567—65.17 (459,459B) Manure management plan content requirements. All manure management plans are to be submitted on forms or electronically as prescribed by the department. The plans shall include all of the information specified in Iowa Code section 459.312 as amended by 2009 Iowa Acts, Senate File 432, section 2, and as described below.
	   65.17(1) General.
	      a.    	 A confinement feeding operation that is required to submit a manure management plan to the department shall not apply manure in excess of the nitrogen use levels necessary to obtain optimum crop yields. A confinement feeding operation shall not apply manure in excess of the rates determined in conjunction with the phosphorus index. Information to complete the required calculations may be obtained from the tables in this chapter, actual testing samples or from other credible sources reviewed and approved by the department including, but not limited to, Iowa State University, the United States Department of Agriculture (USDA), a licensed professional engineer, or an individual certified as a crop consultant under the American Registry of Certified Professionals in Agronomy, Crops, and Soils (ARCPACS) program, the Certified Crop Advisors (CCA) program, or the Registry of Environmental and Agricultural Professionals (REAP) program.
	      b.    	 Manure management plans shall comply with the minimum manure control requirements of 567—65.2(459,459B) and the requirements for land application of manure in 567—65.3(459,459B).
	      c.    	 Manure management plans shall include all of the following:
	       (1)  	 The name of the owner and the name of the confinement feeding operation, including mailing address and telephone number.
	       (2)  	 The name of the contact person for the confinement feeding operation, including mailing address and telephone number.
	       (3)  	 The location of the confinement feeding operation identified by county, township, section, 1/4 section and, if available, the 911 address.
	       (4)  	 The animal unit capacity of the confinement feeding operation and, if applicable, the animal weight capacity.
	      d.    	 A person who submits a manure management plan shall include a phosphorus index as part of the manure management plan as required in subrule 65.17(17).
	      e.    	 For persons who anticipate the need to apply liquid manure on frozen or snow-covered ground, manure management plans shall include a description of land identified for the application of liquid manure due to an emergency if allowed pursuant to subrule 65.3(4). The phosphorus index for each potential emergency application field must be calculated, and application rates should be calculated appropriately. Locations of downgradient surface water drain tile intakes within all fields included in the plan should be identified by map or coordinates. Future applications of liquid manure must take the nutrients added during emergencies into consideration.
	   65.17(2) Manure management plans for sales of manure. Selling manure means the transfer of ownership of the manure for monetary or other valuable consideration. Selling manure does not include a transaction where the consideration is the value of the manure, or where an easement, lease or other agreement granting the right to use the land only for manure application is executed.
	      a.    	 Confinement feeding operations that will sell dry manure as a commercial fertilizer or soil conditioner regulated by the Iowa department of agriculture and land stewardship (IDALS) under Iowa Code chapter 200 or 200A shall submit a copy of their site-specific IDALS license or documentation that manure will be sold pursuant to Iowa Code chapter 200 or 200A, along with the department-approved manure management plan form for sales of dry manure. Operations completely covered by this paragraph are not required to meet other manure management plan requirements in this rule.
	      b.    	 A confinement feeding operation not fully covered by paragraph “a” above and that has an established practice of selling manure, or a confinement feeding operation that contains an animal species for which selling manure is a common practice, shall submit a manure management plan that includes the following:
	       (1)  	 An estimate of the number of acres required for manure application calculated by one of the following methods:
	      1. 	  Dividing the total phosphorus (as P2O5) available to be applied from the confinement feeding operation by the corn crop removal of phosphorus. The corn crop removal of phosphorus may be estimated by using the phosphorus removal rate in Table 4a at the end of this chapter and an estimate of the optimum crop yield for the property in the vicinity of the operation.
	      2. 	  Totaling the quantity of manure that can be applied to each available field based on application rates determined in conjunction with the phosphorus index in accordance with 65.17(17), and ensuring that the total quantity that can be applied is equal to or exceeds the manure annually generated at the operation.
	       (2)  	 The total nitrogen available to be applied from the confinement feeding operation.
