Manure Spreader Calibration

Transcription

1 Agronomy Facts 68 Manure Spreaer Calibration Manure spreaer calibration is an essential an valuable nutrient management tool for maximizing the efficient use of available manure nutrients. Planne manure application rates liste in nutrient management plans must correlate ith actual application rates. Calibrating the manure spreaer is the only ay to kno actual manure application rates. Manure spreaer calibration combine ith soil test recommenations an manure analysis results enable the etermination of nutrient application rates that meet crop nutrient nees. The most critical an challenging aspect of both soil an manure analysis is obtaining a representative sample to submit to the laboratory. It is critical to learn an follo recommene soil an manure sampling proceures in orer to obtain a representative sample an test results. The manure nutrient levels an crop nutrient requirements from test results are use to etermine manure application rates that ill aequately meet crop nees. Manure spreaer calibration ensures that manure application rates are realistic, practical, an attainable. Manure application rates are etermine by equipment spees an settings along ith application management, such as overlaps. Manure spreaer calibration can be use to ays in nutrient management planning: Before planning Spreaers can be calibrate to etermine the rates that can be applie at typical application settings an spee. These rates are then use as the possible planne rates hen the nutrient management plan is evelope. After planning Spreaers can be calibrate to meet planne application rates by changing spees, settings, or management. In this case, esire application rates are etermine as the nutrient management plan is evelope an the spreaer is calibrate accoringly. Overvie of Spreaer Calibration An application rate is efine as the amount of manure applie per unit of lan area. For manure, it is usually expresse in tons per acre (soli) or gallons per acre (liqui). Generally, application rate equals the amount of manure applie (in tons or gallons) ivie by the area covere (in acres). Manure spreaer calibration requires reliable estimates of both the amount applie an area covere. There are to common calibration techniques. The sath or loa-area metho involves measuring both the amount of manure in a typical spreaer loa an the lan area covere by applying one loa of manure. While this metho can be use for all manures, it is the best metho for liqui manure applicators. The tarp or eight-area metho involves eighing the manure sprea over a small surface an computing the amount of manure applie per acre. This metho is the best metho for soli manure applicators. Calibration Methos Belo are escriptions of the to most common calibration methos. Sath (Loa-Area) Metho Liqui manure applicators use in pump-an-haul application systems are best calibrate by the sath or loa-area metho, hich involves lan applying a full loa of manure an measuring the lan area covere. If possible, choose an area that is typical of the lan here manure ill be sprea. If appropriate, a relatively level area long enough for the loa to be applie in a single pass makes measurements an calculations simpler. A rectangular fiel pattern shoul be use to make measuring easier. The application rate of PTO-riven spreaers epens on groun spee. Therefore, it is important to maintain a uniform groun spee throughout the sath length. Groun-riven spreaers eliver reasonably uniform application rates regarless of groun spee. For liqui application equipment, application rates an patterns vary epening on groun spee or PTO spee, gear box settings, gate openings, operating pressures, sprea iths, an overlaps. To change the application rates, ajustments must be mae in tractor/pto spees, spreaer output settings, or application management. The

2 calibration process shoul be folloe for each change or combination of changes. Several calibration passes may be necessary to etermine the settings require for the esire application rate. Use the sath (loa-area) metho proceure an recor sheet provie at the en of this publication for this calibration metho. Tarp (Weight-Area) Metho Soli manure applicators are best calibrate by the tarp or eight-area metho, hich involves measuring the amount of manure (eight) applie over a small measure area (tarp). The application rate is etermine by iviing the amount (eight) of manure collecte on the tarp by the size of the collection area (tarp). For soli application equipment, applications rates an patterns vary epening on groun spee or PTO spee, gear box settings, gate openings, operating pressures, sprea iths, an overlaps. To change the application rates, ajustments must be mae in tractor/pto spees, spreaer output settings, or application management. The calibration process shoul be folloe for each change or combination of changes. Several calibration passes may be necessary to etermine the settings require for the esire application rate. Use the tarp (eight-area) metho proceure an recor sheet provie at the en of this publication for this calibration metho. Determining Manure Spreaer Capacity The loa-area metho of manure spreaer calibration requires knolege of the manure spreaer s capacity. Manure spreaer capacity can be etermine by one of the folloing methos. Manufacturer s Capacity Ratings The rate capacity for liqui spreaers can be use irectly if the spreaer is typically fille to capacity. In many cases, the spreaer is not fully loae. Therefore, ajustments must be mae for less than full capacity. The rate capacity of box-type soli or semisoli spreaers must be ajuste accoring to the fullness of a typical loa of manure. Make sure to note hether the rating specifications are for heape or pile or level loas. If there is any uncertainty about the rate capacity, then a more accurate metho is neee to measure the actual volume of manure. Measure Spreaer Volume Spreaer volume can be estimate by using the calculations in Figure 1. All imensions use in the folloing formulas must be in feet in orer to obtain volumes that are in cubic feet. After calculating volume in cubic feet, convert the cubic feet to pouns an then convert pouns to tons or gallons base on manure ensity using the conversion factors in Table 1. Figure 1. Calculating estimate manure spreaer volumes. Soli or Semisoli [A] Box spreaer (level loa)* volume = length x ith x epth [B] Box spreaer (pile loa)* volume = length x ith x [epth + (stacking height** x 0.8)] [C] Roun-bottom open-top spreaer (level loa) volume = length x epth x epth x 1.6 [D] Roun-bottom open-top spreaer (pile loa) volume = length x epth x 1.6 x (epth + stacking height**) Liqui [A] Box spreaer (level loa)* volume = length x ith x epth [C] Roun-bottom open-top spreaer (level loa) volume = length x epth x epth x 1.6 [E] Tank spreaer (roun) volume = length x tank iameter x tank iameter x 0.8 [F] Tank spreaer (noncircular) volume = length x ith x epth x 0.8 *For a box spreaer ith sloping sies, use an average ith. **Stacking height is the height of any moune manure above level. A. B. C. h Table 1. Commonly require conversions for manure spreaer volumes. To convert From To Multiply by bushels cubic feet 1.24 gallons cubic feet gallons pouns 8.3 (liqui) gallons tons (liqui) tons gallons 240 (liqui) cubic feet gallons 7.48 cubic feet tons (liqui) or (soli) cubic feet pouns 62 (liqui) or 55 (soli) See the next page for instructions to etermine the actual manure ensity. D. E. F. h 2

