Land Application for Effective Manure Nutrient Management

Transcription

1 Land Application for Effective Manure Nutrient Management Livestock operations produce meat, as well nitrogen, phosphorus, and potassium in animal manures, nutrients that can be important by-products when effectively managed and used for field crops. By properly recycling these nutrients, a producer can reduce an operation s reliance on energy-intensive commercial fertilizer for high-yield crops. Manure that is properly managed and effectively applied presents little hazard to surface or ground water and improves soil tilth. Manure is an asset rather than a liability for the livestock producer. Good manure nutrient management includes efficient handling, proper storage, and proper land application of animal wastes. This publication shows two methods to plan for effective land application of livestock manure. Method A is a simplified procedure to plan a new facility; Method B is a more detailed procedure to fine-tune existing operations. Both methods help the producer determine land area needed for best application of manure nutrients to maximize returns and avoid overapplication. How to manage manure nutrients Management of nutrients in animal manure is not difficult. Basically, manure nutrient management allows the operator to determine the land area required to accept manure at a set rate University Extension Ames, Iowa that provides adequate nutrients for plants, and avoids endangering the environment. A three-part procedure is shown for two methods, A or B, that can be used for any given livestock or crop operation. Each method follows these procedures: Determine crop nutrient needs based on an individual yield goal. Calculate nutrients available in manure. Calculate the land required to spread manure. Summarize the total amount of nitrogen, phosphorus, and potassium in the manure application. Realistic yield goals The first step in any nutrient plan is to establish realistic yield goals. A yield goal that is too high will result in overapplication and wasted nutrients. A yield goal that is too low may sacrifice yield from lack of nutrients. A realistic yield goal can be determined several ways. Historical yield information is available from the Consolidated Farm Service Agency (CFSA), which maintains official yield information. Soil-based yield potential estimates can be found in county soil survey books. You also may want to use your own records of past yields, or those from a previous owner. Calculating Realistic Yield Goals, Worksheet A1 on page 17 of this publication, is provided if you plan to set a yield goal using soil information. Once a yield goal is set, use Method A or B to complete your nutrient plan. Method A: Planning a new facility Method A is a simplified procedure to determine the best way to apply manure based on the nitrogen content of animal wastes. Use this six-step procedure when planning a new facility. The nitrogen goal referred to in Method A may be the rate for your yield goal or some other value, such as maximum rates mandated by rules or regulations. The Iowa Department of Natural Resources (IDNR) recommends manure application based on agronomic rates developed by Iowa State University. Agronomic rates can be based either on crop utilization or recommended fertilizer rates. In the past, the IDNR has set maximum recommended rates. Your application rate should not exceed regulatory limits. Method A assumes that no soil or manure samples have been taken, and uses previously set values for manure nutrient concentrations. Nutrient utilization and fertilizer values in Tables 1, 1a, 2, and 3 are compiled from commonly used estimates and 1 Pm-1599 October 1995

2 current research data. The values in Tables 2 and 3 are estimates only. Actual amounts may vary significantly, depending on handling methods, storage facilities, and other management considerations. Method A can be used to plan a new system that will be either continuous corn or a corn-soybean rotation. This method assumes that manure will be applied every year or every other year, and calculates the amount of manure nitrogen needed each year. It assumes that all nitrogen in manure is available for crops except for that portion lost during land application. Method A also assumes livestock buildings are used at capacity throughout the year. Method A: Planning a new facility Crop nutrient needs (nitrogen only) 1. Determine base application amount of nitrogen. How much nitrogen do you want available to plants? (Remember that allowable rates are subject to change by the IDNR or the Iowa Legislature.) Plan according to either how many nutrients are removed from the soil by various crops (see Table 1 on page 13), or fertilizer recommendations for corn (see Table 1a on page 13). Combine the Nutrient Removal Factor with the Individual Yield Goal determined either from Worksheet A1 (page 17) or by other methods. Nutrient Removal Factor (from Table 1 or 1a) lb./unit Individual Yield Goal (Worksheet A1) bu./acre Base Application Amount = lb. N/acre (1) 2. Deduct soybean and starter fertilizer credit. You must credit nitrogen from previous soybean crops and from any commercial nitrogen you use. From your Base Application Amount (1), subtract 1 pound of nitrogen/acre for each bushel of soybean yield from last year s crop. If land has been used for legumes other than soybeans, use Method B, rather than Method A, to determine land area for manure application. Base Application Amount (1) lb. N/acre If previous crop was soybeans, subtract yield bu./acre If commercial fertilizer will be applied, subtract fertilizer credit lb. N/acre Nitrogen Application Goal = lb. N/acre (2) 3. Correct for land application losses. Figure in the nitrogen that will be lost to the air when manure is spread on the field to determine an Adjusted Nitrogen Rate (3). Losses vary according to how manure is applied. Table 2 on page 14 shows correction factors to use depending on manure application method. Manure Application Method: Correction Factor (see Table 2): Nitrogen Application Goal (2) Correction Factor (see Table 2) lb. N/acre Adjusted Nitrogen Rate = lb. N/acre (3) 2

