1. Chapter 5: Proper Applications of Waste Products

2. Proper Application of Waste Products Proper waste application involves knowledge of the:Proper waste application involves knowledge of the: –waste application system –soils and crops –the required buffers that must be adhered to This chapter will explain the required buffers and all other factors that must be considered when you are trying to determine when and how much animal waste to land apply.This chapter will explain the required buffers and all other factors that must be considered when you are trying to determine when and how much animal waste to land apply.

3. What Buffers Are Required When I Make Land Applications? There are three different sets of buffers you should consider when land applying animal waste:There are three different sets of buffers you should consider when land applying animal waste: –perennial streams –groundwater wells –“good neighbor” buffer

4. Buffers Perennial Streams: Under the existing 15A NCAC 2H.0200 Nondischarge Rules, you can not land apply animal wastes within 25 feet of perennial streams.Under the existing 15A NCAC 2H.0200 Nondischarge Rules, you can not land apply animal wastes within 25 feet of perennial streams. Perennial streams are defined as streams indicated by a solid blue line on a United States Geological Survey map.Perennial streams are defined as streams indicated by a solid blue line on a United States Geological Survey map. Effective October 1, 1995 for new or expanding swine farms, you may not apply waste within 50 feet of perennial streams.Effective October 1, 1995 for new or expanding swine farms, you may not apply waste within 50 feet of perennial streams.

5. Buffers Groundwater Wells: A 100-foot buffer is required around wells for:A 100-foot buffer is required around wells for: –location of lagoons –other waste treatment facilities –land application sites Even on a properly managed site it is best to maintain the buffer to reduce the potential for problems.Even on a properly managed site it is best to maintain the buffer to reduce the potential for problems.

6. Buffers “Good Neighbor” Buffer: Maintain a minimum distance of 200 feet from any homes or other buildings frequented by people.Maintain a minimum distance of 200 feet from any homes or other buildings frequented by people. Do not make land applications on days with excessive wind. Drift on these days may irritate neighbors or pollute surface waters.Do not make land applications on days with excessive wind. Drift on these days may irritate neighbors or pollute surface waters.

7. Proper Application of Waste Products Irrigation Scheduling: Proper land application of lagoon liquid involves the use of water management strategies to best achieve a balance between:Proper land application of lagoon liquid involves the use of water management strategies to best achieve a balance between: –optimizing the timing of nutrient application to match crop uptake –maintaining adequate storage in the lagoon to handle extreme rainfall without overtopping –applying water at a rate and amount such that no direct surface runoff or percolation below the root zone occurs

8. Irrigation Scheduling Decision Making: Do I need to irrigate?Do I need to irrigate? How much water should I apply?How much water should I apply?

9. Irrigation Scheduling Determining When to Irrigate: Ask yourself:Ask yourself: –Do I have an actively growing crop (or will a crop be planted or actively start growing within 30 days)? –Do I have a nitrogen deficit remaining for this crop cycle? –Is the liquid level in my lagoon above the minimum storage depth? –Are my land application fields dry enough to be irrigated? –Do I have a waste analysis within 60 days of this irrigation? If the answer to all five questions above is yes, then you should schedule an irrigation.If the answer to all five questions above is yes, then you should schedule an irrigation.

10. Irrigation Scheduling Basic Soil-Water Relationships: Saturationall soil pores are filled with water and conditions are undesirable for good crop growth or wastewater irrigation.Saturation  all soil pores are filled with water and conditions are undesirable for good crop growth or wastewater irrigation. Field capacitythe soil has had time to drain away excess water, but still remains in a very moist condition.Field capacity  the soil has had time to drain away excess water, but still remains in a very moist condition. Permanent wilting pointplants cannot remove water from the soil.Permanent wilting point  plants cannot remove water from the soil.

11. Irrigation Scheduling Basic Soil-Water Relationships: Gravitational Watergravitational water is computed as the volume of water in the soil between saturation and field capacity.Gravitational Water  gravitational water is computed as the volume of water in the soil between saturation and field capacity. Plant-Available Water (PAW)the difference between the water content at field capacity and the permanent wilting point. Irrigation should be scheduled to maintain the water content of the soil between these two extremes.Plant-Available Water (PAW)  the difference between the water content at field capacity and the permanent wilting point. Irrigation should be scheduled to maintain the water content of the soil between these two extremes.

