Daily Manure Production Per Animal We have estimates of manure production –4.5 kg/day/hd for swine (liquid manure) –45-50 kg/day/hd for dairy cow (liquid) –25-30 kg/day/hd for beef cow (liquid) Solid portion ~ 13-15% of total
Animal Waste Nutrient Utilization Scenario Swine Confinement Facility kg / animal Nutrient Content in kg/ day / 1000 kg 0.52 kg N / day / 1000 kg animal wt kg P / day / 1000 kg animal wt kg K / day / 1000 kg animal wt.
Manure Characteristics In general… –Nitrogen (ammonia) is in urine –Phosphorus is in feces In the U.S. we’re working on ways to keep urine and feces separate
Manure Management Issues Animal manure is a liability in high density livestock production areas where fertilizers are cheap Animal manure is an asset if fertilizers are unavailable or expensive Odor and ammonia emission to air-global warming Odor issues are serious in residential areas Pollution of soil and water resources-water quality Hypoxia problems in international water
Nitrogen Is mobile in some forms (NO 3 ) –not in others (organic, NH 4 ) Does not carryover like P Is not determined by soil test
Negative Environmental Impacts Nitrogen - Nitrates leaching to tilelines and/or groundwater - Ammonia runoff into surface water causing fish kills
Negative Environmental Impacts Phosphorus Loss with soil erosion Eutrophication (algae growth) of surface waters
Phosphorus Is bound to the soil particles Remains in the soil year to year Moves if soil erodes Is determined by soil test Does not volatilize like nitrogen
Manure Nutrient Planning Determine the hectares needed to maximize nutrient use and minimize negative environmental impacts
Question 1 Which Nutrient should I use for planning... Nitrogen? Phosphorus?
U.S. Manure Law says... Use nitrogen for nutrient planning - Results in least land area needed - May not be best use of nutrients because phosphorus is overapplied - Laws in U.S. are changing to require P planning
N:P Ratio of Manure N:P ratio is different for different types of manure N:P Cattle ratio… ~ 2:1 Swine ratio… ~ 1.5:1 Poultry ratio… ~ 1:2
Phosphorus Planning Requires more hectares Results in lower application rates Maximize economic value of manure Depends on crop & manure application frequency Requires additional commercial N fertilizer