Category: Manure Nutrients

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Liquid Manure Sampling Procedures

When testing manure, your nutrient management plan is only as good as your ability to obtain a representative sample. In liquid manure storage, agitation is critical to spreading uniform manure and to getting a representative sample. Agitating for 2-4 hours is the minimum. Depending on the type of storage longer agitation times may be required. The agitation for sampling should be similar to the agitation done when the storage is emptied. For this reason the most practical time to sample is when the storage is being emptied for field application.

If the storage is not adequately agitated there will likely be stratification. The figure below illustrates how manure analysis can vary within a storage without adequate agitation. In this example manure in the last 15 loads spread from this storage has 2 to 3 times more phosphorus than in the first 45 loads spread. If the storage is known to be stratified, separate samples should be taken as the manure consistency changes during emptying.

diagram

cc2.5 Les Lanyon

Sampling As Manure Storage Is Emptied

Agitate the storage thoroughly before sampling. Use a bucket to collect at least 5 samples during the process of loading several spreader loads and save them in the bucket. When all of the samples are collected, thoroughly mix the samples and take a subsample from this to fill the lab manure test container. When filling containers with liquid manure never fill the container more than ¾ full. If samples are collected over a several hour period, the bucket with manure sample should be stored on ice to limit ammonia losses.

Sample Manure When Pumping From Storage. Photo courtesy of Ontario Ministry of Agriculture, Food and Rural Affairs. Photo Source: http://www.thecattlesite.com/articles/1307/sampling-liquid-manure-for-analysis


Sampling From the Manure Storage

Picture Source: http://www.extension.iastate.edu/pages/communications/epc/Winter02/manure.html

Sampling a storage directly is much more difficult and likely to result in more variable results than sampling as the manure is loaded into the spreader. Agitate the storage thoroughly before sampling. Use a small bucket or tube to collect at least 5 samples from different locations in the storage. Combine these samples in a bucket and thoroughly mix the samples and take a subsample from this to fill the lab manure test container. When filling containers with liquid manure never fill the container more than ¾ full.

Liquid Manure Sampling Video

This video from the Iowa Learning Farms Project shows two sampling techniques for liquid manure storage prior to agitation. As indicated above, samples of agitated liquid manure should be obtained when possible, but in cases where the information from the lab analysis (which can take several days) is needed before manure can be applied to crop land.

Part 2: Sampling Liquid Manure

Sampling Manure During Application

This method is good for irrigated manure. Place buckets around the field to catch manure from the spreader or irrigation equipment. Place these to collect manure from more than one spreader load. Combine and mix the manure collected from different locations, and take a subsample from this to fill the lab manure test container. This method may give you “crop available ammonia nitrogen” as any ammonia losses may have already occurred prior to reaching bucket. What reaches the bucket is likely to soak into the soil and be available to the crop.

Related Web Pages

Overview of Manure Testing

Page Authors: Douglas Beegle, Penn State University and John Peters, University of Wisconsin

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Total and Available Nutrients In Manure

Standard manure analysis procedures determine the total N, P, K, and other nutrient content in the manure. Some special analyses such as ammonium-N and water extractable P determine the concentration of specific forms of nutrients in manure. These special tests should be clearly labeled as such on the manure test report.

Availability of Manure Nutrients

However, the total amount of nutrients in manure may not all be available or may become available only over a period of time. States and regions have developed “availability factors” that are applied to the manure analysis results to estimate the availability of the manure nutrients to the immediate crop and to future crops. This availability is usually a fertilizer equivalent availability. This is important because soil test recommendations are made on the basis of applying fertilizer nutrients. This means that by using the availability factors you can substitute “available” manure nutrients for recommended fertilizer nutrients on a 1 to 1 basis.

