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Table 1 Area of U.S. cropland, soil disturbance sequence, total soil organic carbon stored (SOC) annually, total SOC stored after 20 years, and average rate of SOC storage

From: What might it cost to increase soil organic carbon using no-till on U.S. cropland?

Tillage Sequencea Area (Mha) Area (% of total) Total C (CO2) (Tg C year−1) (Tg CO2 year−1) Total C after 20 years (Tg C year−1) (Tg CO2 year−1) Total C (% of total) Weighted average storage rate (Mg C year−1) (Mg CO2 year−1)
CTCTNT 72.3 58.0 27.6 (101.2) 552 (2025) 72.2 0.38 (1.4)
CTRTNT 28.9 23.2 6.2 (22.7) 124 (453) 16.2 0.21 (0.8)
CTNTNT 2.7 2.2 0.0 (0.0) 0 0.0 0.0 (0.0)
RTCTNT 0.1 0.0 0.0 (0.0) 0 0.0 0.33 (1.0)
RTRTNT 1.1 0.9 0.2 (0.7) 5 (18) 0.6 0.23 (0.8)
RTNTNT 6.0 4.8 0.0 (0.0) 0 0.0 0.0 (0.0)
NCCTNT 8.6 6.9 3.3 (12.1) 67 (246) 8.8 0.39 (1.4)
NCRTNT 3.8 3.1 0.8 (2.9) 16 (60) 2.2 0.21 (0.8)
NCNTNT 1.1 0.9 0.0 (0.0) 0 0.0 0.0 (0.0)
Total 124.7   38.2b (140.1) 765 (2803)   
  1. aCTCTNT = Conventional tillage (CT) in 1982, CT in 1997 and no-till (NT) in 2017; CTRTNT = CT in 1982, reduced tillage (RT) in 1997 and NT in 2017; CTNTNT = CT in 1982, NT in 1997 and NT in 2017; RTCTNT = RT in 1982, CT in 1997 and NT in 2017; RTRTNT = RT in 1982, RT in 1997 and NT in 2017; RTNTNT = RT in 1982, NT in 1997 and NT in 2017; NCCTNT = Non-cropland (NC, e.g., hay, pasture, etc.) in 1982, CT in 1997 and NT in 2017; NCRTNT = NC in 1982, RT in 1997 and NT in 2017; NCNTNT = NC in 1982, NT in 1997 and NT in 2017
  2. bRef. [44] estimated SOC sequestration from NT adoption of 35.0 Tg C year-1 from a smaller area of NT adoption that excluded highly erodible land removed from crop production