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!!
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kg/acre to mg/kg conversion
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Re: kg/acre to mg/kg conversion
Originally posted by Unregistered View Posta standard weight for an acre of soil?
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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.
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Originally posted by JohnS View PostAny 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.
Thanks for the information.
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