Understanding a Fall Soil Sample


As harvest wraps up in the fall, many farmers look forward to their cropping plan for the next season. One of the primary considerations is how much fertilizer you’ll need to get the highest return on your investment. Taking soil samples from your fields is the best way to assess the overall health of your soil and decide if any adjustments need to be made before the next season to help your crop reach its full potential.


What Your Soil Sample Will Tell You

Soil testing can give you various essential data points to indicate the health of your fields.

  • Soil pH - A soil test can help farmers evaluate their soil’s acidity. Most row crops grow best in slightly acidic soils, so a low pH tells a producer they may need to add lime to raise the pH and help the crop perform at its greatest potential. If the soil has a high pH, nutrients in the soil can bind up, causing them to be unavailable to the plant. Agnition’s Procure® can help plants access those nutrients under high pH conditions.

  • Fertility - A soil test can help farmers assess their soil’s nutrient levels and determine their need for additional fertilizer applications. Soil tests can accurately measure the non-mobile primary nutrients such as phosphorus and potassium; secondary nutrients, such as calcium, magnesium and sulfur; and the micronutrients necessary for plant health.

  • Organic Matter - Many soil tests account for organic matter (OM) levels in the soil and adjust their nitrogen recommendations based on the OM levels. Generally, every 1% of soil OM releases 20 lbs. of nitrogen per acre to the crop.

Fall is an Excellent Time for Soil Sampling

Fall is an ideal time to take soil samples for several reasons. Sampling in the fall allows time to address any issues the soil samples might uncover and often, farmers have more time to take samples. Lime needs time to change soil pH, so fall applications are ideal. Fall applications also let farmers purchase fertilizer before the end of the year. If an application has to be made in the late fall/winter, farmers may be able to take advantage of the frozen soils, allowing them to drive the heavy equipment in the field without compacting the soil. Remember dry soils can impact potassium results, so if summer was exceptionally dry, keep that in mind as you evaluate your test results.


Key Tips for Taking a Soil Sample

So what are some best practices for taking soil samples in your fields? Here are our suggestions:

  1. Take samples before tillage and ideally after temperatures are below 50 degrees F.

  2. Use a probe to collect soil samples from six inches deep to get the most accurate results.

  3. Take 10-15 samples per acre from random locations across the field.

  4. Avoid gravel areas and tree lines.

  5. Test your soils at least every three years.

Get More from Your Soil’s Nutrient Load

Agnition’s proven biostimulant Generate® has been shown to increase the availability of macro-and micronutrients for your plants. Don’t waste your fertilizer budget on nutrients already in your soil; increase nutrient uptake, improve plant health, and experience higher yields.


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