• Basic Information
• Additional Info

Basic Information

• Project No. and Title: NCERA59 : Soil Organic Matter: Formation, Function and Management
• Period Covered: 10/01/2020 to 09/30/2021
• Date of Report: 01/23/2022
• Annual Meeting Dates: 12/17/2021 to 12/17/2021

Participants

Present: Sindhu Jagadamma – Univ. of Tennessee Will Horwath – Univ. of California-Davis Ron Turco – Purdue Univ. – Administrative Advisor Larry Cihacek - North Dakota State Univ. Ann-Marie Fortuna – USDA-ARS, Oklahoma Sandeep Kumar – USDA-NIFA Advisor Stephen Machado – Oregon State Univ. Rhae Djriber – Univ. of Nebraska Michelle Wander – Univ. of Illinois Ray Weil – Univ of Maryland Dan Olk - USDA-ARS, Iowa Visitors: Rashad Alghamdi – North Dakota State Univ. - Post-Doc Associate (L. Cihacek) Maria Batool – North Dakota State Univ. – Graduate Student (L. Cihacek) Not Present (but submitting reports): Thea Whitmann – Univ. of Wisconsin Matt Ruark – Univ. of Wisconsin Anna Cates – Univ. of Minnesota Julie Grossman – Univ. of Minnesota Jessica Gutknecht – Univ. of Minnesota Carmen Ugarte – Univ. of Illinois Jehangir Bhadha – Univ. of Florida Mark Coyne – Univ. of Kentucky Hannah Poffenberger – Univ. of Kentucky

