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2021 NCSS National Conference – Abstracts (Pre-Recorded Presentations)

Live Oral Pre-Recorded Posters Focus Teams

Pre-Recorded Presentations

Dynamic Soil Properties Ecological Site Descriptions Soil Health Soil Survey Partnerships and Outreach


Dynamic Soil Properties

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DSP—Potomac River Phosphorus values for cropped versus forestland sites
Presenting Author: Ben Marshall, USDA-NRCS, Southeast Soil Survey Region
Team Members: Phil King, Dave Verdone, Debbie Anderson, Matt Duvall

The fate and transport of phosphorous in fluvial system in the piedmont of Maryland and Virginia is not well understood. Historic land use in these systems along the Potomac river can best be described as conventional row crop production. However, over the last 60 years many of these actively farmed areas have been removed out of production through federal and state easements and or traditional abandonment. As a result, we have the opportunity to investigate phosphorous removal/residence time in three distinctly different land uses. Furthermore, we can leverage this project to document dynamic soil properties associated with soil health indicators that will be reflective of actively cropped, abandon, and steady state conditions under deciduous forest.
 



Scaling Soil Organic Carbon in Space and Time Using Soil Taxonomy and Land Management in the Southern Coastal Plain
Presenting Author: Rajneesh Sharma, Department of Crop and Soil Sciences, University of Georgia, Athens
Co-authors: Matthew Levi and Aaron Thompson, Department of Crop and Soil Sciences, University of Georgia, Athens, GA

Quantitative measurements of dynamic soil properties (DSP) such as soil organic carbon (SOC) are time and labor-intensive. Time-series of point measurements taken at the same locations is the best way to compare changes in SOC across a region, but regional-scale efforts like this are rare and expensive. To overcome this challenge, we compared SOC fluctuations over the Southern Coastal Plain by creating groups of similar soils using taxonomic classifications. The SOC point measurements were grouped by similar soil taxonomy and land management at three different times. The specific objectives were to develop prediction maps of SOC for three time periods between 2002-2018 and compare SOC predictions to static SOC data available in current soil survey databases. We found a strong relationship between soil taxonomy and SOC concentrations, which supports the approach of predicting other DSPs with soil taxonomic groups. The importance of drainage class on SOC was evident whereas the effect of the erosional phase was not as significant over the SOC point measurements. We used 686 SOC point measurements spread over three time periods between 2002- 2018, in the region to predict carbon stock for soil type and land management. This project overcomes several challenges including the inconsistent spatial and temporal distribution of SOC data, the lack of SOC predictions for this large area, and the complex linkage between land management and inherent soil-landscape properties on SOC fluctuations over this region.


Ecological Site Descriptions

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SSURGO-QT: A New User-Driven Web App to Aid in Ecological Site Development and Beyond
Presenting Author: Carrie-Ann Houdeshell, Soil Scientist, NRCS-CEAP-Grazing Lands Team
Co-authors: Loretta Metz, USDA-NRCS, Resource Inventory and Assessment Division (RIAD), Conservation Effects Assessment Project (CEAP)-Grazing Lands Component; Jason Nemecek, USDA-NRCS, Soil and Plant Science Division; Warren Rich and Alan Hammersmith, Stone Environmental, Inc.

Have you ever wanted a straight-forward way to query a soil series or ecological site within a Major Land Resource Area (MLRA) based on soil properties that you choose?  If yes, then there is a new web application to meet your needs. The CEAP-Grazing Lands team developed a new app called the SSURGO-Query Tool (SSURGO-QT) in coordination with the Soil and Plant Science Division (SPSD) and Stone Environmental. The map-based web app allows the user to choose soil physical and chemical characteristics for all mapped soil components based on the July 2020 official Soil Survey Geographic (SSURGO) and gridded Soil Survey Geographic (gSSURGO) data. The soil information for the tool will be updated yearly as new official SSURGO data is released. The purpose of this tool is to enable soil scientists, ecological site specialists, conservation planners, CEAP modelers, and the general public to identify soil/ecological site concepts, group landscapes for modeling purposes, and find management-pertinent soils data for more efficient conservation planning.
 



Ecological Site Data Collection Accelerated
Presenting Author: Delaney B. Johnson, State Soil Scientist, USDA-NRCS, Mississippi
Co-authors: Christopher Hatcher, MLRA Soil Survey Project Leader; Charles Stemmans, Ecological Site Specialist (Ecologist); James Curtis, Assistant State Soil Scientist; and Jerome Langlinais, MLRA Soil Survey Project Leader — USDA-NRCS

The Mississippi Natural Resources Conservation Service (NRCS), has a defined policy on land uses which provides for many sustainable benefits, including continuing research and technology developments to enhance conservation and productivity and to make optimum use of all resources. Ecological sites are the basic component of a land-type classification system that describes ecological potential and ecosystem dynamics of land areas. All land/land use types are identified within the ecological site system, including rangeland, pasture, and forest land.

