Lime Applications to Correct Soil pH using Variable Rate Application​

Acidic soil needs lime in order to neutralize acidity. Doing so allows better growth for crops and other plant life. But what causes soil to become acidic in the first place?

Soil acidity

The acidification of soil isn't an unusual phenomenon; it is a natural process that is expected of soil that has experienced different crop production practices. For example, the use of nitrogen fertilizers contributes to the acidity of soil.

Although soil acidification is a natural process, certain properties – chemical and biological to be exact – change. One such change is the increase in the solubility of aluminum and manganese, both elements being dangerous for plants. Which are both dangerous for plants.

However, plants do have a tolerance for aluminum and manganese but the levels vary. This leads to needing specific soil pH requirements to plant certain crops. If there are certain crops you want to plant, custom agronomics can help you determine the right soil pH needed for them.

Adding lime to soil increases its pH and therefore reduces its acidity. Lime also adds calcium and magnesium into the soil, which then help it minimize the solubility of aluminum and magnesium.

Lime applications

Soil acidification can be reversed with the help of a liming material, which include carbonates, hydroxides, oxides, and silicates of calcium or magnesium. Components of the liming materials react with the acidity of the soil, leading to its neutralization.

The question now becomes: just how much lime needs to be added to the soil to neutralize acidity?

First, a lime requirement test needs to be performed. The results of the test serve as a basis for the amount of lime needed. You can get the help of a custom agronomics company to determine the lime application rate for your desired crops.

Variable rate application

The amount of lime needed by soil to plant a certain crop depends on its cation exchange capacity (CEC), which tells you the cations attracted to soil particles. The CEC of soil is related to a number of factors, including soil texture, content of organic matter, and the type of clay present.

An increase of clay and organic matter leads to an increase in CEC. This leads to an increase in the amount of hydrogen ions that need to be neutralized. A lime requirement test provides recommendations for soils with different CEC.

There will be different liming requirements for soils located in the same field that have very different texture, organic matter and soil pH. If this is the case, variable rate application (VRA) is usually recommended. In fact, of all of the VRA used, this is the one most recommended.

A decision also needs to be made regarding the kind of VRA to be used. Map-based VRA uses an electronic map to adjust the application rate. On the other hand, a sensor-based VRA doesn't need a map and uses a sensor located on the applicator instead.

While it is normal to have acidic soil, it changes the biological and chemical properties of soil. This can include an increase in elements that are harmful for plants and also make other essential nutrients unavailable to the plant. Acidity, however, can be solved by adding lime and in the case of different kinds of soil, variable-rate application is recommended. 

​Precision Agronomics is located at 9438 West SR 28 in West Lebanon, IN and is proud to serve: Marshfield, Johnsonville, Foster, Stone Bluff, Bismarck, and the surrounding areas. Contact us today for more information!