3 Weigh Manure Loa The most accurate ay to etermine the capacity of a spreaer is to irectly eigh the spreaer. The spreaer shoul be eighe using rive-on scales or eigh pas. First, eight the spreaer empty an then eight at least three typical loas of manure. Obtain an average eight of the full loas an subtract the eight of the empty loa to etermine the eight of the manure. Convert this eight to tons or gallons. Determining Manure Density Manure ensity (eight per cubic foot) varies ith moisture content primarily epening on the amount of being. To calculate a more accurate estimate of manure ensity, use the proceure belo. 1. Weigh an empty 5-gallon bucket. Recor the eight in pouns. 2. Fill the 5-gallon bucket ith a typical sample of the manure to be applie an eigh the bucket an manure. Recor the eight in pouns. 3. Subtract the eight of the empty bucket (step 1) from the eight of manure an bucket (step 2). Recor the eight of manure in pouns. 4. Repeat steps 2 an 3 at least six times an calculate the average manure eight (a the six eights together an ivie by six). Recor average eight of manure in pouns. 5. Multiply the average manure eight (step 4) by 1.5 to obtain the estimate manure ensity in pouns per cubic foot. Recor the manure ensity in pouns per cubic foot. Sath (Loa-Area) Metho Calibration Proceure Obtain calibration equipment an supplies. Measuring heel (available from any farm supply catalog, such as NASCO). 1. Determine manure spreaer capacity. Use manufacturer s ratings or actual eighing of the spreaer, or estimate by using spreaer volume calculations escribe above. Recor the capacity in gallons (liqui manure) or tons (soli manure). Loa the spreaer consistently ith the capacity etermination above. 2. Sprea one full loa of manure in a rectangular pattern. Note the etails of the operating conitions (e.g., tractor gear, throttle setting, PTO spee, tractor spee, spreaer settings). 3. Measure the length an the effective application ith of the application coverage area. Recor the istances in feet. An alternative metho of measuring the application length is to note the groun spee an time require to make the application pass. To calculate length covere, multiply the groun spee (in mph) by the number of secons by 1.46 feet per secon. 4. Calculate the size of the coverage area. Multiply the length by the ith an ivie by 43,560 square feet per acre. Recor the coverage area in acres. 5. Calculate the application rate. Divie the volume of the spreaer loa of manure (step 1a) by the acres covere (step 4b). Recor manure application rate in gallons or tons per acre. 6. Repeat the calibration proceure one or to more times. Repetition is necessary to increase reliability of the application rate. A certain amount of variation is inevitable. Hoever, if there is significant variation among repetitions, check over the equipment an revie your calibration proceure to try to etermine the cause of the variation. Repeat steps 2 through 5. Calculate the average of each of the measure manure application rates. Recor the final calibrate rate in gallons or tons per acre. 3

