Problem: The concept of Common Practice, as currently applied, creates unnecessary uncertainty. Uncertainty creates risk and risk discourages action. Potential proponents cannot be sure if an activity will be declared “common” at between 5% to 30% penetration. The assumption that a market will continue to grow through a take off point along a smooth curve driven by carbon offsets, after the offsets are no longer available, is unsound. There is no research into what happens to the shape of a Curve of Market Adoption when the incentive driving buyers up the curve is changed. One indicator could be what happened the response to changes in availability of rebates for solar energy installations in the 5 years to 2010.
No provision has been made for reversal of trends, such as is apparent in no-till cultivation. A national survey of no-till use by farmers in 2008 found between 45% and 90% of cropping operations in major grain producing regions use the technique. This would eliminate no-till as potentially Additional. But there are three other elements acting to reverse the trend into no-till: 1. Difficulty getting through vegetation afer recent good rainfall years. 2. Weed resistance to herbicides. 3. Extension services (eg. NSW DPI) are encouraging reintroduction of traditional tillage under the heading “strategic cultivation”, ie. as a solution to resistance. (Rick Llewellyn and F. H. D’Emden, Adoption of no-till cropping practices in Australian grain growing regions, GRDC, 2010) Practical solution: Allow proponents to submit combinations of activities as an “activity” for the purposes of assessment for Common Practice. Carbon farmers commonly apply a portfolio of practices to a paddock, eg. no-till and natural fertilisers; eg. grazing management and pasture cropping. This reflects actual practice, widens the range of options available to the farmer, and maximises soil carbon sequestration.