Bamert customers often ask if they should fertilize, or request a fertilization recommendation based on the species of reclamation seed in the blend they’re planting. However, without a soil test, any response would be just a guess.
Results from a proper soil test provide the best available picture of nutrient levels in the soil and allow a professional to responsibly offer a fertilization recommendation for the establishment of the native blend. Application of the proper fertilizer amounts depends upon knowing nutrient levels. Under-application leads to undesirable results, while over-application wastes time and money.
The site of a reclamation project is often in a degraded state because of previous management, land use, or extreme disturbance. This means the soil nutrients will not be present in sufficient amounts for stand establishment. At Bamert Seed Company, we normally suggest applying Phosphorus (P) and Potassium (K) and adjusting pH to appropriate levels according to the results of a soil test for establishment. Proper P and K levels are especially important for establishment and root development. A soil pH level that is too low or too high can make the nutrients in the soil unavailable to the plant and hinder or slow stand establishment. We don’t normally recommend applying Nitrogen (N) for establishment. More often than not the N will just grow weeds and not aid in the establishment of a native blend.
A soil test performed incorrectly is just as useless as no soil test at all. To find an option in your area, contact your local extension office to locate a reputable lab.
To take a proper soil test, keep in mind:
- Proper testing depth – Soil nutrients are stratified through the soil profile and soil tests are calibrated to account for this. Shallow soil samples will show more nutrients than are actually present, while too deep of a sample will show too few. Most labs call for a 6-inch sample, but be sure to sample according to the recommendation of the lab you use.
- Take a representative test – Often, the specifications on a reclamation project will call for the stockpiling of topsoil to be placed back over the project, or the incorporation of a higher quality material into the existing soil. The best time to take a soil sample is after the stockpiled topsoil is spread or incorporated. Taking a test from the pile will not give you realistic results. The test needs to be taken in a way that samples the top 6 inches of the soil profile that reclamation seed is being planted into. Also, 10 to 15 sub-samples, or cores, need to be taken throughout the area to get a representative sample of that area. The cores should be mixed together, and then about a quart of all the cores combined is used as the sample to be sent to the lab.
- Let the lab know your intentions – The lab will be able to give a recommendation for the amount of nutrients that are needed to be put down, but they must understand what the recommendations are for. Be sure to note the recommendations should be for the establishment of native grasses or reclamation seed on the form sent in with the sample. The recommendations from the lab will vary based on crop and yield goals, so getting the recommendation for establishment will be important.
Taking a soil sample could seem like added time and expense, but it is the only way to determine the type and amount of a fertilizer blend to use. In the long run, this practice will either save money or save time. Understanding the amount of nutrients present in the soil results in only paying for the nutrients actually needed. Using the correct amounts of nutrients ensures a sufficient stand is achieved in the shortest amount of time.
The expense of fertilizer application doesn’t meet the economic objectives of every project. However, if fertilizer is going to be used, make sure your dollars are spent wisely with a proper soil test. To learn about soil tests in more detail, please watch the great video our friends at the Noble Research Institute put together.