4 Manure Spreaer Calibration Recor Sheet Sath (Loa-Area) Metho Spreaer Ientification Date 1. Determine the capacity of the spreaer (use gallons for liqui manure an tons for soli manure). a. Spreaer capacity gallons or tons 2. Sprea one full loa in a rectangular pattern. Forar spee, gear, or throttle setting PTO spee or setting Spreaer gate opening setting 3. Measure the coverage area. Trial 1 Trial 2 Trial 3 a. Sprea area ith feet feet feet b. Sprea area length feet feet feet 4. Calculate the area covere. a. Sprea area (3a x 3b) ft 2 ft 2 ft 2 b. Sprea area (4a 43,560) acres acres acres 5. Calculate the manure application rate. a. Application rate (1a 4b) gallons or tons/acre 6. Average each of the calibration trials to etermine the final application rate. Final calibrate application rate (average of trials in 5a) gallons or tons/acre 4

5 Tarp (Weight-Area) Metho Calibration Proceure Obtain calibration equipment an supplies. Tarp or plastic (heavy) sheet approximately 100 square feet in size (9 x 12, 10 x 10, 10 x 12, etc.) Tent pegs or long nails Scales (spring-tension or platform) Bucket (optional to assist in eighing) 1. Measure the exact surface area of the trap or plastic sheet (length x ith). Recor the surface area in square feet. Weigh the empty tarp or plastic sheet. If using a bucket, eigh the tarp or plastic sheet ith the bucket. Recor the eight (empty) in pouns. (3a) 2. Position the tarp in the fiel here the manure can be sprea. Place it far enough into the fiel to allo enough istance to get the spreaer in gear an the tractor up to the esire spee. Avoi placing the tarp here the beginning or en of the loa is likely to fall. Secure each corner of the tarp ith a tent peg or long nail. Sprea the first pass of manure irectly over the center of the tarp. Operate the spreaer at the spee normally riven hen applying manure. Note the etails of the operating conitions (e.g., tractor gear, throttle setting, PTO spee, tractor spee, spreaer settings). Sprea to aitional passes on opposite sies of the center of the tarp. Apply these passes at the normal spreaer overlap spacing. 3. Remove an fol the tarp. Be careful not to spill any of the collecte manure. If using a bucket for eighing, place the manure an tarp in the bucket. Weigh the tarp an manure (an bucket). Recor the eight (gross) in pouns (step 3b). Subtract the empty tarp eight (an bucket if using a bucket) (step 3a) from the gross tarp eight (step 3b). Recor the eight of collecte manure in pouns. 4. Determine the manure application rate. Divie the amount of manure collecte (in pouns) (step 3c) by the tarp area (in square feet) (step 1a). Multiply this value by 21.8 (43,560 ft 2 /acre 2,000 lbs/ton) to convert pouns per square foot to tons per acre. Recor the manure application rate in tons per acre. 5. Repeat the calibration proceure one or to more times. Repetition is necessary to increase reliability of the application rate. Repeat steps 2 through 4. Calculate the average of each of the measure manure application rates. Recor the final calibrate rate in tons per acre. 5

6 Manure Spreaer Calibration Recor Sheet Tarp (eight-area) Metho Spreaer Ientification Date 1. Measure tarp surface area. Weigh the empty tarp an recor uner 3a belo. Sprea an secure the tarp or plastic sheet in the fiel. a. Tarp surface area: ith x length = ft 2 2. Sprea manure over the center f the tarp an on each sie of the tarp at the normal overlap spacing. Forar spee, gear, or throttle setting PTO spee or setting Spreaer gate opening setting 3. Fol an eigh the tarp (an eighing container) ith an accurate set of spring-tension or platform scales. Trial 1 Trial 2 Trial 3 a. Empty eight lbs lbs lbs b. Gross eight ith manure lbs lbs lbs c. Net eight (3b 3a) lbs lbs lbs 4. Calculate the manure application rate. a. Application rate (3c 1a) lbs/ft 2 lbs/ft 2 lbs/ft 2 b. Application rate (4a x 21.8) tons/acres tons/acres tons/acres 5. Average each of the calibration trials to etermine the final application rate. Final calibrate application rate (average of trials in 4b) tons/acre Prepare by Geral Martin, senior extension associate, an Douglas Beegle, professor of agronomy. Peer-revie feeback provie by William Clouser, nutrient management program supervisor, State Conservation Commission; Douglas Goolaner, nutrient management program irector, State Conservation Commission; Robert Meinen, senior extension associate, Penn State Extension; an Jennifer Wel, project associate, Penn State. Penn State College of Agricultural Sciences research an extension programs are fune in part by Pennsylvania counties, the Commonealth of Pennsylvania, an the U.S. Department of Agriculture. Where trae names appear, no iscrimination is intene, an no enorsement by Penn State Extension is implie. This publication is available in alternative meia on request. Penn State is committe to affirmative action, equal opportunity, an the iversity of its orkforce. Prouce by Ag Communications an Marketing The Pennsylvania State University 2008 Coe UC200 04/14po 6