3 Manure nutrients 4. Calculate animals per acre in livestock operation to provide manure nutrients. Using Table 3 on pages 14 and 15, select the species and manure storage method (pit, lagoon, or solid) that fit your system to determine nitrogen levels in manure. Then determine how large an operation will support the nitrogen levels you need for field use. If you have more than one species or system, do each species separately. Table 3 assumes full building occupancy all year. Estimate the amount of nitrogen produced in your livestock operation each year. Use Table 3, column 1. System Type: Animal Manure Nutrient Production: lb. N/year per animal space (4a)* Determine the number of animals per acre needed to supply crop nutrients from manure. Divide the Adjusted Nitrogen Rate (3) by the Animal Manure Nutrient Production (4a) to determine the number of animals per acre needed to provide proper nutrient levels. Adjusted Nitrogen Rate (3) lb. N/acre Animal Manure Nutrient Production (4a) lb. N/year per animal space Animal Capacity/acre = animal spaces/acre (4b) Land required to spread manure 5. Determine land area needed for the manure from this livestock operation. Divide the total building capacity by the number of animal spaces needed to provide adequate nitrogen for each acre. This will give you the number of acres needed to spread manure from your operation. Building Capacity total head Animal Capacity/acre (4b) animal spaces/acre Minimum land area needed for manure application = acres (5) Nutrient summary 6. Determine other manure nutrient levels. P and K application rates are determined by the adjusted rate at which manure is applied to fields. Adjusted Nitrogen Rate (3): lb. N/acre (6a) P 2 : (see Table 3, col. 2) Animal Capacity/acre (4b) = lb./acre P 2 O: (see Table 3, col. 3) Animal Capacity/acre (4b) = lb./acre O (6b) *This is a one-time animal capacity, not the number of animals marketed. 3

4 Method A: An example You plan to build a new 500-sow farrow-to-finish facility in Cerro Gordo County. The manure from all buildings will go into an anaerobic lagoon, and be irrigated each fall on continuous corn ground (use the broadcast loss factor from Table 2). Your yield goal is 150 bushels per acre. Use Method A to determine the land area required for the manure, and the nutrients provided. Note that data from tables are bold italics. Step bu./acre 1.2 lb. N/bu. = 180 lb. N/acre needed Step 2 Credit from previous beans and starter fertilizer = 0 Step lb./acre 0.7 = 257 lb. N/acre to spread Step 4 Lb. N/yr./sow capacity = 44 lb./sow/yr.* (257 lb. N/acre) (44 lb./sow/yr.) = 5.8 sows/acre/yr. Step sows 5.8 sows/acre/yr. = 86 acres/yr. needed for spreading Step 6 Nutrient summary: N = 257 lb./acre P 2 = = 191 lb./acre O = = 255 lb./acre *This value is for each sow in the herd and includes manure from her and her offspring (18 pigs/sow/year assumed) through finishing. 4

