By Zifei Liu, North Carolina State University Biological & Agricultural Engineering 1
History: Family farm system Small operations Resources were cycled: a closed loop for most nutrients Low productivity Now: Farms grew larger Became specialized Productivity increased Nutrients concentrated in certain regions Disconnected nutrient cycle 2
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All manure must be handled properly if the environment and public health are to be protected. 4
Reduced N leaching potential Increased soil carbon levels Better soil structure for resisting erosion and reducing runoff Improved productivity while replacing commercial fertilizers Reduced energy demands for natural gas intensive N fertilizers Reduced demand for commercial P fertilizer, which is a limited resource 5
Manure can produce both substantial benefits and severe environmental degradation. The actual environmental results often depends on choices that producer make. Water quality Air quality 6
Possible pollutants Nitrate-N Ammonia-N Phosphorus Pathogens Organic matter Environmental Risk Health Fish kill Eutrophication Health oxygen depletion 7
1. Runoff 2. Leaching 3. Movement down a well casing 4. Ammonia Volatilization and Deposition 5. Macropore Flow 8
Ordor Hydrogen sulfide Ammonia VOC Airborne microorganism Dust 9
Manures are almost exclusively used as soil amendments for agricultural crop production. Solid manure, liquid manure, litters, composts, and lagoon effluents represent the most common types of manure that are now applied to soils through a variety of spreading, tillage, and irrigation practices. 10
Environmental stewardship is a set of principles to help producers and advisors make decisions that will maximize the benefits of manure and minimize problems for the environment. 11
1. Awareness of Environmental Risks 2. No Point Source Discharges 3. Balance in the Use of Nutrients 4. Nutrient Plan for Land Application 5. Be a Good Neighbor 6. Know the Rules 7. Considers Environment before Expansion 12
Agricultural production has changed over time Disconnected nutrient cycle Benefits of manure Environmental issues related to animal production Water quality Air quality Environmental stewardship 13
Whole Farm Nutrient Balance and Manure Utilization Plan Sizing Manure Storage Facilities 14
Farm boundary Inputs Feed Manure Managed Outputs By Zifei Liu, North Carolina State University Losses or Soil Storage Biological & Agricultural Engineering 15
Define whole farm nutrient balance for animal feeding operations and its importance in understanding environmental risk Identify strategies to improve nutrient balances Understand the components of a manure utilization plan 16
Inputs Feed Farm boundary Managed Outputs Animals Fertilizer Feed Manure Animals Crops Irrigation Legume N Losses or Soil Storage Manure 17
A P balance provides a preferred indicator of the risk to water quality. Livestock and poultry operations with a large imbalance (1.5:1 and greater) would expect steadily increasing soil P levels. Runoff and erosion from land application sites will carry an increasing P load as soil P levels increase. 18
Efficient use of manure nutrients in crop production Alternative livestock feeding programs Marketing of manure nutrients Manure treatment 19
A manure utilization plan addresses manure production on a farm and how the manure nutrients are utilized. Typically, the manure is used as a nutrient and organic matter source in a cropping system. 20
Manure generation and other sources of nutrients Manure nutrient availability Crop selection and crop nutrient requirements Best management practices (BMPs) Summary of laws, rules, and regulations 21
How much N and P 2 O 5 should be applied when growing corn (for grain) where the Realistic Yield Expectation is 140 bushels/acre? (The N requirement is 0.90 lb N/bushel of grain, and the P 2 O 5 requirement is 0.36 lb N/bushel of grain) Solution: N application rate =140 x 0.90 = 126 lbs N/acre P 2 O 5 application rate =140 x 0.36 = 50.4 lbs N/acre 22
If manure analysis shows 2.0 pounds N and 3.5 pounds of P 2 O 5 per 1000 gallons of lagoon liquid, what is the manure application rate for the above cornfield? Solution: Based on N Manure application rate = 126/(2.0/1000) = 63000 gal/acre Based on P 2 O 5 Manure application rate = 50.4/(3.5/1000)= 14400 gal/acre 23
