Soil Organic Carbon Beneath Croplands and Re-established Grasslands in the North Dakota Prairie Pothole Region.

Phillips, Rebecca; Eken, Mikki; West, Mark

Grassland ecosystems established under the conservation reserve program (CRP) in the Prairie Pothole Region (PPR) currently provide soil conservation and wildlife habitat services. We aimed to determine if these lands also sequester soil organic carbon (SOC), as compared with neighboring croplands across multiple farms in the North Dakota PPR. We sampled soil from small plots at 17 private farms in the central North Dakota PPR, where long-term (≥15 years) grasslands managed under the CRP were paired with neighboring annual croplands. Cores were collected to 100 cm and split into 0-10, 10-20, 20-30, 30-40, 40-70, and 70-100 cm soil depth layers. We hypothesized the effect of land use on soil organic carbon (SOC), root carbon (C), and bulk density would be greatest near the surface. For 0-10 and 10-20 cm layers, grasslands managed under the CRP were lower in bulk density and higher in SOC. From 0 to 70 cm, grasslands managed under the CRP were higher in root C. Average (±standard error) SOC for re-established grasslands and croplands was 25.39 (0.91) and 21.90 (1.02), respectively, for the 0-10 cm soil layer and 19.88 (0.86) and 18.31 (0.82), respectively, for the 10-20 soil layer. Compared to croplands, re-established grasslands sampled in the North Dakota PPR were 3-13 % lower in bulk density and 9-16 % higher in SOC from 0 to 20 cm, while root C was 2-6 times greater from 0 to 70 cm.

NORTH Dakota; PRAIRIE Pothole Region; CARBON in soils; HUMUS analysis; SOIL sampling; GRASSLAND management; ECOLOGY; GRASSLANDS

Environmental Management, 2015, Vol 55, Issue 5, p1191

0364-152X

Academic Journal

10.1007/s00267-015-0459-3