5 Method B: Detailed manure nutrient planning Method B is a more detailed nutrient management procedure than Method A. Use Method B when soil and manure analysis results are available, when you plan applications of nutrients other than nitrogen, and when manure will not be applied either every year or every other year. After a facility is established, both manure and soils must be sampled to determine whether nutrient applications should be based on nitrogen or phosphorus. Different fields may need different nutrients. Phosphorus planning generally requires more acres than nitrogen planning. As with Method A, manure applications should be based on realistic yield goals. In Method B, first determine how many gallons of manure accumulate in the livestock operation between each land application. Then determine nutrients available each year. The land required can then be calculated from the total nutrients available and the per-acre application rates. Volumes and sample results from your own operation provide best results, but estimated values from Table 3 also can be used if others are not available. Rates may need to be adjusted for applications other than every year, and for different crops. This planning procedure should be repeated each year in a multi-year crop rotation, and for each field if more than one field is used. Crop nutrient considerations Just as with Method A, the first step is to determine crop nutrient needs. The crop s nitrogen needs should take into account any nitrogen in the organic fraction of manure not available the first year, also nitrogen carryover from previous legume crops, nitrogen carryover from previous manure applications, and any commercial nitrogen that will be applied. Seventy-five percent of the nitrogen that remains after land application losses is available the first year. Another 15 percent is available the second year, and another 10 percent the third year. For long-term planning, assume all nitrogen not lost during application is available on areas that receive manure frequently on a regular schedule. You may want to base manure applications on phosphorus. Phosphorus soil test levels in many parts of Iowa are high to very high. Phosphorus is not a health hazard or ground water concern, but high levels can contribute to algae growth in surface water if soil erosion occurs. Producers who have land that tests very high in phosphorus should use phosphorus rather than nitrogen as the limiting element for manure management planning. In general, phosphorus planning is more restrictive and requires more land than nitrogen planning. If the phosphorus level in soil is 30 parts per million (ppm) or more, plan manure applications based on phosphorus demands of the crop. Phosphorus rates can be based on crop needs for all crops between manure applications, but nitrogen rates are based on only one year s crop needs. After calculating land requirements based on phosphorus, compare them to the nitrogen-based requirements and use the appropriate nutrient to plan application rates. For good environmental stewardship and maximum economic benefit, manure should be applied over the largest land area determined by nitrogen and phosphorus planning. Apply commercial fertilizer to make up deficiencies in other nutrients not provided by the manure application. Tables 1 and 1a show nutrient requirements for crops typically grown in Iowa. Method B allows you to calculate the total acres needed each year to most efficiently use the available nutrients in the manure produced in your livestock operation. If you apply manure more frequently than once a year, adjust the acres for each application accordingly. Having calculated the nutrients to be applied via manure, you can now supplement any nutrient deficiencies with commercial fertilizer to meet the overall crop nutrient needs. 5

6 Method B: Detailed manure nutrient planning Crop nutrient needs 1. Determine the crop s nitrogen needs. Enter the yield goal you have established for this crop. Use Worksheet A1 on page 17 to calculate a realistic goal or use other methods suggested. Crop: Individual Yield Goal: yield/acre How much nitrogen do you want available to plants? Plan for either nutrients removed by various crops (use Table 1, page 13), or fertilizer recommendations (use Table 1a, page 13). Nutrient Removal Factor (from Table 1 or 1a) lb./unit Individual Yield Goal (Worksheet A1) yield/acre Nitrogen needed = lb. N/acre (1) 2. Determine nitrogen credits. Take credit for previous manure applications as well as legume and commercial fertilizer nitrogen. Nitrogen available from last year s manure application: Nitrogen applied as manure previous year: lb. N/acre Amount available as carryover.15 Nitrogen applied as manure two years ago: Carryover 1 = lb. N/acre (a) Amount available as carryover.10 Nitrogen from legume crop, previous year (see Table 4, page 16): Nitrogen from legume crop, two years ago (see Table 4, page 16): Commercial nitrogen applied: lb. N/acre Carryover 2 = lb. N/acre (b) Total nitrogen credits: Credit 1 = lb. N/acre (c) Credit 2 = lb. N/acre (d) Credit 3 = lb. N/acre (e) Sum of all carryovers and credits (add lines a through e) = lb. N/acre (2) 3. Determine net nitrogen needs. Determine the net nitrogen needed by subtracting the credits from the total amount needed: Nitrogen needed (1) lb. N/acre Total nitrogen credits (2) lb. N/acre Net Nitrogen Amount = lb. N/acre (3) 6

