Air dry moisture content (2A1)

This method is required to adjust soil chemical results based on air-dry samples to an oven-dry (105^oC)
basis. When the air-dry moisture content (M%) is known, the correction from air-dry
to oven-dry is as follows:

            Oven-dry result  =   [Air-dry result  x  (100+ M%)]/100

Total carbon - high frequency induction furnace (with prior physical removal of (6B3)

Following quantitative action / pre-treatment to account for or to physically remove (if present) charcoal and to chemically remove carbonate with excess 5% H₂SO₃ solution on a hot plate in a fume cabinet, the residual, re-dried soil sample is analysed for soil C by a suitable method, preferably Method 6B2b. The method involving carbonate removal and soil C analysis uses finely-milled air-dry sample, with weights varying with expected C concentrations. The method specifies reporting as %C on an oven-dry (105^oC) basis.