Because availability is influenced by local climate and soil conditions and may be customized for local management practices, it is very important that availability factors developed for the area where the manure is applied are used. Most state land grant universities have published availability factors for manure nutrients. Check with your local cooperative extension service for the appropriate factors for your area or State Specific Manure Nutrient Management Information

diagram

cc2.5 Doug Beegle

Some labs will apply availability factors to the analysis results and show “Available Nutrients” on the manure test report in addition to the analyzed total nutrient concentrations. It is very important to check to see if these factors are appropriate for the area where the manure will be spread. Some labs serve a large geographic area and while their analytical results may be excellent, availability factors may not be appropriate for all areas that they cover. It is always a good practice to check with the local cooperative extension service to make sure the availability factors a lab is using are appropriate for that area. Even if the availability factors use by a lab are not appropriate, the analytical results for total nutrients can be used with local availability factors to get valid estimates of available nutrients.

Related Web Pages

Page Authors: Douglas Beegle, Pennsylvania State University and John Peters, University of Wisconsin

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Manure Test Results

Livestock and Poultry Environmental Learning Center:

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Manure Testing

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Which Tests Do I Need?

Most labs have a basic manure test with the option to add other tests for an additional fee. Make sure the tests or the package you select includes at least the following analyses for nutrient management planning:

  • % Moisture or % Solids,
  • Total N,
  • Ammonium-N (NH4-N),
  • Total P, and
  • Total K.

Other analysis that may be useful in some situations include: pH, Carbon:Nitrogen ratio (C:N), water extractable P, calcium carbonate equivalent, secondary nutrients (Ca, Mg, & S), and micronutrients.

Manure Test Results Can Be Reported Differently

Dry Matter or As-Sampled?

Manure analysis results can be reported in several different ways. It is important that you clearly understand how your results are reported. The first consideration is whether the results are reported on an as-sampled basis or on a dry-weight (dwt) basis. Most agricultural labs that do manure testing report the results on an as-sampled basis. If the results are reported on a dry-weight basis the analyses will have to be converted back to as-sampled to be practical for use in a nutrient management plan. Example calculations for converting analyses results from % dry-weight (% dwt) or ppm to “as-is” results (lb/ton or lb/1000 gal are at Common Manure Test Results Conversions.

Reporting Units

Another, issue with reporting manure test results in the units used. When results are reported on an as-sampled basis the most common units used are lb/ton for more solid samples and lb/1000 gal for liquid samples. However, carefully check the units on the manure test because other units are sometimes used. For example, some labs report liquid manure test results in lb/100 gal. Lb/acre-inch may be preferred by producers using irrigation systems. Also, particularly when results are reported on a dry-weight basis, percent (%) and parts per million (ppm) may be used. Example calculations for converting analyses results from % dry-weight (% dwt) or ppm to “as-is” results (lb/ton or lb/1000 gal) are at Common Manure Test Results Conversions.

Elemental or Oxide?

Results may be reported as the elemental form for example P and K, or in the oxide form as P2O5 and K2O. Most agricultural labs that do manure testing report the results in the oxide form since this is how fertilizer recommendations are made. If the results are reported in the elemental form, they will have to be converted to the oxide form for use in nutrient management planning. Example calculations for converting analysis results from elemental to oxide are at Common Manure Test Results Conversions.

Solid or Liquid?

Finally, there may be situations where the results are reported for a liquid ie. lb/1000 gal but the manure is spread on a ton basis ie. tons/acre. The density of the manure can be used to convert from liquid to solid analysis. Example calculations for converting analysis results from liquid to solid or solid to liquid at Common Manure Test Results Conversions.

For more information see Reporting Manure Analysis Results taken from the publication “Recommended Methods of Manure Analysis”.

Related Web Pages

Page Authors: Douglas Beegle, Pennsylvania State University and John Peters, University of Wisconsin

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Calibration of Manure Application Equipment

In order to beneficially apply nutrients contained in animal manure to crops and to protect the environment, it is necessary to calibrate land application equipment. In addition, many states require calibration of manure application equipment on a regular basis via regulations and permitting requirements. Records of calibration results may be a requirement of your permit.

