Recalculate:

(mg N/kg soil X kg soil/ha to 25cm) divide by 1000 to concert to kg of N/ha

Forget about water

1 Ha=10000 m2

Soil density =1.474 g/cm3=1474 kg/m3

Soil volume= 10000 m2X .025 m=250 m3

1gm/cm3=1000 kg/m3

you can use absolute humidity in the soil.

This is only mistake of humidity.

To convert nitrogen in mg/kg to kg/ha, you need to know the bulk density of the soil. Once you have the bulk density, you can use the following formula:

Nitrogen (kg/ha) = Nitrogen (mg/kg) x Depth (cm) x Bulk Density (g/cm3) / 10

For example, if you have a soil sample with 20 mg/kg of nitrogen, a depth of 10 cm, and a bulk density of 1.2 g/cm3, the calculation would be:

Nitrogen (kg/ha) = 20 mg/kg x 10 cm x 1.2 g/cm3 / 10 = 2.4 kg/ha

So the soil sample contains 2.4 kg of nitrogen per hectare.

To convert nitrogen concentration in mg/kg to kg/ha, you need to know the bulk density of the soil in question. The bulk density represents the mass of soil per unit volume, usually expressed in grams per cubic centimeter (g/cm³) or kilograms per cubic meter (kg/m³).

Once you have the bulk density, you can use the following formula to convert nitrogen concentration in mg/kg to kg/ha:

Nitrogen (kg/ha) = Nitrogen concentration (mg/kg) x Bulk density (kg/m³) x 10,000

For example, if you have a soil with a bulk density of 1.2 kg/m³ and a nitrogen concentration of 50 mg/kg, the calculation would be:

Nitrogen (kg/ha) = 50 mg/kg x 1.2 kg/m³ x 10,000 = 600 kg/ha

Therefore, the nitrogen content in this soil is 600 kg/ha.

Morris

I work through a similar problem for both pounds per acre and kilogram per hectare. Although I use a different bulk density and soil depth the results are (@ 1.33g/cm3, 15cm) 1 mg/kg = 2 kg/ha.

see attached