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.
|Number of pages||18|
|Journal||Soil Science Society of America Journal|
|State||Published - May 1 2022|
Bibliographical noteFunding Information:
The NAPESHM project is part of a broader effort titled, “Assessing and Expanding Soil Health for Production, Economic, and Environmental Benefits”. The project is funded by the Foundation for Food and Agricultural Research (grant ID 523926), General Mills, and The Samuel Roberts Noble Foundation. The content of this publication is solely the responsibility of the authors and does not necessarily represent the official views of the Foundation for Food and Agriculture Research. The application of NAPESHM data to develop pedotransfer functions for plant available water was supported by the United Soybean Board (project number 1920‐172‐0118). The authors acknowledge the following individuals and groups for their contribution to the long‐term research sites: Melissa Bell, Nancy Creamer, Alan Franzluebbers, Tomas Moreno, Paul Mueller, Chris Reberg‐Horton, Mike Zink, Matthew Helmers, Lisa Schulte‐Moore, Matt Mortenson, Sean Vink, George Kapusta, Ronald Krausz, Karla Gage, Dr. Rachel Cook, Amanda Weidhuner, Orla Willoughby, Deanna L. Osmond, Bob Blevins, Donald C. Watts, Dr. Kenneth A. Barbarick, Robert S. Dungan, Joshua L. Heitman, James Custis, John Mason, April B. Leytem, Mark A. Liebig, Amy L. Shober, Michael L. Thompson, Bryan B. William, and Lamesa Cotton Growers. Foundation for Food and Agricultural Research (grant ID 523926), United Soybean Board (project no. 1920‐172‐0118), General Mills, and The Samuel Roberts Noble Foundation.
© 2022 The Authors. Soil Science Society of America Journal © 2022 Soil Science Society of America.
ASJC Scopus subject areas
- Soil Science