Limestone, Gypsum, and Magnesium Oxide Influence Restoration of an Abandoned Appalachian Pasture
- K. Dale Ritchey * and
- J. Diane Snuffer
When restoring abandoned pastures on acidic hill-land soils to productivity, it is important to bring soil Ca and Mg to adequate levels. Gypsum is a readily available Ca amendment that is sufficiently soluble to move rapidly into the soil when surface-applied. Gypsum has been shown to reduce detrimental effects of subsurface acidity in soils of the southeastern USA. A 4-yr experiment was initiated to measure effects of surface gypsum application on forage production and to evaluate Mg-containing amendments to avoid gypsum-induced Mg deficiency. The study site was a southern West Virginia Gilpin silt loam (fine-loamy, mixed, mesic, Typic Hapludult) where abandoned hill-land pasture was being restored to productivity. Treatments included 0, 1000, 8000, 16000, and 32000 kg/ha flue gas desulfurization coal combustion by-product gypsum (gypsum) together with dolomitic limestone and five additional treatments to evaluate sources of supplemental Mg. Application of 16000 kg/ha gypsum together with limestone increased forage yields of mixed orchardgrass (Dactylis glomerata L.) and tall fescue (Festuca arundinacea Schreb) pasture during establishment by 42% and production by 11% compared with limestone alone. About 8% of the mean 790 kg/ha yield increase could be attributed to acidity-neutralizing effects of alkaline constituents in the gypsum by-product. Plants in higher gypsum treatments had higher concentrations of K and P, but gypsum application decreased soil and plant Mg concentrations. This indicated that gypsum should not be applied on typical acid soils without supplemental Mg.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © 2002. Published in Agron. J.94:830–839.