Selecting soil hydraulic properties as indicators of soil health: Measurement response to management and site characteristics
Authors: Bagnall Dianna K. , Morgan Cristine L. S. , Bean G. Mac , Liptzin Daniel , Cappellazzi Shannon B. , Cope Michael , Greub Kelsey L. H. , Rieke Elizabeth L. , Norris Charlotte E. , Tracy Paul W. , Aberle Ezra , Ashworth Amanda , Tavarez Oscar Bañuelos , Bary Andy I. , Baumhardt R. L. , Gracia Alberto Borbón , Brainard Daniel C. , Brennan Jameson R. , Reyes Dolores Briones , Bruhjell Darren , Carlyle Cameron N. , Crawford James J. W. , Creech Cody F. , Culman Steve W. , Deen Bill , Dell Curtis J. , Derner Justin D. , Ducey Thomas F. , Duiker Sjoerd W. , Dyck Miles F. , Ellert Benjamin H. , Entz Martin H. , Solorio Avelino Espinosa , Fonte Steven J. , Fonteyne Simon , Fortuna Ann‐Marie , Foster Jamie L. , Fultz Lisa M. , Gamble Audrey V. , Geddes Charles M. , Griffin‐LaHue Deirdre , Grove John H. , Hamilton Stephen K. , Hao Xiying , Hayden Zachary D. , Honsdorf Nora , Howe Julie A. , Ippolito James A. , Johnson Gregg A. , Kautz Mark A. , Kitchen Newell R. , Kumar Sandeep , Kurtz Kirsten S. M. , Larney Francis J. , Lewis Katie L. , Liebman Matt , Ramirez Antonio Lopez , Machado Stephen , Maharjan Bijesh , Gamiño Miguel Angel Martinez , May William E. , McClaran Mitchel P. , McDaniel Marshall D. , Millar Neville , Mitchell Jeffrey P. , Moore Amber D. , Moore Philip A. , Gutiérrez Manuel Mora , Nelson Kelly A. , Omondi Emmanuel C. , Osborne Shannon L. , Alcalá Leodegario Osorio , Owens Philip , Pena‐Yewtukhiw Eugenia M. , Poffenbarger Hanna J. , Lira Brenda Ponce , Reeve Jennifer R. , Reinbott Timothy M. , Reiter Mark S. , Ritchey Edwin L. , Roozeboom Kraig L. , Rui Yichao , Sadeghpour Amir , Sainju Upendra M. , Sanford Gregg R. , Schillinger William F. , Schindelbeck Robert R. , Schipanski Meagan E. , Schlegel Alan J. , Scow Kate M. , Sherrod Lucretia A. , Shober Amy L. , Sidhu Sudeep S. , Moya Ernesto Solís , St. Luce Mervin , Strock Jeffrey S. , Suyker Andrew E. , Sykes Virginia R. , Tao Haiying , Campos Alberto Trujillo , Van Eerd Laura L. , van Es Harold M. , Verhulst Nele , Vyn Tony J. , Wang Yutao , Watts Dexter B. , Wright David L. , Zhang Tiequan , Honeycutt C. Wayne 
Published: July 2022

Farmers, scientists, and other soil health stakeholders require interpretable indicators of soil hydraulic function. Determining which indicators to use has been difficult because of measurement disconformity, spatial and temporal variability, recently established treatments, and the effect of site characteristics on management practice differences. The North American Project to Evaluate Soil Health Measurements includes 124 sites uniformly sampled across a range of soil health management practices in North America in 2019. We compare and recommend indicators of hydraulic function that best characterize soil health. We assessed the relationship of each indicator to a suite of soil inherent properties and climate variables, the response of each indicator to soil health management practices, the effect that soil inherent properties (clay content, sand content, and pH) and climatic variables (10‐yr mean annual precipitation and temperature) had on response to management practices, and the relationship among the responses of the indicators to soil health management practices. Field capacity measured on intact cores (θFC_INTACT) was the best measure of soil hydraulic function, because it responded to management, represents a direct measure of soil hydraulic function, is proximal to stakeholder values, and its response to management was not significantly influenced by inherent and climatic variables. Other suitable indicators are bulk density, soil organic carbon (SOC), and aggregate stability, which are not direct measures of soil hydraulic function but do respond to management and may be practical in situations in which measuring θFC_INTACT is not. This study informs selection of soil health indicators to measure soil hydraulic function.