Calibration Procedures Will Vary

Depending on the type of manure or the type of equipment being used to apply manure, there are different calibration procedures to follow. See the following pages for information on specific procedures.

Calibrating Manure Application Equipment Makes Economic and Environmental Sense

Proper calibration of manure application equipment is necessary to insure that field application rates are consistent with nutrient management plans. As nutrient plans have attempted to more accurately balance nutrient supplied by manure and fertilizer and crop requirements, calibration is also critical to avoid under applying nutrients and reducing yields.

Properly calibrated and operated equipment will help eliminate:

  • ponding or runoff of manure into waterways
  • leaching of nutrients and pathogens into shallow groundwater
  • accumulation of nutrients or metals in the soil
  • reduced crop yields from insufficient nutrients

Manure is a valuable resource that should be applied in an ecological and environmentally sensitive manner. As the value of the nutrients in manure increases due to increases in commercial fertilizer cost, calibration of manure application equipment becomes even more important.

Other good reasons to calibrate are to monitor equipment performance changes over time (wear and tear) so that timely maintenance is performed, and to troubleshoot any equipment operational problems. Calibration should be done annually even if regulatory requirements require less frequent calibration. Also, it is a critical to re-calibrate when the consistency or liquid content of the waste changes considerably as changes in material characteristics can change the performance of the application equipment.

Tractor

cc2.5 Garry Grabow

Important Considerations for Calibrating Manure Application Equipment

Calibration of equipment used to land apply manure considers two aspects:

  1. the amount of manure (nutrients) applied, and
  2. how uniformly the manure is applied over the field.

Some nutrient management plans may be based upon nitrogen limited application, while other will be based on phosphorus limited plans; regardless it is critical to know the amount and uniformity of applied manure. Depending upon the equipment used, calibration will involve field measurement of flow or unloading rates, equipment speed and settings, operating pressure, application width, and application overlap.

Manure application equipment can be categorized into three types:

Application equipment varies depending upon the type of manure, e.g. lagoon liquid, poultry litter, or fresh manure. Calibration of each type of equipment will vary in which measurements are required and how application rate and uniformity are quantified and assessed.

Recommended Educational Resources

Author: Garry Grabow, North Carolina State University
Reviewers:Marsha Mathews, University of California-Davis, Rick Koelsch, University of Nebraska, and Doug Beegle, Pennsylvania State University

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Calibrating Solid Manure Application Equipment

Why should you calibrate solid manure spreaders? Simple, because you should know how much manure was applied to your fields. Combined with a manure testing program, you can calculate the amount of manure nutrients that were applied. This can save money on commercial fertilizer purchases AND improve water quality. Related: Calibrating liquid manure spreaders and irrigation equipment.

What Can Cause Manure Application Rates to Change?

Solid spreaders can have poor uniformity if operated improperly, so proper operation and calibration of these types of systems are critical. The system needs to be recalibrated if any of the following are changed:

  • Tractor speed
  • Gate opening (and spinner settings for spinner spreaders)
  • RPM
  • Width of spread
  • Manure characteristics
  • Wind
  • Slope
  • Operator (experience and consistency)

It is helpful to know the capacity and setting ranges available with solid spreaders. Solid spreader capacity is noted in the manufacturer’s specifications and may be listed in tons, cubic feet or cubic yards. Capacity is normally listed in struck level (flush with top of unit) height but may also be rated in “heaped” load.

This video shows how tarps that are laid out and manure spread on them can be collected and weighed. it was produced with smaller farms in mind, but the concepts and procedures apply to equipment of all sizes. Produced by: Rutgers University Cooperative Extension.

What Are the Steps in Calibrating Solid Manure Spreaders?

This video shows a process for weighing the  manure spreader and measuring the area over which manure was applied. The worksheet referenced is Know How Much You Haul Produced by the University of Wisconsin Cooperative Extension.

