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What Is a Comprehensive Nutrient Management Plan?

A Comprehensive Nutrient Management Plan (CNMP) is a strategy for making wise use of plant nutrients to enhance farm profits while protecting water resources. It is a plan that looks at every part of your farming operation and helps you find better ways to use manures, fertilizers and other nutrient sources. Successful nutrient management requires thorough planning and recognizes that every farm is different. The type of farming you do and the lay of your land will affect your CNMP. For example, CNMPs on farms that do not have animals will not require as much detail as those that do. The best CNMP is one that is matched to the farming operation and the needs of the person implementing the plan—the Georgia farmer!

Who Is Required to Have CNMPs?

The United States Environmental Protection Agency and the United States Department of Agriculture have recently released a Unified National Strategy for managing animal feeding operations. This strategy sets a national goal for all animal feeding operations to have CNMPs. In Georgia, any animal feeding operation that receives a permit through the Georgia Environmental Protection Division is required to have a CNMP.

Other producers who are not required to have a permit are being encouraged to voluntarily adopt CNMPs. Many organizations such as the Georgia Poultry Federation and the Georgia Pork Producers have established initiatives to assist producers to better manage nutrients on the farm.

What Are the Parts of a Successful CNMP?

A Comprehensive Nutrient Management Plan looks at how nutrients are used and managed throughout the farm. It is more than a nutrient management plan that only looks at nutrient supply and needs for a particular field. Nutrients are brought to the farm through feeds, fertilizers, animal manures and other off-farm inputs. These inputs are used, and some are recycled by plants and animals on the farm. Nutrients leave the farm in harvested crops and animal products. These are nutrient outputs. Ideally, nutrient inputs and outputs should be roughly the same. When the inputs to the farm greatly exceed outputs from the farm, the risk of nutrient losses to groundwater and surface water is greater. When you check nutrient inputs against nutrient outputs, you are creating a mass balance. This nutrient mass balance is an important part of a CNMP and important to understand for your farming operation.

Another important part of a successful CNMP is best management practices (BMPs). BMPs, such as soil testing and manure analysis, help you select the right nutrient rate and application strategy so that crops use nutrients efficiently. This not only reduces nutrient losses and protects the environment but also increases farm profitability. BMPs may also include managing the farm to reduce soil erosion and improve soil tilth through conservation tillage, planting cover crops to catch excess nutrients or using filter strips and buffers to protect water quality. Preventative maintenance, record keeping, mortality management and emergency response plans must also be included in a CNMP for livestock and poultry operations.

The Basic Steps

CNMPs consist of six major parts: evaluation of nutrient needs, inventory of nutrient supply, determination of nutrient balance, mortality management, preventative maintenance and inspection, and an emergency response plan. Not all farms will require all six parts. For example, farms without livestock or poultry may not need sections on mortality management or emergency response plans.

Evaluation of Nutrient Needs

Maps and Field Information You will need a detailed map of your farm. The map should include the following: farm property lines, your fields with the field identification, the location of all surface waters such as streams, rivers, ponds or lakes, arrows showing the direction that streams or rivers flow, and a soils map, if available. This map will serve as the basis for the entire plan, so each field should have a unique identification. In addition to the map, prepare a list of the crops to be grown in each field with a realistic yield goal for each crop. Most of this information is available at your local USDA Farm Service Center.

Locate Critical Areas

Certain areas on your farm such as streams and rivers, wellheads, and lakes or ponds are sensitive to nutrient overload. You should create zones around these areas on your map where nutrient use will be reduced or eliminated. By buffering these areas, water quality problems may be decreased. Areas such as roads, off-site dwellings and areas of public gatherings should also be noted on your map. Your plan may want to limit the use of manures near these types of areas to reduce odor complaints.

Soil Testing Complete and accurate soil tests are important for a successful nutrient management plan. You will need annual soil tests to determine how much nutrient addition is needed. The needed nutrients can be supplied from commercial fertilizer and/or organic sources. Be sure to take representative soil samples and have them tested by a reputable laboratory familiar with Georgia soils and crop production. Your county Extension agent can help you submit samples to the University of Georgia Extension Soil, Plant and Water Laboratory.

Determine Nutrients Needed for Each Field

Once you have set realistic yield goals and you have your soil test results, you can determine the nutrients that your crops will need. The amount of nutrients needed should be based on your local growing conditions. At a minimum, the amounts of nitrogen, phosphorus and potassium should be listed in the plan for each field. Most soil and plant analysis labs will give you recommended application rates based on the soil test results. Your county Extension agent can also help you with this.

Inventory of Nutrient Supply

Many of the nutrients needed to grow your crops are already present on your farm in the soil, in animal manures, or in crop residues. Knowing the amounts of nutrients already present in these sources is important so that you do not buy more nutrients than needed.