	       (3)  	 The total phosphorus (as P2O5) available to be applied from the confinement feeding operation if the phosphorus index is required in accordance with paragraph 65.17(1)“d.”
	       (4)  	 An estimate of the annual animal production and manure volume or weight produced.
	       (5)  	 A manure sales form. If manure will be sold, the manure sales form shall include the following information:
	      1. 	  A place for the name and address of the buyer of the manure.
	      2. 	  A place for the quantity of manure purchased.
	      3. 	  The planned crop schedule and optimum crop yields.
	      4. 	  A place for the manure application methods and the timing of manure application.
	      5. 	  A place for the location of the field including the number of acres where the manure will be applied.
	      6. 	  A place for the manure application rate.
	      7. 	  A place for a phosphorus index of each field receiving manure, as defined in paragraph 65.17(17)“a,” including the factors used in the calculation. A copy of the NRCS phosphorus index detailed report shall satisfy the requirement to include the factors used in the calculation.
	       (6)  	 Statements of intent if the manure will be sold. The number of acres indicated in the statements of intent shall be sufficient according to the manure management plan to apply the manure from the confinement feeding operation. The permit holder for an existing confinement feeding operation with a construction permit may submit past records of manure sales instead of statements of intent. The statements of intent shall include the following information:
	      1. 	  The name and address of the person signing the statement.
	      2. 	  A statement indicating the intent of the person to purchase the confinement feeding operation’s manure.
	      3. 	  The location of the farm where the manure can be applied including the total number of acres available for manure application.
	      4. 	  The signature of the person who may purchase the confinement feeding operation’s manure.
	       (7)  	 The owner shall maintain in the owner’s records a current manure management plan and copies of all of the manure sales forms; the sales forms must be completed and signed by each buyer of the manure and the applicant, and the copies must be maintained in the owner’s records for three years after each sale. The owner shall maintain in the owner’s records copies of all of the manure sales forms for five years after each sale. An owner of a confinement feeding operation shall not be required to maintain current statements of intent as part of the manure management plan.
	   65.17(3) Manure management plan for nonsales of manure. Confinement feeding operations that will not sell all of their manure shall submit the following for that portion of the manure which will not be sold:
	      a.    	 Calculations to determine the land area required for manure application.
	      b.    	 The total nitrogen and total phosphorus (as P2O5) available to be applied from the confinement feeding operation.
	      c.    	 The planned crop schedule and optimum crop yields.
	      d.    	 Manure application methods and timing of the application.
	      e.    	 The location of manure application.
	      f.    	 An estimate of the annual animal production and manure volume or weight produced.
	      g.    	 Methods, structures or practices that will be used to reduce soil loss and prevent surface water pollution.
	      h.    	 Methods or practices that will be utilized to reduce odor if spray irrigation equipment is used to apply manure.
	      i.    	 A phosphorus index of each field in the manure management plan, as defined in paragraph 65.17(17)“a,” including the factors used in the calculation. A copy of the NRCS phosphorus index detailed report shall satisfy the requirement to include the factors used in the calculation.
	   65.17(4) Manure management plan calculations to determine land area required for manure application.
	      a.    	 The number of acres needed for manure application for each year of the crop schedule shall be determined as required in subrule 65.17(17).
	      b.    	 Operations evaluated with the master matrix pursuant to 65.10(3) that claim points for additional separation distance for the land application of manure must maintain those distances for each year of the manure management plan.
	      c.    	 Nitrogen in addition to that allowed in the manure management plan may be applied up to the amounts, indicated by soil or crop nitrogen test results, necessary to obtain the optimum crop yield.