Tarp Method

Normally calibration of solid spreaders will involve collecting the discharged manure in a tarp to determine application rate and collecting manure in a series of pans laid across the travel path to assess spread pattern, uniformity and to adjust pass width. Click on the following link for an illustration of the procedure for this method. (Source: Rick Koeslch, University of Nebraska). Manure density is normally determined to allow conversion from volume to weight (e.g. tons) applied.

Weighing the Spreader

If manure spreader capacity can be weighed, then the only field measurements required are distance traveled to empty the spreader and width of spread pattern (or distance you move laterally with each pass through the field). From that information, a fairly simple estimate of application rate can be made.

Moisture content of manure has a large impact on manure density and actual spreader capacity. When calibrating, it is important to correctly interpret the nutrient analysis reports provided by the analytical lab. Some analyses report manure nutrient concentration at the moisture content submitted. Other analysis reports may give the nutrient analysis at a moisture content that is different than either the sampled material or the material to be applied. For accurate calibration, match moisture content of manure samples with moisture content of the manure being spread.

Adjustments to achieve the proper application rate and uniformity include adjusting travel speed, gate openings and hammer clearance, and adjusting spinners for spinner spreaders. Narrowing the effective width (pass distance) generally increases application uniformity but also increases application rate.



Types of Solid Manure Application Equipment

Manure is generally handled as a solid at a solids content of 20% or more. Solid manure spreaders come in various types. Spinner spreaders use spinning disks at the rear of the unit to propel the manure, box spreaders use a paddle and/or auger to discharge manure from the rear of the unit, and side discharge spreaders typically use augers and flailing hammers to “throw” the manure out the side of the unit. Spinner spreaders are used to apply poultry litter and are widely used as commercial fertilizer applicators. Side discharge units can handle materials with a wide range of moisture contents. Rear discharge spreaders are commonly used with scraped manure solids from open lots and manures with significant bedding.

Recommended Educational Resources

Author: Garry Grabow, North Carolina State University
Reviewers: Marsha Mathews, University of California-Davis, Rick Koelsch, University of Nebraska, Doug Beegle, Pennsylvania State University

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Management of Land-Applied Manure Phosphorus

Land applied manure is an excellent source of phosphorus (P) for meeting crop growth needs but needs to be managed to minimize P delivery to surface waters. See Phosphorus in Aquatic Systems. Phosphorus movement from agricultural land to surface water is determined by the interaction of:

  • soil characteristics and management practices with
  • mechanisms of P transport, such as runoff and erosion.

Management Practices

Several soil and P management options may be considered to reduce P delivery to surface waters:

  • Maintain soil test P levels near the optimum for crop growth. Risk of loss is greatest when soil test P levels are excessively high. Soil test P is often increased with repeated manure application.
  • Practice conservation tillage or no-tillage to minimize erosion, and therefore, the potential of P delivery.
  • Apply manure when there is a relatively low risk of runoff during the weeks after application. Avoid application on frozen and snow-covered soil as a runoff event may occur with snow-melt.
  • Incorporation of manure may reduce potential for P runoff but may increase the potential loss to erosion. For more see Agricultural Phosphorus Management.

Injection of slurry manure can reduce risk of P runoff if ground cover is maintained to prevent erosion. CC 2.5 Charles Fulhage or Joe Harner

Phosphorus Delivery

Phosphorus transport to surface waters is largely determined by erosion and runoff, distance to concentrated water flow or to surface waters, and by management practices that trap sediments and nutrients carried by runoff and erosion before these enter surface waters.

  • The potential for erosion and runoff are determined by the amount of precipitation and intensity of rainfall events, slope steepness and length, soil type, crops grown, and crop and conservation management practices. Some of the erosion P is readily available to aquatic vegetation and some eventually becomes available.
  • Conservation practices, such as terraces and farm dams, that reduce runoff, erosion and sediment delivery generally reduce P delivery to surface waters.
  • Vegetative filter strips on hillsides and well-placed vegetative buffer zones along streams can be effective in filtering out sediments and some nutrients before they enter surface waters.
  • Most of the P that enters surface waters may come from only 10-20% of the area of a watershed, and especially from areas that are very near to concentrated water flow. Alternative management practices may be needed for these sensitive areas.

