By Brian Hefty
If you raise 100 bushel wheat, when that wheat grain leaves the field, here are the micronutrients that also leave the field:
- 0.09 pounds of Copper
- 0.03 pounds of Manganese
- 0.11 pounds of Zinc
- 0.01 pounds of Boron
- 0.20 pounds of Iron
Plus, just to produce 3 tons of wheat stover, it takes approximately:
- 0.03 pounds of Copper
- 0.50 pounds of Manganese
- 0.26 pounds of Zinc
- 0.07 pounds of Boron
- 0.55 pounds of Iron
Now, when you look at these numbers and add them all up, they total LESS THAN 2 POUNDS! That’s why it’s easy for people to say, “Micronutrients are not a big deal.” That’s also what gets a lot of people in trouble, including us on our farm.
Prior to 10 years ago, we weren’t doing anything about micronutrients. Then we started doing more complete soil tests and testing plant tissue samples during the growing season. Now I wouldn’t even dream of planting a crop without checking micronutrients and addressing them.
Let me give you a quick example of what commonly happens on the farm. You may have enough N, P, and K to raise 100 bushel wheat, but you only have enough copper to raise 90 bushel wheat. What will your wheat yield be? 90. Now, think about all the money you invested in N, P, and K, besides all the other costs you’ve got on the farm. If you would have invested $5 in micronutrients, you may have gotten that 100 bushel yield you were hoping for. Don’t get me wrong. Micronutrients aren’t the most important issue on the farm, nor are they often the biggest yield-limiting factor. However, if you don’t have good micronutrient levels, you absolutely will restrict your yield potential.
Here’s the flip side. Micronutrients are cheap, so you figure you’ll just dump a bunch out there. Many people hear that copper is an issue in wheat, so they literally apply 10 years worth of copper in one shot, because it’s cheap. Here are the two problems with that. First, copper may now be excessive in the plants, and that’s a bad thing. Second, excess copper can lead to reduced availability of other micronutrients, so there will most likely now be a shortage of something else in your fields.
Here’s what we do and what we recommend. Pick a blended micronutrient product that’s right for the crop, and use what you need each year. That will keep your micronutrients in balance in the soil, and it will most likely keep your crop from being yield-limited from a lack of micros. This small investment of only a few dollars per acre will often pay you back many times over. You can apply micronutrients pre-plant, at planting-time, as a foliar application, or we even streambar our micros on sometimes. There are lots of different ways to do it, just don’t ever forget about micronutrients.