How do you measure soil heath?
On this episode of RealAgriculture’s Soil School, OMAFRA soil scientist and land use specialist Dan Saurette joins Bernard Tobin to look at some of the assessment tools available to farmers and the type of insights they provide.
One of the most well known soil health tests is Cornell’s Comprehensive Assessment of Soil Health. It focuses on key indicators and whether these measures are within an optimal range. In the case of organic matter, Saurette notes that more is better and a higher score contributes to better soil health.
For other indicators, less is better. This is the case for surface hardness, which is measured using a soil penetrometer. When more pressure is required for this probe to vertically penetrate the soil, compaction is likely the problem.
When it comes to an indicator like soil pH, however, it’s best to land in the neutral range where the soil is neither highly acidic or alkaline. When pH is in the neutral range that’s where nutrient cycling is optimal, notes Saurette.
In the video, Saurette also looks at other available tests, including the Haney Test and two tests from Solvita — the CO2 Burst respiration test and the Soil Labile Amino Nitrogen (SLAN) test, which measures nitrogen availability in the soil. (Story continues after the video.)
Saurette discusses the difference between soil health tests and soil health frameworks. Individual tests tell us about specific soil properties — for example, organic matter and surface hardness — whereas frameworks are really an ensemble of individual tests and a system to evaluate them and provide an overall soil health score.
Saurette stresses that regional frameworks are important because they allow Ontario farmers, for example, to compare their soil to those across the region and make soil health assessments that reflect local soil and cropping systems. He also discuses goals and objectives for a new Ontario soil sampling program and the development of an Ontario soil health planning tool for farmers in the province.
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