Manure management planning

Overview

Manure management planning is an overarching strategy that addresses the entire manure management system to maximize the benefits of the manure and minimize the costs and impacts on the crop production system and environment. Planning to manage manure helps you allocate manure so you can manage it more effectively and efficiently in an environmentally responsible manner while improving your bottom line.

The process helps you determine if your farm has sufficient manure storage and collection capacity and enough crop land for manure application. This in turn helps you identify opportunities for improving the sustainability of your farm or operation by assessing which beneficial management practices (BMPs) can be adopted to manage manure more effectively as a nutrient resource, optimizing nutrient use and improving soil quality while minimizing environmental and nuisance concerns. Below are some key areas to help you get started on your plan.

Manure inventory

The Beneficial Management Practices – Environmental Manual for Livestock Producers in Alberta discusses different manure management systems, risks associated with liquid and solid manure and BMP options for improving manure utilization and reducing risks associated with manure management.

Determining how much manure is produced and collected is key to effectively utilizing the resource. Extensive livestock production systems, where animals are grazed or fed in the field, can adopt BMPs such as targeted feeding or riparian area fencing, to reduce the risk and increase the benefit associated with manure deposition.

Intensive livestock production systems or confined feeding operations (CFOs), where manure is collected, stored and later mechanically applied to the field, can adopt BMPs such as injection or composting to reduce the risk and increase the benefit associated with manure produced.

Chapter 4 of the Nutrient Management Planning Guide can help with general manure-production estimates.

Storage and collection

Manure may be collected and stored in permanent manure storage facilities or at temporary storage sites. Protecting water quality by managing solid or liquid manure and surface runoff is a legislative requirement. When deciding the location of permanent or temporary manure storage sites or collection areas, you need to consider the manure management guidelines and legislation, as well as the site’s potential for nuisance (for example, odours and flies), environmental and safety concerns, as well as ease of access and economic impacts.

For more information on siting, designing, maintaining and monitoring manure storage and collection areas, see Chapter 3 of the Beneficial management practices: Environmental manual for livestock producers in Alberta.

Solid manure

A long-term solid manure storage site at a permitted CFO must have a liner, natural, compacted or constructed, with very low permeability, to prevent contaminants from seeping into the subsoil and eventually into the groundwater. Sites need to be selected or structures need to be installed to allow for the prevention of surface runoff from flowing through stored manure and becoming contaminated.

For short-term or temporary manure storages, select sites that avoid surface water run-on into the stored manure and prevent runoff from leaving the site. Move short-term manure storage sites on a regular basis to prevent nutrient accumulation at the site and leaching (that is, downward movement of nutrients).

Liquid manure

A liquid manure storage facility that is permitted at a CFO must have a liner, natural, compacted or constructed, with very low permeability to prevent contaminants from seeping into the subsoil and eventually into the groundwater. It is best to divert surface water run-on around and runoff from manure storage areas to minimize liquid volumes that would need to be managed when emptying the storage, as well as prevent contamination of surface water.

A properly sized earthen manure storage (EMS) is an important consideration to prevent environmental concerns. To calculate earthen manure storage volume, use the online Dugout Volume or Manure Storage Calculator.

Catch basin contents

For CFOs or long-term manure storage facilities such as feedlots, a properly sized catch basin can be an important tool to manage runoff of surface water impacted by manure. The Catch Basin Dimension Calculator can be used to design a catch basin based on catchment area and potential surface water runoff from feedlot pens. Anyone using a catch basin to control runoff may require a permit that would specify design, construction and management of the facility. For more information, see Catch Basin Design and Management.

Managing surface water

Whether you are a permitted CFO or not, controlling run-on and runoff on your farm helps protect water quality, conserve valuable nutrient-rich manure for land application and to maintain livestock pens while improving herd health. In order to manage surface water around your farm or operation, identify where the water is coming from and map the surface water flow paths around your facilities and fields. This will help identify any surface water risks that may need to be mitigated through the use of a surface water control system. Remember, if you choose to install a surface water control system, you may have to get a permit. As well, permitted CFOs may be required to have an approved surface water run-on or runoff control system (for example, a catch basin to capture runoff).

