**Eastern Tennessee / Western North Carolina\
Outdoor Ornamental Nursery Scenario**

[]{.mark}

This scenario is one of a suite of scenarios intended to represent
outdoor ornamental nursery scenarios in the United States. It should be
noted that nurseries are diverse and represent a range of topographic,
cultivation, and plant types. Scenarios, when possible have been
developed to represent conservative nursery practices that will yield
"high-end" runoff, but not unrealistic of actual nurseries in the area.
Similarly, selection of curve numbers are based on best available data
from TR-55 until further calibration can be performed using regional
runoff data, which at the time of scenario development is generally
unavailable for nurseries. Figure 1 provides an overview of available
curve numbers from TR-55 in order to provide context to the relative
magnitude of the curve number used in this scenario. The closest curve
number that could be associated with outdoor nurseries is for
"farmsteads", due to similar cover conditions. Curve numbers are
generally among the highest available, exceeded primarily by soils in
poor condition.

[]{.mark}

This scenario is parameterized to generally represent outdoor ornamental
nursery production in eastern Tennessee/western North Carolina. The
scenario nominally represents outdoor ornamental nurseries in Warren
County, TN since it is the county with the most number of acres in
production in the region. In 2002, the state of Tennessee ranked 4^th^
in the U.S. for total number of ornamental nursery acres in the outdoors
(i.e., not under glass), with nearly 40,500 acres in the open (USDA
2002a). In 2002, North Carolina ranked 9^th^ in the U.S. for outdoor
nursery acreage. In Tennessee, over 50% (21,884 acres) of the total
acreage is located in Warren County which has been referred to as "the
nursery capital of the world". Warren County ranks number 1 in the U.S.
with approximately 21,900 acres of outdoor nurseries in the county
according to the 2002 USDA census of agriculture (USDA 2002a). The total
value of agricultural products sold in Warren Co. in 2002 was
approximately 94 million dollars, of which approximately 87% of the
revenue was generated from the sale of nursery and greenhouse crops.
Warren County produces a large volume of nursery stock and ranks number
1 in the U.S. for nursery stock production (USDA, 2002b). MLRAs 122,
125, 128, and 130 dominate eastern Tennessee and western North Carolina;
however the majority of Warren County is located in MLRA 122.

[]{.mark}

Plants cultivated by outdoor nurseries are diverse. For this scenario,
crop parameters have been selected when possible to be representative of
typical outdoor nursery practices in eastern Tennessee and western North
Carolina. In general, this scenario represents outdoor deciduous nursery
stock, including production shade trees, flowering ornamental trees and
shrubs. Traditional nursery production in the area is in the field and
the majority of nurseries are wholesale (Halcomb, 2002; Craig Adkins,
personal communication). Although container planting is used in the
region, many species are commonly grown in propagation ground beds. As a
general rule local experts recommend that nurseries produce about 70% of
tried and true plants such as sugar maple, dogwoods, pin oak, 'Andora'
juniper, etc. A lesser extent of plants include plants such as clethra,
fothergilla, deciduous holly, hostas, red maple, crab apple, hydrangea,
etc (Halcomb, 2002). In western North Carolina the trend is similar;
plants are grown for landscape size material, and include several
hundred species/cultivars of shade trees, flowering ornamental trees and
shrubs, conifers, and broadleaved evergreens. Up to 40% of nursery
fields can be roadways, field borders, fence rows, wooded areas, and
areas too steep for growing. Fields are generally divided into blocks
divided by roadways (Halcomb, 2002). Irrigation is often used. Methods
are primarily overhead irrigation with travelling gun. Irrigation is
applied to newly planted fields, and to fields that are approaching
permanent wilting point at a rate of one inch of water per acre per 24
hours per week. Trees leaf out in mid-March and senesce in late October
(Craig Adkins, personal communication).

[]{.mark}

Metfile W13882 is the closest meteorological station to Warren County,
TN and is within approximately 60 miles to the southeast of the county
centroid. Its data were collected in Chattanooga, TN located in the
eastern part of the state. The station is located approximately 211
meters above mean sea level (AMSL) which is comparable to McMinnville TN
(central Warren County), which is approximately 290 meters AMSL.
Chattanooga receives an average rainfall of 55 inches (NOAA, 2006).