We propose data needs which define ecosystems within settings and landscape positions. Most positions on the landscape have margins which are transitional. It is further intended to identify shifts from pristine to newer vegetative dynamics. We plan to acquire this data by contracting with private entity. Due to NRCS being limited on staff, in order to efficiently collect the data needed to generate Provisional Ecological Site (PES). The purpose of this contract is acquire high quality ecological site descriptions (ESD) and supporting information at selected areas of non-federal lands and also selected areas of federal lands administered by U.S. Forest Service and National Park Service throughout Mississippi

The contractor shall assemble existing resource inventory data, professional scientific literature, data from cooperating agencies/organizations, and personal knowledge/experience. This information shall be developed into bibliographies. The contractor shall analyze the information gained through field reconnaissance as appropriate, and synthesize into initial draft ecological site description legend(s) to serve as a framework to help guide subsequent ESD field work and soil-site correlation. 
 



Development of Ecological Site Concepts for Southwest Montana Using Legacy Data
Presenting Author: Elizabeth Crowe, Vegetation Ecologist, Cleverbird Ecological Consulting
Co-authors: Jeff Dibenedetto, Vegetation and Landscape Ecologist, USDA Forest Service (Retired) and Mary Manning, USDA Forest Service, Northern Region Vegetation Ecologist

An interagency collaborative project was initiated in 2016 to develop preliminary ecological site description (ESD) concept papers, following guidance in the Interagency Ecological Site Handbook for Rangelands and the USFS Terrestrial Ecological Unit Inventory Technical Guide. We developed preliminary concepts using field experience, a legacy of accumulated knowledge and information from habitat type descriptions and data, literature review, vegetation classifications, existing NRCS and USFS integrated field plot data, Montana Rangeland Ecological Site Key, and geospatial data. This effort will refine current information about sage-grouse habitat in southwest Montana. ESDs for sage-grouse habitat on NFS lands in Montana allow us to identify quality habitat, design vegetation objectives and prioritize restoration activities that will provide the greatest benefit to sage-grouse. There is a rich history of interagency collaboration to facilitate this partnership. A first step, data preparation and reconciliation, included rigorous error checking prior to analysis. This ensures consistency, more robust outputs, and associated site description concept products. Combining the NRCS legacy data set with the USFS legacy integrated plot data set will further improve upon these site concepts. These ecological site concept papers will provide valuable, data-supported information for further development of ESDs, which will be useful to land managers working in southwest Montana. This process will provide a template for integrating ESDs and habitat types across public-private land ownership boundaries.
 



Ecological Sites of Glacier National Park: ESDs, raster mapping and Story Map
Presenting Author: Stephanie Shoemaker, NRCS Ecologist, Missoula Soil Survey Office

Collaboration with partner agencies was fundamental in gaining access to reference materials and datasets. These were used by the NRCS Soil Survey to create broad Provisional Ecological Site concepts for all of western Montana and further developed and data supported ecological sites that were described in Ecological Site Descriptions for Glacier National Park. Vegetation datasets from previous studies allowed for statistical analysis using the R program for hierarchical clustering, analysis of soil attributes and eventually Digital Soil Modelling (DSM) of Ecological Sites for Glacier National Park. This project is continuing to be developed with novel DSM approaches before going through the approval process. Raster mapping of ESDs provides a more spatially explicit product that can inform park staff in different ways than the standard polygon SSURGO product. A Story Map combines all ecological sites for Glacier National Park into one product that is very user friendly. Collaboration with park staff helps to convey how this information in tandem with the soil survey can be used for management.
 


Soil Health

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Critical source area index use for agricultural runoff management targets best management practice implementation
Presenting Author: Patrick Drohan, Ecosystem Service and Management, Penn State University
Co-authors: Emily Lesher(1), Ian Thomas(2), Jhony Benavides(1), Faruk Djodic(3), Peter Kleinman(4), John Spargo(5), Jennifer Weld(1)

(1) Ecosystem Service and Management, Penn State University
(2) Dooge Centre for Water Resources Research, School of Civil Engineering, University College Dublin
(3) Swedish University of Agricultural Sciences
(4) Agricultural Research Services, U.S. Department of Agriculture
(5) Agricultural Analytical Lab, Penn State University

Advising farm operators how to reduce phosphorus (P) runoff from non-point source agricultural fields is typically done in the central Appalachians USA using a combination of farm visits, conservation plan development and P-Index application. However, recent research in Europe has shown that the identification of areas of high runoff mobilization potential (hydrologically sensitive areas (HSA)) that coincide with a P sources (a critical source areas (CSA)) can better identify site-specific areas of risk of P transfer to surface waters. We developed a CSA Index model for four case study sub-watersheds within the Mahantango watershed using: LiDAR to model sub-field topography; SSURGO data; agronomic based soil test P levels; and field geophysics to identify restrictive layers. The CSA index was developed using agronomic (within field boundary) Mehlich-3 soil test P analysis at 5 and 15 cm and evaluated using high-resolution within field environmental testing (within CSA). Results suggest that both approaches to CSA Index development produce similar site-specific field data. Environmental testing more specifically identifies areas to target for management and can give farmers site-specific information on how their behavior change can improve water quality. Most importantly, the application of a CSA index shows that traditional riparian buffer designs being used may in some cases be inadequate to capture current runoff and in many other cases over-designed.
 



