[10 pts] A soil profile with 18 cm (depth) and two horizons. Horizon A is 7 cm deep and has 2.5% of carbon per mass of soil. Horizon B is 11 cm deep and has 1% of carbon per mass of soil. The bulk density of the soil is equal to 1.6 g/cm³.

Calculate the total soil carbon stock to 18 cm per area (in ton C/ha). 

Equations and conversion factors:

Stock per Area = Mass / Area

1 ton = 1,000,000 g = 10⁶ g

1 ha = 10,000 m² = 100,000,000 cm² = 10⁸ cm²