Aggregate stability is a commonly used indicator of soil health because improvements in aggregate stability are related to reduced erodibility and improved soil–water dynamics. During the past 80 to 90 years, numerous methods have been developed to assess aggregate stability. Limited comparisons among the methods have resulted in varied magnitudes of response to soil health management practices and varied influences of inherent soil properties and climate. It is not clear whether selection of a specific method creates any advantage to the investigator. This study assessed four commonly used methods of measuring aggregate stability using data collected as part of the North American Project to Evaluate Soil Health Measurements. The methods included water stable aggregates using the Cornell Rainfall Simulator (WSACASH), wet sieved water stable aggregates (WSAARS), slaking captured and adapted from SLAKES smart-phone image recognition software (STAB10), and the mean weight diameter of water stable aggregates (MWD). Influence of climate and inherent soil properties at the continental scale were analyzed in addition to method responses to rotation diversity, cash crop count, residue management, organic nutrient amendments, cover crops, and tillage. The four methods were moderately correlated with each other. All methods were sensitive to differences in climate and inherent soil properties between sites, although to different degrees. None measured significant effects from rotation diversity or crop count, but all methods detected significant increases in aggregate stability resulting from reduced tillage. Significant increases or positive trends were observed for all methods in relation to cover cropping, increased residue retention, and organic amendments, except for STAB10, which expressed a slightly negative response to organic amendments. Considering these results, no single method was clearly superior and all four are viable options for measuring aggregate stability. Therefore, secondary considerations (e.g., cost, method availability, increased sensitivity to a specific management practice, or minimal within-treatment variability) driven by the needs of the investigator, should determine the most suitable method.
|Original language||English (US)|
|State||Published - Dec 15 2022|
Bibliographical noteFunding Information:
The North American Project to Evaluate Soil Health Measurements is part of a broader effort titled, “Assessing and Expanding Soil Health for Production, Economic, and Environmental Benefits”. The project was 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 authors acknowledge the following individuals and groups for their contribution to the long-term research sites: Robert Dungan, Alan Franzluebbers, Joshua Heitman, April Leytem, Mark Liebig, Deanna Osmond, Michael Thompson, Dr. George Kapusta, Ronald Krausz, Dr. Karla Gage, Dr. Rachel Cook, Amanda Weidhuner, Bob Blevins, Con Campbell, Brian McConkey, Hong Wang, Reynald Lemke, Kelsey Brandt, B. Hohner, M.R. Reeb, D. Lawrence, M. Soultani, and K. Rinas. Support for the sampling by Michigan State University was provided by the U.S. National Science Foundation's Long-term Ecological Research program at the Kellogg Biological Station ((DEB 1832042), the US Department of Agriculture’s Long-term Agroecosystem Research program, and MSU AgBioResearch.
© 2022 The Author(s)
- Aggregate stability
- Cover crops
- Organic amendments
- Soil health