7. Soil organic carbon concentration (SOC, %)in top 0.05-m soil layer in beds and
furrows with traffic (F + T) in the permanent (PB), decompacted permanent (DPB)
and conventional (CB) bed planting systems from 2007 to 2012. Values from 2007 to
2009 were taken from Boulal et al. (2012). Bars are half standard deviations. Dashed
and solid lines indicate growing seasons for cotton and maize.