	   65.17(5) Total nitrogen and total phosphorus (as P2O5) available from the confinement feeding operation.
	      a.    	 To determine the nitrogen available to be applied per year, the factors in Table 3, “Annual Pounds of Nitrogen Per Space of Capacity,” multiplied by the number of spaces shall be used. To determine total phosphorus (as P2O5) available to be applied per year, the factors in Table 3a, “Annual Pounds of Phosphorus Per Space of Capacity,” multiplied by the number of spaces shall be used. If the tables are not used to determine the nitrogen or phosphorus available to be applied, other credible sources for standard table values or the actual nitrogen and phosphorus content of the manure may be used. The actual nitrogen and phosphorus content shall be determined by a laboratory analysis along with measured volume or weight of manure from the manure storage structure or from a manure storage structure with design and management similar to the confinement feeding operation’s manure storage structure.
	      b.    	 If an actual sample is used to represent the nutrient content of manure, the sample shall be taken in accordance with Iowa State University extension publication PM 1558, “Management Practices: How to Sample Manure for Nutrient Analysis.” The department may require documentation of the manure sampling protocol or take a split sample to verify the nutrient content of the operation’s manure.
	   65.17(6) Optimum crop yield and crop schedule.
	      a.    	 To determine the optimum crop yield, the applicant may either exclude the lowest crop yield for the period of the crop schedule in the determination or allow for a crop yield increase of 10 percent. In using these methods, adjustment to update yield averages to current yield levels may be made if it can be shown that the available yield data is not representative of current yields. The optimum crop yield shall be determined using any of the following methods for the cropland where the manure is to be applied:
	       (1)  	 Soil survey interpretation record. The plan shall include a map showing soil map units for the fields where manure will be applied. The optimum crop yield for each field shall be determined by using the weighted average of the soil interpretation record yields for the soils on the cropland where the manure is to be applied. Soil interpretation records from the Natural Resources Conservation Service shall be used to determine yields based on soil map units.
	       (2)  	 USDA county crop yields. The plan shall use the county yield data from the USDA Iowa Agricultural Statistics Service.
	       (3)  	 Proven yield methods. Proven yield methods may only be used if a minimum of the most recent three years of yield data for the crop is used. These yields can be proven on a field-by-field or farm-by-farm basis. To be considered a farm-by-farm basis, the fields must be owned, rented or leased for crop production by the person required to keep records pursuant to subrule 65.17(13) or included in a manure application agreement in that person’s manure management plan. Crop disaster years may be excluded when there is a 30 percent or more reduction in yield for a particular field or farm from the average yield over the most recent five years. Excluded years shall be replaced by the most recent nondisaster years. Proven yield data used to determine application rates shall be maintained with the current manure management plan. Any of the following proven yield methods may be used:
	      1. 	  Proven yields for USDA Farm Service Agency. The plan shall use proven yield data or verified yield data for Farm Service Agency programs.
	      2. 	  Proven yields for multiperil crop insurance. Yields established for the purpose of purchasing multiperil crop insurance shall be used as proven yield data.
	      3. 	  Proven yields from other methods. The plan shall use the proven yield data and indicate the method used in determining the proven yield.
	      b.    	 Crop schedule. Crop schedules shall include the name and total acres of the planned crop on a field-by-field or farm-by-farm basis where manure application will be made. A map may be used to indicate crop schedules by field or farm. The planned crop schedule shall name the crop(s) planned to be grown for the length of the crop rotation beginning with the crop planned or actually grown during the year this plan is submitted or the first year manure will be applied. The confinement feeding operation owner shall not be penalized for exceeding the nitrogen or phosphorus application rate for an unplanned crop, if crop schedules are altered because of weather, farm program changes, market factor changes, or other unforeseeable circumstances. However, the penalty preclusion in the previous sentence does not apply to a confinement feeding operation owner subject to the NPDES permit program.
	   65.17(7) Manure application methods and timing.
	      a.    	 The manure management plan shall identify the methods that will be used to land-apply the confinement feeding operation’s manure. Methods to land-apply the manure may include, but are not limited to, surface-apply dry with no incorporation, surface-apply liquids with no incorporation, surface-apply liquid or dry with incorporation within 24 hours, surface-apply liquid or dry with incorporation after 24 hours, knifed in or soil injection of liquids, or irrigated liquids with no incorporation.
	      b.    	 The manure management plan shall identify the approximate time of year that land application of manure is planned. The time of year may be identified by season or month.