7 4. Determine phosphorus needs. Calculate the phosphorus needed, based on yield goals, for upcoming years between this year s application and the next application. Use Worksheet A1 or other methods described to calculate realistic yield goal. First-year crop (upcoming): Individual Yield Goal 1 yield/acre Nutrient Removal Factor (use Table 1, page 13) lb./unit Second-year crop: Phosphorus needed 1 = lb. P 2 /acre (a) Individual Yield Goal 2 yield/acre Nutrient Removal Factor (use Table 1, page 13) lb./unit Third-year crop: Phosphorus needed 2 = lb. P 2 /acre (b) Individual Yield Goal 3 yield/acre Nutrient Removal Factor (use Table 1, page 13) lb./unit Phosphorus needed 3 = lb. P 2 /acre (c) Total phosphorus needs: Sum of all applicable years needs (add lines a through c) = lb. P 2 /acre (4) Manure nutrients 5. Determine the volume of manure produced each year and the nutrients contained in it. Using gallons for liquid manure, or tons for solid manure, enter your actual manure volume on line 5 below, if known. If you do not know the volume of manure produced, estimate it from Table 3. Common conversion factors are listed in Table 5 on page 16. Enterprise: Storage type: Total Capacity (number of head) Volume of manure (use Table 3, col. 4) gal. or T/day* 365 days/year Percentage of time building is full percent 100 Total annual volume of manure = gal. or T (5) *Use gallons or tons but be consistent throughout your planning. 7

8 Using your own manure sample results, calculate the pounds of nutrients in storage to be applied on land each year.* Columns 5, 6, and 7 in Table 3 show nutrient content estimates if you do not have your own sample results. These are the total nutrients you have available in your manure to use as crop fertilizers each year. If you apply more than once per year, adjust the numbers accordingly. For example, if you haul every six months, the volume and nutrients shown are only half the amounts provided each year. Add nutrients from each livestock operation or building, if you have more than one, to get totals for each period: Nitrogen: gal. or (T) from (5) lb. N/gal. (T) = lb. N (6) P 2 : gal. or (T) from (5) lb. P 2 /gal. (T) = lb. P 2 (7) O: gal. or (T) from (5) lb. O/gal. (T) = lb. O (8) 6. Correct for the nitrogen lost during application. Calculate spreading losses. The nitrogen calculated in line 6 is the amount contained in the storage structure. When it is spread on the field, some will volatilize and be lost to the atmosphere. Correct for losses during spreading to determine the amount that will remain after spreading. Manure Application Method: Correction Factor (see Table 2, page 14) Nitrogen (6) lb. N Nitrogen remaining after application losses = lb. N (9) Calculate N availability during first year. Of the amount remaining on the soil, about 75 percent will be available to plants the first year. Correct for the amount that will become available from this year s application: Nitrogen remaining (9) lb. N Amount available to plants during first year.75 lb. N Net usable nitrogen in manure = lb. N (10) 7. Determine how many pounds of each nutrient are available during each application. Determine the total number of pounds of usable nutrients that are available at each application.** From these figures, you can calculate the pounds of nutrients in each gallon of manure by dividing pounds by the volume. Total usable nitrogen in manure (10) lb. Total annual volume of manure (5) gal. or T Usable nitrogen/gal. manure = lb./gal. or T (11) *If you have your own samples, you may have to convert from parts per million (ppm) or percent to pounds per gallon. Use the following factors: Multiply ppm times to get pounds per gallon. Multiply percent times.0834 to get pounds per gallon. Multiply ppm times.002 to get pounds per ton. Multiply P times 2.27 to get P 2. Multiply K times 1.20 to get O. **Although values are listed for open feedlots, wide variability makes estimates very crude. Use your own values if at all possible. 8

9 Total usable P 2 available each period (7) lb. Total annual volume of manure (5) gal. or T Usable P 2 /gal. manure = lb./gal. or T (12) Total usable O available each period (8) lb. Total annual volume of manure (5) gal. or T Usable O/gal. manure = lb./gal. or T (13) Land required to spread manure 8. Determine land area needed for manure application. Select the greater of the two values calculated below to have the least impact on the environment and provide you with the greatest economic benefit. You have calculated the total pounds of usable nutrients available, and the pounds of nutrients available to plants in each gallon of manure you spread. Based on this information, you can now calculate the number of acres you need for manure application. From nitrogen planning: Net usable nitrogen available (10) lb. Net Nitrogen Amount (3) lb. N/acre Land area needed for spreading nitrogen = acres (a) From phosphorus planning: Net usable P 2 available (7) lb. Total P 2 needs (4) lb. P 2 /acre Land area needed for spreading P 2 = acres (b) Acres required should be the greater of the two above values (a or b): (14) 9. Determine manure volume to apply. Total annual volume of manure (5) gal. or T Land area required for spreading (14) acres Manure volume to apply = gal. or T/acre (15) If the field is smaller than the acres calculated in (14), calculate the manure to apply to this field: Land area in field Determine the number of gallons (or T) of manure remaining to be spread: acres Manure volume to apply (15) gal. or T/acre Manure volume used on field = gal. or T (16) Total annual volume of manure (5) gal. or T Manure volume uses on field (16) gal. or T Manure volume remaining = gal. or T (17) 9

