How do you convert kilogram per hectare to part per million?

Answer 1

You cannot.

Kilogram per hectare is a measure of mass per area whereas part per million is a pure ratio - without units. According to basic principles of dimensional analysis, any attempt at conversion from one to the other is fundamentally flawed.

Answer 2

To convert kilogram per hectare (kg/ha) to part per million (ppm), you need to know the density or volume of the substance being measured. First, convert kg/ha to mg/m^2 (by multiplying by 10), and then divide by the density or volume of the substance in m^2. Finally, multiply by 1,000,000 to convert mg/m^2 to ppm.