Soil Health Targets for three cotton-producing soilscapes
Presenting Author: Nate Looker, Soil Health Institute
Co-authors: Cristine Morgan, Vance Almquist, and Wayne Honeycutt, Soil Health Institute

Enhancing outcomes from soil health management systems (SHMS) requires a practical framework for estimating potential improvements in soil health across diverse soil types and climates. Rank-based approaches to soil health scoring indicate soil health status of one soil relative to other available observations; however, ranking provides limited insight into how much healthier a soil could be, particularly in contexts where few long-term SHMS are available for reference. Here, we present the results of a pilot study on establishing Soil Health Targets—ambitious yet attainable goals tailored to specific pedoclimatic settings—for upland cotton production in four Major Land Resource Areas (MLRAs) in Texas and Arkansas. After stratifying SSURGO map units based on taxonomic criteria relevant to soil health and selecting the major strata used for cotton production, we measured a suite of soil health indicators under perennial vegetation and under cotton grown with and without SHMS in strata hypothesized to differ in soil health potential. Additionally, we compared perennial vegetation types (e.g., with and without woody species) to guide the selection of appropriate reference states across MLRAs. We highlight critical methodological refinements (e.g., accounting for sub-map unit heterogeneity) and prospects for establishing Soil Health Targets at scale. Estimates of soil health under business-as-usual conditions and Soil Health Targets based on perennial vegetation provide producers with an intuitive tool to more quantitatively factor soil health into their planning and demonstrate outcomes to other players in the agricultural sector.
 



Microbes Under Your Fingernails? Using Community Science to Understand Soil-to-Skin Transfer During Gardening
Presenting Author: Gwynne Á. Mhuireach, PhD, Institute for Health in the Built Environment, University of Oregon
Co-author: Gail Langellotto, PhD, Extension Master Gardener Coordinator, Professor of Horticulture, Oregon State University

Accumulating research has improved our understanding of soil microbial life and how it affects the growth, health, and survival of agricultural/horticultural crops. However, we still know very little about how exposure to soil microbes might affect the health of farmers and gardeners who spend a great deal of time in direct contact with soil. To begin filling this knowledge gap, I orchestrated a community science project recruiting 40 Master Gardeners from two different climate zones in Oregon to characterize microbial communities in garden soil and their ability to transfer onto the skin during gardening, as well as their persistence on the skin for 24 hours afterward. Preliminary results suggest that the skin microbiome is substantially altered by gardening activities that involve direct soil contact, such as weeding and transplanting seedlings. The majority of soil microorganisms, however, are non-pathogenic and transient on skin, largely disappearing after 12–24 hours. In addition, we found that management practices (e.g., conventional, organic) and location/climate zone had small but significant effects on taxonomic composition. With improved understanding of how many microorganisms are transferred onto skin during gardening, to which taxa they belong, and how long they persist, producers will be better able to make important health decisions, such as whether to wear gloves while working directly in the soil.
 



Arsenic Contamination in Soil & Groundwater in Gangetic Plains of Saran, Vaishali & Patna districts of Bihar
Presenting Author: Subhajit Pal, Dr. Rajendra Prasad Central Agricultural University, Pusa, Samastipur, Bihar -848125, India
Co-authors: Sanjay Kumar Singh1, Pankaj Singh1, Prasanta Kumar Patra2, Sukanta Pal2, Kiran Pilli2

1Dr. Rajendra Prasad Central Agricultural University, Pusa, Samastipur, Bihar -848125, India
2Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, West Bengal- 741235, India

Geogenic aquifer rocks releasing arsenic (As) leading to chronic and epidemic effects on human health, water and crop contamination, which receives global attention. An investigation was carried out in the mid-Gangatic Plains of Saran, Vaishali and Patna districts of Bihar. For the study, soil (two depths) and groundwater samples were collected from adjoining villages nearby river Ganga, and was analysed for its As content and other physico-chemical properties. Groundwater As content ranged between 7.8 (Shankarpur Khas, Dist. Patna) and 0.002 mgL-1 (Panapur Dharampur, Dist. Vaishali) with 0.87 mg L-1 a mean value. 90.47% of the samples exceeded the WHO drinking water permissible limit. The pH, Na, K and Cl contents were within the WHO limit. Fe content in all the samples ranged between 0.1 and 0.68 mgL-1 with 85.71% of the samples surpassing the WHO drinking water limit. The total As concentration of surface and subsurface soil ranged between 0.069 and 0.789 mgkg-1, 0 and 0.566 with 0.395 and 0.294 mg kg-1mean values respectively, which were below the acceptable limit for agricultural soil (20 mgkg-1), recommended by European Community. The soils had medium to low OC, low available N and K, medium available P and Fe contents. As content of the soil shown significant positive correlation with available Fe and OC contents.
 



Assessing the accuracy and precision of pXRF measurements of potentially toxic trace elements in field soils
Presenting Author: Justin Richardson, Department of Geosciences, University of Massachusetts Amherst
Co-authors: Sandra Walser and Nicolas Perdrial, Department of Geology, University of Vermont, Burlington; Eric Sirkovich, Department of Geosciences, University of Massachusetts Amherst

Urban environments are enriched in toxic metals, but analyses of soils can be costly and inaccessible to many communities. Portable XRF (pXRF) offers rapid determination of toxic metals but understanding of soil characteristics on measurement precision and accuracy are limited. We collected 460 surface soil samples from Lexington MA, Springfield MA, and Hartford CT to test the effect of field moisture, rock fragments, and organic matter content on the concentrations of As, Cd, Cr, Cu, Pb, and Zn. Samples were subsequently analyzed with a SciAps X-200 pXRF. PXRF Cu, Pb, and Zn concentrations strongly agreed with ICP-MS analyses (R2 > 0.87, slope = 0.98 to 0.74). PXRF As, Cd, and Cr concentrations poorly agreed with ICP-MS analyses due to their low concentrations (< 10 mg/kg). Field moist, oven dried, and sieved samples had similar pXRF values.

