A variety of new and diverse soil measurements are included in soil health tests. The tests can help you determine whether you have the microbial activity needed to supply nutrients to your plants or whether the soil structure is sufficient to allow the flow of water and air.
Soil health can always be assessed visually. For instance, you can look for the signs of fungal hyphae on the crop residue for evidence of microbial activity or better yet, you can count earthworms. Evaluate aggregate stability by doing a slump test. Estimate your residue cover that physically protects soil from water and wind erosion and serves as microbial food. If you’re looking to buy soil then take a look at Redbud Soil no-till living soil – it’s an excellent product and could provide what you’re looking for.
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If you plan to send some soil samples to the laboratory, the quality of those samples matters a lot. Below are some of the rules you need to adhere to for a proper soil health test sampling.
The vast majority of tests performed on soil, such as soil respiration are used for estimating the level of activity of soil microbes. Microbes prefer temperatures between 85°F and 105°F and moisture levels of between 60 and 75 percent. Outside these windows, they generally work more slowly.
It isn’t always bad to measure microbial activity outside the ideal window as long as you measure in the same window. Try sampling at the same time each year with similar temperature and moisture levels. This will ensure that you sample microbes with similar resources available, which means that they should have similar activity.
Fall and spring are generally the ideal times to take your soil samples, either before tillage and plating in spring, or after the harvest and before the tillage in fall, when the soil hasn’t been disturbed too recently.
Soil has incredibly complex mixture of solid, gas, liquid, and living organisms that it generally takes time for features to change. If you change your N rate by approximately 5 percent, you should not expect major shifts in the soil nitrate. Similarly, you should not expect significant shifts in microbial activity of you have just 1 year of cover cropping or the cover crop was not properly established because of a wet fall.
It is advisable to look for changes after 3 to 5 years of changed management or perhaps even longer in case of minimal management change or if your soils have high organic matter to begin with. Microbial activity also ebbs and flows all through the growing season, which is why you shouldn’t be surprised if you seem to move backwards in some years. It is perhaps simply a result of variation within the year or field.
3. Set Benchmarks
To properly understand the potential of your soil, it can be a good idea to sample a natural area or fencerow where there’s undisturbed perennial cover with living roots throughout the year. This embodies 4 of the 5 principles for soil health (i.e. minimize disturbance, keep it covered, maximize living roots, diversify aboveground, integrate livestock).
It is important to have a clear difference between that natural area and any tilled annual cropland. To ensure that you are on similar soil to the cropland, you should consider using the SoilWeb app or Web Soil Survey.
4. Know Your Lab
Labs usually offer a variety of soil health packages. Compare what tests are involved and at what price. Call to enquire whether the lab does the tests in-house or if they are sent to a different lab. While sending the samples off is not necessarily bad, it is still important to know where the actual analysis is being done.
Ask yourself what tests you are most interested in so that you can prioritize those expensive samples. You should then stick with the same lab to ensure that you compare apples to apples and oranges to oranges in the coming years.
Read the sampling instructions carefully before setting out to sample if there are special instructions regarding mixing composite samples or even keeping fresh soil on ice.
5. Think of It as One Big Adventure
Soil tests give farmers a great opportunity to have a better understanding of some of the microbes and invertebrates working under their tractor tires, roots, and feet. Since these tests are relatively new, however, it can be advisable not to expect a lot from the metrics.
Data is still not enough to use such tests as a basis for making management decisions such as when to apply pesticides or fertilizer. Instead, soil health data can be considered an attempt to see the world from the perspective of the microbes. How much habitat is available? What about food? Even if it is practically impossible to imagine it perfectly, it is still something worth thinking about.