NRCS Nutrient Management Code 590 Conservation Practice


Overview of Potential Changes to the NRCS Nutrient Management Code 590 Conservation Practice Standard

The Nutrient Management (Code 590) conservation practice standard has always been an important nutrient planning tool for cattle producers.  It was never, however, designed to be a regulation.  Recently, the NRCS decided to propose changes to the standard.  Generally, NCBA is very concerned about the content of the proposed 590 standard changes.  The 590 standard will be used by the EPA and many state regulatory agencies for nutrient management planning, so it is essential that NRCS gets it right with regard to the content of the standard.  One of our concerns is the fact that the proposed changes have taken on a regulatory tone.  NCBA is hopeful the NRCS to continue to treat it as a planning tool, not a regulation. 

For centuries, animal manure has been recognized as an important source of macro and micro nutrients for healthy crop growth, and organic matter which is critical to improving soil quality.  Manure improves the availability to crops of essential nutrients like nitrogen (N), phosphorus (P), potassium (K), and micronutrients such as iron and zinc.  Increasing organic matter is critical for healthy soils since it increases the nutrient holding capacity of soil, prevents nutrients from becoming permanently unavailable to plants, improves water infiltration, decreases evaporation, increases the water holding capacity of soils, encourages root development, improves aggregation which helps prevent erosion, and prevents soil compaction, among other benefits.
  
NCBA believes the use of animal manure as a fertilizer and a readily available organic-matter-builder should be encouraged, promoted and incentivized by the NRCS, instead of regulated in such a way that would prevent their application on many crop and grazing lands throughout the US.  Placing burdensome requirements and prohibitions on their use will have the unfortunate effects of increasing the stockpiling manure, discouraging farmer applications, and increasing the fertilization of fields with expensive commercial fertilizers.

Some of the issues that cause NCBA great concern with the proposed 590 standard include, but are not limited to, the following:

  • It is inappropriate to include an arbitrary cut-off level for soil phosphorus in the 590 standard.  Instead, it is critical to the viability of the animal agriculture industry that the current standard be retained and that states be encouraged to implement effective risk-based assessments for P.  The P Index provides this risk-based assessment by evaluating scientifically the source and transport issues for each field.  As proposed by the NRCS, a 10X soil test P level is arbitrary and is not correlated to water quality concerns as evidenced by the fact that it is ONLY a source-based threshold and does not encompass the critical second half of a risk assessment – transport - which is designed to protect water quality.  An arbitrary cut-off level for P application without consideration of environmental impact will prevent the land application of manure on many soils throughout the US, and will devastate the livestock industry.
  • Potassium is abundant in many soil types across the US.  In areas where manure or commercial potassium has been applied, there are many soils that will exceed the 10X soil potassium level proposed in the 590 standard.  As proposed, an arbitrary cut-off level of 10X for potassium is not based on science, will prevent the land application of manure on many soils throughout the US, and will devastate the livestock industry.
  • Similarly, the following proposed prohibitions on the land application of manure would have a devastating impact on the livestock industry:
    • “To frozen and/or snow covered soils” – In some areas of the country, application to frozen and/or snow covered soils is necessary and essential to provide for proper manure and wastewater management.  NCBA agrees that appropriate management practices need to be implemented; however, the key word is “management” and Code 590 should not prohibit this practice.
    • “During seasons of high runoff potential” – This provision is not defined and will place an unnecessary burden on producers to determine when these “seasons” exist.  Even then, manure and wastewater application are day-to-day management decisions and cannot be scheduled by the Farmer’s Almanac.
    • “During periods of winter dormancy” – Again, this provision is not defined and would restrict application on fields/crops that are currently permitted by state permitting authorities to receive manure and/or wastewater.  Proper application during winter dormancy, with appropriate management practices in place, may in fact be the best time to apply nutrients to allow for mineralization to occur in advance of the active growing season. 
    • “When the top two inches of soil are saturated…” – If incorrectly interpreted by regulatory personnel or field staff, this provision could prevent the application of all wastewater by any means of surface application.  For example, it is common for the top two inches of soil to be saturated during application of wastewater using a center pivot irrigation system.
  • Regarding the “Phosphorus Application Criteria:”
    • The proposed 590 standard would require the “PI risk assessment shall be based on the annual soil loss value associated with the crop interval including the manure application.”  This is a heavy lift for producers and an expensive proposal.  Essentially, this provision requires re-calculation of the water and wind loss calculations for every manure application.  In fact, many of the crop rotations, tillage practices, etc, remain unchanged from year-to-year, or only experience minor adjustments.  To re-run all soil loss equations every year would be excessive, expensive, and unnecessary.
    • The proposed standard also pre-determines the phosphorus application rate to be “equal to the recommended phosphorus application, or estimated phosphorus removal in harvested plant biomass…”  Here again, NRCS already has in place the tools necessary to make these decisions based on a scientific assessment instead of arbitrary cut-offs -- the Phosphorus Index.  The Phosphorus Index system works well in most States, and its use is critical to the livestock industry.  If there are states that cause NRCS concern, then NRCS should address those concerns individually and not devastate the entire livestock industry for the transgressions of a few states.  The critical issue here is that in fields that have received even moderate amounts of manure over the past several years, the laboratory recommendation for phosphorus will be “ZERO” and the crop removal rate will be something in the range of 20-80 lbs of P2O5.  In this situation, a beef cattle manure application rate would be 2-3 tons of manure per acre.  This is not even a feasible application rate for manure spreaders.  Conversely, allowing the current phosphorus index system to work would allow the land application of manure under certain circumstances.  If the Phosphorus Index rating is low, manure would be applied at nitrogen rates.  If the Phosphorus Index rating is high, manure should be applied at rates that are some multiple of the crop phosphorus requirement or removal (0.5x, 1x, 1.5x or 2x).  Such an analysis and ability to land apply manure as long as the science-based phosphorus index determines land application is appropriate has been and always will be critical to the livestock industry.