[]{.mark}

Nearly two-dozen different soils in Warren County have been identified
as fair to very good for nursery production (Halcomb, 2002). Nurseries
require soils that are well drained internally and on the surface. Deep
soils free of large rocks are also important as many outdoor nurseries
grow nursery stock that is dug, balled, and burlapped for sale. Exact
locations and geographic extent of nurseries in the region are not
available; therefore soils were selected based on soil recommendations
listed in Halcomb (2002), the geographic extent of the listed soils in
the area, the drainage group, slope, and erodibility. In developing this
scenario, preference was given to selecting a benchmark soil that is in
hydrologic group "C" or "D", and is capable of supporting outdoor
nurseries (EPA, 2004). The Captina series was selected for this scenario
since it is of large extent in the region (USDA, 2006a) and is the most
common benchmark soil in Warren County that is also in hydrologic group
C. Captina soils are capable of supporting nursery production and are
listed as "fair" soils for the modeled use (Halcomb, 2002). Captina
represents the 90^th^ percentile of vulnerability in drainage for soils
in Warren County (the most extensive benchmark soil in drainage group C
and the third most extensive soil overall in Hydrologic group C). It is
in the 90^th^ percentile for erodibility (0.43) and is within the
typical slope range for outdoor nurseries in the area (Halcomb, 2002;
Craig Adkins, personal communication) (Table 5).

[]{.mark}

Captina is a Hydrologic Group C soil, which represents approximately 2%
of the soils in Warren County. Captina soils have a USLE K factor of
0.43, which is common to eight other soils in Warren County. Based on
representative values from USDA (2006) approximately 67% of Warren
County soils have a pH lower than 5.5, the representative pH of Captina
soils. However, soil pH is not currently a PRZM input parameter and is
not expected to often affect chemical fate in the acidic range. Captina
soils have an A horizon from 0 to 9 inches (0-23 cm) deep, and a B
horizon from 9 to over 60 inches (23-152 cm) deep (USDA, 2006b).

+-----------------+----------+-----------------------------------------+
| []{.mark}       |          |                                         |
|                 |          |                                         |
| **Table 1. PRZM |          |                                         |
| 3.12 Climate    |          |                                         |
| and Time        |          |                                         |
| Parameters for  |          |                                         |
| Eastern TN /    |          |                                         |
| Western NC --   |          |                                         |
| Ornamental      |          |                                         |
| Nurseries.**    |          |                                         |
+-----------------+----------+-----------------------------------------+
| **Parameter**   | *        | **Source/Comments**                     |
|                 | *Value** |                                         |
+-----------------+----------+-----------------------------------------+
| Starting Date   | Jan. 1,  | Meteorological File Chattanooga, TN     |
|                 | 1961     | (W13882)                                |
+-----------------+----------+-----------------------------------------+
| Ending Date     | Dec. 31, | Meteorological File Chattanooga, TN     |
|                 | 1990     | (W13882)                                |
+-----------------+----------+-----------------------------------------+
| Pan Evaporation | 0.75     | PRZM Manual Figure 5.1. Value           |
| Factor (PFAC)   |          | represents most of eastern Tennessee.   |
+-----------------+----------+-----------------------------------------+
| Snowmelt Factor | 0.16     | PRZM Manual Table 5-1. Max of the min   |
| (SFAC)          |          | range of values for mixed               |
|                 |          | coniferous/deciduous open areas.        |
+-----------------+----------+-----------------------------------------+
| Minimum Depth   | 17.5 cm  | PRZM Manual Figure 5.2 (EPA, 1998)      |
| of              |          |                                         |
|                 |          | Set to guidance default for free        |
| Evaporation     |          | draining soils.                         |
| (ANETD)         |          |                                         |
+-----------------+----------+-----------------------------------------+

