Spatially explicit heteroskedastic modeling for the Soil Health Assessment Protocol and Evaluation version 1.0S

Authors: Veum, Kristen; PARKER, PAUL - University Of California Santa Cruz; HOLAN, SCOTT - University Of Missouri; PAIS, NAMITHA - Orise Fellow; WILLS, SKYE - Natural Resources Conservation Service (NRCS, USDA); AMSILI, JOSEPH - Cornell University; NUNES, MARCIO - University Of Florida; VAN ES, HAROLD - Cornell University; SEYBOLD, CATHY - Natural Resources Conservation Service (NRCS, USDA); KARLEN, DOUGLAS - Retired ARS Employee

Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/3/2025
Publication Date: 5/4/2025
Citation: Veum, K.S., Parker, P.A., Holan, S.H., Pais, N.V., Wills, S.A., Amsili, J.P., Nunes, M.R., Van Es, H.M., Seybold, C.A., Karlen, D.L. 2025. Spatially explicit heteroskedastic modeling for the soil health assessment protocol and evaluation version 1.0S. Soil Science Society of America Journal. 89. Article e70065. https://doi.org/10.1002/saj2.70065
DOI: https://doi.org/10.1002/saj2.70065

Interpretive Summary: Adoption of conservation management practices has been hampered by lack of a regionally relevant soil health interpretation tool. The Soil Health Assessment Protocol and Evaluation (SHAPE) tool was developed to meet this need. Version 2.0 of SHAPE accounts for nearness in addition to site-specific characteristics using a soil ‘peer group’ approach to provide regionally relevant soil health scores and benchmarks. The SHAPEv2.0 tool can be used to evaluate and monitor soil health changes under variable management, set goals for conservation planning, calculate soil health opportunity gaps, and help landowners understand how their management practices are impacting soil health. Overall, this tool benefits producers and conservation planners, and supports local and national programs related to soil health and sustainable agriculture.

Technical Abstract: Greater awareness of the role of soil management in achieving global production goals and mitigating emerging environmental challenges has focused the spotlight on soil health assessment and interpretation. The role of site-specific characteristics in soil health assessment has long been recognized through small-scale experimental studies, and the soil health assessment protocol and evaluation (SHAPE) tool was developed to facilitate cross-site comparisons and provide regionally relevant interpretation by accounting for site-specific factors. Specifically, SHAPE version 1.0 was developed to account for primary climate-edaphic factors including long-term climate means (temperature and precipitation) and edaphic characteristics (soil texture and soil suborder). Version 1.0S of SHAPE further incorporates a spatially explicit, heteroskedastic approach into the Bayesian linear regression model to refine peer-group scoring curves and benchmark values based on proximity. This approach captures regional variability in soil characteristics and improves the relevance and interpretability of the SHAPE scores and benchmark values.