Do you have too much calcium, magnesium, salt, sodium, or any other nutrient in your soil?
If so, your soil health is not ideal, and your yield is likely suffering!
Here are our general guidelines on some common excesses and how you can get your levels back into a more favorable range.
Calcium
If your calcium level is higher than 80% in a base saturation test or if you see the Excess Lime test showing medium or high, you have too much calcium in relation to other nutrients.
If your Excess Lime reading is low while your base saturation calcium is higher than 80%, it’s possible you could balance your soil nutrients by simply raising your magnesium and/or potassium levels. However, if the Excess Lime is anything other than low, you’ll want to flush some calcium out of your soil.
Magnesium
We get asked about “high mag” soils all the time. Anything higher than 20% in a base saturation test is where we consider magnesium “high”.
However, there’s a big difference between 22% magnesium and 42% magnesium. The higher the number, the more likely your yield is impacted, and therefore the more you can invest and still get a good return.
Salt
Anything over 1.0 on a soluble salts test is where we would tell you to start addressing it.
Sodium
Anything over 1% on a base saturation test is concerning. 5% is considered a sodic soil.
Just to be clear, sodium is not salt. Sodium is an individual nutrient. However, if you combine it with something like chloride, it becomes a salt.
Potassium, Copper, & Zinc
You might say, “Sign me up for an excess of potassium, copper, and zinc!” However, if you are above 8% potassium in heavy soils or above 10 and 20 ppm on copper and zinc, respectively, your extremely high level is likely impacting the availability of at least one other nutrient, and yield is suffering.
Boron & Sulfur
Since both of these nutrients are leachable, the only time you are likely to see them in excess is where drainage is poor.
With boron, divide your calcium parts per million by 1000. If your boron level is higher than that, it may be damaging your crop. With sulfur, if the level is higher than 100 ppm, we would probably consider it too high, but sometimes we’ll see much higher readings and still find good yields.
5 STEPS TO REMOVING EXCESSES
1. Improve your drainage.
If you are going to flush anything out of your soil, you may need drain tile, especially in heavy soils. In addition, do what you can to reduce compaction, build organic matter, and make sure your calcium levels are at least 65% in the base saturation test so your soil has good porosity.
2. Make your excess nutrient leachable.
In most cases, this means turning it into a salt. For example, magnesium and sodium aren’t going to move well on their own, but if they are combined with sulfate (magnesium sulfate and sodium sulfate), they become salts. Neal Kinsey has told us over the years it takes roughly 1 pound of sulfur to remove 1 pound of sodium, and it takes about 2 pounds of sulfur to get rid of 1 pound of magnesium.
3. Stop applying whatever is in excess.
If you normally spread manure but now your potassium or any other nutrient is too high, it is time to stop using manure, at least for a while. Crops use lots of nutrients, even things like calcium, magnesium, and the micronutrients. If you start mining those elements out of your soil and only applying what your crop is short on, you’ll solve your problem(s) over time.
4. Do everything you can to raise an amazing crop.
The higher your yields, the more fertility your crop will pull out of the soil. On top of that, the more root channels and microbial activity you’ve got because of your great crop, the easier it will be to solve any of your soil problems.
5. REPEAT AND REPEAT AND REPEAT.
If you’ve got a heavy soil, it could take decades to completely fix a sodic or a high magnesium problem. Just give it some time. Have some patience, but keep monitoring things to make sure everything is headed in the right direction.