Soil Monitoring, Could it Become a Thing?
In the land of 10,000 lakes (technically 11,842 lakes), it is obvious why water testing is so critical. Funds are spent annually to test surface and ground water quality with recommendations, impairment listings, regulations, and laws resulting from these studies. This testing is imperative to understanding the conditions to keep our citizens and biological communities safe. How is soil monitoring or testing being completed around the state? Generally we are completing and relying on the traditional soil testing which provides us with the chemical analysis of our soils on private lands. Understanding that our soils are degraded and that many factors are impacted by the quality of our soils makes one wonder if more attention to soil monitoring would be beneficial. The condition of the soil directly impacts quantities and qualities of our waters as well as our crops, forests, and natural areas. Soil health testing has begun to be integrated in the last few years but isn’t widespread and trained individuals aren’t plentiful.
Why Test Soil?
Soil testing/monitoring doesn’t need to lead to rules and regulations but it can provide us with information to better manage the resource which will in turn provide benefits to our production, waters, and wildlife. The Natural Resources Conservation Service (NRCS) has been diligently training staff to understand the dynamics of soils and complete soil health testing. They understand that soil is our foundation and many benefits can be realized by improving our soil quality. Completing the standard soil tests will provide you information about the chemical components of your soils but what about your compaction, infiltration, structure, and biology?
Soil Composition
Soils are comprised of 3 systems - chemical, physical, and biological. All 3 components work together to make your soil what it is. We have been focusing on the chemical component for production and are realizing to include physical and biological in our understanding. Farmer mentors from the Minnesota Soil Health Coalition can help you with testing your soils this fall and select FFA students will be provided training and tools to complete this assessment. You can check with your local field office to see about borrowing an infiltration ring (6” metal ring).
Soil Testing Options
How do we test our soils for their health? There are some fancy laboratory methods that can be used (Haney, Solvita, PFLA, aggregate stability, and more) but there are easy ways we can observe our soils.
What you’ll need:
Shovel
Thermometer
Penetrometer or a wire flag
6” metal ring
Block of wood
Mallet
A bottle of water
Timer
What to do:
First, make sure you conduct your test when the soils are fit for field work-not too wet, not too dry, during the growing season or after harvest.
Dig an area 12”x12”x12” and count worms.
0-1 worms is considered low
2-10 is moderate
10+ is great!
Put the thermometer 2” deep in exposed soil and soil with cover (residue/crop/cc).
Use the penetrometer or flag to test compaction-what depths are easy to push in, where does it get harder? Does it coincide with tillage depth? Crop roots struggle to get through 275 psi.
Use the wood block on top of the 6” metal ring and pound it half way into the ground with the mallet. Use a water bottle with 500mL of water (standard size), take a sip of the water, then start your timer while you have your hand over the ring and pour the water on your hand to brace the rush of water hitting the soil, this replicates an inch of rain. How long does it take to infiltrate?
<5 min is great
5-15 min good
16-30 min decent
>30 min not so great
Look at the soil that was dug up to look for worms, does it resemble cottage cheese or does it come apart in angular chunks? Do you see a layer of compaction, does the soil break apart horizontally?
Analyzing Your Results
Soils vary across the landscape. Rather than comparing results with your neighbors, compare on your own fields on the same soil type with different management practices. Test a field border as a comparison.
