Evaluating common soil health tests for dryland wheat systems of inland Pacific Northwest

Purpose Currently, several soil health testing approaches are available to assess soil health such as comprehensive assessment of soil health (CASH) and Haney soil health test (HSHT). However, suitability and interpretation of these tests vary considerably across regions due to inherent soil and climatic variability. Although CASH and HSHT have shown promise in their respective region of origin, suitability of these methods for inland Pacific Northwest region is unknown. Therefore, this study was conducted to evaluate suitability of CASH and HSHT in dryland wheat systems.Methods This study was conducted with samples collected during the Soil Health Institute's North American Project to Evaluate Soil Health Measurements (NAPESHM). Soil samples were collected from multiple long-term grass pastures (GP), crop residue management under wheat-fallow (CR), tillage management under wheat-fallow (WT), and wheat-pea (WP) systems, which include treatments like tillage intensity, organic amendments, nitrogen (N) rates, and stubble burning. Samples were analyzed for indicators of CASH and HSHT methods.Results Among field studies, soil health scores for CASH and HSHT were greater under GP than other treatments and showed overall trend of GP > WP > CR > WT. Although most CASH and HSHT scores and indicators varied under treatments across field studies, there were only a few significant differences among treatments within any study. Both CASH and HSHT did not discern among soil health of any treatment within any study, except CR.Conclusions The lack of sensitivity of CASH and HSHT for management-induced soil health changes within field studies highlights the need for further extensive evaluation and/or calibration before regional adoption.