Soil profile carbon and nitrogen in prairie, perennial grass–legume mixture and wheat-fallow production in the central High Plains, USA.

Highlights: [•] Tilled wheat-fallow practices had less SOC stock at 0–30cm depth (∼10Mgha−1). [•] No-till wheat-fallow had more SOC at 0–30cm, but not in whole profile (0–120cm). [•] CRP grass–alfalfa mixture had more SOC at 0–30 and whole profile than tilled wheat-fallow. [•] However, soil inorganic C ranged from 8.1 to 24.9Mg/ha and was greatest under wheat-fallow practices. [•] CRP grass–alfalfa mixture has greater potential for SOC storage and to improve soil quality. [ABSTRACT FROM AUTHOR]