|Ohio Farm News
By Steve Bartels
The proper use of lime and fertilizer is required for high crop yields. Lime is used to supply calcium and magnesium as well as to increase the soil pH. Calcium and magnesium are minerals that are required for plant health.
Most crops grown in Butler County, Ohio require a pH of 6.5 to 7.0. This is the range where nutrients, such as nitrogen, phosphorus, potassium, sulfur, calcium and magnesium, are most available. Lime replaces harmful levels of aluminum, manganese and iron. Microbial activity, which releases organically bound nutrients, also increases in this pH range.
There are those who go around telling farmers that if you put enough lime on you can greatly reduce the amount of fertilizer you apply. Be wary of those recommendations.
As the wise old county agent once said, “show me the research,” research done by a non-biased source. We have seen a couple of instances in this county where lime was applied at such a high rate that it took the pH above 7.8. At a pH above 7.5, nutrients such as nitrogen, phosphorus, and magnesium are less available to the plant. You can always overdo a good thing.
You might be thinking, why would anyone ever pay for more lime than needed? Besides the idea of maybe saving on fertilizer input cost, if you get a product from a water treatment plant delivered at what seems like a bargain price, you might be tempted to put on more than you need.
It is also amazing to me how many farmers in this county do not soil test on a regular basis. They don’t know how much lime they might need, so when the guy comes around trying to find a place to get rid of the water treatment lime and tells them he will spread it for just $7 per ton, they bite.
In Ohio, lime materials are labeled based on their effective neutralizing power (ENP). Aglime superfine has an ENP of 2,000 lbs. per dry ton and a total neutralizing power (TNP) of 100.
Dolomitic hydrated aglime has an ENP of 2,520 lbs. per dry ton and a TNP of 140. Calcitic aglime has an ENP of 1,168 lbs. per ton of 96 percent dry matter and a TNP of 99. Dolomitic aglime has an ENP of 1,953 lbs. per ton of 96 percent dry matter and a TNP of 105. Wastewater lime has an ENP of 530 lbs. per ton of 26 percent dry matter and a TNP of 102.
This data is given as examples of each, as published in the 14th edition of the Ohio Agronomy Guide on page 25. Actual label guarantees may vary slightly from product to product.
The ENP of the material considers the material equivalence, purity, fineness of grind, and percent moisture. The ENP of the product gives you a good way to figure out which product is most economical. The soil test results from your laboratory will recommend how many tons of Aglime superfine you should apply.
As an example, if the soil test calls for 2 ton of Aglime superfine, you would need almost 8 ton of water treatment lime based on the ENP, in the Agronomy Guide, to be equal.
This farm news was published in the April 19, 2006 issue of Farm World.