Digging In

Out in the Field: Soil Sampling

Out in the Field: Soil Sampling

By Abigail Peterson on Thursday, 09 May, 2019

The season of soil sampling has begun at SHP! The daffodils have bloomed, the robins are chirping, and soon ATVs with a soil prob, iPad, and many tiny bags will be taking to the field. Spring has always been a busy time for SHP as we gear up for the thousands of soil samples that will be cored, bagged, shipped, and processed for our dataset. Every year we get a little closer glimpse at what our soils are doing in the Midwest.

For a short SHP overview, our 220 full partner sites get soil sampled every year. Each farmer starts with a routine and soil health analysis and then continues for five years getting a routine analysis every year and soil health test every other year.

The fun begins with looking at the field layout, with our cover crop treatments, and marking the GPS coordinates where our samples will be taken. Our very detail-oriented staff (specifically Anne, Stacey, Jack, and Debbie) organizes and ships out boxes containing maps, protocols, shipping labels, sampling bags, coolers and specific laboratory analysis forms for each sampler. This is no small feat - each field is unique with GPS coordinates, the number of sampling points, and what test is being taken. The field team is very grateful for how streamlined our process has become. We know that each box that goes out the door has been put together with extreme care.

Once that box hits the sampler’s doorstep, we’re at the mercy of the weather to get the job done. When the fields are firm enough to get out on, rain or shine, calm or windy, samplers are out collecting cores. I try to meet a sampler or two out in the field (somehow, I always pick the lovely, bright, sunny day) to gauge how the spring is going and to get to know who’s sampling the field. It is always great to hear if our SHP fields, usually in no-till and cover crops, are any different from other soils they have sampled so far. “Easier to drive out on”, “less ponding”, and “better overall structure” are usually the keywords you hear. There’s nothing like discussing the field right on the interstate that has chisel plowed, with resulting rill erosion, on 0-2% slopes that is an eye sore. And we all know which field we’re talking about.

Just as our soils are being cored, bagged and shipped to a lab to be ground and analyzed, the physical characters are already starting to shine. From that initial conversation, agronomists and farmers are curious to know what are we testing. Is there a difference? What is this information worth? But how do we measure and define soil health? These are good questions! Soil health is a hot topic and I don’t need to explain why.

The Soil Health Partnership is trying to find that answer, working alongside a myriad of groups from land-grant colleges, industry, and non-profits. We began collecting soil data in 2014. From percent organic matter to aggregate stability, year after year the soils are tested. From that jumping off point, we now have over 26,000 data points (and growing!). Finding correlations within that dataset is giving us a glimpse into what our soils are trying to tell us in a quantifiable way. Can higher yields be linked to aggregate stability? Can we see an active carbon number that has increased with increased cover crop usage?

This is what SHP is doing. Correlating soil health tests along with soil texture and yield to understand how the soils are adapting to farmer management practices. We are not in Timbuktu working with 14-way mixes at $50/acre cover crop fields. We’re in your backyard with corn, soybeans and wheat, in your soil texture class, where glaciers and prairie formed our land, looking into what is going to increase the capacity of your soil to function as a vital living ecosystem.

We may not have all the answers yet, but we are working with great farmers that help explore what the truth is. Every Spring holds a new opportunity to dig deeper into what questions we can start to answer. As we continue to grow and share our story, we hope you look forward to what exciting things we find.    

Learn more about soil sampling and the life of a field manager.