We subsequently conducted laboratory experiments to explore accuracy and precision across pXRF instruments (SciAps X-200 vs Hitachi XMET8000). The two pXRF instruments Cu, Pb, and Zn measurements agreed with each other but not always with digestion results. For each metal, 20% soil moisture increased measurement error by 12.2-17.4%. Glass beads did not produce a significant increase in error for either instrument, nor did increasing organic matter simulated with confectioners sugar. Our preliminary results show that pXRF measurements can be precise and accurate under varying field conditions but that the low concentration elements (< 10 mg/kg) lack sufficient precision. We look forward to hosting a virtual conference on soil analysis by pXRF in Winter 2021/22.
 


Soil Survey

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The Dominant Soil Subgroups in the Republic of Yemen—Their characteristics and occurrence
Presenter: Prof. Dr. Abughanem Abdulellah Ahmed, Head of Soil, Water and Environmental Department, Faculty of Agriculture and Environment, Sana'a University, Yemen

In the studied area four major climatic types were distinguished according to the application of the Thorntwaite method of the climate classification, those climatic types are:

  • Aridic.
  • Semearidic.
  • Tropical sub humid.
  • Tropical humid.

Regarding the geology of the studied area, four geological zones were determined as fellow:

  • Precambrian shield.
  • Sedimentary rocks.
  • Tertiary and quaternary volcanics.
  • Quaternary alluvial deposits.

Concerning the natural vegetation of the studied area, five natural vegetation types were recognized as fellow:

  • Maritime Vegetation
  • Desert Vegetation.
  • Savanna Bush land.
  • Mountain Vegetation.
  • Wadies and drainage group.

By Appling the scientific methodology of soil classification (SOIL TAXONOMY) on the selected, analytical data and morphological characteristics and the interpretation and extrapolation of satellite images for the delineation of soil subgroups boundaries a seven dominant soil subgroups had recognized as fellow:

  • Typic Calciorthids.
  • Typic Torriorthents.
  • Typic Ustorthents.
  • Typic Ustifluvents.
  • Typic Ustropepts.
  • Typic Haplustolls.
  • Rock outcrops.


Tuskegee Soil Survey Office Activities
Presenter: Cooper R. Nichols, Senior Soil Scientist, USDA-NRCS
Contributors: John L. Burns, Soil Survey Project Leader and George Otto, Ecological Data Quality Specialist — USDA-NRCS

The 7-TUS soil survey office covers the majority of the Upper and Middle Coastal Plain of Alabama, MLRA 133C, along with a large portion of the Alabama Blackland Prairie, MLRA 135A, while reaching into the nine counties in western Georgia. These areas are strongly contrasting geographical units and are composed of a diverse and unique suite of soils.

Ongoing projects in FY2021 consist of soil survey updates, NOTCOM, Dynamic Soil Properties (DSP) and Ecological Site Description (ESD) projects. The 7-TUS staff also serve as assistant coaches for the Tuskegee University Soil Judging Team, collaborate with the 7-LOX office on Coastal Zone Soil Survey projects, execute Resource Soil Scientist responsibilities for the central and southern portions of Alabama and a host of other Technical Soil Service (TSS) requests.

Soil survey projects range from extensive line work revisions to composition changes. These revisions consist of broad association mapping (Order 3), to very detailed (Order 2) soil surveys, including soil series updates and soil chemical parameters (e.g., kandic versus non-kandic). NOTCOM projects recently completed in FY2020 were on Maxwell Airforce Base and Dannelly Field in Alabama. In FY2021, the 7-TUS office completed the Fort Benning Soil Survey and a DSP study on the Troup soil series.

Ecological Sites (ESs) for MLRA 152A, Eastern Gulf Coast Flatwoods, is led by the 7-TUS office in cooperation with 7-LOX and 7-TAL and personnel from associated states. This MLRA ranges from Louisiana to Florida. Currently, 32 draft ESs are being reviewed for Provisional ES (PES) development and approval. Sites are located on early and late Pleistocene fluviomarine coast parallel terraces of the near gulf coast lowlands. These sites include concepts for uplands to wetlands to coastal marshes on natric, silty, loamy, sandy, organic, and shallow to limestone regions plus a suite of sites for the barrier islands.
 



Subaqueous Temperature Regimes… do we need them?
Presenting Author: Matt Dorman, GIS Specialist/Soil Scientist, USDA-NRCS, Connecticut and Coastal Zone Soil Survey (CZSS) Focus Team Member

This presentations agenda is for getting people to think about the current soil temperature regimes and their application towards subaqueous soils. Their specific requirements defined by Taxonomy. This is a review of the current Taxonomic temperature regimes and how they may or may not be what we need for subaqueous soils, by asking questions such as:

How were the current temperature regimes developed, and standards created to define them in Taxonomy? Do the current temperature regimes apply to Subaqueous soils? Can a coastal system/soils adopt the same growing season as terrestrial soils? Are the temperature breaks and temp requirements relevant to subaqueous soils, and ecosystems?  What kind of indicators such as plants or organisms would be helpful in determining different ocean temperatures? If we have different regimes what temperatures are important, what indicator species or plants are important? What should the new standards look like for subaqueous soils? In addition, do we need a different moisture regime for marshes or tidal flats once the tide is out? Do we need to distinguish continually submerged soils and tidal influenced soils? What info is helpful, what info is needed, what answers are we seeking to answer?
 



