kg/acre to mg/kg conversion

[Unregistered]

How do I convert the amount of N,P and K in soil from kg/acre to mg/kg? Is there a standard weight for an acre of soil? I would really appreciate it if anyone can maybe help!!

[Guest]

Re: kg/acre to mg/kg conversion

a standard weight for an acre of soil?

http://cropsoil.psu.edu/turf/extension/factsheets/acre-furrow-slice

[Madesh]

Concert kg/acre to mg/kg

[JohnS]

Any conversion is very approximate and based on assumptions. The first assumption is that the fertilizer is active in the top foot of soil, so acre is 43560 ft² x 1 ft = 43560 ft³. The second assumption is that topsoil is around 100 lb/ft³, which varies considerable with soil composition and moisture content. Thus an application of 1 kg/acre is roughly 1 kg fertilizer to 2 million kilograms of soil. In smaller quantities this would reduce to 0.5 mg/kg. This is probably only good to one significant figure (closer to 0.5 than to 0.4 or 0.6).

Another way to approach this might be mass/volume and 1 kg/acre would roughly equate to 0.8 mg/L of soil.

[Amit bajpayee]

Any conversion is very approximate and based on assumptions. The first assumption is that the fertilizer is active in the top foot of soil, so acre is 43560 ft² x 1 ft = 43560 ft³. The second assumption is that topsoil is around 100 lb/ft³, which varies considerable with soil composition and moisture content. Thus an application of 1 kg/acre is roughly 1 kg fertilizer to 2 million kilograms of soil. In smaller quantities this would reduce to 0.5 mg/kg. This is probably only good to one significant figure (closer to 0.5 than to 0.4 or 0.6).

Another way to approach this might be mass/volume and 1 kg/acre would roughly equate to 0.8 mg/L of soil.

Hi John, very well explained, how we can convert the kg/acre to mg/kg conversion.
Thanks for the information.