[sigmaprimus]

You are both right, farmers measure rainfall in inches, (which translates to inch acres) so it is both a mesurement of distance (inches) and acres (how many they own) think of centimeters per year the same way. Yes topsoil can be made much faster than these numbers given but there are consiquesnces, methane is released from the process of composting which is 19 times the greenhouse gas than the CO2 released from burning. Also the volume is affected by soil compaction and the production potential is affected by increased salinity from unused fertilizer, the outlook is scary but humans always adapt.