Water extractable phosphate in composts and land-applied organic materials
Link to this table.

Feedstock Biosolids treatment Total solids(%) pH P2O5 (% dry wt) P (% dry wt) WEPa(% of Total P)
Leaf / yard wastes NA 39.4 7.7 0.34 0.15 8.4
Leaf / yard wastes / food NA 47.5 7.4 0.42 0.18 7.4
NA 53.9 7.4 0.43 0.19 6.8
Biosolids / wood chips2 No P removal 39.8 7.2 0.78 0.34 20.5
An. digest /No P removal 59.2 7.2 1.87 0.82 7.7
No P removal 48.1 6.7 1.6 0.7 22.3
Chemical P removal 38.8 5.5 3.65 1.59 1.8
Biosolids / wood chips / yard wastes2 No P removal 72.1 6.6 0.81 0.35 12.2
Biosolids / yard wastes / WTRb2 No P removal 53.5 8.3 1.67 0.73 4.6
No P removal 47.8 7.9 1.68 0.73 4.1
Leaf / yard wastes / gelatin residuals NA 51.1 8.3 2.19 0.96 2.0
Biosolids / wood shavings2 Biological P removal 42.8 5.7 2.41 1.05 13.3

aWEP = Water extractable phosphorus, bWTR = water treatment residuals (Source: Phosphorus and Compost Use Dynamics, Alexander, 2016)
2Minnesota does not compost biosolids per rule. Only source separated organic matter and yard waste are allowed in compost.

This page was last edited on 2 August 2022, at 14:19.