12. Irrigation Scheduling Estimating Soil-Water Content: There are three practical methods of determining if the field is dry enough to be irrigatedthese include:There are three practical methods of determining if the field is dry enough to be irrigated  these include: –a subjective method that involves “feeling” the soil –objective methods utilizing soil-moisture measuring devices –an accounting approach (checkbook method) to estimate soil-water

13. Irrigation Scheduling Determining How Much to Irrigate: Irrigation should be scheduled and timed so that:Irrigation should be scheduled and timed so that: –no surface runoff occurs during the irrigation –the root zone is not completely saturated at the conclusion of the irrigation –the irrigated water does not leach below the root zone

14. Irrigation Scheduling Determining How Much to Irrigate: The amount of wastewater that can or should be applied during any single irrigation cycle is dictated by how much water the soil can “soak up.”The amount of wastewater that can or should be applied during any single irrigation cycle is dictated by how much water the soil can “soak up.” This varies from day to day and is influenced by:This varies from day to day and is influenced by: –rainfallwhen and how much it last rained –rainfall  when and how much it last rained –crop maturitywater uptake rate of the crop –crop maturity  water uptake rate of the crop –soil typetexture, structure, depth, and cover –soil type  texture, structure, depth, and cover –effective root depth –evapotranspirationwhich is influenced by temperature, wind, and relative humidity –evapotranspiration  which is influenced by temperature, wind, and relative humidity

15. Approximate Water Infiltration Rates for Various Soil Textures and Slopes

16. Irrigation Scheduling Operational Considerations: Discharge ratethe volume of water exiting a sprinkler per unit of time.Discharge rate  the volume of water exiting a sprinkler per unit of time. Precipitation ratenormally expressed as unit depth of water (inch) per unit of time (usually hour).Precipitation rate  normally expressed as unit depth of water (inch) per unit of time (usually hour). Total application volumecomputed based on the amount of time the system operates at a given rate on a given field.Total application volume  computed based on the amount of time the system operates at a given rate on a given field.

17. Example If your target application volume to achieve the required annual PAN is 3.0 inches, and you should apply no more than 0.5 inch at each irrigation, how many times must you irrigate?If your target application volume to achieve the required annual PAN is 3.0 inches, and you should apply no more than 0.5 inch at each irrigation, how many times must you irrigate? To answer this, use Formula 7:To answer this, use Formula 7:

18. Typical Layout of a Stationary Sprinkler System

19. Stationary Sprinklers Determination of Precipitation Rate: Determine the discharge rate (sprinkler flow rate) and wetted diameter from manufacturer’s literature.Determine the discharge rate (sprinkler flow rate) and wetted diameter from manufacturer’s literature. Determine sprinkler spacing. Recommended sprinkler spacing is 50 to 65 percent of wetted diameter.Determine sprinkler spacing. Recommended sprinkler spacing is 50 to 65 percent of wetted diameter. Precipitation rate is then computed using Formula 8:Precipitation rate is then computed using Formula 8: Precipitation rate (in./hr)= 96.3 sprinkler flow rate (gpm) sprinklerspacing (ft) lateral spacing (ft) x x

20. Stationary Sprinklers Determination of Precipitation Rate: Time of operation is computed using Formula 9:Time of operation is computed using Formula 9:

21. Typical Layout of a Traveling Gun Irrigation System

22. Traveling Gun Sprinklers Determination of Precipitation Rate: Precipitation rate is computed using Formula 10:Precipitation rate is computed using Formula 10: Precipitation rate (in./hr)= 96.3 sprinkler flow rate (gpm) 3.14 [0.9 sprinkler radius (ft)] 360 w 2 x xx x

23. Traveling Gun Sprinklers Determination of Application Volume: Application volume is computed using Formula 11:Application volume is computed using Formula 11:

24. Traveling Gun Sprinklers Determination of Traveling Speed: Traveling speed is computed using Formula 12:Traveling speed is computed using Formula 12:

25. Irrigation System Calibration Calibration involves collecting and measuring flow at several locations in the application area.Calibration involves collecting and measuring flow at several locations in the application area. Any number of containers can be used to collect flow and determine the application rate:Any number of containers can be used to collect flow and determine the application rate: –rain gauges –pans –plastic buckets –jars

26. Irrigation System Calibration For stationary sprinklers, collection containers should be located randomly throughout the application area at several distances from sprinklers.For stationary sprinklers, collection containers should be located randomly throughout the application area at several distances from sprinklers. For traveling guns, sprinklers should be located along a transect perpendicular to the direction of pull.For traveling guns, sprinklers should be located along a transect perpendicular to the direction of pull. Set out collection containers 25 feet apart along the transect on both sides of the gun cart.Set out collection containers 25 feet apart along the transect on both sides of the gun cart.

