Paul C. Kassel

Using Ground Eggshells as a Liming Material in Corn and Soybean Production

Eggshells are a byproduct from egg breaking facilities and potentially useful as an amendment for liming soils. Ground eggshells were evaluated as a liming material at two sites in Iowa with acidic surface soil. The study compared soil pH response and corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] grain yield with multiple rates of agricultural lime (aglime) and ground eggshells (eggshells). Eggshells proved to be an effective liming material and land application for soil pH correction offers a practical use of eggshells. However, the reported effective calcium carbonate equivalent (ECCE) value for the ground eggshells was low as soil pH increase was greater than found with equivalent ECCE rates from aglime. Based on the soil pH responses in this study, it is suggested that ground eggshell ECCE values should be increased 2 to 3 times from reported values. That correction should help avoid over-application and unintended high soil pH levels.