Understanding Soil Test Results: What to Plan for Before Spring Planting
Jan 26, 2026
Once soil samples are pulled and results are in, the next step is putting that information to work. Understanding soil test results allows producers to fine-tune fertilizer plans, prioritize inputs, and make confident decisions before spring planting begins. These soil samples tell a story, but only if you know how to read the results.
When reading your soil test, start with pH since everything else you apply builds off that. Soil pH measures acidity or alkalinity on a scale from 0 to 14; any value below 7 is considered acidic. pH affects nutrient availability in your soil, making certain nutrients lock up, which, in turn makes soil toxic. Depending on the crops you plan to grow, soil pH may vary, making this a critical consideration for crop placement.
For example, corn needs a pH of 6.0-6.8. If one of your fields tests at 5.5 then it would be more cost effective to plant corn there, allowing you to spread less lime. Alfalfa prefers a higher pH — around 6.8 to 7.2 — so adjustments on field placements would be useful here with the use of sulfur to lower it or lime to raise it.
This is also where micronutrients come into play. Elements like boron, copper, chlorine, iron, manganese, molybdenum, nickel, and zinc are all essential in small quantities, but their availability is strongly influenced by soil pH. For instance, high pH can limit crop access to certain micronutrients verses when pH is low, it can increase the amount of manganese and iron.
Most soil test results list micronutrient levels in parts per million (PPM) or pounds per acre, with ratings like very low, low, medium, optimum, high, or excessive. These ratings help determine which nutrients should be included in your fertilizer blends and which do not require additional input.
Another major soil need is macronutrients, phosphorus, potassium, and nitrogen. A key point to remember is that your soil tests do not measure your nitrogen levels. Due to nitrogen’s mobility and complex behavior, soil tests for it are unreliable. While phosphorus and potassium develop slowly over time, you may only need to adjust these nutrients in fields showing deficiencies. Nitrogen, on the other hand, is more dynamic and often applied in-season.
Timing is just as important as rate. Some nutrients are best applied before planting, while others are more effective as side-dress or foliar applications. Using soil test data, producers can schedule applications to match crop growth stages, maximizing nutrient uptake, and minimize success.
Since no two fields are exactly alike, reviewing soil test results by field or management zone allows producers to apply nutrients more precisely. This is time consuming and might seem like a hassle, but could end up saving you hundreds of dollars on unnecessary inputs while supporting better crop performance.
Soil test results are more than just numbers; they are the roadmap for spring planting decisions. Taking the time to understand and apply this information allows producers to manage inputs responsibly. Your local Co-ops, Extension agents, and neighboring farmers can help interpret the data and create a customized fertility plan, ensuring your operation is ready for a successful planting season before the first seed goes in the ground.
When reading your soil test, start with pH since everything else you apply builds off that. Soil pH measures acidity or alkalinity on a scale from 0 to 14; any value below 7 is considered acidic. pH affects nutrient availability in your soil, making certain nutrients lock up, which, in turn makes soil toxic. Depending on the crops you plan to grow, soil pH may vary, making this a critical consideration for crop placement.
For example, corn needs a pH of 6.0-6.8. If one of your fields tests at 5.5 then it would be more cost effective to plant corn there, allowing you to spread less lime. Alfalfa prefers a higher pH — around 6.8 to 7.2 — so adjustments on field placements would be useful here with the use of sulfur to lower it or lime to raise it.
This is also where micronutrients come into play. Elements like boron, copper, chlorine, iron, manganese, molybdenum, nickel, and zinc are all essential in small quantities, but their availability is strongly influenced by soil pH. For instance, high pH can limit crop access to certain micronutrients verses when pH is low, it can increase the amount of manganese and iron.
Most soil test results list micronutrient levels in parts per million (PPM) or pounds per acre, with ratings like very low, low, medium, optimum, high, or excessive. These ratings help determine which nutrients should be included in your fertilizer blends and which do not require additional input.
Another major soil need is macronutrients, phosphorus, potassium, and nitrogen. A key point to remember is that your soil tests do not measure your nitrogen levels. Due to nitrogen’s mobility and complex behavior, soil tests for it are unreliable. While phosphorus and potassium develop slowly over time, you may only need to adjust these nutrients in fields showing deficiencies. Nitrogen, on the other hand, is more dynamic and often applied in-season.
Timing is just as important as rate. Some nutrients are best applied before planting, while others are more effective as side-dress or foliar applications. Using soil test data, producers can schedule applications to match crop growth stages, maximizing nutrient uptake, and minimize success.
Since no two fields are exactly alike, reviewing soil test results by field or management zone allows producers to apply nutrients more precisely. This is time consuming and might seem like a hassle, but could end up saving you hundreds of dollars on unnecessary inputs while supporting better crop performance.
Soil test results are more than just numbers; they are the roadmap for spring planting decisions. Taking the time to understand and apply this information allows producers to manage inputs responsibly. Your local Co-ops, Extension agents, and neighboring farmers can help interpret the data and create a customized fertility plan, ensuring your operation is ready for a successful planting season before the first seed goes in the ground.