Table 6: Use of pretillage treatment 1988, 2000, and 2012 SOC during 24 years of tillage treatments.

Tillage treatment Depth cmSeptember 1988 August 2000June 2012
(pretreatment baseline)Mg C ha−1 layer−1

0–1528.5a**26.8a**26.3a**
NT15–7523.6a20.2a24.6a
0–75 (all)52.1a47.0a50.9a

0–1528.4a25.0a20.3b
CP15–7523.5a18.7ab21.7a
0–75 (all)51.9a43.7ab42.0b

0–1528.3a19.9b18.9b
MP15–7523.1a17.8b24.3a
0–75 (all)51.4a37.7b43.1b

**Means six replications with the same letter and in the same year and depth with a different tillage treatment are not significantly different at .