Potential for P loss from a field, or part of a field, to surface waters is often assessed using a P index that considers field and management factors as well as transport factors.

Educational Resources on Manure Phosphorus Management

  1. Basic Concepts of Soil and Water Phosphorus
  2. Field and Management Factors
  3. Transport Factors
  4. Assessment of the Risk of Agricultural P Delivery

Extension Resources on Manure Phosphorus Management

Scientific Resources on Manure Phosphorus Management

Page Manager: Charles S. Wortmann, University of Nebraska-Lincoln

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Calibrating Irrigation Equipment for Manure Application

Irrigation equipment can be used to land apply manure with a solids content of up to 2-3 percent depending upon the type of equipment used and nozzle size. The types of systems typically used are stationary (also called solid-set), traveling guns, and center pivots. Irrigation equipment is typically used to land apply liquid manure from anaerobic lagoons and runoff holding ponds. If applied manure is undiluted, calibration requirements may differ slightly from those systems using diluted manure. If manure is diluted with freshwater, nutrient concentration must be adjusted by the dilution ratio when calculating nutrient rates. Always check with your state regulatory agency for calibration and reporting requirements.

Related: Calibrating solid manure spreaders and irrigation equipment.

As with the other types of equipment used for land applying manure, calibration consists of verifying application rates and application uniformity. Application rate and uniformity is measured by collecting applied manure in rain gages that are placed in a line for traveling gun and center pivot systems or in a grid for stationary systems. Systems using undiluted manure may require measurement and reporting of application rate from the gun or nozzle and not what is collected in a rain gage if plant available nutrients are calculated to include evaporative losses and volatilization.

If measuring application rate from the gun, a flow meter or pressure measurement at the nozzle and a manufacturer’s performance chart for the gun/sprinkler and nozzle will be required. Collected depths are used to calculate commonly-used measures of irrigation equipment uniformity such as the Christiansen uniformity coefficient (CU or Uc) or distribution uniformity (DU). Details of how to setup uniformity evaluations and calculate measures of uniformity and application rates are given in the links in a paragraph at the end of this document.

Uniformity of irrigation-type equipment can be affected by:

  • Operating pressure
  • Nozzle condition
  • Pump impeller condition
  • Wind
Center pivot irrigation

It is important that these types of systems be operated as designed. Normally this means that pressure and flow rate should be field-verified in the calibration procedure and compared to the design values or the ranges recommended by the manufacturer. Pressure should always be measured at the nozzle, not at the pump or other location. Pressure can be measured either with a pressure gauge mounted on the sprinkler riser or mounted on the gun body (for big guns) or measured using a pitot tube placed directly in the nozzle stream. For center pivots with drop nozzles, pre-set pressure regulators are normally located on the drop tubing, so nozzle pressure is known. In addition to pressure and flow rate measurement, the wetted diameter of the sprinkler or gun (for solid set and traveling gun systems respectively) should be measured.

It is generally recommended that flow rates be within 10 percent of the design rate, and that wetted diameter be within 15 percent of that specified in the manufacturer’s chart at the measured nozzle pressure. Flow rates may be obtained either by using a flow meter or by using values obtained from the manufacturer’s chart at the measured pressure. For animal waste systems, flow meters are normally temporarily placed in the main irrigation line either in-line or temporarily strapped on depending upon the type of flow meter used.

Adjustments to achieve the proper application rate and uniformity include adjusting operating pressure, travel speed (for traveling gun or pivot systems), replacing worn nozzles, and operating systems when there is little wind. Changes in equipment (e.g. nozzle size) should not be done without consultation with an irrigation specialist.