Talking Points

  • NRCS’ effort is to “level the playing field” among the states regarding application of 590
  • The fact is the playing field should not be level.  There are too many legitimate differences in soils, climate, cropping systems, water body sensitivities, etc. to support a single approach.
  • Places where potential for nutrient runoff risk is high should be treated differently from where it is low
  • A rigid national tool is not better science.  States need flexibility in approaches to address nutrient application.  For example, if it is determined that risk of runoff is high, appropriate approaches might be to cut nutrient application or implement soil/water conservation measures
  • This decision should be based on objective scientific soundness, not arbitrary cut-off points
  • Each of the following provisions in the proposed standard is not based on sound science, would prevent the land application of manure on many lands, and would devastate the livestock industry:
    1. Forbid Manure Application on Soils with 10X Soil Test Phosphorus Level:  It is inappropriate to impose an arbitrary cutoff level for soil phosphorus.  Instead, states should be encouraged to implement effective risk-based assessments for P.  The P Index provides this assessment by evaluating scientifically the source and transport issues for each field.  A 10X soil test P level is arbitrary and not correlated to water quality concerns since it is ONLY a source-based threshold, and does not address transport potential
    2. Forbid Manure Application on Soils with 10X Soil Test Potassium Level: Potassium is abundant in many soils across the US.  Where manure has been applied, soil is likely to exceed 10X.
    3. Forbid Manure Application on Frozen and/or Snow-Covered Soils:  In some areas of the country, application to frozen/snow covered grounds is essential for proper manure management.  Management practices should be implemented.
    4. Forbid Manure Application During Periods of Winter Dormancy:  Proper application during winter dormancy, with management practices in place, may be the best time to apply nutrients to allow for mineralization to occur prior to active growing season
    5. Forbid Manure Application During Seasons of High Runoff Potential:  Provision is not defined.  Manure application is day to day management decision and cannot be scheduled by the Farmer’s Almanac
    6. Forbid Application When the Top Two Inches of Soil Are Saturated:  Could prevent the application of wastewater by center pivot irrigation system
    7. The P Application Rate is Pre-determined to be “equal to the recommended phosphorus application, or estimated phosphorus removal in harvested plant biomass . . .” Again, this is an arbitrary cut-off and is not based on the scientific assessment which is at the core of the PI. Fields on which moderate amounts of manure have been applied over past several years would receive a lab recommendation for P of “ZERO” and the crop removal rate will be in the range of 20-80 lbs of P2O5.  Beef cattle manure application rate would be 2-3 tons manure per acre – not feasible for manure spreaders.  Use of the PI is essential.                
  • It is essential that NRCS get the 590 standard right since the standard is a required component of the nutrient management plan portion of many state Clean Water Act NPDES permit programs.
  • NCBA is hopeful the NRCS will use sound science and not adopt a standard that would make it difficult if not impossible to land apply manure on fields where the risk of runoff is minimal. 
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