Manure Nutrient Value Calculator

Poultry litter carries about 60 lbs N, 55 lbs P₂O₅, and 40 lbs K₂O per ton in this calculator's book values, versus dairy manure's much more dilute 10-4-8. Poultry manure is drier and more concentrated to begin with, while dairy manure is typically handled as a wetter slurry, so a ton of it simply contains less usable nutrient — the calculator's per-ton value follows directly from that nutrient density difference.

Only a fraction of manure nitrogen — 40% for dairy up to 60% for poultry litter in this model — is estimated available the first year, because a large share of manure N is organically bound in the manure solids and has to mineralize through microbial activity before plants can use it. The rest becomes available in future seasons, which is why the calculator reports both total N applied and available N as separate figures.

Entering a moisture percentage above zero multiplies every nutrient content per ton by (1 − moisture% ÷ 100), diluting the N, P₂O₅, and K₂O figures proportionally. This models the fact that the book values assume a typical moisture content for each manure type, so wetter-than-typical manure delivers less actual nutrient per ton hauled, even though the volume applied is the same.

No — it only prices the replacement value of the N, P₂O₅, and K₂O against the commercial fertilizer prices you enter. It doesn't account for manure's other agronomic benefits, like added organic matter, improved soil biology, or better water-holding capacity, nor does it weigh downsides like odor, pathogen load, or runoff risk, so treat the output as a fertilizer-offset estimate rather than manure's total value to the farm.