	   65.17(8) Location of manure application.
	      a.    	 The manure management plan shall identify each farm where the manure will be applied, the number of acres that will be available for the application of manure from the confinement feeding operation, and the basis under which the land is available.
	      b.    	 A copy of each written agreement executed with the owner of the land where manure will be applied shall be maintained with the current manure management plan. The written agreement shall indicate the number of acres on which manure from the confinement feeding operation may be applied and the length of the agreement. A written agreement is not required if the land is owned or rented for crop production by the owner of the confinement feeding operation. Owners of dry bedded confinement feeding operations required to have a manure management plan may execute a written agreement with the landowner or the person renting the land for crop production where the dry bedded manure will be applied.
	      c.    	 If a present location becomes unavailable for manure application, additional land for manure application shall be identified in the current manure management plan prior to the next manure application period.
	   65.17(9) Estimate of annual animal production and manure volume or weight produced. Volumes or weights of manure produced shall be estimated based on the numbers of animals, species, and type of manure storage used. The plan shall list the annually expected number of production animals by species. The volume of manure may be estimated based on the values in Table 5 at the end of this chapter and submitted as a part of the plan. If the plan does not use the table to determine the manure volume, other credible sources for standard table values or the actual manure volume from the confinement feeding operation may be used.
	   65.17(10) Methods to reduce soil loss and potential surface water pollution. The manure management plan shall indicate for each field in the plan the crop rotation, tillage practices and supporting practices used to calculate sheet and rill erosion for the phosphorus index. A copy of an NRCS RUSLE2 erosion calculation record shall satisfy this requirement. The plan shall also identify the highly erodible cropland where manure will be applied.
	   65.17(11) Spray irrigation. Requirements contained in subrules 65.3(2) and 65.3(3) regarding the use of spray irrigation equipment to apply manure shall be followed. A plan which has identified spray irrigation equipment as the method of manure application shall identify any additional methods or practices to reduce potential odor, if any other methods or practices will be utilized.
	   65.17(12) Current manure management plan. The owner of a confinement feeding operation who is required to submit a manure management plan shall maintain a current manure management plan at the site of the confinement feeding operation or at a residence or office of the owner or operator of the operation within 30 miles of the site. The plan shall include completed manure sales forms for a confinement feeding operation from which manure is sold. If manure management practices change, a person required to submit a manure management plan shall make appropriate changes consistent with this rule. If values other than the standard table values are used for manure management plan calculations, the source of the values used shall be identified.
	   65.17(13) Record keeping. Records shall be maintained by the owner of a confinement feeding operation who is required to submit a manure management plan. This recorded information shall be maintained for three years following the year of application or for the length of the crop rotation, whichever is greater. Records shall be maintained for five years following the year of application or for the length of the crop rotation, whichever is greater. Records shall be maintained at the site of the confinement feeding operation or at a residence or office of the owner or operator of the facility within 30 miles of the site. Records to demonstrate compliance with the manure management plan shall include the following:
	      a.    	 Factors used to calculate the manure application rate:
	       (1)  	 Optimum yield for the planned crop.
	       (2)  	 Types of nitrogen credits and amounts.
	       (3)  	 Remaining crop nitrogen needed.
	       (4)  	 Nitrogen content and first-year nitrogen availability of the manure.
	       (5)  	 Phosphorus content of the manure if required in accordance with 65.17(3)“i.” If an actual sample is used, documentation shall be provided.
	      b.    	 If phosphorus-based application rates are used, the following shall be included:
	       (1)  	 Crop rotation.
	       (2)  	 Phosphorus removed by crop harvest of that crop rotation.
	      c.    	 Maximum allowable manure application rate.
	      d.    	 Actual manure application information:
	       (1)  	 Methods of application when manure from the confinement feeding operation was applied.
	       (2)  	 Date(s) when the manure from the confinement feeding operation was applied.
	       (3)  	 Location of the field where the manure from the confinement feeding operation was applied, including the number of acres.
