The interpretation of soil organic carbon is fraught because the initial measurements were made after sowing (hence soil throw is a factor in No Till paddocks but less so in Till paddocks). Apart from Patchewollock, the No Till paddocks have tended to have lower organic carbon, and these patterns have been reinforced by measurements at harvest in 2007. For the paddocks with decreases in organic carbon, there is a negative relationship with change in topsoil mineral nitrogen over a similar period (sowing 2006 to sowing 2008), perhaps indicating that soil organic matter in No Till paddocks is being mineralised to provide nitrogen.

Table 13. Soil organic carbon 0-10cm at emergence 2006 and harvest 2007.