Influence of Limestone and Nitrogen on Soil pH and Coastal Bermudagrass Yield1

Abstract

Abstract‘Coastal’ bermudagrass was grown on an extremely acid Cecil sandy loam soil in order to study the influence of limestone rate (0, 7,846, and 40,349 kg/ha), limestone placement (surface and mixed), and N levels (0, 224, 448, 896, and 1,793 kg/ha) on forage production, rooting, and changes in soil properties.Without limestone, annual forage production declined with time at the 448‐kg/ha N level and above, and Coastal bermudagrass plants exhibited a severe chlorosis. At the two highest N levels (896 and 1,793 kg/ha), up~o 90% of the plants died.Limestone increased annual forage yields at N rates of 896 kg/ha and above. Mixing the limestone with the surface soil resulted in significantly higher forage yields at the 1,793‐kg/ha level. The movement of Ca and Mg into all soil zones down to the 30‐ to 45‐cm zone confirmed the changes in soil pH.Soil pH was reduced by annual applications of 448 kg/ha of 1N and forage yields of Coastal bermudagrass were severely restricted.Coastal roots penetrated to 120 cm in soil with a range in pH from 4.0 to 4.5, emphasizing the extreme tolerance of this grass to very low soil pH.