	       (4)  	 The manure application rate.
	      e.    	 The date(s) and application rate(s) of commercial nitrogen and phosphorus on fields that received manure. However, if the date and application rate information is for fields which are not owned for crop production or which are not rented or leased for crop production by the person required to keep records pursuant to this subrule, an enforcement action for noncompliance with a manure management plan or the requirements of this subrule shall not be pursued against the person required to keep records pursuant to this subrule or against any other person who relied on the date and application rate in records required to be kept pursuant to this subrule, unless that person knew or should have known that nitrogen or phosphorus would be applied in excess of maximum levels set forth in paragraph 65.17(1)“a.” If manure is applied to fields not owned, rented or leased for crop production by the person required to keep records pursuant to this subrule, that person shall obtain from the person who owns, rents or leases those fields a statement specifying the planned commercial nitrogen and phosphorus fertilizer rates to be applied to each field receiving the manure.
	      f.    	 A copy of the current soil test lab results for each field in the manure management plan.
	      g.    	 For sales of manure under 65.17(2)“b,” record-keeping requirements of 65.17(2)“b”(7) shall be followed.
	   65.17(14) Record inspection. The department may inspect a confinement feeding operation at any time during normal working hours and may inspect the manure management plan and any records required to be maintained. As required in Iowa Code section 459.312(12), Iowa Code chapter 22 shall not apply to the records which shall be kept confidential by the department and its agents and employees. The contents of the records are not subject to disclosure except as follows:
	      a.    	 Upon waiver by the owner of the confinement feeding operation.
	      b.    	 In an action or administrative proceeding commenced under this chapter. Any hearing related to the action or proceeding shall be closed.
	      c.    	 When required by subpoena or court order.
	   65.17(15) Enforcement action. An owner required to provide the department a manure management plan pursuant to this rule who fails to provide the department a plan or who is found in violation of the terms and conditions of the plan shall not be subject to an enforcement action other than assessment of a civil penalty pursuant to Iowa Code section 455B.191.
	   65.17(16) Soil sampling requirements for fields where the phosphorus index must be used. Soil samples shall be obtained from each field in the manure management plan at least once every four years. Each soil sample shall be analyzed for phosphorus and pH. The soil sampling protocol shall meet all of the following requirements:
	      a.    	 Acceptable soil sampling strategies include, but are not limited to, grid sampling, management zone sampling, and soil type sampling. Procedural details can be taken from Iowa State University extension publication PM 287, “Take a Good Soil Sample to Help Make Good Decisions,” NCR-13 Report 348, “Soil Sampling for Variable-Rate Fertilizer and Lime Application,” or other credible soil sampling publications.
	      b.    	 Each soil sample must be a composite of at least ten soil cores from the sampling area, with each core containing soil from the top six inches of the soil profile.
	      c.    	 Each soil sample shall represent no more than ten acres. For fields less than or equal to 15 acres, only one soil sample is necessary.
	      d.    	 Soil analysis must be performed by a lab enrolled in the IDALS soil testing certification program.
	      e.    	 The soil phosphorus test method must be an appropriate method for use with the phosphorus index. If soil pH is greater than or equal to 7.4, soil phosphorus data from the Bray-1 extraction method is not acceptable for use with the phosphorus index.
	   65.17(17) Use of the phosphorus index. Manure application rates shall be determined in conjunction with the use of the Iowa Phosphorus Index as specified by the USDA Natural Resources Conservation Service (NRCS) Iowa Technical Note No.	25.
	      a.    	 The phosphorus index shall be used on each individual field in the manure management plan. The fields must be contiguous and shall not be divided by a public thoroughfare or a water source as each is defined in this chapter. Factors to be considered when a field is defined may include, but are not limited to, cropping system, erosion rate, soil phosphorus concentration, nutrient application history, and the presence of site-specific soil conservation practices.
