Tone Ag Consulting Ltd.

Back in spring, I wrote a post discussing What is Manure Worth? In that post I estimated the value of manure from three different kinds of hog operations. In this post, I’m going to run through the same calculations for liquid dairy manure, solid beef manure, and liquid poultry manure. I will include the Tri-Provincial figures for liquid hog manure for ease of comparison.

I’m using the manure analysis numbers from the Tri-Provincial Manure Application and Use Guidelines, application by injection for liquids and broadcast for solids, and the target nutrient rate of 100 lbs. N/acre. I’m using the same fertilizer prices as this spring to make comparisons simpler, even though prices have changed. These are rough, hand-wavy figures but can serve to give some idea of the value of manure.

Value of Nitrogen in Manure

The spring price of N was about $0.53/lb. If you are applying manure at about 100 lbs. N/acre, that is worth about $53.00 /acre. I’m assuming that all NH4-N is available and that 1/4 of the remaining total N will be available the first year. This is the first place where things get complicated. When you’re dealing with solid manure, nutrients are in more of a slow-release form so the nutrient payoff may be a ways off rather than being available for this year’s crop. Don Flaten is involved in at least on study that’s trying to get better number for this.

• Liquid Swine manure has an average NH4-N of 19 lbs./1000 gal. Average Total N is 31 lbs./1000 gal. Total available N is 19 + .25 * 12 = 22 lbs. available N/1000 gal.
• Liquid Dairy manure has an average NH4-N of 15 lbs./1000 gal. Average Total N is 34 lbs./1000 gal. Total available N is 15 + .25 * 19 = 20 lbs. available N/1000 gal.
• Solid Beef manure has an average NH4-N of 1.1 lbs./ton. Average Total N is 12 lbs./1000 gal. Total available N is 1.1 + .25 * 10.9 = 4 lbs. available N/ton.
• Liquid Poultry manure has an average NH4-N of 58 lbs./1000 gal. Average Total N is 80 lbs./1000 gal. Total available N is 58 + .25 * 22 = 64 lbs. available N/1000 gal.

Target N is 100 lbs./acre, so you would apply:

• 4,500 gal/acre of Liquid Swine manure
• 5,000 gal/acre of Liquid Dairy manure
• 25 tons/acre of Solid Beef manure
• 1,600 gal/acre of Liquid Poultry manure

Value of Phosphate in Manure

• Liquid Swine manure has an average P2O5 of 23 lbs./1000 gal.
• Liquid Dairy manure has an average P2O5 of 21 lbs./1000 gal.
• Solid Beef manure has an average P2O5 of 6 lbs./ton
• Liquid Poultry manure has an average P2O5 of 64 lbs./1000 gal.

Phosphate (P2O5) was worth about $0.72/lb. in spring

• 4,500 gal/acre * 23 lbs./1000 gal. * $0.72 / lb. = $74.52 /acre for Liquid Swine manure
• 5,000 gal/acre * 21 lbs./1000 gal. * $0.72 / lb. = $75.60 /acre for Liquid Dairy manure
• 25 tons/acre * 6 lbs./ton * $0.72 / lb. = $108.00 /acre for Solid Beef manure
• 1,600 gal/acre * 64 lbs./1000 gal. * $0.72 / lb. = $73.73 /acre for Liquid Poultry manure

Value of Potash in Manure

• Liquid Swine manure has an average K2O of 17 lbs./1000 gal.
• Liquid Dairy manure has an average K2O of 38 lbs./1000 gal.
• Solid Beef manure has an average K2O of 14 lbs./ton
• Liquid Poultry manure has an average K2O of 40 lbs./1000 gal.

Potash(K2O) was worth about $0.58/lb. in spring

• 4,500 gal/acre * 17 lbs./1000 gal. * $0.58 / lb. = $44.37 /acre for Liquid Swine manure
• 5,000 gal/acre * 38 lbs./1000 gal. * $0.58 / lb. = $110.20 /acre for Liquid Dairy manure
• 25 tons/acre * 14 lbs./ton * $0.58 / lb. = $87.50 /acre for Solid Beef manure
• 1,600 gal/acre * 40 lbs./1000 gal. * $0.58 / lb. = $37.12 /acre for Liquid Poultry manure

Value of Micronutrients and Other Manure Benefits

It’s difficult to say what micronutrients will be included in manure.  There are a variety of micronutrients supplied in manure, but which micronutrients will be supplied and at what levels depends on the types of animals and their diets.  One proven benefit of manure application is an increase in soil quality, particularly soil organic matter.  I have opted not to include these in the value of manure due to their variability.

Naive Calculation for the Value of Manure

Using only the Nitrogen, Phosphate, and Potash values, here is the value per acre of manure

• Liquid Swine manure is worth about $171.89 / acre
• Liquid Dairy manure is worth about $238.80 / acre
• Solid Beef manure is worth about $248.50 / acre
• Liquid Poultry manure is worth about $163.85 / acre

This is a naive calculation because it assumes that all nutrients supplied are exactly what is needed by the crop.  Based on the examples above, you’re going to be getting 102-150 lbs. P2O5 / acre.  There are very few crops that can use that much P2O5, so the extra is used to build up the soil for next year.  It’s a similar situation for the K2O.  It’s not likely that a landowner will be willing to pay for these excess nutrients.

I couldn’t find any figures for solid poultry manure, but I’d like to do these calculations for that as well.