Download all worksheets mentioned in this document - MS Word

NRCS NUTRIENT MANAGEMENT PLANNING

Steven Hollister
U.S. Department of Agriculture
Natural Resources Conservation Service

The Current Situation

The U.S. Department of Agriculture, Natural Resources Conservation Service (NRCS) in Illinois has developed revised Nutrient Management and Waste Utilization standards. These come as a result of recent State of Illinois laws regarding livestock and Federal cost-share programs such as the Environmental Quality Incentives Program (EQIP) available through NRCS. These issues created more awareness and interest in planning nutrient management as it relates to livestock manure among Illinois farmers. NRCS has provided training on these standards to field staff and maintains specialists to assist them in writing manure management plans as needed. These plans are a part of a comprehensive planning method to identify and address all natural resource concerns on the farm.

Illinois NRCS Nutrient Management Standard

The Nutrient Management standard (practice code 590) in Illinois identifies the minimum acceptable requirements for the inventory and management of plant nutrients from all sources, including animal manure. This standard applies to all NRCS planning related to nutrient application to agricultural lands.

Items to be considered in planning include:

1. Identify the water quality concern as surface water, ground water, or both.
2. Determine the potential vulnerability rating from nitrate nitrogen leaching
3. Evaluate water quality standards and designated use limitations that exist locally or statewide. Manage nitrogen and phosphorus as the nutrients that have primary impact on water quality.

The Illinois 590 standard indicates the specifications to be followed which include:

1. Establish realistic crop production goals
2. Apply nutrients according to soil tests and take appropriate nutrient credits
3. Control soil erosion to tolerable (T) level
4. Maintain soil pH
5. Organic wastes shall be applied according to the WASTE UTILIZATION (practice code 633) standard.
6. Nutrient management plan will include rates, timing, methods of application and sources of nutrients

Illinois NRCS Waste Utilization Standard

The Illinois Waste Utilization Standard (practice code 633) gets more specific on the use of waste, oriented towards animal manure, for crop nutrients. It covers many of the items included as a part of the current State of Illinois Livestock Facilities Act and the IEPA Title 35 Livestock Waste Regulations dealing with field application of manure. These include:

1. Manure will not be applied to frozen or snow-covered soil over 5% slope unless runoff control methods are used
2. No application is to be made within 200’ of wells, sinkholes, or surface waters.
3. Application to cropland requires erosion control to sustainable (T) levels. Do not apply to cropland over 15% slope.
4. Do not apply in an established waterway or any area where there may be a concentrated water flow unless using irrigation.
5. Manure may not be applied in a 10-year floodplain unless injected or incorporated.
6. Liquid manure shall not be applied to soils with less than 10 inches of at least moderately permeable soil ( > 27% clay) over fractured bedrock, sand or gravel.

Both the 590 standard and the 633 standard allow rates of manure application to supply the nitrogen needs of the following crop until the Bray P1 test reaches 150 PPM (300 lb./ac). At this level, research suggests there can be a risk of phosphorus pollution to surface waters. If no recent soil tests are available or the soil test P1 level exceeds 150 PPM (300 lb./acre), wastes should be applied to fields with a lower P1 or shall be applied based on phosphorus removed by harvested crops, unless that rate would be greater than the nitrogen rate needed for the crop. In no case will waste be applied at rates that exceed the nitrogen needs of the next crop.

The philosophy behind the above planning requirements for NRCS nutrient management plans is simple. At the extremely high P1 test of 150 PPM, there is no agronomic reason to apply more phosphorus. However, a livestock producer still needs to utilize manure nutrients. The compromise is to allow manure to be applied at the rate of phosphorus use so the soil test P level does not get any worse than before planning a management system. In the meantime, the producer should be looking for other fields to apply the manure to or find another producer who would be willing to accept the manure as a fertilizer source.

This philosophy will apply to NRCS nutrient management planning in Illinois until a more defined and accepted method for evaluating the need for phosphorus management becomes available. Efforts are currently underway to identify such methods, but may take a few years to develop.

At the same time, we encourage planning with the producer to limit manure applications to a rate that will not increase the soil test P level above the agronomic rates, even if the P1 test is below 150 PPM. This can have definite economic as well as environmental advantages to the producer in cases where the use of manure over more acres supplies more of the fertility needed by the crops on the farm. In many cases, if manure is applied to supply the nitrogen needs of the crop, excess phosphorus is applied over crop removal rates. This results in ‘storage’ of the excess phosphorus and an increase in the soil test P level. The end result over time can be soils that have ‘stored’ large amounts of phosphorus that cannot be utilized by crops. A certain portion of soil bound phosphorus becomes available each year. The amount depends on the soil type and other environmental conditions. However, the rate of phosphorus availability is fairly constant. The higher the soil test P level the higher the total volume of phosphorus in soil water each year which can translate into a water pollution potential. So besides wasting the phosphorus available in the manure as fertilizer, it can become an environmental concern.

No such environmental concern exists for potassium at this time. However, proper application of manure with this nutrient can also result in economic and crop production advantages for producers.