	      b.    	 When sheet and rill erosion is calculated for the phosphorus index, the soil type used for the calculation shall be the most erosive soil map unit that is at least 10 percent of the total field area. Effective September 15, 2010, in all original and complete manure management plans submitted to the department for approval, the dominant critical soil map unit consistent with NRCS conservation planning guidelines shall be used to calculate sheet and rill erosion for the phosphorus index. (See NRCS Technical Note No.	29).
	      c.    	 The average (arithmetic mean) soil phosphorus concentration of a field shall be used in the phosphorus index.
	      d.    	 Soil phosphorus concentration data is considered valid for use in the phosphorus index if the data is four years old or less and meets the requirements of 65.17(16).
	      e.    	 For an original manure management plan, previous soil sampling data that does not meet the requirements of subrule 65.17(16) may be used in the phosphorus index if the data is four years old or less. In the case of fields for which soil sampling data is used that does not meet the requirements of subrule 65.17(16), the fields must be soil-sampled according to the requirements of subrule 65.17(16) no more than one year after the original manure management plan is approved.
	      f.    	 The following are the manure application rate requirements for fields that are assigned the phosphorus index site vulnerability ratings below as determined by the NRCS Iowa Technical Note No.	25 to the NRCS 590 standard rounded to the nearest one-hundredth:
	       (1)  	 Very Low (0-1).
	      1. 	  Manure shall not be applied in excess of a nitrogen-based rate in accordance with 65.17(18).
	      2. 	  If, pursuant to 65.17(19), manure is applied at phosphorus-based rates within soil sampling periods on fields in the Very Low risk category, each soil sample may represent up to 20 acres for the next required soil sampling.
	       (2)  	 Low (>1-2).
	      1. 	  Manure shall not be applied in excess of a nitrogen-based rate in accordance with 65.17(18).
	      2. 	  If, pursuant to 65.17(19), manure is applied at phosphorus-based rates within soil sampling periods on fields in the Low risk category, each soil sample may represent up to 20 acres for the next required soil sampling.
	       (3)  	 Medium (>2-5).
	      1. 	  Manure may be applied at a nitrogen-based rate in accordance with 65.17(18) if current or planned soil conservation and phosphorus management practices predict the rating of the field to be not greater than 5 for the next determination of the phosphorus index as required by 65.17(17)“h”(3).
	      2. 	  Manure shall not be applied in excess of two times the phosphorus removed with crop harvest over the period of the crop rotation.
	      3. 	  If, pursuant to 65.17(19), manure is applied at phosphorus-based rates within soil sampling periods on fields in the Medium risk category, each soil sample may represent up to 20 acres for the next required soil sampling.
	       (4)  	 High (>5-15). Manure shall not be applied on a field with a rating greater than 5 and less than or equal to 15 until practices are adopted which reduce the phosphorus index to at least the Medium risk category.
	       (5)  	 Very High (>15). Manure shall not be applied on a field with a rating greater than 15.
	      g.    	 Additional commercial fertilizer may be applied as follows on fields receiving manure:
	       (1)  	 Phosphorus fertilizer may be applied in addition to phosphorus provided by the manure up to amounts recommended by soil tests and Iowa State University extension publication PM 1688, “General Guide for Crop Nutrient Recommendations in Iowa.”
	       (2)  	 Nitrogen fertilizer may be applied in addition to nitrogen provided by the manure to meet the remaining nitrogen need of the crop as calculated in the current manure management plan. Additional nitrogen fertilizer may be applied up to the amounts indicated by soil test nitrogen results or crop nitrogen test results as necessary to obtain the optimum crop yield.
	      h.    	 Updating the phosphorus index.
	       (1)  	 When any inputs to the phosphorus index change, an operation shall recalculate the phosphorus index and adjust the application rates if necessary.
	       (2)  	 If additional land becomes available for manure application, the phosphorus index shall be calculated to determine the manure application rate before manure is applied.
	       (3)  	 An operation must submit a complete manure management plan using a new phosphorus index, including soil sampling as required in subrule 65.17(16), for each field in the manure management plan a minimum of once every four years.
