Efficiency of Commercial Agricultural-Grade Limestone

Abstract

The University of Georgia (GA) lime recommendation equation includes a multiplier of 1.5 to account for agricultural (ag) lime that is less reactive than reagent-grade calcium carbonate (CaCO₃). Research has not been conducted with ag lime to arrive at this multiplier with GA soils typical of the coastal plain or with ag limes available in GA. These ag limes may differ in their reactivity from others tested previously. The efficiency of five dolomitic ag limes were compared to reagent-grade CaCO₃ on two GA soils with different pH-buffering capacities. Reactions other than acid neutralization by lime affected pH, especially in the soil with low pH-buffering capacity. Results from the soil with high pH-buffering capacity yielded multipliers of 1.17, 1.16, 1.48, 1.34, and 1.73 for ag limes 1 through 5, respectively, with an average multiplier of 1.38. Based on these results, continued use of a multiplier of 1.5 is appropriate.

Keywords:

• Calcium carbonate
• lime
• soil fertility