A Digital Soil Survey Mapping Approach to a Coastal Zone Soil Survey of West Galveston Bay
Presenting Author: Kenneth Hall, USDA-NRCS, South Central Soil Survey Region   
Co-author: Stacey Kloesel, USDA-NRCS, South Central Soil Survey Region

Coastal Zone Soil Surveys are currently being used for habitat restoration projects along the East Coast and Gulf of Mexico. The Rosenberg, TX SSO has begun working on a Coastal Zone Soil Survey of West Galveston Bay, which includes Brazoria and Galveston Counties.

When we were designing a procedure for mapping this project, we knew we wanted to take a Digital Approach to Sample Design. This presentation covers some of the challenges we faced while choosing our sampling scheme including environmental factors, lack of relief, and the general makeup of our bay systems, as well as ongoing challenges with the covariates we are using.

The publication of an updated soil survey of the coastal zone for Brazoria and Galveston Counties will include technical data and updated maps, and soil interpretations related to marine land use practices will be provided. Some of the practices include oyster restoration, shoreline erosion control, seagrass restoration, boat moorings, and dredging. For subaerial areas, updated maps and soil map unit concepts will reflect a better understanding of daily and storm tides, wildlife habitat requirements, fresh versus salt water, and impacts by human habitation. Municipalities, aquaculture farmers, parks and wildlife managers, and conservation groups are using these updated maps in their planning process.
 



Examination of the Soil Mass Movement Risk Rating in Puerto Rico using the Hurricane María Landslide Inventory
Presenting Author: K. Stephen Hughes, Associate Professor, Department of Geology, University of Puerto Rico
Co-authors: Edwin Irizarry Brugman and Desireé Bayouth García, Department of Geology, University of Puerto Rico; Manuel Matos Rodríguez, USDA-NRCS, Caribbean Area

The soil mass movement risk rating is an interpretation scheme designed to estimate a soil’s propensity to move downslope due to gravity.  In 2017, more than 70,000 mostly shallow mass wasting sites were generated by high intensity – long duration rainfall associated with Hurricane María.  The areas most affected by these landslides were not correlated to the zones identified as most vulnerable in the soil mass movement interpretation.  The discrepancy of the model prediction and the effects of the hurricane may be a result of the distinct tropical chemical weathering climate in Puerto Rico, compared to the continental United States.

A comprehensive event inventory of landslide sites is an important tool to refine our understanding of soil units and combinations of soil characteristics that are more likely to result in mass movement activity.  A complementary goal of the study is to better understand the area-volume scaling of mass wasting sites in target vulnerable soils. 

Approximately 700 SSURGO soil map units on the island of Puerto Rico were analyzed with the Hurricane María landslide inventory and a frequency-ratio (FR) score was assigned to each unique “mukey.”  The FR scores and diverse soil unit data mined via Soil Data Access allow for multivariate analysis approaches in order to gauge the important distinctions between soil units that combine to produce vulnerable soils vs. those that are less susceptible to mass movements.  Results from the study are intended to guide a mass movement interpretation specific for Puerto Rico, given its particular geographical and climatic concerns.
 



Comparison of Spline Depth Interval and Point-Depth Approaches for Predicting Soil Properties
Presenting Author: Suzann Kienast-Brown, USDA-NRCS, National Soil Survey Center
Co-authors: Jessica Philippe, Stephen Roecker, and Zamir Libohova, USDA-NRCS; Travis Nauman, U.S. Geological Survey Southwest Biological Science Center; James Thompson, West Virginia University, Davis College of Agriculture

Soil property maps are critical for assessing natural resource concerns and solutions to support effective land management decisions. Predictions of continuous soil properties for regional, national, and global extents have been successfully created using point observations of soil properties and machine-learning prediction algorithms. Depth interval estimates from spline functions and point-depth estimates are the two fundamental approaches for representing property values at various depths within the soil profile. Both methods have been widely applied but not successfully compared for model performance and prediction accuracy. This study compares the performance of the two methods for predicting organic carbon, pH, sand, silt, and clay content for six depths (0, 5, 15, 30, 60, and 100 cm) in the Upper Colorado River Watershed at 30 m resolution. Predictions for each property were generated using Kellogg Soil Survey Laboratory measurement data and quantile random forests. Relative prediction intervals (RPI) were used to compare prediction uncertainty and cross-validation performance metrics (R2 and RMSE) were used to compare prediction accuracy. Results indicate no significant difference in model performance metrics between the two methods. However, the point-depth approach makes fewer assumptions in the treatment of training data and should be considered over the spline approach for predicting continuous soil properties.
 