10 Manure volume remaining (17) gal. or T Manure volume to apply (15) gal. or T/acre Additional land area needed for spreading = acres Use the Field Application Inventory, Worksheet A4 on page 20, to keep track of your manure inventory as it is spread. Nutrient summary 10. Calculate your actual nutrient application rate per acre. Nitrogen: gal./acre (15) usable N/gal. (11) = lb. usable N/acre P 2 : gal./acre (15) usable P 2 /gal. (12) = lb. usable P 2 /acre O: gal./acre (15) usable O/gal. (13) = lb. usable O/acre Method B: An example You have a 1,000-head swine finishing unit with an earthen storage pit. You inject the manure ahead of corn in a corn-soybean rotation. No other fertilizer is applied to the corn ground. Calculate the land needed for proper manure application to grow 150 bushels of corn and 50 bushels of beans. (The manure has not been tested for nutrients.) Note that data from tables are bold italics. Step 1 Crop nutrient needs/nitrogen: Corn crop 150 bu./acre 1.2 (Table 1a) = 180 lb. N/acre Step 2 N credits: from manure last year = 0 from manure two years ago = 18 from soybeans last year (Table 4) = 50 Step 3 Net nitrogen needed: ( ) = 112 lb./acre Step 4 Crop nutrient needs/phosphorus: Corn crop 150 bu./acre 0.4 (Table 1a) = 60 lb. P 2 /acre Bean crop 50 bu./acre 0.8 (Table 1) = 40 lb. P 2 /acre Net phosphorus needed ( ) = 100 lb./acre Step 5 Annual manure nutrients available: a. Volume 1,000 hd. cap 1.2 gal./hd./day (Table 3, col. 4) 365 days = 438,000 gal./yr. b. Nutrients Nitrogen: 438,000 gal..05 lb./gal. = 21,900 lb. N Phosphorus: 438,000 gal..035 lb./gal. = 15,330 lb. P 2 Potassium: 438,000 gal..025 lb./gal. = 10,950 lb. O 10

11 Step 6 a. Correct nitrogen for field losses: 21,900 lb (Table 2) = 20,805 lb. N remaining after spreading b. Correct nitrogen for first year availability: 20,805 lb (from Method B worksheet) = 15,600 lb. usable Step 7 List nutrients available: Nitrogen = 15,600 lb. ( lb./gal.) P 2 = 15,330 lb. (0.035 lb./gal.) O = 10,950 lb. (0.025 lb./gal.) Step 8 Calculate land needed: From nitrogen planning: 15,600 lb. usable 112 lb./acre needed = 140 acres From phosphorus planning: 15,330 lb. 100 lb./acre needed = 153 acres Use 150 acres. Given the accuracy of tabular values, a value within 10 acres is adequate for planning purposes. Step 9 Manure application rate: 438, acres = 2,920 gal./acre Step 10 Nutrient summary: Nitrogen: 2,920 gal./acre lb./gal. = 104 lb. N/acre P 2 : 2,920 gal./acre lb./gal. = 102 lb. P 2 /acre O: 2,920 gal./acre lb./gal. = 73 lb. O/acre Manure testing The procedures above can be completed using either the manure nutrient estimates provided in Table 3, or your own data obtained from testing. Testing is better if done correctly. Manure nutrient content is highly variable so it s important to test properly to obtain better data than tabular estimates. Although proper manure sampling is difficult, it is the key to a good manure nutrient analysis. Manure has both solids and liquid, and one sample may not truly represent the nutritional value. Research data shows that pits become stratified, and solids are more concentrated near the bottom of the pit. Just sampling the top of a pit will not provide a good sample because nitrogen and phosphorus are related to the amount of solids in the sample. Lagoons have more liquid content than pits, and typically are quite large, so a sample near the edge of a lagoon may not be representative of the bulk of the liquid. It is very difficult to sample solids at the bottom of a pit or lagoon. If management and rations do not change, a manure analysis will not change much from year to year. Samples should be taken each year for several years until you are sure you know the nutrient value of the manure. Once the nutrient value is established, a sample every three to five years is sufficient. The objective of sampling is to get a representative sample of the manure that will be spread on the land. Taking a liquid sample pumped from storage Liquid manure should be agitated vigorously for several hours before sampling. Sample while the agitator is running and/or the spreader is being loaded. Samples should be taken at least three times during hauling near the beginning, halfway, and near the end. Samples can be analyzed either separately, or combined for analysis. If they are analyzed separately and consistent differences exist from year 11

