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

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

Tillage Sequence^a	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		38.2^b (140.1)	765 (2803)

^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
^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

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