Applying rNewhall for dynamic soil survey interpretations of soil moisture
Presenting Author: Matt Levi, Department of Crop and Soil Sciences, University of Georgia
Co-authors: Grant Snitker1,2, Rajendra Panda1, and Kevin Achieng1

1Department of Crop and Soil Sciences, University of Georgia
2Center for Forest Disturbance Science, US Forest Service Southern Research Station

Soil moisture information is an important property used in drought monitoring, irrigation management, wildfire prediction, soil taxonomy, and numerous other applications. Predicting spatial and temporal dynamics in soil moisture conditions over large areas is a very challenging task given the multitude of drivers influencing variability in a given landscape. The Newhall Simulation Model (NSM) is a simple water budget approach that has been used for more than 30 years to assign soil moisture regimes (SMR) in Soil Taxonomy with minimal conceptual advancement. We modified the original NSM to run in the R programming language (rNewhall) to improve estimates of soil moisture conditions in the profile and estimate SMR using a daily soil moisture model. Updates to NSM include the incorporation of variability in soil texture, soil water holding capacity, and soil depth. Predicted soil moisture is compared to point measurements at mesonet sites across the south-central U.S. and remotely-sensed soil moisture from the Soil Moisture Active Passive (SMAP) satellite mission. The root zone predictions yielded more promising results than surface soil predictions with the strongest daily correlations in volumetric soil moisture between the SMAP root zone product and the 0-100cm predictions from rNewhall. The development of rNewhall as an R package is currently underway which will increase the accessibility of the NSM and provide a mechanism for improving the spatial and temporal representation of soil climate conditions for dynamic soil survey interpretations.
 



Developments in Measuring and Classifying Halinity in Coastal Zone Soils
Presenting Author: C. Evan Park, University of Maryland, Dept. of Environmental Science and Technology
Co-author: Martin C. Rabenhorst, University of Maryland

Halinity, the ocean-derived salt content of coastal waters and soils, is an important characteristic of soils in the coastal zone, including subaqueous soils. This study proposes standards for subaqueous soil halinity research. First, we propose a system for classifying soil halinity that is based on the Venice System and includes modifications that incorporate recent research on the threshold between fresh and saltwater subaqueous soils. Second, we propose a standard methodology to determine soil halinity that is simple and reliable and reports in terms of practical halinity (or parts per thousand) in order to facilitate interdisciplinary communication. We successfully tested the method on the subaqueous soils of South River, a western subestuary of Chesapeake Bay. For the method to be useful, care must be taken to prevent sulfide oxidation and changes in soil moisture content.
 



Using Mn IRIS (Indicator of Reduction In Soils) for early growing season redox assessment
Presenting Author: Martin C. Rabenhorst, University of Maryland, Dept. of Environmental Sci. & Technology
Co-authors: Patrick J. Drohan (Pennsylvania State Univ., University Park, PA), John M. Galbraith (Virginia Tech, Blacksburg, VA), Colby Moorberg (Kansas State Univ. Manhattan, KS), Lesley Spokas (Univ. of Massachusetts, Amherst, MA), Mark H. Stolt (Univ. of Rhode Island, Kingston, RI), James A. Thompson (West Virginia Univ., Morgantown, WV), Judith Turk (Univ. of Nebraska, Lincoln, NE), Bruce L. Vasilas (Univ. of Delaware, Newark, DE), and Karen L. Vaughan (Univ. of Wyoming, Laramie, WY)

Iron-coated Indicator of Reduction In Soils (IRIS) devices have been used for almost two decades to help document reducing conditions in soils, and official guidance has been approved by the National Technical Committee for Hydric Soils (NTCHS) for interpreting these data. Because Mn oxides are reduced under more moderately reducing conditions than Fe oxides (which require strongly reducing conditions), there has been growing interest in Mn-coated IRIS devices which are expected to be better proxies for some important ecosystem services like denitrification. However, only in the lasty few years has the necessary technology become available to produce Mn-coated IRIS.  There is now a need for guidance in interpreting data derived from Mn IRIS. In our study, 96 data sets were collected over a two year period from 40 plots at 18 study sites among eight states. The performance of Mn-coated IRIS was compared with Fe-coated IRIS with a goal to assess the impact of duration of saturation and soil temperature (as environmental drivers) on the reduction and removal of the oxide coating. It appears that the current Fe-coating removal threshold of 30% prescribed by the NTCHS is appropriate when soil temperatures are warmer (> 11oC). However, when soil temperatures are cooler (5 - 11oC), a 30% threshold is unnecessarily conservative. On the other hand, Mn-coated devices appear to be particularly useful early in the growing season when soil temperatures are cool. Our data show that when using a threshold of 30% removal of Mn oxide coatings, one can be essentially 100% confident of the presence of reducing soil conditions under cool (<11oC) conditions.
 