12 to year or location to location in the pit, manure rates can be varied according to withdrawal location. If variation is random, use an average of the sample values. Taking a liquid sample from a loaded vacuum tank If you use a vacuum tank wagon and cannot agitate manure before sampling, probe the pit prior to hauling with a long, rigid plastic tube. Run a string or wire through it and attach to a rubber ball. Sample all the way to the bottom by inserting the tube, then pulling on the string to seat the ball and close the bottom of the tube. Take samples from at least three locations if access ports are available. If you cannot gain access to sample the pit from the outside, take samples from the wagon during loading or unloading. Always remember safety first: Never enter a pit to sample it! Taking a solid sample from an open lot Scrape across the surface of concrete or earthen lots with a shovel to get a representative sample. Do this in several locations, making sure you have scraped at least 25 feet of manure. Mix these samples with the shovel and take a subsample for analysis. Getting an accurate manure sample is difficult. By doing your best to sample carefully, and doing it each year, you will soon have an accurate account of the nutrient content of manure in your operation. Only with this information can you do the best job of nutrient management. For more information, see another ISU Extension publication, How to Sample Manure for Nutrient Analysis, Pm Soil testing Soil testing is a well established procedure. For soil test information see the following extension publications: Soil Testing to Optimize Nitrogen Management, Pm-1521; Taking a Good Soil Sample, Pm-287; Understanding Your Soil Test, Pm-429; Interpretation of Soil Test Results, Pm-1310; and Protecting Water Quality with Effective Soil Samples, Pm-1428c. You can list soil tests for various fields on Field Application Inventory, Worksheet A4, on page 20 of this publication. References Information and research in this publication are based on the following sources: Manure Production and Characteristics, ASAE Standard (1993) American Society of Agricultural Engineers, St. Joseph, Mich. On-Farm Measurement of Available Manure N. (1993) R. J. Fleming, J. E. McLellan, and S. H. Bradshaw. Paper # presented to the American Society of Agricultural Engineers, St. Joseph, Mich. The Fertilizer Value of Swine Manure from Different Management Systems and Methods of Application. (1993) R. Killorn and G. Brenneman. Proceedings of the 1993 Professional Swine Managers Conference. ASB 1993: PJH-307, Ames, Iowa. Animal Manure: A Source of Crop Nutrients, Pm (1985) R. Killorn. Iowa State University Extension, Ames, Iowa. Livestock Waste Facilities Handbook, MWPS-18. (1993) Midwest Plan Service, Ames, Iowa. Dairy Manure Management. (1989) Northeast Regional Agricultural Engineering Service. Proceedings of the 1989 Dairy Manure Management Symposium, Syracuse, N.Y. Agricultural Waste Management Field Handbook. (1992) Soil Conservation Service, Washington, D.C. Animal Manure as a Plant Nutrient Resource, ID-101. (1993) A. L. Sutton, D. D. Jones, B. C. Joern, and D. M. Huber. Purdue University Extension Service, Lafayette, Ind. 12

13 Table 1. Nutrient removal for Iowa crops pounds/unit Crop Units N P 2 O Corn-grain bu Corn silage ton Soybeans bu Alfalfa ton Oats bu Wheat bu Smooth brome ton Orchardgrass ton Tall fescue ton Switch grass ton Sorghum-sudan ton Vetch ton Red clover ton Perennial ryegrass ton Timothy ton Wheat straw ton Oat straw ton LYON SIOUX OSCEOLA O'BRIEN DICKINSON CLAY EMMET PALO ALTO KOSSUTH WINNEBAGO HANCOCK WORTH CERRO GORDO MITCHELL FLOYD HOWARD CHICKASAW WINNESHIEK ALLAMAKEE FAYETTE CLAYTON PLYMOUTH CHEROKEE BUENA VISTA POCAHONTAS HUMBOLDT WRIGHT FRANKLIN BUTLER BREMER WOODBURY MONONA 3. HARRISON IDA 2. WEBSTER BLACK HAWK BUCHANAN DELAWARE DUBUQUE SAC CALHOUN HAMILTON HARDIN GRUNDY CRAWFORD CARROLL GREENE BOONE STORY SHELBY AUDUBON GUTHRIE DALLAS POLK 3. TAMA BENTON LINN JONES JACKSON MARSHALL CLINTON CEDAR JASPER POWESHIEK IOWA JOHNSON SCOTT MUSCATINE POTTAWATTAMIE CASS ADAIR MADISON WARREN MARION MAHASKA KEOKUK WASHINGTON LOUISA MILLS MONTGOMERY ADAMS UNION CLARKE LUCAS MONROE WAPELLO JEFFERSON HENRY DES MOINES FREMONT PAGE TAYLOR RINGGOLD DECATUR WAYNE APPANOOSE DAVIS VAN BUREN LEE Table 1a. Fertilizer recommendations for corn harvested as grain pounds/unit Location Units N P 2 O Zone 1 bu Zone 2 bu Zone 3 bu

