With the arrival of spring, farmers across the country are gearing up for the 2021 growing season and getting ready to plant this year’s crop. Soil fertility is important for growing healthy crops, so before heading out to the fields to prep the soil, it’s a good idea to test your soils first. Most soil tests performed in a lab are useful in determining the chemistry of the soil and what the essential plant nutrient levels are (macronutrients/ micronutrients), but they don’t always tell the whole story when it comes to overall health of the soil.
Testing your soils for essential plant nutrients is always recommended, and it’s important to take multiple samples from different areas of your field(s) as some areas may have more or less of certain nutrients. Some soil samples may need to be frozen prior to transporting them to a lab, so be sure to know what the lab recommends for the most accurate testing.
Traditionally, soil testing has been used to provide an analysis of the chemical composition of the soil, and test results would be used for prescriptive treatments. More recently, growers have also started to consider the overall properties of the soil, including the physical and biological properties. While chemical analysis and input management are critical to producing healthy crops, other aspects are should also be considered as important to the overall health of the soil.
Testing for the chemical properties of soil can identify available essential nutrient levels, soil pH, salt levels, and even heavy metals, but they don’t generally identify any of the physical or biological properties of the soil. For example, a standard soil test does not generally indicate soil texture or density, water infiltration rates, aggregate stability, or even cation exchange capacity. When it comes to the biological aspects of soils, some lab tests may reveal the presence of nematodes, but may not indicate the levels of other organisms living in the soil, like earthworms, or microorganisms like certain bacteria and fungi. We know that adding organic matter into the soil can have a positive effect on the physical and biological properties of soil, but these are rarely tested for.
Visit our Small Farm Canada resources page for more information on soil.