	   65.17(18) Requirements for application of a nitrogen-based manure rate to a field.
	      a.    	 Nitrogen-based application rates shall be based on the total nitrogen content of the manure unless the calculations are submitted to show that nitrogen crop usage rates based on plant-available nitrogen have not been exceeded for the crop schedule submitted.
	      b.    	 The correction factor for nitrogen losses shall be determined for the method of application by the following or from other credible sources for nitrogen volatilization correction factors.
Knifed in or soil injection of liquids	0.98	
Surface-apply liquid or dry with incorporation within 24 hours	0.95	
Surface-apply liquid or dry with incorporation after 24 hours	0.80	
Surface-apply liquids with no incorporation	0.75	
Surface-apply dry with no incorporation	0.70	
Irrigated liquids with no incorporation	0.60	
	      c.    	 Nitrogen-based application rates shall be based on the optimum crop yields as determined in 65.17(6) and crop nitrogen usage rate factor values in Table 4 at the end of this chapter or other credible sources. However, subject to the prohibition in 65.17(20), liquid manure applied to land that is currently planted to soybeans or to land where the current crop has been harvested and that will be planted to soybeans the next crop season shall not exceed 100 pounds of available nitrogen per acre. Further, the 100 pounds per acre application limitation in the previous sentence does not apply on or after June 1 of each year; in that event 65.17(6) and Table 4 would apply as provided in the first sentence of this paragraph.
	      d.    	 A nitrogen-based manure rate shall account for legume production in the year prior to growing corn or other grass crops and shall account for any planned commercial fertilizer application.
	   65.17(19) Requirements for application of a phosphorus-based manure rate to a field.
	      a.    	 Phosphorus removal by harvest for each crop in the crop schedule shall be determined using the optimum crop yield as determined in 65.17(6) and phosphorus removal rates of the harvested crop from Table 4a at the end of this chapter or other credible sources. Phosphorus crop removal shall be determined by multiplying optimum crop yield by the phosphorus removal rate of the harvested crop.
	      b.    	 Phosphorus removal by the crop schedule shall be determined by summing the phosphorus crop removal values determined in 65.17(19)“a” for each crop in the crop schedule.
	      c.    	 The phosphorus applied over the duration of the crop schedule shall be less than or equal to the phosphorus removed with harvest during that crop schedule as calculated in 65.17(19)“b” unless additional phosphorus is recommended by soil tests and Iowa State University extension publication PM 1688, “General Guide for Crop Nutrient Recommendations in Iowa.”
	      d.    	 Additional requirements for phosphorus-based rates.
	       (1)  	 No single manure application shall exceed the nitrogen-based rate of the planned crop receiving the particular manure application.
	       (2)  	 No single manure application shall exceed the rate that applies to the expected amount of phosphorus removed with harvest by the next four anticipated crops in the crop schedule.
	      e.    	 If the actual crop schedule differs from the planned crop schedule, then any surplus or deficit of phosphorus shall be accounted for in the subsequent manure application.
	      f.    	 Phosphorus in manure should be considered 100 percent available unless soil phosphorus concentrations are below optimum levels for crop production. If soil phosphorus concentrations are below optimum levels for crop production phosphorus availability, values suggested in Iowa State University extension publication PMR 1003, “Using Manure Nutrients for Crop Production” or other credible sources shall be used.
	   65.17(20) Liquid manure on land planted to soybeans. Effective May 14, 2013, the owner of a confinement feeding operation that is required to submit a manure management plan shall not apply liquid manure to land that is currently planted to soybeans or to land where the current crop has been harvested and that will be planted to soybeans the next crop season. Not later than November 14, 2012, the commission shall review the available scientific evidence and determine whether any further or alternative action is necessary. The prohibition on applying liquid manure shall not become effective unless the commission publishes a notice in the Iowa Administrative Bulletin confirming that it has reviewed the available scientific evidence and that the prohibition shall take effect on May 14, 2013.
[ARC 8120B, IAB 9/9/09, effective 10/14/09; ARC 8998B, IAB 8/11/10, effective 9/15/10]