Benefits of applying lime to harvested cropland in winter

 
       

By Matt Mullen

Applying lime to cropland in winter
For large commercial farmers and hobby farmers alike, making sure soils don’t become too acidic is critical to getting good yields. It’s important to measure your soil’s acidity levels and take action if needed. An application of lime after harvest will reduce soil acid levels if they are too high and help keep plants healthy. Read on to learn more about liming, its benefits, how to do it right and why winter is a great time to get it done.

A spreader truck about to apply lime to the land.Why apply lime?
Soils that are too acidic can stunt root growth and inhibit plant development. Soils become acidic when levels of positively charged ions of hydrogen and aluminum grow too high. The high levels of hydrogen and aluminum prevent the plants' roots from taking up nutrients within the soil.

Soils can also become too acidic when calcium and magnesium leach out of the soil, decomposing organic materials add hydrogen, or farmers add fertilizers, according to crop specialists with North Carolina Cooperative Extension.

Fortunately, with lime, there is an easy solution. Lime works its magic by dissolving and releasing a base into the soil that reacts with the hydrogen and aluminum, lowering the acidity of the soil.

Benefits of lime applications
According to North Carolina Extension, farmers and gardeners will do well to add lime when necessary to keep soils from becoming too acidic. Why? Liming helps growers in a number of ways:

  • Ideal soil acidity levels boost the nutrients in the soil that are available to plants, effectively increasing their nutrient supply.
  • Plants develop healthier roots, which may enhance drought tolerance.
  • Lime adds calcium to the soil. Dolomitic limestone also adds magnesium.
  • For legumes, such as soybeans, liming improves nitrogen fixation, the process in which bacteria living on legume roots convert atmospheric nitrogen into a form the plant can use.
  • Ideal soil acidity levels improve the performance of certain herbicides and nematicides.
  • Ideal soil acidity levels promote the breakdown of some herbicides, preventing damage to crops planted later in the field.

Why is winter a good time to apply?
Winter is a great time to apply lime to fields. Lime is not very leachable, except in very sandy soils, and so growers can generally apply it whenever practical. The slow winter months serve as a convenient time to get the task accomplished.

In fact, it's best to apply it in the fall or winter. Agronomists recommend putting down lime several months prior to planting, so that the lime has enough time to react with the soil and neutralize acidity.

Applying lime soon after harvest also has the added benefit of saving valuable time just prior to spring planting.

The importance of pH
Before considering an application, you will need to determine your soil's pH by taking a soil sample and submitting it to a state laboratory or a local Extension office. Often the report from your soil test will include a recommendation of how much lime you need to apply.

Soil pH values indicate the acidity or alkalinity of soil. A value of 7.0 indicates the soil is neutral. A value below 7.0 indicates acidic soil and values above 7.0 indicate alkaline, or basic, soil.

The ideal soil pH for your farm or garden depends on your region of the country, your soil conditions and the type of plant. Most plants grow best in slightly acidic soils, from 6.0 to 7.0. Check with a specialist at your local Extension office or Southern States dealer to help determine what pH levels work best for your area and crop.

How do you apply it?
The keys to getting the most from your lime application are applying the lime as evenly as possible and incorporating it into the soil.

For larger fields or commercial farmers, North Carolina Extension specialists recommend spreading lime with a box or boom spreader for the most evenly distributed application. If growers use a spinner spreader, they should try to make sure it distributes the lime as evenly as possible. To incorporate the lime into the soil, disk it in or use a heavy-duty rotary tiller. In no-till situations, surface applications without incorporation will suffice, as long as growers correct any pH problems in the field prior to no-till management.

For smaller farms or gardens, growers can spread lime with a garden tractor spreader. To promote uniform application, apply half of the required amount in swaths heading in one direction, and then spread the remainder in swaths perpendicular to the first passes. Incorporate the lime into the soil with a rake or rototiller to a depth of 4 to 8 inches.

What about your fields? Have you experienced situations in which an application of lime helped correct a problem on your farm? Share your comments below!