Temporal changes in soil profile chemical properties in an 18‐year grassland restoration in the US Mid‐Atlantic Coastal Plain

Abstract

AbstractMany grassland restorations have been established in the United States over the past few decades, as native tallgrass prairies have often been converted to agriculture. However, only a few of the restorations have been initiated on the east coast of the United States. The objective of this field study was to evaluate the short‐ (∼3.5 years) and long‐term (∼15 years) changes in soil chemical properties among soil depths in a grassland restoration initiated in 1999 on previously cultivated, highly weathered soils of the Mid‐Atlantic Coastal Plain. Soil was collected in 2006 and 2018 to a depth of 20 cm and sectioned into 2.5 or 5 cm depth intervals and compared to pre‐burn conditions from 2003. Soil pH was 0.2 to 0.3 pH units lower in the 2.5–20 cm depth interval in 2018 compared to 2003. Extractable soil calcium was 25% lower and magnesium was 35% lower in the 2.5–5.0 and 2.5–20 cm depth intervals, respectively, in 2018 compared to 2003. Total carbon (TC) and total nitrogen (TN) were greater in the 2.5–5.0 and 2.5–10‐cm depths, respectively, in 2018 compared to 2003. Measured soil carbon (C) and nitrogen sequestration rates were 82 g TC m−2 year−1 and 0.27 g TN m−2 year−1 in the top 20 cm of soil. Grassland restorations contribute ecosystem services, including soil C sequestration; however, land managers may need to consider adding lime to grassland restorations on nutrient‐poor soils that are naturally acidic or have become acidified over time if the land is returned to agricultural production.