With it finally becoming dry enough for grain producers to aggressively harvest both corn and soybeans, the fall application of swine manure to the harvested fields has begun. The ‘smell of money’ was evident in Mankato this weekend, even with almost all producers now injecting this liquid gold to both reduce odors and to reduce nitrogen losses.
I received 2 text messages on Saturday asking about the fertilizer value of swine manure from deep pits this fall. In pricing the manure, I assumed the NPK analysis was 50-35-25 pounds per 1000 gallons of product as injected into the harvested field and the cost of injection was $0.015/gal. For prices I used the latest Iowa commercial fertilizer prices as reported by USDA (NW_GR210).
Last week Iowa anhydrous ammonia averaged $462/ton ($0.28/lb N), MAP (monoammonium phosphate, 11% N and 52% P) averaged $445/ton ($0.37/ lb P2O5), and potash averaged $317/ton ($0.26/lb K2O).
With these prices and nutrient analysis, the swine manure had $33.45 of value based on the N, P and K content. Keep in mind that there is additional value from other nutrients such as sulfur (generally about 9 lb per 1000 gal when ddgs are included in diets) and the organic matter contribution to soil tilth and water holding capacity.
At a cost of $15 per 1000 gal for injection of this manure (using either a drag hose or slurry tanks), the net value before any nitrification losses becomes $17.45 per 1000 gal. If a grow-finish site uses wet/dry feeders or bowl drinkers, the manure production averages about 1 gal/pig/day. At 120 days average days on feed (Metafarms.com), this is 120 gallons of manure per pig. This makes the net value of the manure (based on NPK only) after land application costs are accounted for of $2.09 per pig placed.