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Individual Highlight

Liming Effects Help Maintain Sugar Maple Growth and Health and Persist for More Than 20 years

Photo of Soil pit with golf tees marking horizons to be sampled. Robert Long, USDA Forest ServiceSoil pit with golf tees marking horizons to be sampled. Robert Long, USDA Forest ServiceSnapshot : Long-term inputs of acidic deposition have depleted soils of calcium (Ca) and magnesium (Mg) on ridge-top, unglaciated sites in Pennsylvania. Sugar maple requires adequate supplies of these elements to maintain growth, crown health, and flower and seed production. Soils sampled as part of a long-term liming study in northern Pennsylvania show that Ca and Mg levels have remained elevated through the soil profile to a depth of 1.5 feet for 21 years after an initial treatment with 10 tons per acre of dolomitic limestone.

Principal Investigators(s) :
Long, Robert P. 
Research Location : Susquehannock State Forest in Potter County, Pennsylvania
Research Station : Northern Research Station (NRS)
Year : 2014
Highlight ID : 650


Long-term inputs of acidic deposition on ridge-top, unglaciated sites in Pennsylvania have depleted many soils of adequate supplies of calcium (Ca) and magnesium (Mg). By adding limestone in 1985, Forest Service scientists desired to reduce soil acidity and the availability of potentially toxic aluminum (Al) in the soil. Soils were sampled at 3- to 5-year intervals through 2006. Calcium, Mg, and alkalinity (as measured by pH) increased from 1985 to 1996 and then remained stable through 2006 in the upper 2 inches of mineral soil. Exchangeable Al and manganese (Mn), both potentially toxic to trees, were significantly reduced by lime treatment, though effects were slower to develop at the deeper sampled depths. By 2006, Ca and Mg were significantly greater than the untreated controls even at the deepest sampled depth of 14 to 18 inches. Sugar maple foliage, also sampled in 2006, showed significantly higher Ca and Mg in samples from limed plots compared with foliage from untreated control plots. These results, and those demonstrating the benefit of liming to sugar maple, show the persistence of the added Ca and Mg in the soil system and its utilization by sugar maple 21 years after the initial application.

Forest Service Partners

External Partners

  • Dr. S. B. Horsley (retired), and Dr. S. W. Bailey
  • The Pennsylvania DCNR, Bureau of Forestry, Dr. T. J. Hall
  • The Pennsylvania State University, Dr. D. R. DeWalle