27. Application Using Spreader Equipment Wastes that have a higher solids content than can not easily be handled through an irrigation system may require land application through a pump and haul system.Wastes that have a higher solids content than can not easily be handled through an irrigation system may require land application through a pump and haul system. The decision process for waste application is more related to the stage of crop growth and whether the crops need nutrient applications.The decision process for waste application is more related to the stage of crop growth and whether the crops need nutrient applications.

28. Application Using Spreader Equipment One important issue is the “trafficability” of the fields, or how easily your equipment can be operated to obtain uniform waste application without rutting the field or causing soil compaction.One important issue is the “trafficability” of the fields, or how easily your equipment can be operated to obtain uniform waste application without rutting the field or causing soil compaction. Once the decision has been made to perform waste application, you must be aware of your equipment’s waste application rate. This requires the calibration of the land application equipment.Once the decision has been made to perform waste application, you must be aware of your equipment’s waste application rate. This requires the calibration of the land application equipment.

29. Calibration of Manure Spreaders Applicators can apply manure, bedding, and wastewater at varying rates and patterns, depending on:Applicators can apply manure, bedding, and wastewater at varying rates and patterns, depending on: –forward travel and/or PTO speed –gear box settings –gate openings –operating pressures –spread widths –overlaps

30. Calibration of Manure Spreaders Calibration defines the combination of settings and travel speed needed to apply manure, bedding, or wastewater:Calibration defines the combination of settings and travel speed needed to apply manure, bedding, or wastewater: –at a desired rate –to ensure uniform application

31. Calibration Liquid Manure Spreaders: Spread at least one full load of waste, preferably in a square or rectangular field pattern for ease of measuring, with normal overlaps.Spread at least one full load of waste, preferably in a square or rectangular field pattern for ease of measuring, with normal overlaps. Measure the length and width of coverage, recognizing that the outer fringe areas of the coverage will receive much lighter applications than the overlapped areas.Measure the length and width of coverage, recognizing that the outer fringe areas of the coverage will receive much lighter applications than the overlapped areas.

32. Calibration Liquid Manure Spreaders: Multiply the length by the width and divide by 43,560 to determine the coverage area in acres:Multiply the length by the width and divide by 43,560 to determine the coverage area in acres: –Formula 13 –Formula 14 Coverage area (area of rectangle in ft 2 ) = length (ft) × width (ft)

33. Calibration Liquid Manure Spreaders: Divide the gallons of wastewater in the spreader by the acres covered to determine the application rate in gallons per acre (Formula 15):Divide the gallons of wastewater in the spreader by the acres covered to determine the application rate in gallons per acre (Formula 15): Repeat the procedure at different speeds and/or spreader settings until the desired application rate is achieved.Repeat the procedure at different speeds and/or spreader settings until the desired application rate is achieved.

34. Calibration Spreader Capacity: Solid and semi-solid spreaders are rated by the manufacturer either in bushels or cubic feet (multiply bushels by 1.25 to get cubic feet).Solid and semi-solid spreaders are rated by the manufacturer either in bushels or cubic feet (multiply bushels by 1.25 to get cubic feet). Most spreaders have two rating capacities:Most spreaders have two rating capacities: –struck or level full –heaped Calibration of solid manure spreaders based on its capacity (volume) is difficult to estimate because the density of manures are quite variable.Calibration of solid manure spreaders based on its capacity (volume) is difficult to estimate because the density of manures are quite variable.

35. Calibration Spreader Capacity: Weigh an empty 5-gallon bucket.Weigh an empty 5-gallon bucket. Fill the bucket level full with the material to be spread. Do not pack the material in the bucket but ensure that it settles similar to a loaded spreader.Fill the bucket level full with the material to be spread. Do not pack the material in the bucket but ensure that it settles similar to a loaded spreader. Weigh the bucket again. Subtract the empty bucket weight from this weight to calculate the weight of the contents.Weigh the bucket again. Subtract the empty bucket weight from this weight to calculate the weight of the contents.