Assessing the relationships between soil color variables of two field-based methods and their potential application for wetland soils
Presenting Author: Stephanie A Schmidt, George Mason University, Environmental Science & Policy Department (PhD Candidate)
Co-author: Changwoo Ahn, George Mason University, Environmental Science & Policy Department

While the Munsell Soil Color Chart (MSCC) is a well-established field method for reading soil color, the Nix Color Sensor (NCS) is an inexpensive, app-based alternative that can potentially complement or replace the MSCC. In this study, soil colors were measured from four forested sites across Northern Virginia using both the MSCC and NCS. Three MSCC variables and 15 NCS variables were collected in the field; from these measured variables, 9 NCS calculated variables were derived. A stepwise correlation identified three final NCS variables most suitable for relating the NCS to each of the MSCC attributes—hue (H), value (V), and chroma (CM). H, V, and CM were ultimately best represented by the following NCS variables, respectively: HRGB calculated from the RGB color space (ρ=0.56); L from the CIE-Lab color space (ρ=0.73); and ẑ=Z/(X+Y+Z) from the XYZ color space (ρ=-0.80; p<0.001 for all). These final NCS variables (HRGB, L, ẑ) explained 26%, 54%, and 62% of variance in Munsell H, V, and CM, respectively (p<0.01). Despite overlapping ranges, significant differences in ẑ between colors indicative of hydric versus nonhydric soils suggest the capacity for the NCS to complement the MSCC in an accessible and reproducible manner when identifying hydric soils. Further study covering more diverse soil types is necessary to strengthen relationships between the NCS and MSCC; nonetheless, our methodology of assessing color variables from the two field methods can serve as a template for future studies or environmental education programs desiring to complement the MSCC with the NCS.
 



Digital Soil Mapping in the Western US
Presenting Author: Claire Simpson, RedCastle Resources, Inc., U.S. Forest Service Contractor, Geospatial Technology and Applications Center
Co-authors: Robert Vaughan1, Nathan Pugh1, Vincent Archer2, Joe Brennan3, Jeff Bruggink4, Robert (Andy) Colter5, Brian Gardner6, Jane Karinen7, Suzann Kienast-Brown7, Larry Laing8, Kevin Megown1, Kristi Mingus9, Benjamin Moore10, Eva Muller7, Carla Rebernak11, Jay Skovlin12

1U.S. Forest Service, Geospatial Technology and Applications Center, Salt Lake City, UT
2U.S. Forest Service, Missoula, MT
3USDA-NRCS, St. Paul, MN
4U.S. Forest Service, Ogden, UT
5U.S. Forest Service, Campton, NH
6USDA-NRCS, Moscow, ID
7USDA-NRCS Bozeman, MT
8U.S. Forest Service, Washington, DC
9USDA-NRCS, Price, UT
10USDA-NRCS, Dillon, MT
11USDA-NRCS, Idaho Falls, ID
12USDA-NRCS, Missoula, MT

Digital soil mapping (DSM) refers to a framework that combines soil science and quantitative analysis within the geospatial domain to produce seamless maps of soil properties or classes. DSM incorporates multiple data types, including observations and remotely sensed products, within spatial soil prediction models. To fulfill USFS business needs for critical forest management in the western US and the Soils2026 goal of providing soil information on all lands by 2026, USDA-NRCS and USFS soil scientists and land managers have collaborated in DSM work across several western Forests including the Ashley National Forest in Utah, the Bob Marshall Wilderness in Montana, and the Salmon-Challis and Payette National Forests in Idaho. By capitalizing on local soils and ecology knowledge of NRCS and USFS soil scientists, we are able to create efficient sample designs and ultimately model soils at finer resolutions than allowed by conventional soil mapping methods. To address a primary limitation of soil mapping – imbalanced or scarce pedons from which to derive maps – we use statistical methods to distribute target locations so as to capture the variability of the land management areas while limiting the travel distance and effort needed to collect each sample. Using DSM, we can customize the amount of data collection and level of mapping required to meet land management agencies’ needs across multiple land use objectives while considering timeframes for inventory completion. DSM is highly flexible and as such, we can modify our methodology to meet the needs of multiple stakeholders and respond to unique soil-landscape relationships.
 



Opportunities and challenges for disaggregating the US soil map using legacy data
Presenting Author: Arnaud J. Temme, Department of Geography and Geospatial Sciences, Kansas State University
Co-authors: Jordan T. Watson and Nathan A. Brownstein

We explore nationwide what opportunities current SSURGO data provide for potential disaggregation and provision of higher-resolution soil data to stakeholders. SSURGO soil products are widely used as inputs in agricultural processes, which means that there is a benefit to maintaining the current and future SSURGO data structure during the process of disaggregation.

Most attention is currently given to Digital Soil Mapping (DSM) methods, where statistical methods are used to relate pedon-scale soil observations (such as from NASIS) to sets of explanatory variables. Although mainly used to predict individual soil properties, DSM can be used to predict soil series, and can thus maintain the SSURGO data structure. However, DSM approaches for the moment are held back by availability of randomly-sampled data, limited predictive power of explanatory variables, and inflexible statistical models.

It is therefore necessary to ask whether existing soil surveys – SSURGO polygon maps and map unit descriptions –themselves provide opportunity for improvements in soil map resolution and accuracy when paired with modern data. We explore this question by 1) disaggregating SSURGO soil maps for areas in MI and MN and calculating improvement in SSURGO resolution and accuracy, and 2) approximating potential improvements in SSURGO resolution for the entire covered area.

Results show that disaggregated SSURGO maps have radically finer resolution while simultaneously achieving modest improvements in map accuracy. The success of the disaggregation process is conditional to the consistency and contrast in the original SSURGO data. Some soil map unit descriptions nationwide are inconsistent with independent elevation datasets.
 