+-----------------+--------+-------------------------------------------+
| **Table 2. PRZM |        |                                           |
| 3.12 Erosion    |        |                                           |
| and Landscape   |        |                                           |
| Parameters for  |        |                                           |
| Eastern TN /    |        |                                           |
| Western NC --   |        |                                           |
| Ornamental      |        |                                           |
| Nurseries.**    |        |                                           |
+=================+========+===========================================+
| **Parameter**   | **V    | **Source/Comments**                       |
|                 | alue** |                                           |
+-----------------+--------+-------------------------------------------+
| Method to       | 4      | PRZM Manual (EPA, 1998)                   |
| Calculate       | (MUSS) |                                           |
| Erosion         |        |                                           |
| (ERFLAG)        |        |                                           |
+-----------------+--------+-------------------------------------------+
| USLE K Factor   | 0.43   | USDA NRCS Soil Data Mart                  |
| (USLEK)         |        | (http://soildatamart.nrcs.usda.gov/)      |
|                 |        |                                           |
|                 |        | Value listed for the soil series Captina. |
+-----------------+--------+-------------------------------------------+
| USLE LS Factor  | 0.3    | LS equation (Haan and Barfield, 1978)     |
| (USLELS)        |        |                                           |
|                 |        | LS value for 2% slope and 400' slope      |
|                 |        | length                                    |
+-----------------+--------+-------------------------------------------+
| USLE P Factor   | 0.6    | Rows are contoured whenever possible      |
| (USLEP)         |        | (Halcomb, 2002). Set to 0.6 for 1-2 %     |
|                 |        | slope and contouring as per PRZM Scenario |
|                 |        | Guidance (EPA, 2004).                     |
+-----------------+--------+-------------------------------------------+
| Field Area      | 172 ha | Area of Shipman Reservoir watershed (EPA, |
| (AFIELD)        |        | 1999)                                     |
+-----------------+--------+-------------------------------------------+
| NRCS Hyetograph | 3      | PRZM Manual Figure 5.12 (EPA, 1998)       |
| (IREG)          |        |                                           |
+-----------------+--------+-------------------------------------------+
| Slope (SLP)     | 2%     | USDA NRCS Soil Data Mart                  |
|                 |        | (http://soildatamart.nrcs.usda.gov/)      |
|                 |        |                                           |
|                 |        | Mid-point for the soil series Captina.    |
|                 |        | PRZM Scenario Guidance (EPA, 2004).       |
+-----------------+--------+-------------------------------------------+
| Hydraulic       | 600 m  | Shipman Reservoir (EPA, 1999)             |
| Length (HL)     |        |                                           |
+-----------------+--------+-------------------------------------------+
| Irrigation Flag | 2      | Craig Adkins, Area Specialized Agent,     |
| (IRFLAG)        |        | North Carolina Cooperative Extension      |
|                 |        | Service. Irrigation is applied to newly   |
|                 |        | planted fields, and to fields that are    |
|                 |        | approaching permanent wilting point.      |
+-----------------+--------+-------------------------------------------+

