland WA. The workshop cover topics on data management, experimental design for proteomics, metabolomics, transcriptomics, lipidomics and gained experience in analyzing data from experiments. How have the results been disseminated to communities of interest?Results have been dissemenated via scientific meetings, round table discussions, and field days. Additionally, the post doctoral scholar supported by this grant participated in an FFA Career Development Event. What do you plan to do during the next reporting period to accomplish the goals?We will conitinue to maintaing the experimental site and collect samples. We will conduct a pulse chase experimetn in the next period. We also have planned addional lab experiments examing how differences in cover crop composiiton impact litter decomposition, and an assessment of the resistance/resilience of soil communiites sourced from across different ag manangemnt practices to global change.

Impacts
What was accomplished under these goals? During this period we planted the first year od cover crop regimes, applied compost, and planted the second year of the intercrop treatments.Soil samples taken Spring 2023 after compost treatment established and prior to spring planting. These samples have so far been processed for gravimetric water content, water holding capacity, pH, Substrate Induced Respiration, C-mineralization, and N-mineralization. They are currently being processed for inorganic N (NH4 and NO3) and P (PO4) nutrient analyses, microbial biomass and MaOM/POM.Soil samples taken from the fall 2022 have been run for POXC and inorganic Nitrogen. POXC results showed no significant difference between intercrop and monocrop, nor between the cover crop treatments. This is likely due to it being the end of the first year of treatment, and the plots had not gone through all the treatments at this point. The ammonia and nitrate amounts were also not significant, although there was an insignificantly higher amount of both in the intercrop treatments. Finally during this period we tested two different methods to assess enzyme activity and are assessing the effect of cover crop diversity on microbial enzyme activity.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Strickland, M.S. 2022. Opportunities for incorporating soil biology: A scientific round-table discussion. SoilCon, Washington State University, Pullman, WA, USA.
• Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Richardson, K., Bauer, A., Strickland, M.S. 2022. Comparing the effects of antibiotics and alternative treatments used in the dairy cattle industry on soil microbial communities. Soil Ecology Society 2022 Biennial Meeting, Richland, Washington, USA.
• Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Richardson, K., Bauer, A., Strickland, M.S. 2022. Antibiotic Alternative in the Dairy Industry: Comparing how AHV and antibiotics affect the soil microbial community. National Diversity in STEM Conference. San Juan, PR, USA.

Progress 10/01/21 to 09/30/22

Outputs
Target Audience:The target audience during this period included scientists and stakeholders in Idaho. This research also reached individuals associated with industry developing products (i.e., microbial inoculants)for use in the agriculture sector. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Two Ph.D. students, one M.S. student, and one post-doc are working on various aspects of this project. These personnel have received training in project management, field and lab research, and experimental design. Personnel have also worked directly with NRCS staff to facilitate planting and harvest. How have the results been disseminated to communities of interest?PD Strickland and Kayler presented the experimental design to Idaho stakeholders and scientists during a regional meeting in Twin Falls, ID. What do you plan to do during the next reporting period to accomplish the goals?Analyses of soils collected in fall 2022 will be completed. In spring 2023, we will initiate the simulated graving and compost treatments associated with the cover crops. Soil samples will be collected from these treatment combinations prior to the next intercropping regime, including samples for microbial community composition and metagenomes. Also in spring 2023, cover crops will be terminated, and the intercrop treatments will be established. Harvest and sampling of these treatments will occur in Fall 2023.

Impacts
What was accomplished under these goals? We initiated and completed the first series of intercropping treatments (barley and barley intercropped with spring peas). The cash crop was planted in May 2022 and harvested in September 2022. Soil samples were collected both pre- and post-planting and are undergoing analysis for carbon stocks, permanganate oxidizable carbon (POxC), inorganic nitrogen, and phospholipid fatty acid (PLFA). The first year of cover crop treatments were planted in October 2022. In addition to the above analyses, we are evaluating enzyme activities via two methodologies: fluorometric and colorimetric. We selected these methodologies in order to identify which of them offers the most robust estimates in terms of sensitivity, reproducibility, effectiveness and efficiency.

Publications

• Type: Conference Papers and Presentations Status: Accepted Year Published: 2022 Citation: Strickland, M.S., Kayler, Z. 2022. Soil Health: Lessons learned from diversifying cropping systems. Twin Falls, ID, USA.