Virtual Tour of The Southern Piedmont Province Within Georgia and Alabama
Presenting Author: Stephon D Thomas, Soil Scientist, USDA-NRCS
Co-authors: Damian Hans and Ian MatiasRullan, USDA-NRCS

The Piedmont Plateau region extends from Eastern Alabama into Maryland and Pennsylvania. The Piedmont Plateau contains some of the oldest soils in the Western Hemisphere. Piedmont soils weathered from ancient igneous and metamorphic rocks. Parent material of the Piedmont soils include granite, gneiss, schist, gabbro, quartzite, etc. The 3-GRI Soil Survey Office manages about 13,000,000 acres of the Southern Piedmont. This management area extends from the eastern state line of Georgia to the central part of Alabama. The 3-GRI Soil Survey Office has learned to utilize forever evolving technology to manage this extensive area. With the use of mobile technology and digital media we have the ability to explain a complicated discipline to our customers. This project will give the viewer a brief look into the beauty and complexity of the Southern Piedmont Province.
 



Seamless 3D geological mapping
Presenting Author: Harvey Thorleifson, Minnesota Geological Survey

Research, mapping, monitoring, modeling, and management contribute to benefits. Procedures are mature for static paper-format geological maps. Concurrently, all information is transitioning to regularly-updated, multi-resolution, machine-readable, seamless, standardized databases. Nations now foresee a national 3D geology and a 4D digital twin that will house observations and inferences, while supporting monitoring and management. Our work thus consists of publications, standards, and seamless databases. In 3D, a layer is a 2D map polygon whose thickness can be mapped, which becomes removable by mapping extent, thickness, properties, heterogeneity, and uncertainty. In layers, we map strata, and in basement, we map structures, then discretized properties. Cross-sections are needed to resolve stratigraphic issues. 3D requires a jurisdictional commitment to databases, collections, and geophysical surveys, with emphasis on public-domain drillhole data. Horizontal resolution is about 100 km for global, 10 km for continental, 1 km for national, 100 m for detailed, and 10 m for soil mapping. Soil mapping is used by modelers to infer properties for the 1st meter. Status mapping based on local judgement will help to clarify goals, to monitor and manage our progress, to stimulate funding, and to cause us all to strive. We are ready to build seamless 3D from mature 2D for continental resolution, after regional experts clarify what will be layers, and what will be basement. We can begin national resolution seamless 3D within a few years, when we have seamless 2D surficial and bedrock. Detailed seamless will now focus on 2D, and seamless 3D may be geostatistical.
 


Partnerships and Outreach

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The Cooperative Extension System-An Overview
Presenting Author: Caroline (Crocoll) Henney, Ph.D., Executive Director, Cooperative Extension System and Extension Committee on Organization and Policy

 

The Cooperative Extension System (CES) provides trusted outreach education in food, agriculture, natural resources and human sciences to help people solve problems, develop skills, and build a better future. With+32,000 land-grant university-and county-based employees and 2.8 million volunteers, CES crosses every state and U.S. territory. Working with a network of public and private organizations, CES brings science-based resources to the people who need them most. This presentation will provide an overview of the Cooperative Extension System and opportunities for partnerships around current and emerging priorities, including climate, health, broadband, and urban agriculture.
 



Climate and Soil Collaborations with Extension
Presenting Author: Chuck Ross, Extension Foundation Catalyst

The Cooperative Extension Section and the National Cooperative Soil Survey have been working side-by-side to support healthy soils and regenerative agriculture practices since their inceptions. Extension has trusted relationships with landowners across the country and a record of success implementing soil conservation practices. Extension’s ability to educate, motivate and implement science-based changes with landowners is critical given the challenges of climate variability and extreme weather. Extension’s national network, present in all 3140 counties; its research-based information; and its trusted relationships give it the ability to not only implement but accelerate the changes needed to address climate challenges. This work is becoming more relevant every day, especially with the new presidential priority on Climate. To achieve its potential Extension needs to expand its research, education and outreach. A strategic partnership with NRCS could dramatically increase Extension’s research, reach and effectiveness with respect to climate. This partnership could also enable Extension to engage other partners and bring additional resources and outreach capacity to this work to move more acres across the US into conservation and healthy soil practices. In so doing, this partnership between will help mitigate climate variability, increase landowner business viability and undergird our food system for the benefit of all.
 



NCSS Contributions to GSP Global Soil Property Maps
Presenting Author: Stephen Roecker, USDA-NRCS
Co-authors: Suzann Kienast-Brown, David Lindbo, Skye Wills, Chad Ferguson, and Jessica Philippe — USDA-NRCS, Soil and Plant Science Division

The Global Soil Partnership is a collaborative effort (similar to the National Cooperative Soil Survey (NCSS)) facilitated by the Food and Agricultural Organization (FAO) of the United Nations (UN). The GSP’s mission is broad, but one of its objectives is to develop the Global Soil Information System (GLOSIS) in order to answer global questions that require soil data. The GSP partners with National Institutions, such as the USDA-NRCS, to contribute the best available data for their country. To date the GSP has developed 1-kilometer (km) global raster maps for soil organic carbon (SOC), pH, Electrical Conductivity (EC), Exchangeable Sodium Percentage (ESP), and “Black Soils” (which are largely similar to Mollisols). A 4th initiative is also underway to estimate soil carbon sequestration potential. This presentation will review the US’s contributions to GLOSIS, the challenges creating continental soil maps, and overlap between the GSP’s initiatives and Soils 2026.