Soil is perhaps the most important resource we have in agriculture. Without healthy soils, we may not realize the full yield potential of our crops. To better understand the state of our soils, a soil test is an important tool to keep in your toolbox. The results from a soil test can help determine what fertilizers or other amendments are needed to grow a bountiful crop. Taking a soil sample for a test is a relatively straightforward process. The United States Department of Agriculture Natural Resources Conservation Service (USDA-NRCS) recommends dividing a field into zones and taking approximately 15-20 samples in each zone. For example, in a 20-acre field, breaking the field into four five-acre zones can help give a more accurate picture of the state of the soil in the field. Samples can be collected with a soil probe or a spade and should be around six to eight inches deep. Each sample in a zone should then be placed into a bucket, where things such as leaves or stalks should be removed. Take the soil from the bucket and put it into a paper or plastic bag so it can dry. Once the soil is dry, place it into a separate bag and label which zone it came from. Once all samples from each zone have been collected, reach out to the soil testing lab of your choice. A list of certified testing labs can be found using this link: https://extension.illinois.edu/soil/soil-test-labs.

A basic soil test will have data in several categories, including soil organic matter, soil pH, cation exchange capacity (CEC), phosphorus (P) and potassium (K) levels, and any other nutrients present in the soil. Soil organic matter is one indication of how productive soil will be, with higher organic matter increasing the productivity of the soil. Organic matter helps soil retain water and provides a sound structure to support root development. pH is a measure of acidity or alkalinity in the soil and is on a scale of 0-14, with values less than seven indicating acidic soil, seven being neutral, and above seven being alkaline. Most plants and crops we grow like neutral soils. A pH that is too low or too high can impact a plant’s ability to take in nutrients. CEC also impacts how well a plant can take up nutrients. A CEC value between 15-20 will be able to hold nutrients in the soil and have it available for plants, while a CEC of less than six could lead to nutrient deficiencies in a plant. University of Illinois Extension educators can help interpret the results of a soil test, so reach out to your local Extension office for more information and resources. 

While soil and nutrient availability are important for a successful growing season, the equipment used for planting crops must be functional to ensure seeds can get into the ground. That is why proper maintenance for planters and seeders must be conducted in the days and weeks leading up to planting. Planter maintenance is especially important if you are planting a no-till or reduced tillage field since the planter would be the first implement to work the soil. In a no-till or reduced tillage field, the planter creates a furrow for the seed, which is different from a field with a prepared seedbed through conventional tillage. A key part of the planter in these fields are the seed openers. If the edges of a seed opener are not narrow and sharp, then the row unit cannot get down deep enough into the soil to place the seed at the correct depth. The coulter is another key part, especially if planting into corn stalks or cover crops. The coulter helps clear a path for the seed opener to make the furrow for the seed. A dull coulter will push residue around and not correctly clear a path. Ensure coulters have a sharp enough edge to slice through any residue that could get in the way of the seed opener. 

Down pressure is another element important in planting. The weight of the frame pushing down on the seed openers, row units, and coulters help clear residue, cut a deep enough furrow, and put the seed in the correct spot. If there is not enough down pressure, the seed may not go deep enough into the furrow and may not get sufficient moisture and nutrients. On the other hand, if there is too much down pressure, then the soil around the seed may be too compacted and the plant may not be able to force its way through the surface of the soil. Once you are in the field and planting, a good way to check that everything is working is to get out of the tractor and check the areas of the field that you have already planted. This is also a good time to check if the seed is at the correct depth and make any necessary adjustments. You should also work with your equipment dealer to ensure any other parts of your planter are ready to go once the time is right. 

This blog post is the first in a two-part series on preparing for the planting season. As Winter gives way to Spring, it is important to begin the preparations for getting into the field and planting seeds for the upcoming growing season. This post discussed the importance of a soil test, the meaning of some of the data in a test result and maintaining planters before going into the field. The second post will discuss the weather and how planting date can impact yields and plant development. 

For further reading, visit the following links: 

• Planter Maintenance (Iowa State University Extension): https://crops.extension.iastate.edu/encyclopedia/equipment-maintenance-planters.
• Illinois Agronomy Handbook (Illinois Extension): https://extension.illinois.edu/global/agronomy-handbook.
• Interpreting Soil Test Results (Illinois Extension): https://extension.illinois.edu/soil/interpreting-test-results.
• Soil Testing (USDA-NRCS): https://www.nrcs.usda.gov/sites/default/files/2022-09/stelprdb1167377-soil-testing.pdf.
• Soil Testing Labs (Illinois Extension): https://extension.illinois.edu/soil/soil-test-labs.