14 Table 2. Correction factor for nitrogen loss to air after manure application Method Correction Factor Direct injection 0.95 Broadcast and incorporate within 24 hours 0.95 Broadcast and incorporate after 24 hours 0.8 Broadcast, no incorporation 0.7 Source: Iowa State University, 1995 Table 3. Nutrients in animal manure Method A Method B N P 2 O N P 2 O Liquid, Pit lb./space/year gal./day lb./gallon Swine Nursery, 25 lb Grow-finish, 150 lb Gestation, 400 lb Sow and litter, lb Farrow-nursery Farrow-finish Dairy, confined Cows, 1,200 lb. or more Heifers, 900 lb Calves, 500 lb Veal calves, 250 lb Dairy herd Beef, confined Mature cows, 1,000 lb Finishing, 900 lb Feeder calves, 500 lb lb./space/year gal./day lb./gallon Swine Nursery, 25 lb Grow-finish, 150 lb Gestation, 400 lb Sow and litter, 450 lb Farrow-nursery Farrow-finish Dairy, confined Cows, 1,200 lb. or more Heifers, 900 lb Calves, 500 lb Veal calves, 250 lb Dairy herd Beef, confined Mature cows, 1,000 lb Finishing, 900 lb Feeder calves, 500 lb Open Lot Runoff lb./space/year gal./day lb./gallon Earthen lots (liquids) Beef, 400 sq. ft./hd Dairy, 1,000 sq. ft./hd Swine, 50 sq. ft./hd

15 Table 3. Continued Method A Method B N P 2 O N P 2 O Open Lot Runoff, continued lb./space/year gal./day lb./gallon Concrete lots (liquids) Beef, 50 sq. ft./hd Dairy, 100 sq. ft./hd Swine, 15 sq. ft./hd lb./space/year T/hd./day lb./ton Open lot (solids scraped) Beef, 400 sq. ft./hd. (dirt lot) Dairy, 100 sq. ft./hd. (paved) Swine, 15 sq. ft./hd. (paved) Solid Manure Swine, confined Nursery, 25 lb Grow-finish, 150 lb Gestation, 400 lb Sow & litter, 450 lb Farrow-nursery Farrow-finish Dairy, confined Cows, 1,200 lb. or more Heifers, 900 lb Calves, 500 lb Veal calves, 250 lb Dairy herd Beef, confined Mature cows, 1,000 lb Finishing, 900 lb Feeder calves, 500 lb lb./1,000 hd./yr T/1,000 hd./yr lb./ton Poultry Layer, caged, 4 lb Broiler, litter, 2 lb Turkeys, litter, 10 lb. 1, , Sow and litter figures are per farrowing crate. 2 Farrow-nursery figures are per sow in the breeding herd and include 1 farrowing sow, 5 gestation sows, and 9 nursery pigs spaces. 3 Farrow-finish figures are per sow in the breeding herd and include 1 farrowing sow, 5 gestation sows, 9 nursery pigs, and 36 finishing pigs spaces. 4 Per productive cow in the herd; includes lactating cow, 330 days; dry cow, 35 days; heifer, 222 day; and calf, 165 days. 5 Weights assumed: beef, 1,000 lb.; dairy, 1,200 lb.; and swine, 150 lb. Source: Iowa State University, This table of estimates has been adopted jointly by ISU Extension, the Iowa Natural Resources Conservation Service, and the Iowa Department of Natural Resources for manure nutrient planning purposes when manure test results are not available. 15

