With many farmers anxious to get started and fieldwork getting well underway, we have some important considerations for you about spring work in the zone building system. We’ll talk about seedbed preparation, doing deep tillage in the spring, placement of nutrients, and planting directly over the deep slot. The reason zone building got started was that planting in wet, no-till fields wasn’t working. The ground was too wet and too cold to get a successful crop out of the ground and residue was hard to handle.
Zone building begins by addressing compaction issues. Zone building requires the creation of a deep slot in the fall with a straight shank and straight point, just below the deepest compaction layer in your field often 20 inches deep. There are a couple of reasons that fall works best. First, anytime you do tillage, you have the potential of drying out the soil. If tillage takes place just before planting, you would need rain very shortly after planting to avoid a disastrous stand. Farmers with irrigation or from areas that normally receive more rainfall are quick to say that moisture is not a concern on their farm. They may be right about that, but the second reason we prefer to see deeper tillage done in the fall is that when done correctly, the tillage will lift up the entire profile and set it back down without turning the soil over. This creates a system of lateral breaks throughout the soil reducing compaction, increasing the oxygen content, and providing pathways for water, roots, and soil life to move. These lateral breaks can be nullified if you return to the field too quickly. Regardless of when you create the deep slots, you really need to stay out of the field for about two weeks to let the soil settle and re-establish itself. Unfortunately, we are not normally blessed with an extra two weeks to do nothing in the spring. If you’re thinking of doing some 20 inch deep zone building this spring, it is possible that it could be done, but we advise you to save your enthusiasm until this fall.
Once you do create deep slots in your fields, they create a unique challenge in preparing the seedbed. There are currently three methods to making an ideal seedbed in a zone system. First, you can use closing coulters with a leveling device right behind the deep tillage tool. Secondly, you could do tillage over the top of the zone, either strip tillage or conventional tillage. The third method is what we’re doing on our farm, running a three-coulter system with our planter to till a strip and plant in one operation.
We’ve chosen to use the coulter system because we feel it is the ideal way to warm up the seedbed, handle residue issues, and also place fertilizer, which we’ll talk about in a minute. You can have success with any of the three methods I just outlined. Just keep in mind the time and equipment needed to accomplish each, and know going into this system that something will have to be done to make the seedbed an even environment for every seed.
Your fertility system should be designed to give each seed an equal chance as well. For that reason and many more, we are banding much of our fertilizer right with our planter. Again following the system zone building pioneers have set up over many years, placing nutrients where they are both easily accessible for roots and more concentrated to avoid tie-up in soils is another way to use the same money you’re already spending and get more response from it.
As you plant into a well-prepared seedbed, your goal is to plant as close to directly over your deep slots as possible. We realize you can’t always do that with terraces, contours, and other challenges, but if you can, you allow roots to literally explode their growth deep into the soil without compaction or lack of nutrients to slow them down.
To sum up the key points for this spring:

1. Don’t build deep slots until this fall and stay out of the field for two weeks after doing it.
2. Make sure your seedbed is exactly the same throughout the field so you have even emergence and an equal opportunity for every plant.
3. Place your nutrients in a banded application for better availability and less soil tie-up.
4. Plant directly over your deep slots or as close to that as possible.