Accomplishments

Impacts

1. Florida: The main activity is shadowing regenerative farming practices of individual growers and assess changes in soil health indicators pre- and post-treatment. Soil health indicators measured include, pH, bulk density, maximum water holding capacity, organic matter, active carbon, cation exchange capacity, soil protein, and nutrients (total and Mehlich-3 extractable). The adoption of cover crops such as sunn hemp and cow peas during summer (fallow period) in south Florida has shown to increase soil organic matter, and maximum water holding capacity. The application of organic amendments such as bagasse as a soil amendment is proving to be a good practice for local growers planting sugarcane particularly on sandy mineral soils with very low organic matter (<2%).Seven growers reported adopting cover crops while two growers reported reduced fertilizer and pesticide use with cover crops. Individual grower land area under cover crops ranged from 240-3800 acres. Land under cover cropping by individual growers ranges from 10 to 80%. Cultivating flooded rice in the summer as a rotation crop has shown to reduce phosphorus loads in farm canals, and also shown to improve soil quality.
2. Illinois: We found direct relationships between three labile C pools (β-glucosidase (BG), fluorescein diacetate (FDA) hydrolysis, and permanganate oxidizable carbon (POXC)) yield (89%), soil respiration (89%), and N2O and CH4 emissions (76%). Relationships were generally positive between SQIs and found that predictive relationships can be improved by measuring influential site covariates along with details about management, sampling, and analysis. Using a meta-database to quantify effect sizes (ESs) of management on these indicators, we found eighty percent of responses were positive, with ESs ranking grassland>organic fertilizer>conservation tillage=cover crop≥residue return exceeding conventional controls. The ESs were, on average, larger for BG (0.34) and FDA (0.35) than POXC (0.29), and responses to site and experimental covariates varied.
3. Illinois: Additional work explored datasets being used to assess the impacts of land use on greenhouse gas emissions. Related efforts included a review of six data sources that are most commonly used to investigate land use change in the contiguous U.S. by highlighting the main characteristics, strengths and weaknesses and considering how uncertainty is assessed by the June Area Survey (JAS), the Census of Agriculture (COA), the Farm Survey Agency (FSA) acreage, the National Resources Inventory (NRI), the National Wetlands Inventory (NWI), and the Forest Inventory and Analysis (FIA); and two remote sensing-based data products, the Cropland Data Layer (CDL) and the National Land Cover Database (NLCD). We find important research gaps limiting current land use/land cover and change studies (e.g., lack of high-quality reference data and uncertainty quantification, etc.) and highlight emerging techniques (data fusion and machine learning) that will improve reliability land use change assessments and associated policies. Additional work explored data used to estimate Nitrogen fertilizer and manure additions to U.S. corn production systems. Researchers developed the first county-level Nitrogen application datasets for corn. Top-down and bottom-up data fusion methods were used, dramatically improving the accuracy of greenhouse gas calculations for the crop. Nationally, the weighted averages of corn nitrogen inputs based on corn planted area exceeded nitrogen needs by 60 kilograms per hectare, with a nitrogen surplus found in 80% of all U.S. corn producing counties; and, excess application was most pronounced in the Midwest, followed by the Northern Plains. The Southeast and Northwest had comparatively low nitrogen application rates and surplus levels. Western states were more variable overall.
4. Illinois: Data on dynamic soil properties collected by NRCS to is being explored to evaluate accuracy, repeatability and usefulness of a standard set of proposed soil health metrics. In Illinois, we collected samples comparing conventional, with no-till and organic grain production systems. In general, POX-C and β-glucosidase were more variable than SOC. While β-glucosidase was more variable, it was still more sensitive to changes in management. SOC and POXC results agree with other findings that row crop organic systems might accumulate more soil organic matter in the subsurface soil (20-50 cm). At the national level, we are evaluating the regional variability of PLFA as influenced by management practices.
5. Kentucky: We observed surprisingly little influence of variation in vegetation type on the recovery of C cycling processes and other soil health measures in highly disturbed soil in plots established in 2002 by the Department of Biosystems and Agricultural Engineering These large (3.04 m x 6.08 m) with controlled drainage plots used three different vegetation treatments: eastern gamagrass (Tripsacum dactyloides), native cane (Arundinaria sp.), and fescue (Festuca arundinacea) to study how vegetation and water table management affect water quality - particularly nitrate (NO3-) concentrations. Disturbed plots with fallow, fescue, or native cane had significantly less mineralizable C, POXC, and total C than an adjacent undisturbed soil. After research was completed, the plots were abandoned and allowed to revegetate naturally. Over time, cane persisted in the cane plots, but the eastern gamagrass and fescue plots became dominated by a mixture of grasses, forbs, and trees typical of natural succession in abandoned Kentucky agricultural environments (e.g. Bradford pear, black cherry, bush honeysuckle, black walnut). In 2020, this naturally revegetated study was modified to recreate three fescue plots in the original eastern gamagrass plots. Trees in three plots with the greatest tree density were kept while trees and shrubs (i.e., bush honeysuckle) in all other plots were removed. This provided four vegetation treatments: cane, fescue, trees, pasture that since 2021 have been used to evaluate nitrogen (N) and carbon (C) dynamics in terms of soil health. The consistent response of soil physicochemical properties in this study site as well as total C, mineralizable C, and POXC shows that the original disturbance (excavation) had adverse effects and values have not returned to their original levels despite an extended period, irrespective of plant type. Because of soil disturbance, soil texture in treatment plots changed from silty loam to silty clay loam with a significant reduction in plant available water and porosity. This structural change appears to be the dominant feature controlling recovery.
6. Minnesota: Two students in the Cates lab began on-farm soil health measurements, including a unique project assessing soil before and after rain events in order to assess the soil resiliency. These on-farm soil health metrics will be added to a database of soil health indicators for MN and the Upper Midwest. This is helping establish benchmarks for different soils, farm systems, and landscape positions and on soil organic matter dynamics in MN cropping systems, with an emphasis on water behavior as an item of interest for farmers considering soil health practices. The Grossman has developed knowledge to allow farmers to successfully implement cover crops and increase soil health measures in high tunnel environments and in complex vegetable rotations without significantly impacting cash crop productivity. Together, two students in the Grossman lab are part of an NRCS-CIG project evaluating warm season cover crop impacts on soil health and nutrient cycling. Aa third student has joined the lab with a research focus on soil health in high tunnel environments. Of these three, two are from underrepresented groups and the third is a Fulbright student from Ecuador. In the Gutknecht lab, one student will be working on a large USDA-CAP project to monitor nutrient cycling and nutrient runoff in Kernza perennial grain systems in relation to improvements in soil health. A second student will monitory soil organic carbon, microbial carbon processing, and greenhouse gas emissions in field scale deployments of regenerative agricultural systems. Through collaboration with the Cates NRCS-CIG project, we have completed most field work, climate resiliency simulations, and have made progress on a large umbrella review of soil health syntheses in the literature. This research is focused on soil health, carbon cycling/storage, and climate resiliency mostly in perennial grain or other regenerative MN agricultural systems.
7. North Dakota: Accumulated post-harvest crop residues in Northern Great Plains cropping systems are low in N (C:N ratios > 30:1) and immobilize N rather than provide N to subsequent crops in appreciable quantities. Research is being shifted to a field environment to validate these laboratory findings. The next phase of this research will be an evaluation of the findings of the laboratory work under field conditions in microplots. In summary, common post-harvest crop residues are generally low in N (wide C:N ratios) and return very little N to subsequent crops in no-till production systems in the northern Great Plains. Two manuscripts have been published and several are in preparation from this work. The microplots are instrumented with TDR probes at 5-cm to continuously measure temperature and moisture across seasons. A parallel lab study similar to the studies in part a using the same treatments is being conducted to collect additional mineralization/immobilization data.
8. Oregon: Oregon State University has developed recommendations of using biochar to increase soil organic carbon (SOC) and soil health in dryland wheat fields of eastern Oregon. Work on biochar continues and now includes local farmers. OSU has established a Carbon Center whose aim is to conduct research and develop approaches to increase soil carbon or improve related soil properties (e.g., soil health; functional optimization of the soil microbiome) that are marked by increased dryland production, while at the same time lowering inputs and improving resilience to weather-related and climate-driven stressors. Specifically, (1) carry out a comprehensive assessment of the soils and crops in the Pendleton long term experiments (LTEs); (2) assess how changes in soil C stocks and soil health indicators in the different LTEs affect dryland grain yields and quality, plant disease incidence, soil microbiology, and weed pressure, and (3) quantify C sequestration in dryland agricultural systems, with emphasis on how N fertilizer and weed control (tillage vs no-till) factor into the carbon balance of a farming operation, within and beyond the farm gate. Our work with the SHI indicates that new pedotransfer functions show organic carbon increases plant-available water; non-calcareous soils show greater effects of organic carbon on plant-available water; mean increase in plant-available water from carbon is more than double earlier estimates; there is a very strong relationship between SOC and permanganate oxidizable C.
9. Tennessee: Our research has found the following: (a )evaluation of the Haney and Cornell soil health tests do not differentiate long-term management impacts on soil health in southeast US region; (b) soil moisture content and soil texture are tightly coupled to influence soil organic carbon cycling; and, (c) sub-soil C storage is increased by growing cover crops with deeper root systems.
10. Wisconsin: The short-term outcome of this research and numerous user oriented presentations are focused on increasing user (farmer) state of knowledge regarding soil organic matter and management practices that will increase quantity and quality of soil organic matter.

Publications