Recommended Educational Resources

Author: Garry Grabow, North Carolina State University Reviewers: Marsha Mathews, University of California-Davis, Rick Koelsch, University of Nebraska

Photo: CC 2.5 Charles Fulhage or Joe Harner

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Calibrating Liquid Manure Application Equipment

Types of Liquid Manure Application Equipment

Liquid manure application equipment includes tankers (sometimes called honey-wagons) and hose-drag (also referred to as drag-hose) systems. Depending upon the type of liquid application system being calibrated, calibration may require weighing the tanker, recording the time to empty a load, measuring application spread width and length and/or recording equipment speed. Also, with some calibration methods, determination of manure density is required.

Related: Calibrating solid manure spreaders and irrigation equipment.

Important Factors For Making Calibration Calculations

Normally calibration requirements are specific to the equipment, i.e. one piece of equipment needs only to be calibrated once during the calibration interval, often annually. However, it is a good idea to calibrate equipment that may be used under different conditions. For instance, adding more hose to a hose-drag system when moving from one field to the next can increase friction loss and alter manure flow rates though the applicator. It may also be valuable to calibrate for multiple travel speeds, each representing a different application rate. This allows one to select an application rate that most closely matches the nutrient requirements of individual fields or crops.

It is important to select the calibration procedure that is consistent with your manure analysis. For instance some analysis reports nutrients in a weight per volume measure (e.g. pounds per thousand gallons) while some analysis is provided on a weight per weight basis (e.g. pounds per ton). Calibration of liquid tanker spreaders can be done by weighing a load or knowing the capacity (volume) of the spreader as specified by the manufacturer. Conversion between volume and weight may be done by determining the manure density.

By knowing the spreader capacity, distance traveled to empty the spreader, and width of spread pattern (or distance you move laterally with each pass through the field), a fairly simple estimate of application rate can be made. This should be repeated several times to determine an average application rate each manure source. The speed of the tractor can be varied to adjust the application rate to achieve the planned application rate(s). The general procedure for calibrating a liquid manure tanker spreader is illustrated in the following file Liquid Spreader Calibration.

Hose drag type systems are calibrated by measuring tractor speed, flow rate of the manure through the system and effective width (distance between passes). These factors allow conversion to volume of manure over area applied, e.g. gallons per acre.

Calibration of hose-drag (drag-hose) equipment requires measurement of (a.) tractor speed, (b.) spread width (We in illustration) and (c.) flow through the hose. Photo: Garry Grabow, All Rights Reserved.

Recommended Educational Resources

Author: Garry Grabow, North Carolina State University Reviewers: Marsha Mathews, University of California-Davis, Rick Koelsch, University of Nebraska, Doug Beegle, Pennsylvania State University

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Manure Production and Characteristics

Manure is an inevitable byproduct of livestock and poultry production. Manure is a valuable material that can be used as a source of organic matter and fertilizer for crop and pasture production. Manure can also be used as source of energy on the farm through anaerobic digestion to produce biomethane or thermochemical process (such as pyrolysis, gasification, or combustion) to produce heat or electricity. Some of the by-products of energy production can be further processed to produce value added chemicals.

Quantity of Manure Produced

Typically, manure includes excreted material from the animal (feces and urine), used bedding, as well as wasted feed, water (drinking and wash), hair, and soil. The quantity of manure produced depend on several factors including:

  • animal type (ruminant or non-ruminant),
  • diet (forage-based or grain-based),
  • animal age (which can influence the amount of feed consumed),
  • animal environment,
  • and animal productivity as well as other factors.

Composition of Manure

The chemical characteristics of manure primarily depend upon the chemical composition of the feed given to the animal. The animal metabolizes the feed to provide itself with energy and produce new body tissues and products. The waste products of metabolism are largely collected in urine and passed out with the feces (which may contain unused feed).