36. Calibration Spreader Capacity: Multiply weight of contents by 1.5 to calculate pounds per cubic feet, which is the manure density.Multiply weight of contents by 1.5 to calculate pounds per cubic feet, which is the manure density. Multiply the manure density by the cubic feet capacity of the spreader and divide by 2000 to get the tons of material in a spreader load (Formula 16):Multiply the manure density by the cubic feet capacity of the spreader and divide by 2000 to get the tons of material in a spreader load (Formula 16):

37. Calibration Solid and Semi-Solid Manure Spreaders: In order to calibrate a spreader for solid manure (20 percent or more solids), the following materials are needed:In order to calibrate a spreader for solid manure (20 percent or more solids), the following materials are needed: –bucket –plastic sheet, tarp or old bedsheetan even size, 8 feet by 8 feet, 10 feet by 10 feet, or 12 feet by 12 feet, will make calculations easier –plastic sheet, tarp or old bedsheet  an even size, 8 feet by 8 feet, 10 feet by 10 feet, or 12 feet by 12 feet, will make calculations easier –scales

38. Calibration Solid and Semi-Solid Manure Spreaders: Locate a large and reasonably smooth, flat area where manure can be applied.Locate a large and reasonably smooth, flat area where manure can be applied. Spread the plastic sheet, tarp, or bed sheet smoothly and evenly on the ground.Spread the plastic sheet, tarp, or bed sheet smoothly and evenly on the ground. Fill the spreader with manure to the normal operating level. Drive the spreader at the normal application speed toward the sheet spread on the ground, allowing the manure to begin leaving the spreader at an even, normal rate.Fill the spreader with manure to the normal operating level. Drive the spreader at the normal application speed toward the sheet spread on the ground, allowing the manure to begin leaving the spreader at an even, normal rate.

39. Calibration Solid and Semi-Solid Manure Spreaders: Drive over the sheet at the normal application speed and settings while continuing to apply manure. If a rear discharge spreader is used, three passes should be made:Drive over the sheet at the normal application speed and settings while continuing to apply manure. If a rear discharge spreader is used, three passes should be made: –first, drive directly over the center of the sheet –the other two passes on opposite sides of the center at the normal spreader spacing overlap Weigh the empty bucket and plastic sheet, tarp, or blanket.Weigh the empty bucket and plastic sheet, tarp, or blanket.

40. Calibration Solid and Semi-Solid Manure Spreaders: Collect all manure spread on the sheet and place it into the bucket.Collect all manure spread on the sheet and place it into the bucket. Weigh bucket and manure and subtract the weight of the empty bucket and ground sheet. This will give you the pounds of manure applied to the sheet.Weigh bucket and manure and subtract the weight of the empty bucket and ground sheet. This will give you the pounds of manure applied to the sheet. Repeat the procedure three times to get an average.Repeat the procedure three times to get an average. Determine the average weight of the three manure applications.Determine the average weight of the three manure applications.

41. Calibration Solid and Semi-Solid Manure Spreaders: Calculate the application rate using Formula 17:Calculate the application rate using Formula 17: Repeat the procedure at different speeds and/or spreader settings until the desired application rate is achieved.Repeat the procedure at different speeds and/or spreader settings until the desired application rate is achieved.

42. Calibration Solid and Semi-Solid Manure Spreaders: Many times it may be necessary to adjust the rate in which waste is applied from the way it is normally spread.Many times it may be necessary to adjust the rate in which waste is applied from the way it is normally spread. In order to perform the necessary calculations, the spreader load (tons), duration of application (minutes), and the average width (feet) of a normal application needs to be known.In order to perform the necessary calculations, the spreader load (tons), duration of application (minutes), and the average width (feet) of a normal application needs to be known.

43. Calibration Solid and Semi-Solid Manure Spreaders: The application rate is computed using Formula 18:The application rate is computed using Formula 18: The travel speed is computed using Formula 19:The travel speed is computed using Formula 19:

44. Calibration Spreader Uniformity: The effective spread width can be found by locating the point on either side of the path center where manure contents caught in the containers is half of what it is in the center.The effective spread width can be found by locating the point on either side of the path center where manure contents caught in the containers is half of what it is in the center. “Flat-top,” “pyramid,” or “oval” patterns are most desirable and give the most uniform application.“Flat-top,” “pyramid,” or “oval” patterns are most desirable and give the most uniform application. “M,” “W,” “steeple,” or “lopside” patterns are not satisfactory.“M,” “W,” “steeple,” or “lopside” patterns are not satisfactory.