Top Reasons to Soil Test: Maximize Yields, Reduce Costs and Balance Nutrients
By Mitchell Japp, MSc, PAg
Why Soil Testing Matters: Key Benefits for Your Farm
Soil testing is one of the smartest, lowest-cost tools available to farmers. It provides valuable insights to guide fertilizer decisions, improve yields, and protect your soil’s long-term health. If you’ve ever wondered whether it’s worth your time, here are some key reasons why soil testing should be part of your regular farm management plan.
1. Knowledge is Power
The most important reason to soil test is simple—knowledge. Soil tests reveal the nutrients currently available and what may become available during the growing season. Nutrient availability can change over time due to uptake, volatilization, leaching, denitrification, and other processes. Understanding your soil’s current status helps you make informed, data-driven decisions for every field.
2. Maximize Economic Returns
Fertilizer is one of the largest input costs on the farm—and one of the biggest opportunities for return. A soil test is a small investment that can save money and boost efficiency. With test results in hand, you can fine-tune fertilizer purchases to avoid overbuying or underapplying. Since fall is typically the best time to secure fertilizer prices, testing in the fall helps you plan and purchase with confidence.
3. Protect the Environment
Over-application of fertilizer doesn’t just waste money—it increases the risk of nutrient losses to the environment. Nitrogen can leach or volatilize, contributing to greenhouse gas emissions and water contamination. Excess phosphorus can run off into lakes and streams, leading to algae blooms and eutrophication. Soil testing helps apply only what’s needed, reducing both input costs and environmental impact.
4. Monitor Soil Health Over Time
Regular soil testing lets you track changes in key nutrients and soil properties from year to year. Macronutrients such as nitrogen (N), phosphorus (P), potassium (K), and sulphur (S) fluctuate regularly, while calcium (Ca) and magnesium (Mg) can slowly decline. Even stable properties like pH and organic matter may shift over time. Monitoring these trends helps you catch issues early and manage zones more effectively.
5. Plan Fertilizer Strategies Across Rotations
Not all nutrients behave the same way. Nitrogen is typically applied to meet crop needs for the current year, but phosphorus and sulphur can be managed across rotations. Applying slightly higher phosphorus rates on less sensitive crops can help build soil reserves for more sensitive crops later in rotation. Strategic soil testing and fertilizer planning keep every crop in the rotation well-fed and balanced.
6. Hit Yield and Quality Targets
For malt barley growers, the right fertilizer balance is essential to meet both yield and quality goals. Excess nitrogen can increase protein levels and lodging risk. Soil testing gives you the data needed to align fertility with target yields while maintaining ideal grain quality. This is especially important as newer malt varieties offer higher yield potential with lower protein profiles.
7. Timing Your Soil Test
The best time to collect soil samples depends on your goals.
- Fall testing: Convenient, provides time to plan and lock in fertilizer prices. Aim for late fall when soil temperatures drop below 10°C to capture post-harvest mineralization.
- Spring testing: Offers the most up-to-date nutrient snapshot before seeding.
If you’re sampling early in fall, confirm whether your lab accounts for expected mineralization, or work with your agronomist to adjust recommendations.
Conclusion
Soil testing is a practical, science-based way to optimize fertilizer use, manage costs, and protect the environment. By testing regularly, you can monitor changes in soil health, fine-tune fertility plans, and ensure your crops have what they need to thrive. It’s one of the most cost-effective investments you can make for profitable, sustainable farming.
