No-tillage based cropping systems like conservation agriculture are not currently eligible for carbon
credits under mechanisms like the Kyoto Protocol for a number of reasons. Soil carbon is considered a
nonpoint source and spatially variable in the field, requiring a large number samples for a field average.
Being very dynamic, soil carbon can change drastically as a result of inversion tillage and low-diversity
cropping systems. While technology is improving, the total carbon changes may be relatively small for
many agricultural management practices and thus long periods may be required to quantify small
differences in carbon accumulation