Calcium Products - Displaying items by tag: zinc
Calcium Product 98G


North American Soils Lack Zinc

While its true calcium may be King, all nutrients have an important part to play in plant health and high yields. I just saw an article on the lack of zinc in North American Soils. Of 4.4 million tests taken in 2010 37% showed less than 1 ppm Zn, with 16% of those less than 0.5 ppm. 

You can order the full IPNI report Soil Test leaves in North America 2010 by clicking on the previous link.

Zinc is a component of enzymes including auxins (plant growth hormones). It is essential to carbohydrate metabolism, protein synthesis and internodal elongation (stem growth). 


Here is a great post by AgriGold Hybrids on Zinc.

Here is a summary of the post:

... showed a 53 bushel increase in yield by adding one pound of zinc to a starter. 


...common symptoms associated with zinc deficiency in corn results in a white or yellow band that runs parallel with the mid rib. Other problems associated with zinc deficiency include:

• Poor root development
• Stunted growth
• Small leaves
• Shortened internodes
• Delayed silking and tasseling
• Chalky kernels

There is also the hidden deficiency that has no symptoms.  Hidden zinc deficiencies are well documented in corn and reductions in yield can be up to 40%.  Therefore the best method to determine if zinc is deficient is by taking soil samples to determine the levels of zinc in the soil.

Calcium Product's Note: It is well documented that many deficiencies can take up to 2 weeks to show visual response and up to 2 more weeks to correct. This whole time you are losing yield you cannot recover.

Don't let your yields suffer from hidden hunger, make sure you include micronutrients as part of your fertility program.


Yield Starts Here is a blog for farmers, focusing on increasing yield and profitability by focusing on the soil. It is managed by Craig Dick, a Blogronomist and Sales and Marketing Manager at Calcium Products. Find other articles by Craig and guest writers at .







Low Boron and Excess Iron, is there an interaction?



One of our customers emailed in with some questions. They wanted to know about lower pH levels and higher iron levels & potential correlations and were seeing seeing sub Boron and excess irons in tissue samples.

After some research, near as I can tell boron and iron have no interactions. Both are however affected by calcium (See chart 1).

More calcium will reduce iron uptake. Boron and silicon help to increase calcium uptake.

In low pH excess phosphorus can reduce boron uptake

High potassium can reduce boron uptake

Boron deficiency

  • Reduces growth of soil bacteria.
  • Poor movement of sugar and carbohydrates in the plant.
  • Affects timing of maturity, pollination, and reproduction.

Some old articles on boron and silicon:


What about Iron?

Injury due to high soil iron concentrations is not common under neutral or high pH soil conditions. Toxic situations occur primarily on acid soils (< pH 5.0) and where excess soluble iron salts have been applied as foliar sprays or soil amendments (poor quality limestone).

The first symptoms of iron toxicity are necrotic spots on the leaves. An unusual form of iron toxicity has been observed in Michigan on organic soils and high organic sands. Some iron-rich, low pH, low manganese soils create an environment in which an interaction between the iron and manganese in the soil reduces manganese uptake by plants. The symptoms observed on the plants are of manganese deficiency, but the low plant uptake of manganese is caused by excessive available iron in the soil.

Toxicity Symptoms

Iron toxicity is primarily pH related and occurs where the soil pH has dropped sufficiently to create an excess of available Iron. (I think this statement is wrong, not low pH, low calcium is the issue cmd)

As with some other nutrients, the visible symptoms of Fe toxicity are likely to be a deficiency of another nutrient. Fe toxicity can also occur when Zinc is deficient, or the soil is in a "reduced" condition caused by very wet or flooded conditions. Excess Fe can result in Dark green foliage, stunted growth of tops and roots, dark brown to purple leaves on some plants (e.g. bronzing disease of rice).

High levels of nitrogen and potassium increase iron uptake

Excessive iron can reduce uptake of manganese, additions of sulfur improve uptake of manganese

High iron can reduce zinc uptake, and low zinc uptake is often found with low manganese

Iron excess:

  • Interferes with phosphorus absorption.
  • Requires use of higher levels of potassium to regulate.
  • Can cause Zinc deficiency

To reduce problems with excess iron make sure you have adequate levels of calcium in your soils and the pH is at least 6.5. SupeCal SO4 gypsum and SuperCal 98G limestone are great ways to ensure pro


Interaction of zinc and calcium

Zinc is an extremely important micronutrient that has many roles in plant health and deficiencies are widespread, even if unknown to the grower. Recommendations for zinc levels in soils are dependent on crop, soil type, pH and other nutrient status and can range depending on which institution is offering the recommendation. Generally speaking, below 1ppm on your soil test indicates that you should apply some type of zinc fertilizer. However, growers should pay attention to their soil tests and site-specific factors, because while 1ppm of zinc in one soil type may be sufficient, 4ppm in another soil with zinc antagonists may be a better target.

Deficiency symptoms are generally seen in new growth, early in the life cycle of the plant and result in stunted growth, shortened, sometimes split internodes and discoloration of new leaves—the color of which can vary depending on plant species. Internally, zinc deficiency can result in reduced water uptake, phytohormone (hormones that regulate plant growth) activity and uptake of other nutrients. In corn, zinc deficiency results in a broad band of bleached tissue on either side of the midrib, beginning at the base of the leaf and generally staying in the lower half of the leaf. Severe zinc deficiency may result in new leaves that are nearly white, a phenomenon called 'white bud.'

Zinc availability is very sensitive to pH, and is therefore reduced by over-liming or by other agents causing high pH. However, rates and acidifying forms of N commonly used in agriculture generally alter the pH enough in the rhizosphere to enhance zinc uptake. Zinc is also well known to interact with P; where zinc is deficient, P uptake is increased in certain plants and vice versa. Zinc deficiency is also more common on cool and wet soils with low organic matter.

Specifically, we are interested in the interaction of zinc and calcium, a topic on which there exists little information. Feedback from growers indicates that when zinc levels are not sufficient, they don't see a good response from our products containing calcium. Why this happens, we are not exactly sure, however, we theorize that perhaps the limiting factor is zinc, rather than the calcium, which results in no visible effects from the application. One thing we do know is that alkaline earth cations, specifically calcium, can inhibit zinc uptake. This may have something to do with the fact that a large amount of basic cations in soil generally result in higher pH values, which is known to inhibit zinc uptake. One way to combat this problem is to apply some slightly acidifying N fertilizer that will cause a temporary shift in pH—favorable to zinc uptake—in the rhizosphere to combat the inhibitory effects from calcium. The take-home message is that if calcium-based products are needed in your system, it is prudent to pay attention to your zinc levels and adjust with a zinc fertilizer, or another method to ensure your plants are getting the requisite amount of zinc.



SuperCal SO4 with Zn and N on Corn

SuperCal SO4 has been shown to increase nitrogen uptake as sulfur in SuperCal SO4 aids in the nitrification process. Calcium helps to stabilize nitrogen by decreasing volatilization loss. Calcium is essential to the biochemical process of plants to absorb nutrients. Adding SuperCal SO4 to your fertility program will make your expensive nitrogen and zinc work better.

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