Nutrient requirements by animals vary with animal type and stage of production. Usually, when the animal’s protein requirements decrease, the concentration of protein in the diet can also be decreased, thereby decreasing the concentrations of nitrogen excreted as a percent of body weight. Similarly, increased levels of minerals fed (e.g. copper, phosphorus, sodium, potassium) increase the level of those nutrients in the manure. It is recommended that manure analysis be done regularly especially if diet formulation and major changes in management of the livestock occurs.

Determining Manure Production and Composition

Manure quantities and characteristics can be estimated on an:

  1. as-excreted basis or as
  2. recoverable manure nutrients (the quantity of manure nutrients available for land application or utilization for other purposes).

The nutrient content of manure is influenced by feed intake (which influences the nutrients excreted), manure storage and management choices (which influences the recovery of nutrients), and water additions/evaporation (which influences the concentration of nutrients).

As-Excreted Basis

There are tabulated values that can be used to estimate the amount of manure an animal produces. The American Society of Agricultural and Biological Engineers (ASABE) has prepared a standard (D384.2) that lists the average quantities of manure and their characteristics. Excreted values are provided in Table 1 and Table 2. These average estimates of manure excreted become obsolete due to changes in animal genetics, feeding program strategies, and available feeds. Table 1 and 2 are representative of typical characteristics in 2002.

Although sampling and the use of tabulated estimates are the most common methods of estimating manure nutrients, ASABE D384.2 provide equations for predicting nutrient excretion (primarily nitrogen and phosphorus), dry matter, and (depending upon species) other potential characteristics have been assembled for beef, dairy, swine, horses, and poultry. Software (listed at the bottom of this page) can simplify the use of these equations.

If you want to calculate quantity of manure produced by your animals based on these equations, here are some guidelines to use to decide when it is appropriate to use the equations to calculate manure excretions:

  • When you want to develop a comprehensive nutrient management plans specific to your animal feeding operation (AFO).
  • When you have farm-specific data for your feeding program and animal performance.
  • When feed intake, feed nutrient concentration, feed digestibility, or animal performance varies from the assumptions used to estimate the typical values in Table 1 and Table 2.
  • When industry trends have changed from the assumptions used in Table 1.

Otherwise, use the typical values found in Table 1 and Table 2 for the following situations:

  • When planning estimates are being made on a scale larger than a single farm (e.g. county or regional estimate of nutrient excretion).
  • When a rough approximation is needed for farm planning.
  • When farm-specific information of animal performance and feed intake is not available.

Caution: When using the typical as-excreted manure production and characteristics presented in Table 1 and Table 2, the user should recognize that the reported typical values may become obsolete with time due to changes in animal genetics, feeding programs, alternative feeding technologies, and available feeds. In addition, users should also recognize that under current conditions, excretion of nutrients and other related characteristics will vary for individual situations from the currently listed values due to variations in animal feed nutrient intake, animal performance, and individual farm management.

Bedding

Bedding is sometimes included in the manure. To estimate the amount of bedding used, weigh the bedding added to each pen per week and multiply the number of pens and the weeks between cleaning. Estimate the total weight of bedding and manure by adding the amount of manure produced using Table 1 or Table 2 or calculated using equations to the amount of bedding; subtract any liquid drained off i.r. not absorbed by the bedding (neglect drainage if well bedded).

Total Weight = manure weight + bedding weight

To estimate the volume of the manure and bedding, add manure production volume to 50% of the bedding volume. The volume of the bedding is usually reduced by half during use.

Total Volume = manure volume + (bedding volume/2)

As-Removed Manure Production and Characteristics

Many physical, chemical, and biological processes can alter manure characteristics from its original as-excreted form. The as-removed manure production characteristics values are reported in Table 3. These values represent typical values based on available data sources. These estimates may be helpful but have very high variability. The values may be helpful for an individual farm’s long-term planning prior to any samples being available and for planning estimates addressing regional issues. Whenever possible, site-specific samples or other more localized estimates should be used instead of the national tabular estimates. Permitted Concentrated Animal Feeding Operations (CAFOs) are required to annually report recovered manure for their individual farm. Use the tabulated values for planning purposes until site-specific values are available.

