Illinois Environmental Protection Agency Crooked Creek Watershed TMDL Implementation Plan
38 Draft
5.2.1 Effectiveness
The effectiveness of nutrient management plans (application rates, methods, and timing) in reducing
phosphorus loading from agricultural land will be site specific. The following reductions are reported in
the literature:
• 35 percent average reduction of total phosphorus load reported in Pennsylvania (USEPA, 2003).
• 20 to 50 percent total phosphorus load reductions with subsurface application at agronomic rates
(HWRCI, 2005).
• 60 to 70 percent reduction in dissolved phosphorus concentrations and 20 percent reduction in
total phosphorus concentrations when fertilizer is incorporated to a minimum depth of two inches
prior to planting (HWRCI, 2005).
• 60 to 70 percent reduction in dissolved phosphorus concentrations and 20 to 50 percent reduction
in total phosphorus with subsurface application, such as deep placement (HWRCI, 2005).
• 60 percent reduction in runoff concentrations of phosphorus when the following precipitation
event occurred 10 days after fertilizer application, as opposed to 24 hours after application
(HWRCI, 2005).
• Nutrient management plans will also reduce the dissolved oxygen impairments in the watershed
by reducing the nutrients available to stimulate eutrophication.
5.2.2 Costs
A good nutrient management plan should address the rates, methods, and timing of fertilizer application.
To determine the appropriate fertilizer rates, consultants in Illinois typically charge $6 to $18 per acre,
which includes soil testing, manure analysis, scaled maps, and site specific recommendations for fertilizer
management (USEPA, 2003). The CCSWCD (2003) estimates savings of approximately $10/ac during
each plan cycle (4 years) by applying fertilizer at recommended rates. Actual savings (or costs) depend
on the reduction (or increase) in fertilizer application rates required by the nutrient management plan as
well as other farm management recommendations.
Placing the fertilizer below and to the side of the seed bed (referred to as banding) reduces the required
application by one third to one half to achieve the same crop yields. In Champaign County, phosphorus
application rates were reduced by approximately 13 lb/ac with this method. The equipment needed for
deep placement costs up to $113,000 (Stikkers, 2007). Alternatively the equipment can be rented or the
entire process hired out. The Heartland Regional Water Coordination Initiative lists the cost for deep
placement of phosphorus fertilizer at $3.50/ac per application (HRWCI, 2005).
Table 5-4 summarizes the assumptions used to develop the annualized cost for this BMP.
Table 5-4. Costs Calculations for Nutrient Management Plans.
Item Costs and Frequency Annualized Costs (Savings)
Soil Testing and
Determination of Rates
Costs $6/ac to $18/ac
Every four years
$1.50/ac/yr to $4.50/ac/yr
Savings on Fertilizer Saves $10/ac
Every four years
($2.50/ac/yr)
Deep Placement of
Phosphorus
Costs $3.50/ac
Every two years
$1.75/ac/yr
Average Annual Costs $0.75/ac/yr to $3.75/ac/yr