Listened to two US corn belt advisers at SW Ag Conference, one from southern Minnesota and one from NW Indiana. Both were reviewing corn production practices in their respective areas.
Both come from intensive corn and soybean productions areas that do not grow wheat. Typical rotation are two years corn followed by one year soybeans. Both said 60-70% of corn grown is 2nd year corn and everything is RR Ready. Sounds simple, but looks can be deceiving.
Here is a combination of their recipes for modern continuous corn production and my comments.
1. Moldboard plows are in the scrap heap. Extensive use of chopper heads on combines and vertical tillage tools, Salford RTS and Case IH Turbo-Till being two of most common. One or two passes in spring with cultivator. Fall tillage of corn stalks ahead of soybean planting.
Comments - Keeping fields level, sizing residue for quicker breakdown and easier residue management in the spring. Keep in mind, two years worth of 200 bu corn residue is a lot of residue. "Black dirt" warms ground quicker which allows early planting. Getting over a lot of acres in a hurry is also the goal.
2. Planting rates of 35-36,000 seed per acre. Precision 2020 SeedSenseTM monitors, air bag systems, precision row monitor equipped planters. Trashwhippers are necessary to move corn residue.
Comments - The Precision package of planter modifications is impressive.
3. Plant rootworm resistant hybrids plus additional rootworm insecticide, Counter being one example. This is done on every acre including first year corn.
Comments - The result of too many years of too much corn in the rotation. Rootworms are developing resistance to Monsanto's rootworm technology, so growers are going back in time 30 years to applying rootworm chemical. Yuck. I hoped these days were over.
4. Widespread use of Counter insecticide and other new seed treatments to control root nematodes.
Comments - 86% of corn fields surveyed in Michigan have nematode populations, some of which can cause damage. More prevalent in sandy and sandy loam soil types. This needs more investigating in Ontario because we have nematodes too.
5. Applying soil residual herbicide at planting followed by post application of glyphosate. Glyphosate resistant weeds are common because they got carried away with using too much glyphosate.
Comments - Serves them right. Lack of crop rotation and heavy reliance on one chemical. These guys really need another crop to grow. In Ontario, this is a warning of what not to do.
6. Apply fungicide tank mixed with glyphosate at 5 leaf stage. Second fungicide application at silking time tank mixed with insecticide and foliar N.
Comments - Fungicides are becoming normal in Ontario and I am a believer, but WOW, the chemical bill keeps getting bigger. They have significant leaf disease problems. By now you can guess why. The insecticide is for Western Bean Cutworm control and once you go this far a couple of bucks on extra fertilizer is no big deal. Does it all pay?
7. Harvest corn at moistures above 20% because there is too much header loss harvesting 15% corn.
Comments - I wish we had this issue. Maybe they should slow down, oh never mind!
8. Apply fall fertilizer. P & K , urea or ammonium sulphate to break down corn residue plus soluble humus or gypsum. Gypsum is a source of calcium.
Comments - Fall P & K or manure is always a good idea. The rest is debatable. I assume they know what they are doing, but with more rotation I suspect they would think different. Forget the gypsum, we have too much calcium in our soils already without adding more.
9. Fall burndowns with residual chemicals, like atrazine, to control fall annuals.
Comments - If you love your plow, this is irrelevant. I believe we need to use more fall application in Ontario, but not on every acre.
10. Apply 150 lbs of N pre-plant plus 50-60 lbs of N side-dress.
Comments - These rates guarantee that the debate between production and environment will continue. Economics at the farm gate usually trumps environment. From where I sit, 200 lbs of N is excessive. We can grow 200 bu corn too, with less N. If corn genetics take us to 250 bu, more N may be necessary. This is the motivator that prompts the seed industry to produce corn hybrids that use less commercial N.
11. Starter fertilizer containing MicroEssentials MAP.
Comments - an excellent dry starter with zinc and sulphur available through Cargill and other fertilizer outlets.