Manure Handling Characteristics

The handling characteristics of manure vary depending primarily on the solids content (Figure 20-1). Manure is usually classified as liquid, slurry, semi-solid, or solid depending on the total solids content of the manure. The boundary between handling classifications is not fixed but varies with specific composition.

Manure can be classified according to the dry matter content as liquid, slurry, semi-solid and solid.

  • Liquid manure contains up to 4% solids content and can be handled with irrigation equipment. Liquid manure with this kind of solids content can be obtained by removing larger solids from the manure through some form of solids separation, or adding dilution water. Lagoon treatment systems usually have less than 1% solids if designed and operated properly. Overloaded lagoons can reach up to 2% solids.
  • Slurry manure contains 4% to 10% solids and may require special pumps for handling. *Semi-solid manure contains between 10 and 20% solids. The manure is too thick to pump.
  • Solid manure contains 20% solids content or more. This manure can be stacked or be picked up with a fork or bucket loader.

 

Figure 1. Relative handling characteristics of different types of manure for various animal species (Source: MWPS-18 Section 1, 2004). cc2.5 Jactone Arogo Ogejo

 

 

Software

The spreadsheet, Feed Nutrient Management Planning Economics (FNMP$) is a comprehensive program connecting feed ration characteristics, manure storage type and cropping systems impact on the value of manure as a fertilizer. The spreadsheet provides a straightforward approach for estimating manure excretion based on the ASABE equations standard described above. FNMP$ estimates:

  1. manure nutrients
  2. land requirements
  3. labor and equipment application time, and
  4. costs and value for land application.

This is a spreadsheet-based program.

References

  • MWPS. 2004. Manure Characteristics.MWPS-18 Section 1. MidWest Plan Service, Ames. IA
  • ASABE. 2005. Manure production and characteristics. ASABE Standard D384.2. American Society of Agricultural and Biological Engineers. St. Joseph, MI.

Author: Jactone Arogo Ogejo, Virginia Tech

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State Specific Manure Nutrient Management Information

Why is State Specific Nutrient Management Information Important?

State or regionally specific factors such as climate and soils impact the many manure nutrient management recommendations for application rates and best management practices (BMPs). In addition, state specific public policy may also establish minimum expectations and required practices.

Finally, state land grant university research may have identified preferred procedures for implementing crop nutrient recommendations or manure nutrient management that may differ from other states. Regardless of the driving force, it is recommended that nutrient management plans follow state specific recommendations for crop nutrient requirements, crop availability of manure nutrients, BMPs, and planning and record expectations.

Click on Your State to View Links to State-Specific Nutrient Management Information

If there is no information linked to your state on this map, it is recommended that you contact your land grant university, county Cooperative Extension office, or county or state USDA Natural Resources Conservation office. If your farm falls among those covered by state or federal regulation, your state’s environmental regulatory agency should also be contacted.

View Larger Map

Additional Information Sources on State Specific Nutrient Management

  • The Manure Management Planner computer program developed at Purdue University is one source of state specific information. The software currently supports 34 states (AL, AR, CA, CO, DE, FL, GA, IN, IL, IA, KS, MA, KY, MD, MI, MN, MO, MS, MT, NE, ND, NJ, NM, OH, OK, OR, PA, RI, SD, TN, UT, VT, WA and WI) by automatically generating fertilizer recommendations and estimating manure N availability based on each state’s Extension and/or NRCS guidelines. Check with your state to be sure the Manure Management Planner meets state specific nutrient management plan criteria.

Page Manager. Rick Koelsch, University of Nebraska, rkoelsch1@ unl.edu
Reviewers: Doug Beegle, Pennsylvania State University, and John Lory, University of Missouri

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