I have asked this question to my clients and the answer is usually that of confusion or unknown. In an industry where people are taught to take a soil sample, people are not taught how to effectively use those results. You go out to your plot; you take 10 different soil samples. You send those results to the soil testing lab and you get some results back. Many labs provide “generic” recommendations. Most do not even understand what affects how recommendations are made. Most assume that soil pH is the biggest factor but that is not true. That is only one component. The soil texture and cec levels are what matters most. An example of this would be 3 food plotters with plots with 6.0 pH and average levels of p and k. Do you know there would be 3 different recommendations for all three for something like alfalfa even at the same yield goal? Yes, you fertilize different on sand ground then clay and loam.
Joe Food plotter might have a 6.5 pH on his soil and with ideal soil phosphorous and potassium levels and still experience growth issues. How often have you fertilized according to someone’s recommendations and seen stunted growth or off coloring of leaves? I at times get people calling me asking for help. They did things right but obviously the plots are telling them otherwise. Yes, the weather can be a huge component of that. Timeliness and placement of dry and liquid fertilizers also can affect in season growth. Here is the first thing I ask people to do.
PULL ROOTS. Everyone focuses on top growth when determining success or if there are issues. The roots are the engine. The root development can tell us volumes. When we see underdeveloped roots that can be a driving factor in less-than-ideal growth. How else are you getting moisture, macro, and micronutrients into the “engine?” Perhaps that underdeveloped root system was because of your soil health. Was there compaction? What is your soil oxygen levels? Are your soils full of natural “growth promoters” that helped you more fully develop your “engine?”
Once clients pull roots and share with me what they found, then a list of questions come into play. What was planted previously? Tell me about past herbicide and fungicide applications. How did you work the soil and what equipment did you use? Tell me about the weather preplant and post plant. The more info one received the better one can understand what factors may have contributed to the deficiencies.
Many think of no till as a benefit to healthy soil but what if you over rely on chemicals. What are those chemicals doing to the living microorganisms and the soil profile? Are you tilling the soil or are you trying to maintain living roots? Are you planting forages that reduce fertilizers and “salts” by future crops? Are you planting myco producing blends that help bring the soil alive? Do you have earthworms whenever you dig a shovel of soil? Do you have effective subsoil drainage when you have heavy rains?
Yes, my friends, a soil sample does not tell you how alive your soil is. What tells me how alive a soil is the plants itself. When I scissor cut forages out on my research properties, that tells me how “alive” the plants are. What is taken up by the forages is the true test. I know how the forage is supposed to test and then I compare the current forage test to the norm. If I see less than ideal plant nutrients that tells me that the “engine” wasn’t sending the groceries throughout the “chassis.” This is why we always have a solution when a plot shows stress. We foliar feed. Foliar feeding is basically a form of reverse fertilization. Instead of sending nutrients up from the roots to the plants we send the nutrients from the plant back down to the roots.
Yes, this can get more complex but perhaps this is a start and something for you to ruminate on. Healthy soil is alive and thriving, no matter the pH, and nutrient levels.