With 84 percent of the corn crop and 88 percent of soybean acres harvested, the clock is ticking to prep your field for next planting season. The frigid winter temps are just around the corner, so plan accordingly to ensure your soil is in good health to support next year’s crop. Here are some top tips for fall soil sampling and other field prep.
Test Accordingly
A soil test is only as good as the sample you submit. We recommend starting with a map to label where you plan to take the soil samples. From there, use a grid or zig-zag pattern for testing, taking 10–15 cores per sample for every 2.5 acres. Sample depth should be different for no-till versus tilled soil. For no-till, we recommend taking a sample at 3–4 inches, whereas for tilled soil, we recommend samples taken at 6–8 inches.
Sample for pH
According to the Tri-State Fertilizer Recommendations, for Ohio, Indiana and Michigan, pH levels should fall between the 6.0–6.5 range for corn and soybeans. If soil falls short of the 6.0 level by .2 or .3 pH units, liming is recommended. Because pH level recommendations can vary based on type of soil, we recommend working with a local soil fertility expert or your local university extension office to help test your soil samples and provide more localized recommendations.
Don’t forget the P and K
In addition to pH, phosphorus (P) and potassium (K) should also be tested during fall soil sampling. However, it’s important to consider what crop is being placed in the field next year. Certain crops take more P and K than others, so follow guidelines set in place by your local extension office.
Consider Sulfur and Zinc Applications
While soil testing for sulfur is not recommended, it is important to apply it at the same time as nitrogen. Sulfur applications should be added at a rate of 7 to 14 percent. Sulfur is important for protein synthesis, which is necessary for plant vitality and development, including pollen development. Most sulfur in the soil is located in the organic matter and cannot be taken up by the plant until mineralization, which is when the sulfur is converted to sulfate, or SO4-2, by bacteria in the soil.
Zinc plays an equally important role in the synthesis process. It produces growth hormones and proteins in that plant that are necessary for the production of chlorophyll and carbohydrate metabolism. Essentially, zinc is responsible for transporting calcium through the plant. Zinc can be produced by high levels of iron or phosphorus.
Remember, it’s not just about fertility
Soil samples provide other field information aside from nutrients. Certain soil samples can also detect the presence of soybean cyst nematodes (SCN). In fact, there are ways to get soil tested for SCN free of charge through state soybean promotion boards. Consult with your local board to ask about available soil sampling programs and to confirm the proper sampling measurements and process for SCN testing.
Even if your soil results show that there’s no need for additional nutrient applications or seed traits, sampling now could save you time and money next year. Crops cannot produce top-end yields without adequate nutrients and while the presence of pests still linger underground. Soil sampling is a simple step to get you the right solutions for your operation.
For more advice on fall field prep and soil sampling, contact your local Stine sales agronomist.