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

Currently accepted pedotransfer functions show negligible effect of management‐induced changes to soil organic carbon (SOC) on plant available water holding capacity (θAWHC), while some studies show the ability to substantially increase θAWHC through management. The Soil Health Institute's North America Project to Evaluate Soil Health Measurements measured water content at field capacity using intact soil cores across 124 long‐term research sites that contained increases in SOC as a result of management treatments such as reduced tillage and cover cropping. Pedotransfer functions were created for volumetric water content at field capacity (θFC) and permanent wilting point (θPWP). New pedotransfer functions had predictions of θAWHC that were similarly accurate compared with Saxton and Rawls when tested on samples from the National Soil Characterization database. Further, the new pedotransfer functions showed substantial effects of soil calcareousness and SOC on θAWHC. For an increase in SOC of 10 g kg–1 (1%) in noncalcareous soils, an average increase in θAWHC of 3.0 mm 100 mm–1 soil (0.03 m3 m–3) on average across all soil texture classes was found. This SOC related increase in θAWHC is about double previous estimates. Calcareous soils had an increase in θAWHC of 1.2 mm 100 mm–1 soil associated with a 10 g kg–1 increase in SOC, across all soil texture classes. New equations can aid in quantifying benefits of soil management practices that increase SOC and can be used to model the effect of changes in management on drought resilience.