As we progress through the 2014 harvest (however slow), many of us are turning our attention toward planning for 2015. Many decisions have to be made over the coming weeks that will set the stage for how successful we can be next year. Once you have landed on a mix of acres, your attention will be on which seed to plant and how to fertilize for that crop.
If we look at seed over the past few years, many of us have adapted quickly to new trait packages and hybrids as they come out, due to clear advantages. We have increased our investment because we see yield gain potential that is too good to pass up. However, in a lot of cases, our fertility program hasn’t adapted as quickly. We still apply nitrogen in the same manner (timing, amounts, etc.) that we did 5-10 years ago. I would argue that if we want to capture as much of the genetic potential as possible from the $400/bag seed corn, then we need to be willing to feed it in a way that might be different than when 225 bu/A spikes on the yield monitor were considered wins.
There are a few basic principles that are well established in the market, although not always adhered to.
- Use the CEC of your soil as a guideline for how much nitrogen can be stored in the profile in one application.
If you are like me, most fields have a wide range of CEC levels (8-25). Therefore, I cannot assume that I can put all of my nitrogen out in one shot and expect it to be available for the corn plant in late June – when it starts to rapidly uptake N. With this in mind, use the range of CEC in your fields as a guideline for fall applications in the coming weeks. I generally try to put a base rate of around 100#s out in the fall. My soils can hold this, and it logistically lightens the load for next spring. Generally speaking, I try to avoid spring ammonia – only because I would rather be planting when the soil is fit enough to drag a knife 7 in. deep in the soil.
- Include spring residue breakdown while creating your nitrogen plan.
This fall is anything but early, therefore we will end up with more residue than average in the top 4-6 in. of the soil profile. Aside from physically moving this residue around at planting to ensure proper seed placement, much attention will need to be given to feeding the microbes that will be decomposing this residue in May and June. For continuous corn fields, I would recommend applying at least 60-80 lb. of nitrogen in the top few inches of soil to aid in this breakdown. Without this N, the microbes will use any available nitrogen for breaking down residue and leave your young corn plants starving for their share. This breakdown is how we end up with yellow corn fields in May and early June.
- Consider balance of nitrogen in accordance with your farming system.
As far as the balance of your nitrogen needs, I will leave that up to you to decide what fits best into your farming system. Ideally, we wait until sidedress time to determine what the final needs of the plants will be. However, in many cases the balance of the N will go out before or at planting.
As you plan for 2015, keep in mind how you can feed the crop differently to capture the potential that plant breeders have given us a chance to work with. More to follow, but until then have a safe and bountiful harvest.