For more information on the various management options for controlling run-on and runoff, see Chapter 8 of the Beneficial management practices: Environmental manual for livestock producers in Alberta.

Manure treatment

Manure treatment includes any process that alters its moisture and nutrient content. Farms that are in situations where available cropland is insufficient to use all the manure produced may be interested in adopting manure treatment technologies. While these technologies can be costly, potential benefits include:

• reduced manure volume, making it easier to manage and haul farther
• creation of value-added products
• less environmental risks
• addressing nuisance concerns

Some manure treatment technologies used in Alberta include anaerobic digestion, composting and solid-liquid separation. For more information, see Chapter 4 of the Beneficial management practices: Environmental manual for livestock producers in Alberta.

Manure application

Determine where and how much manure to apply

Determining where and how much manure to apply go hand in hand and require great attention. Consider the following when determining where to apply and what rates to apply:

• identify fields and the acreage of each field where manure can be applied by conducting field assessments to gather the following information:
  • soil physical properties (for example, structure and texture)
  • problematic soil conditions (for example, saline, solonetzic or eroded soils)
  • slope grade and length towards water bodies
  • location of water bodies, courses, drainage areas, springs and wells
  • past and current site management (for example, application history, tillage and seeding practices, crop rotations, presence of irrigation)
• sample and analyze the manure being applied to determine its nutrient content
• determine the method of manure application
• determine the crop being grown and the nutrient requirements for the targeted yield

Soil sampling

Soil sampling is key to managing nutrients, and optimizing fertilizer and manure applications. Knowing about the soil and its characteristics helps to determine nutrient availability, productivity potential and nutrient needs.

Proper soil sampling is required for accurate soil analyses and reliable nutrient recommendations. Soil analysis provides a 'snapshot' of nutrient reserves in the soil and can be a guide for nutrient applications. Soil samples submitted for analysis should be representative of the field. Obtaining representative samples can be difficult because of soil variability. To get a representative soil sample consider:

• timing of sampling
• type of sampling tools
• sampling depth
• sampling frequency
• sampling strategy for parts of the field
• appropriate handling of samples

Every year in late fall or early spring, take soil samples in each field to a depth of at least 60 cm (2 ft). Soil variability is a major concern when trying to obtain a representative soil sample. The strategy used to sample a field can address this challenge. Information collected during a site assessment can assist in choosing an appropriate strategy for a particular field.

Ideally, separate samples into the following depths:

• 0 to 15 cm (0 to 6 in)
• 15 to 30 cm (6 to 12 in)
• 30 to 60 cm (12 to 24 in)

Have samples analyzed for:

• nitrate-nitrogen (at each depth)
• phosphorus (0 to 15 cm)
• potassium (0 to 15 cm)
• sulphate-sulphur (at each depth)
• pH (0 to 15 cm)
• electrical conductivity (0 to 15 cm)
• organic matter (0 to 15 cm)
• texture (at least once, 0 to 15 cm)

Use these samples to identify which nutrients are deficient in each field. Then you will know how much of each nutrient to add to ensure adequate levels for crop growth.

You should also sample the soil to a depth of 1.2 m (4 ft) every few years. This will show you if a nutrient leaching problem is developing. Recognizing leaching early helps you deal with it before it becomes a serious concern.

Manure sampling

To determine an appropriate manure application rate, it is critical to know the nutrient content of manure. This will help meet crop requirements, maximize yields, minimize environmental impact and optimize economic benefit. Alternatively, book values can be used to estimate nutrient content of the manure, see Appendix 4 in the Nutrient Management Planning Guide or the Manure Characteristics and Land Base Code.

Manure nutrient content is highly variable. Variability depends on:

• source
• feed
• method of storage

Total nutrients are elements that are both available and unavailable for absorption by plants. Available nutrients are those elements that can be readily absorbed. When sampling manure, you are specifically looking for:

• nitrogen
• phosphorus
• potassium

Meeting crop needs

Knowing the nutrients that are available in the manure and soil, and what nutrients the crop requires, can help determine a manure application rate. It is extremely unlikely for manure to meet the exact nutrient requirements for all crops. When manure is applied based on one nutrient, there will be either too much or too little of others applied.

