The following is a system to estimate fertilizer nutrients produced on animal feeding operations. The nutrient amounts calculated are 100% plant available and as such can be substituted directly for chemical fertilizer amounts in fertilizer recommendations.

There are many factors that affect actual nutrient production in animal feeding operations. This estimation method tends to deliver conservative (high) estimates of nutrients available for plant uptake.

For the Saline Co. study nutrient production was estimated for only the Class I operations based on public information in MDNR permits. The location of smaller operations was shown but no estimate of nutrient production was made for these operations.

For each animal feeding operations the following information must be included:

· Animal type

swine-sow
swine-nursery
swine-finishing
poultry-broiler
poultry-layer
poultry-turkey
dairy
beef-finishing
beef-cow-calf

· Animal number

for each animal type
number based on animal space in the barn, not annual production

· Manure handling

lagoon
pit (cement, glass lined, earthen)
dry litter
dry stack
feedlot
none (pasture)

· Manure application

injection
surface application <1 day to incorporation
surface application 1-3 days to incorporation
surface application 4-6 days to incorporation
surface application >6 days to incorporation

To determine nutrient production for each location:

For each animal type at the location

Plant available nutrients (lbs.)

                                           = animal number
                                          X annual nutrient production (Table 1)
                                          X nutrient retention in storage and handling (Table 2)
                                          X nutrient retention during land application (Table 3)

Examples:

A 1000 head swine finishing operation that surface applies hog lagoon effluent:

Plant available N = 1,000 X 28 X 0.15 X 0.60 = 2,250 lbs. N
Plant available P₂O₅ = 1,000 X 22 X 0.2 X 1.0 = 4,400 lbs. P₂O₅
Plant available K₂O = 1,000 X 19 X 0.4 X 1.0 = 7,600 lbs. K₂O

A 1000 head swine finishing operation that injects hog lagoon effluent:

Plant available N = 1,000 X 28 X 0.15 X 0.88 = 3696 lbs. N
Plant available P₂O₅ = 1,000 X 22 X 0.2 X 1.0 = 4,400 lbs. P₂O₅
Plant available K₂O = 1,000 X 19 X 0.4 X 1.0 = 7,600 lbs. K₂O

A 50,000 broiler operation that surface applies broiler litter:

Plant available N = 50,000 X 0.9 X 0.50 X 0.71 = 15,975 lbs. N
Plant available P₂O₅ = 50,000 X 0.6 X 0.95 X 1.0 = 28,500 lbs. P₂O₅
Plant available K₂O = 50,000 X 0.4 X 0.95 X 1.0 = 19,000 lbs. K₂O

Calculated Nutrient Production of Animal Feeding Operations

Nutrient production was calculated only for Class I operations as discussed in the Animal Feeding Operation Handout. These operations account for 56% of the swine and 100% of the poultry in the county.

We ran 5 scenarios to estimate the range in total production of plant available nutrients by Class I operations (Table 4). These scenarios capture the full range of available nutrients possible from these operations.

Surface application of lagoon effluent has the lowest available nitrogen possible. Injection of lagoon effluent reduces nitrogen losses increasing available nutrients. Slurry systems retain substantially more nitrogen in storage so has the highest nitrogen production capacity.

Lagoon systems produce less available phosphate than slurry systems because a large percentage of the phosphate is retained in the lagoon. The swine slurry system and poultry dry litter systems apply the majority of the phosphorus excreted by the animal.

Information on actual land application methods for Class I operations in incomplete but most will likely use surface applied lagoon effluent system.

Hauling radius is the maximum distance from the operation the operator would need to travel to spread manure. An important assumption in this analysis is 100% of land suitable for manure application is accessible for manure application.

/1 P availability values for surface or injected manure.

References:

Agricultural Waste Management Field Handbook. 1992. United States Department of Agriculture, Soil Conservation Service.

American Society of Agricultural Engineers,

Livestock Waste Facilities Handbook. 1985. Midwest Plan Service. Publication #18. Ames, IA.

Missouri Department of Natural Resources Plant Available Nitrogen Procedure. April, 1998.

Reduce Environmental Problems with Proper Land Application of Animal Wastes. 1992. University of Missouri guidesheet WQ201, Columbia, Missouri.