Soil pH, Organic Matter and Cation Changes After Four Prescribed Burns of a Grassland Restoration on the Mid-Atlantic Coastal Plain.

Grassland restoration projects have been ongoing in many regions of the United States, however few have been developed on the highly weathered soils of the Mid-Atlantic Coastal Plain. In 1999, 200 acres of low-production agricultural land on the Eastern Shore of Maryland was entered into the Conservation Reserve Program to restore habitat for grassland birds. Prescribed burning has been conducted on a regular basis to manage the grassland fields. The objective of this study was to evaluate the effect of carbon- and base-cation rich, alkaline ash after four prescribed burns on the soil of the restoration site. Soil samples were collected with a split corer from each of 25 sample points to a depth of 20 cm within a 0.4-ha study area in the grassland. Samples were collected 1 day before and 12 days after the fourth burn. Each core was sectioned at 2.5 or 5.0 cm intervals to 20 cm. The soil was analyzed for pH, total organic matter and basic cations. Results were compared to data from soils collected after each of the burns. Increases in pH and organic matter were detectable after the fourth burn throughout the profile and for basic cations at the lower depths. The results suggest that ash from the burn, through hydrolysis of the basic salts of some of the ash, contributed to an increase soil pH and base cations. In addition, retention of residual ash may have increased organic matter contents. Results differ from those commonly found in the more fertile prairie soils of natural grasslands and grassland restorations in the Great Plains and Midwest, where changes in soil pH, organic matter and nutrients are often found to be negligible against the high background concentrations.