To complicate the situation, manure contains nutrients such as nitrogen (N) and phosphorus (P) in a number of different available and unavailable compounds. The unavailable compounds break down and release nutrients at different rates over a period of years.

Most producers apply manure based on N content. This leads to a buildup of soil P. Some fields now exceed 400 lbs per acre of available P in the top 6 inches of soil. This amount is equivalent to 1,770 lb/ac of 12-51-0 phosphate fertilizer.

For example, feedlot manure is applied to meet the N requirements of wheat or barley. When this occurs, P will be applied at approximately 3 to 6 times the rate of crop removal. Repeated applications over a period of years results in high soil P levels.

To draw down soil P levels, change manure application practices. One approach is to:

• apply manure annually for 3 to 4 years on cereal silage to meet N requirements
• follow that with 4 to 6 years of alfalfa to draw down the P soil levels

Another approach is to apply manure to meet P crop requirements and supplement with N fertilizer. A third approach may be to apply manure to meet the N requirements of the first crop after application then manage the rotation with subsequent crops that require less or no N, such as malt barley or annual legumes. There is no single best approach. However, when developing a long-term nutrient management plan, it is best to match P, not N, with crop removal.

For existing operations, this approach may mean expansion of the land base or working with adjacent farms. This will help utilize all the manure produced by the livestock operation. To help with this and improve soil quality, some may want to target fields low in organic matter. In all cases, N fertilizer may need to be added. This will make up the difference between crop requirements and manure contents.

Commercial fertilizer prices have dramatically increased over the past several years. Neighbours near a feedlot or other type of intensive livestock operation or CFO can use manure to offset those costs.

By rotating manure application over a number of fields, the risk of nutrient accumulation in the soil is reduced. To take full advantage of the nutrient applied in the manure, inorganic fertilizer can be used to meet nutrient deficiencies and/or the crop rotation can be manipulated to minimize crop need for specific nutrients, such as using legumes to reduce the need for additional N.

The Alberta Farm Fertilizer Information and Recommendation Manager (AFFIRM) is a decision support tool designed to assist in evaluating nutrient management options for fertilizers and livestock manure to develop nutrient management plans for crop production.

Determine when and how to apply manure

Options for when to apply manure is affected by a number of factors:

• method of application used
• self-application or custom application
• seasonal time availability
• soil and weather conditions
• type of manure
• crops to be grown
• storage capacity

Runoff risk can be minimized and nutrient use or capture can be optimized with manure application right before the crop needs the nutrients (that is, in the spring or into actively growing crops).

More options for application can exist for liquid manure as compared to solid manure as liquid manure can be applied through an irrigation sprinkler system at very low application rates. However, extreme care is required to prevent surface water runoff and N losses to the air.

Manure should not be spread onto frozen or snow-covered soils due to the possibility of runoff from rapid snowmelt. This can carry dissolved and solid manure particulates into surface waters causing contamination.

The longer manure is left on the soil surface, the greater the potential for environmental concerns. When solid or liquid manure is applied, incorporate it into the soil the same day it is applied. Immediate incorporation of manure in soil prevents potential runoff while also reducing N losses to the air and preventing air quality concerns. Liquid manure can be directly injected into the soil, minimizing N losses. The longer manure is left on the soil surface, the greater the N losses. This reduces the value of the manure as an N fertilizer (see Table 1).

Table 1. Expected ammonium nitrogen loss in relation to application method, timing and weather conditions

How and when the manure is applied affects the application rates and the nutrient availability from the manure. Depending on the type of manure, BMP options are available to minimize nutrient loss and optimize manure use.

Planning tool

Using the Manure Management Planner (MMP) can help you allocate manure (where, when and how much) on a monthly basis for the length of the plan (for example, 1 to 10 years). Doing so helps determine if the current operation has sufficient crop acreage, seasonal land availability, manure storage capacity and application equipment to manage the produced manure in an environmentally responsible manner. The MMP tool is also useful for identifying changes that may be needed for a non-sustainable operation to become sustainable and determine what changes may be needed to keep an operation sustainable if the operation expands.

For other manure management planning tools, see Manure and nutrient management tools and resources.

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