We are back with Mark Liebig and Susan Samson-Liebig. In case you missed our last episode, they are two leading soil scientists of the USDA.  Mark works as a soil scientist within the USDA Agricultural Research Service (ARS) and Susan works as a Soil Quality Specialist in the USDA Natural Resources Conservation Service (NRCS). In this episode we focus on metrics of success for soil health. First, Mark defines soil quality through the lens of research on soil management.

“I think of it often in the context of various soil functions; the ability to cycle nutrients, the ability to be a habitat for your soil biology, the ability to be able to take up water and retain it and move it through the soil matrix. It’s all based on soil function.” - Mark Liebig

In regard to soil health, Susan adds that she focuses on the inherent properties and attributes that soil has that will “lend itself to be able to provide those functions that we need.” Both acknowledge that the terms soil health and soil quality is at times viewed as a distinction without a difference and that the semantics of the terms are not significant.

To test and characterize the quality of the soil you are limited by the amount of time and money you want to invest. You can use a shovel and observe the “qualitative attributes” including tactile feel, the color, and the smell. You can also invest in a hydraulic sampler and send off samples for physical, chemical and biological analysis. Mark’s team has developed an easy-to-use soil quality kit to help make some of those decisions. The kit has been designed to measure some major soil health factors including infiltration of water, aggregate stability, pH and electrical conductivity.

“(With) every sampling decision you’ve got to address those trade offs. What information do you want to get and what resources do you have to bring towards addressing those questions? And then find some sort of appropriate approach somewhere in the middle.” - Mark Liebig

Susan and Mark have benefited from each other’s careers through the skill sets they both bring to the table. Susan gets to hear about the new up and coming research and Mark gets to hear about what research is needed within the industry. Both can return to their agencies and share their findings to better prepare and direct their efforts. As Susan talks with producers, she is noticing some trends in what the general public wants to know. Her observation shows the importance of the soil health discussion.

“Another emerging topic that's really starting to take off here is this whole linkage between soil health, plant health, animal health and human health and trying to understand those linkages.” - Susan Samson-Liebig

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Soil Sense Podcast is hosted by Tim Hammerich of the Future of Agriculture Podcast.