In the previous example, if the manure application rate is based on P 2 O 5, how much supplemental N is required? Solution: N supplied on land from manure = 14400 x 2.0 /1000 = 28.8 lb N/acre Since the target rate for N is 126 lb N/acre, the supplemental N needed is 126 28.8 = 97.2 lb N/acre 24
Livestock and Poultry Environmental Stewardship Curriculum (LPES lesson 2 and lesson 31) Online Link: http://www.lpes.org/les_plans.html 25
By Zifei Liu, North Carolina State University Biological & Agricultural Engineering 26
Understand the factors involved in sizing manure storage facilities. Understand the meaning and function of the various volume fractions in manure storage facilities. 27
Regulatory and compliance issues Type of enterprise, animal numbers and species Climatic characteristics (rainfall and evaporation) Type of storage facility (lagoon vs. stackhouse) Suitable storage period Crop consideration Climatic consideration 28
1. Manure and bedding 2. Washwater 3. Lot runoff 4. Sludge accumulation 5. Treatment volume 6. Depth of rainfall-evaporation 7. Volume/depth of 25-year, 24-hour storm 29
Manure Storage Type Solid manure Slurry pit or tank Lagoon Typical Volume Components 1. Manure 2. Bedding (may require runoff controls) 1. Manure 2. Washwater 3. Lot runoff (if applicabale) 4. Rainfall-evaporation (if not covered) 5. 25-yr, 24-hr storm (if not covered) 1. Manure 2. Washwater 3. Lot runoff 4. Rainfall-evaporation 5. Sludge volume 6. Treatment volume 7. 25-yr, 24-hr storm 30
Serve a 300-cow dairy in central Missouri Storage period: 365 days Average cow weight is 1400 lbs Average washwater use is10 gallons/day-cow Includes an exposed dirt exercise lot 1 acre in size and 12000 square ft of exposed concrete and unguttered roof areas 31
Dairy manure volume (ft 3 /d/1000#) 1.3 No. of animals 300 Average cow weight (lbs/animal) 1400 Storage period (days) 365 Volume of manure (ft 3 ) 199290 (Reference: Table 21C-2) 32
Washwater use (gal/day-cow) 10 No. of animals 300 Storage period (days) 365 ft 3 /gal 7.48 Volume of washwater (ft 3 ) 146390 33
Dirt lot (ft 2 ) 43560 Rainfall (inches) 38 Percent runoff 0.27 ft/inches 1/12 Volume of runoff (ft 3 ) Concrete, unguttered roof (ft 2 ) Rainfall (inches) 38 12000 Percent runoff 0.58 ft/inches 1/12 37244 Volume of runoff (ft 3 ) 22040 Volume of total runoff (ft 3 ) 59284 (Reference: Figure 21B-1, -2, -3a, and -3b) 34
Total solids (lb/day/1000#) 10.0 No. of animals 300 Average cow weight (lbs/animal) 1400 Storage period (days) 365 Sludge accumulation ratio (ft 3 /lb TS) 0.0729 Sludge accumulation (ft 3 ) 111756 (Reference: Table 21C-2 and 21C-10) 35
Volatile solids (lb/day/1000#) 8.5 No. of animals 300 Average cow weight (lbs/animal) 1400 Storage period (days) 365 Lagoon loading rate (lb VS/1000 ft 3 /day) 5.0 Treatment volume (ft 3 ) 714000 (Reference: Table 21C-2 and Figure 21B-5) 36
Rainfall (inches) 38 Evaporation (inches) 38 ft/inches 1/12 Depth of rainfall-evaporation (ft) 0 (Reference: Figure 21B-3a, -3b and -4) 37
Depth of 25-yr, 24-hr storm (inches) 6 ft/inches 1/12 Exposed lot/roof area (ft 2 ) 55560 Volume of 25-year, 24-hour storm runoff (ft 3 ) 27780 (Reference: Figure 21B-6) 38
Manure (ft 3 ) 199290 Washwater (ft 3 ) 146390 Lot runoff (ft 3 ) 59284 Sludge accumulation (ft 3 ) 111756 Treatment volume (ft 3 ) 714000 25-year, 24-hour storm runoff (ft 3 ) 27780 Total volume of lagoon (ft 3 ) 1258500 39
Rectangular or round Depths of rainfall-evaporation, the 25-year, 24-hour storm, and freeboard, if applicable, must be added to the manure storage facility depth. 40
Size a circular slurry manure storage tank for a 3300-head swine-finishing operation (under roof) located in central Indiana. Average pig weight is 150 lbs. The storage period is one year. Washwater use averages 50 gallons per day. The tank will not be covered, so include storage for the 25-yr, 24-hr storm and Rainfall-evaporation. Provide sufficient depth for 1 ft freeboard. What should be the total volume of the slurry manure storage tank? If the diameter of the tank is 120 ft, what should be the final depth of the tank? 41
Swine manure volume (ft 3 /d/1000#) 1.00 Rainfall in central Indiana (inches) 40 Evaporation in central Indiana (inches) 33 Depth of 25-yr, 24-hr storm in central Indiana (inches) 5 42
Livestock and Poultry Environmental Stewardship Curriculum (LPES lesson 21) Online Link: http://www.lpes.org/les_plans.html 43