By Andy Westhoven, AgriGold Regional Agronomist, CPAg, CCA
At the conclusion of a harvested field, many options abound for growers on how to prepare their fields for the next season. Inevitably, we want to make the subsequent season better, which may mean enhancing the soil fertility, using cover crops, tillage, no-tillage, fall herbicides, etc. Whatever the decision, the goal is to always leave the field improved and ready for next spring – so make the pass count.
No one wants to waste time, energy, and resources on a pass across the field that will not improve the soil. Many growers will fall-apply nutrients with variable rate(s) and/or different placement methods such as strip till and broadcast. It is extremely important to “know before you throw” fertilizer on/in a field. The importance of soil sampling cannot be forgotten. Simply applying fertilizers because “it’s what we do” or blindly applying fertilizers can go wrong. There are many ways to soil sample, but any sample is better than nothing. With fall fertilizer applications, typically phosphorus and potassium are the main ingredients. When analyzing a soil sample, it is imperative to look at the soil pH and, specifically, the percent calcium and magnesium. Those two nutrients must be in balance before any change to soil fertility can be observed. In general, it is good to see calcium levels greater than 60% and magnesium levels below 20%.
Another growing interest is the use of cover crops. I have much experience on our own farm using cover crops (more for soil erosion). The key is to select the right species for your end goal. There are seemingly endless mixes to try. Be sure to know your goals (i.e. nutrient extraction, soil erosion protection, soil health improvement, etc.). Also keep in mind that some species will winterkill, and some will not. Those that do not winterkill must be handled properly in the spring. A cover crop that gets out of hand can quickly become a weed and competition for the following crop.
This section will not debate tillage versus no tillage. Certainly, each have their place and growers have chosen those paths for specific reasons. I would like to share a few observations from our soybeans harvested thus far with different tillage practices. All fields were following corn. We had one field that was fall chiseled and spring field cultivated. A second field had a vertical tillage (VT) tool in the fall. A third field had a VT application in the spring. These fields were then treated the same (same variety, all three share the same intersection, planted within days of each other, etc.) There was essentially no difference in any of these methods. Possibly a 2-bushel difference from the best to the “worst” was observed. My point is this, make the tillage pass count. What is your goal? Burying / sizing residue, breaking compaction layers, warming the soils, etc. Regardless of the reason(s), always leave the soil level in the fall. I do not mean leave it ready for planting. I mean leave the field level because the spring tillage pass (if there is one) is to prepare the seedbed — no other reason. Therefore, if you are no-till, your goal at the conclusion of harvest is to leave the soil and field conditions ready for planting.
Finally, as weed control seems to get more challenging by the day, some growers will fall-apply herbicides. This is very effective in killing the current germinated weeds but could also help the field stay clean into the start of spring. Be sure to know your planting intentions if this is a new practice. I have been a part of many service calls in the spring when a fall-applied herbicide application dinged the next year’s crop when a grower planted the wrong crop.
As harvest continues, please remember to stay safe and enjoy the ride. Many enjoy this time of learning and reaching the conclusion of a long growing season. As you contemplate your next move across the field, I trust you will make the pass count. I hope you all have a memorable and productive harvest season!