16 Table 4. Nitrogen credits from previous legume crops (A well established stand of forage legume is assumed. For a first-year stand, take no credit.) Year Forage Legume Credit Soybean Credit 1 100%* 1 lb./bu lb./acre _ 3 *ISU recommends no nitrogen the year after a good stand of legume forage is destroyed. Adequate nitrogen is already available from the legume. Table 5. Common conversion factors Multiply By To Get Cubic ft gallons Cubic ft pounds Gallons 8.34 pounds Gallons 231 cubic inches Parts per million (ppm) lb./1,000 gal. Percent 83.4 lb./1,000 gal. P (phosphorus) 2.27 P 2 K (potassium) 1.20 O Other conversions: 1 acre is 43,560 sq. ft. 1 inch over an acre is 27,152 gallons. 1 cubic ft./second is gal./minute. 1 cubic ft./second is 1 inch over an acre/hr. 1 pound per square inch (psi) is the same as 2.31 ft. of water head. Additional resources Other publications in the LIFE series, available from any Iowa State University Extension office, include: Environmental Guidelines for Confinement Swine Housing, Pm-1586 Choosing Fans for Livestock and Poultry Ventilation, Pm-1587 Health Hazards in Swine Confinement Housing: How Bad Is Bad? Pm-1588 Concrete Specifications for Agriculture, Pm-1589 Design and Management of Anaerobic Lagoons in Iowa for Animal Manure Storage and Treatment, Pm-1590 Vented Plumbing for Livestock Manure Handling Systems, Pm-1600 Selecting Manure Management Systems for Swine Operations, Pm-1602 Earthen Pits for Liquid Manure Storage, Pm-1603 Watering Systems for Grazing Livestock, Pm-1604 Guidelines for Minimizing Odors in Swine Operations, Pm-1605 File: Engineering 1-1 and Environmental Quality 4-1 C Prepared by Jeff Lorimor, Ruihong Zhang, and Stewart W. Melvin, Agricultural and Biosystems Engineering; and Randy Killorn, Department of Agronomy. The publication of this document has been funded by the Cooperative Extension Service, Iowa State University, and by the Iowa Department of Natural Resources through a grant from the U.S. Environmental Protection Agency under the Federal Nonpoint Source Management Program (Section 319 of the Clean Water Act). and justice for all The Iowa Cooperative Extension Service s programs and policies are consistent with pertinent federal and state laws and regulations on nondiscrimination. Many materials can be made available in alternative formats for ADA clients. Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Nolan R. Hartwig, interim director, Cooperative Extension Service, Iowa State University of Science and Technology, Ames, Iowa. 16 Tunnel Ventilation to Alleviate Animal Heat Stress, Pm-1606 Environmental Regulations for Livestock Manure Management, Pm-1607 Open or Enclosed Swine Finishing: Making the Decision, Pm-1608 You Can t Afford Not to Haul Manure, Pm-1609 Freestall Housing for Livestock, Pm-1610

17 Calculating Realistic Yield Goals Manure Nutrient Management Worksheet A1 Name Date Field No. Total Acres in the Field Calculate a realistic yield goal based on soil productivity for high-level management. Soil information is available in your county Soil Survey Report or from your county extension or Natural Resources Conservation Service (NRCS) office. Yield Acreage Soil Map Potential Yield Number Soil Type Name Acreage (bu./acre) Potential Total Acreage Yield Potential ( ) = = bu./acre (Individual Yield Goal) Total Acres ( ) 17

18 Fertilizer Recommendations Manure Nutrient Management Worksheet A2 Cooperator Date Soil Test Analysis ISU Nutrient Recommendation,* lb./acre Field Crop: Corn-Soybean Sequence Sample P K Soil Buffer Yield Previous Number Acres (ppm) (ppm) ph ph N P 2 O N P 2 O Goal Crop *See, Ag-65, General Fertilizer Recommendations for Iowa, or contact your county extension office. 18

19 Manure Inventory Manure Nutrient Management Worksheet A3 Manure Analysis* N P 2 O Pit Pit Date of Available Pit No. Type Location lb./1,000 gal. Application Gallons *If lab report uses parts per million (ppm), use Table 5 on page 16 to calculate lb./1,000 gal. 19

20 Field Application Inventory Manure Nutrient Management Worksheet A4 Total manure available: gallons Manure Applied Gallons N P 2 O Gallons Field No. Acres Applied lb./acre lb./acre lb./acre Remaining 20