In many cases, through proper planning and management, manure can be applied that supplies enough nutrients for N as well as P2O5. This can be accomplished because of the ability of phosphorus to be ‘stored’ for the next crop use. Although this may preclude the use of the same acres in future years for manure application, it allows the most efficient use of the nutrients in the manure without environmental concerns.

Planning Manure Management Systems

Illinois NRCS manure management planning begins with a detailed and thorough inventory of the current facilities and livestock numbers. This may include a review of the need for expanded or new storage facilities, or manure handling systems that will affect total manure volume. Another part of this inventory is the identification of cropping systems used by the producer along with realistic crop yields.

Once these items have been agreed to, the manure application plan can be developed. This begins with a review of the crops, land area, and soils potentially available for manure application. Areas with poor soils or other limiting features are identified. If manure cannot be applied to these areas, they are subtracted from the land area available. The nitrogen leaching potential for each application area must be reviewed to identify the need for leach management options (Table 1).

Next an estimate of the available nutrients and total annual volume of manure is developed (Worksheet 1). Estimates of the nutrients are provided in Table IL 11-5 or from previous manure tests. This provides a benchmark for the total nutrients available coming out of the storage or management system to be used. The total annual volume is based on each type of manure (solid or liquid). This helps identify the application method and equipment needed.

The next step is to determine the pH and nutrients needed by the crops to be grown. This is done using the Illinois Agronomy Handbook section on Soil Testing and Fertility. This publication provides data for fertility needs for crop maintenance levels as well as buildup recommendations where soil P or K is limited (Worksheet 2).

After this an estimate of plant available nutrients is developed. This is based on the type of manure application system used, including the equipment and whether the manure is incorporated (Tables 11-6 and 11-9).

Once the crop nutrient needs and nutrient availability are determined, the manure application rate per acre can be calculated (Worksheet 3). The rate then depends on how much manure it will take to supply the nitrogen or phosphorous for the crop (or crops) to be grown. This is known as ‘balancing’ the manure application for the nutrient needs. As mentioned previously, there are situations where more than one nutrient can be ‘balanced’ by the same application rate (see example). At the same time we need to verify the application rate is reasonable for the equipment to be used, and the application method will fit in with the erosion control needs for the application areas.

When the application rate is determined, the total acres needed can also be identified. If there are not enough acres to apply all the manure, there are a few options that can be reviewed. Possibly, the producer has more acres a little farther away that could be used for manure application and still save fertilizer costs. Another option may be to change the crop rotation to increase nutrient use on the same acres. Hay crops and corn silage are examples of high nutrient use crops. Also, there may be some opportunity to review the manure storage system to reduce the total manure volume, such as a more efficient water system or roof gutters. Perhaps it will take a combination of these methods. A final option would be to find another producer willing to use manure as a fertilizer source. More and more Illinois livestock producers are using this option.

A review of the application rate and nutrients supplied needs to be done to verify any nutrient not meeting crop needs is supplemented by commercial fertilizer to provide a ‘complete’ fertility plan. Also, nutrients supplied at higher than needed rates should be identified to allow taking advantage of them in future years nutrient plans (Worksheet 4). We complete the plan with a ‘Manure Management System Plan’ sheet. This identifies on one sheet the basics of the system planned and provides the basis for future reviews.

None of the above activities mean anything unless the manure is actually applied at the rate indicated in the plan using the equipment and methods planned. Here is where equipment calibration is critical. The producer must check this annually to verify the application rate and develop uniform application patterns.

Following the implementation of the manure management plan, the manure should be tested for nutrients prior to each application and the plan revised accordingly. Changes in the type of animals, feeding programs, or storage method will require additional tests. This indicates the annual nature of this type of plan. It is not something that can be done and used more than one year without significant review and revision by the livestock producer.

NRCS and Soil and Water Conservation District staff are available to help producers in each county to plan these systems as a part of a total resource management system. Specialists are also available to assist in this planning effort. As technology and the livestock industry in Illinois change, we will be ready to update our standards and our ability to provide this planning service.

Table 1. Nitrogen Leaching Potential¹ by Application Method for Coarse, Medium, and Fine Textured Soils

General Guidelines: Given the same climatic conditions, the more permeable the soil and the greater the time between application and plant utilization, the greater is the potential for leaching loss. Therefore,

• Use sidedress or split application programs on coarse textured soils.
• Use spring and sidedress or split applications on medium textured soils.
• Avoid using nitrogen sources which contain nitrate nitrogen when conditions indicate a medium or high loss potential.
• Use nitrification inhibitors with ammonium forming fertilizers in those conditions where nitrogen loss potential is moderate or high. In fall application programs, use inhibitors when soil temperature at the 4-inch depth is 50 to 63 degrees F.
• If applying manure:
  1. Do not apply liquid manure on course textured soils unless through irrigation during crop growth season.
  2. Apply liquid manure on soils with Moderate probability for leaching (M) in fall after soil temperature at 4-inch depth is less than 50 degrees F.