Soil is the most valuable and expensive investment on a farm and yet many Ontario farmers do not sample soil regularly. Without an understanding of your soil, you run the risk of either under or over applying nutrients and impacting your production and the environment. Soil sampling is a foundational part of a producer’s ability to make decisions on crop production and soil health. Making a cropping plan without understanding the quality of your most valuable production input can be a recipe for poor soil health.
OSCIA completed a study in 2020 to understand how many producers regularly sample and test their soil and found that data is fragmented and limited. Based on survey responses from soil testing labs, Certified Crop Advisors and other stakeholders, soil sampling varies by region. In some areas in the province less than 20% of the farmers are soil sampling.
Soil labs indicated that farmers who soil test are very committed to the practice. It appears that farmers who regularly soil sample and use the results see value and a return on investment. As one participant in the 2021 OSCIA Accelerate Your Soil Health pilot project noted “you need to have insight into the challenges of the soil through actual measurement, otherwise you are left walking around in the dark.” This sentiment was echoed by many of the pilot project participants and 53% indicated that they will sample every 3-5 years and an additional 30% will probably continue the practice.
A dairy farmer in Renfrew County, remarked that “Soil testing takes the guesswork out of our nutrient applications.” Prior to soil sampling they typically purchased a general fertilizer for all fields. After soil testing, they realized that they could tailor applications to each field to focus on what the field needs most to better manage their budget and time. They usually put lime on every field once the alfalfa died out, but the soil testing revealed that in one field pH wasn’t the main limiting factor; it was low fertility. They will use the soil tests as benchmarks to focus their soil sampling in the future and will cycle back on a regular basis to see if things have changed.
Soil testing on a regular basis will ensure that management and fertility practices are effective over the long term as well. A beef farmer who participated in the pilot project shared that testing proved that his rotational grazing along with appropriate stocking density was maintaining good soil nutrient levels. He shared that the “economics of custom grazing require good cost/margin control, soil testing allows the farm to monitor soil nutrient levels overtime to see impact of grazing management while keeping fertilizer costs as low as possible. Also testing metals gives a better understanding of potential deficiencies or even possible toxicities. Testing every 5 years will track nutrient trends and impact the grazing management plan.”
Most producers who moved beyond composite soil sampling and used the pilot program to try grid sampling were surprised at the extent of variability in their fields. A Lambton area farmer discovered that the application of uniform rates was not putting the right nutrients in the right place. He knew “that we can do a better job of nutrient management with both manure and commercial fertilizer.” For the 2022 growing season he applied variable rates according to the test results. He used less fertilizer overall, even though he applied heavier rates to the spots that needed it. Yield was normal in areas that had higher nutrient levels in the soil but areas that needed more nutrients had yields that were better than in average years.
OSCIA members can receive a discount on soil testing at select Soil Labs. If you are a member, contact your local Association Secretary for the coupon.