Determine the Quantity of Nutrients Available on Your Farm

Supply planning starts with an inventory of the nutrients produced on the farm. Animal manure is an important source of nutrients. The quantity of manure collected and stored, either dry or liquid should be determined. An inventory should also be performed of any other byproducts available, such as: mortality compost, lagoon sludge (if lagoon cleaning is planned), crop residue nutrients or nitrogen from legumes. This information will allow you to balance your nutrient purchases with what is available on your farm for the realistic production level of the crops grown.

Nutrient Analysis Animal manure and other organic products are not all the same as far as nutrient content is concerned. An analysis of these products tells you the nutrient content so that you can match this up with soil test recommendations and determine application rates. The lab results will help you determine how much of the nutrients in the manure will be available to your crops. The amount credited to the nutrient budget should be based on plant available nutrient levels, which may be substantially different from the total nutrient content. The county Extension office has information on manure and litter testing.

Determining Nutrient Balance

Balance Between Supply and Need Once you have determined both the supply and need of nutrients for each of your fields, a critical aspect of CNMPs is balancing the two. This can be done in several ways. Currently, most CNMPs are developed based on nitrogen; however, other factors such as phosphorus or metals could control how much poultry litter or manure you can put out under certain conditions. A phosphorus index is currently being developed to help producers determine when nutrient management based on phosphorus would be advisable. If your crop acreage is small relative to the number of animals, the nutrient balance will also allow you to evaluate how much manure or litter you may need to move off your farm to avoid over-application of nutrients.

Can the Nutrient Supply on Your Farm Be Managed or Changed?

After evaluation of the nutrient supply on your farm and the nutrient needs of your crops, you may find that the balance of nutrients is not ideal. You may have more of one or more nutrients (usually phosphorus) than you need. Many management practices can change the nutrient balance. These include:

• changes in storage practices,
• adjustments of animal feeds,
• modification of treatment methods, and
• chemical amendments.

For example, you may be able to reduce nutrient losses in your manure treatment and/or storage system. Sometimes reducing nitrogen losses can make manures a better-balanced fertilizer for your crops. In addition, animal diets can sometimes be changed to reduce nutrient excretion in their manure. Enzymes can be added to the diet to reduce nutrients in the manure. Phytase is a supplemental enzyme that allows better use of the phosphorus already present in grains, so less phosphorus has to be added to the animal’s diet.

Manure Storage Manure storage is critical. It effects both the quantity and quality of nutrients that will need to be land applied or exported from the farm. The storage structures and design capacities need to be identified as part of a CNMP. These structures also need to be managed to prevent nutrient losses and protect water quality. For example, clean water should always be diverted from barnyard and manure storage areas to reduce the potential for nutrients reaching ground or surface waters.

Manure Application to Fields Manures should be applied near the time that crops need nutrients using calibrated spreaders or irrigation equipment. Solid or slurry manure should be incorporated into the soil when appropriate. Incorporation or mixing into the soil greatly reduces losses of nitrogen to the air and keeps more in the soil where it is needed. This reduces potential odor emissions. Slurry manure can also be injected into the soil so that incorporation is not required. Accurate records of application rates and times are also essential.

Identify Alternative Uses for Excess Manures

If your manure production exceeds nutrient needs on-farm, you should identify alternatives to land application of your manure. Potential options include selling manures to other farmers, composting manures for use by homeowners or possibly selling it to other off-farm users.

Mortality Management

A complete CNMP should identify how livestock or poultry mortalities will be managed. This should include:

• estimated amounts of normal mortality,
• methods of disposal or utilization, and
• plans for dealing with catastrophic mortality events.

The Georgia Department of Agriculture regulates mortality disposal and all plans should meet its requirements. Approved methods of disposal include burial, composting, incineration and rendering.

Preventative Maintenance and Inspections Keeping good, detailed records that help you monitor your progress is essential to know if your CNMP is accomplishing the goals you have set. You should keep all results from soil, plant and manure tests, and examine how they change with time due to your management practices. Records should also be kept on crop yields, manure production, manure exports, nutrient application rates, timing and application methods. Keep detailed schedules and records on calibration of spraying and spreading equipment, maintenance of pumps and other machinery, and inspections and current capacities on manure storage facilities. When you have a major change in production, your plan should be updated to reflect these changes.

Emergency Response Plans

The final aspect of your plan should include the procedures to be followed in an emergency. This may include actions taken to contain or manage any unauthorized discharge of manure or wastewater, listing of the proper authorities to notify when certain events occur and any authorizations necessary to obtain essential equipment or access to neighboring properties during these events. It should also outline a plan for training new employees in these procedures.

Where Can You Obtain Information Needed for Your CNMP?

The University of Georgia Cooperative Extension Service, the USDA Natural Resources Conservation Service, the Georgia Department of Agriculture and Certified Crop Advisors, or other private consultants, should all be able to assist you in developing parts of a comprehensive nutrient management plan. In addition, computer software and publications will be available through your county Extension agent to aid you in the process.

A CNMP is a good tool to help you use your on and off farm resources more efficiently and prevent future problems. A successful CNMP will help you obtain the maximum profit while protecting the environment.

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Bulletin 1185, December 1999

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