+-----------------+--------+-------------------------------------------+
| **Table 3. PRZM |        |                                           |
| 3.12 Crop       |        |                                           |
| Parameters for  |        |                                           |
| Eastern TN /    |        |                                           |
| Western NC --   |        |                                           |
| Ornamental      |        |                                           |
| Nurseries.**    |        |                                           |
+=================+========+===========================================+
| **Parameter**   | **V    | **Source/Comments**                       |
|                 | alue** |                                           |
+-----------------+--------+-------------------------------------------+
| Initial Crop    | 1      | Default value                             |
| (INICRP)        |        |                                           |
+-----------------+--------+-------------------------------------------+
| Initial Surface | 2      | 2 = cover crop. Halcomb (2002) and Craig  |
| Condition       |        | Adkins, Area Specialized Agent, North     |
|                 |        | Carolina Cooperative Extension Service.   |
| (ISCOND)        |        |                                           |
+-----------------+--------+-------------------------------------------+
| Number of       | 1      | Set to number of crops in simulation.     |
| Different Crops |        | Default value.                            |
| (NDC)           |        |                                           |
+-----------------+--------+-------------------------------------------+
| Number of       | 30     | Set to weather data in meteorological     |
| Cropping        |        | file: Chattanooga, TN (W13882).           |
| Periods (NCPDS) |        |                                           |
+-----------------+--------+-------------------------------------------+
| Maximum         | 0.1    | Table 5-4 PRZM manual, light density      |
| rainfall        |        | crops (EPA, 1998).                        |
| interception    |        |                                           |
| storage of crop |        |                                           |
| (CINTCP)        |        |                                           |
+-----------------+--------+-------------------------------------------+
| Maximum Active  | 76 cm  | Craig Adkins, Area Specialized Agent,     |
| Root Depth      |        | North Carolina Cooperative Extension      |
| (AMXDR)         |        | Service.                                  |
+-----------------+--------+-------------------------------------------+
| Maximum Canopy  | 15%    | Up to 40% of nursery field can be covered |
| Coverage        |        | in roads, wooded areas, field borders,    |
| (COVMAX)        |        | and areas to steep to grow, leaving 60%   |
|                 |        | available for production (Halcomb 2002).  |
|                 |        | Assumes light density planting such that  |
|                 |        | one-quarter (15%) of remaining area is    |
|                 |        | canopy.                                   |
+-----------------+--------+-------------------------------------------+
| Maximum Canopy  | 183 cm | Height varies widely as many different    |
| Height (HTMAX)  | (6ft)  | cultivars are grown. Transplants may be   |
|                 |        | up to 6ft tall (Halcomb 2002)             |
+-----------------+--------+-------------------------------------------+
| Soil Surface    | 2      | 2 = cover crop. Halcomb (2002) and Craig  |
| Condition After |        | Adkins, Area Specialized Agent, North     |
| Harvest (ICNAH) |        | Carolina Cooperative Extension Service.   |
+-----------------+--------+-------------------------------------------+
| Date of Crop    | 16     | Craig Adkins, Area Specialized Agent,     |
| Emergence       | /03/61 | North Carolina Cooperative Extension      |
|                 |        | Service. Values are set to keep E/T and   |
| (EMD, EMM,      |        | canopy coverage terms working correctly   |
| IYREM)          |        | for this deciduous scenario. Set to       |
|                 |        | typical leaf bloom dates (March 15).      |
|                 |        | Adjusted to the nearest corresponding     |
|                 |        | RUSLE date (RUSLE Project; Nb0OCOCM).     |
+-----------------+--------+-------------------------------------------+
| Date of Crop    | 15     | Values are set to keep E/T and canopy     |
| Maturity        | /04/61 | coverage terms working correctly for this |
|                 |        | deciduous scenario. Set to 1 month post   |
| (MAD, MAM,      |        | leaf bloom.                               |
| IYRMAT)         |        |                                           |
+-----------------+--------+-------------------------------------------+
| Date of Crop    | 22     | Craig Adkins, Area Specialized Agent,     |
| Harvest (HAD,   | /10/61 | North Carolina Cooperative Extension      |
| HAM, IYRHAR)    |        | Service. Values are set to keep E/T and   |
|                 |        | canopy coverage terms working correctly   |
|                 |        | for this deciduous scenario. Set to       |
|                 |        | typical leaf-off dates.                   |
+-----------------+--------+-------------------------------------------+
| Maximum Dry     | 0.0    | Not used in scenario                      |
| Weight (WFMAX)  |        |                                           |
+-----------------+--------+-------------------------------------------+
| SCS Curve       | 82,    | TR-55, Table 2-2c (USDA 1986). Value for  |
| Number (CN)     | 82, 82 | farmsteads, buildings, lanes, driveways,  |
|                 |        | and surrounding lots. Up to 40% of        |
|                 |        | nursery fields can be covered in roads,   |
|                 |        | wooded areas, field borders, and areas to |
|                 |        | steep to grow, leaving 60% available for  |
|                 |        | production (Halcomb 2002).                |
+-----------------+--------+-------------------------------------------+
| Manning's N     | 0.014  | RUSLE Project; Nb0OCOCM for Asheville, NC |
| Value (MNGN)    |        | orchards with cover in alleyways (USDA,   |
|                 |        | 2000). These data were used to            |
|                 |        | approximate values for nurseries in       |
|                 |        | eastern TN / western North Carolina as no |
|                 |        | data for ornamental nurseries were        |
|                 |        | included in the project.                  |
+-----------------+--------+-------------------------------------------+
| USLE C Factor   | 0      | RUSLE Project; Nb0OCOCM for Asheville, NC |
| (USLEC)         | .058 - | orchards with cover in alleyways (USDA,   |
|                 | 0.273  | 2000). These data were used to            |
|                 |        | approximate values for nurseries in       |
|                 |        | eastern TN / western North Carolina as no |
|                 |        | data for ornamental nurseries were        |
|                 |        | included in the project. Note: RUSLE      |
|                 |        | dates and C factors from the RUSLE        |
|                 |        | project have been reordered and tied to   |
|                 |        | emergence dates.                          |
+-----------------+--------+-------------------------------------------+

+---------------+-------------------+---------------------------------+
| **Table 4.    |                   |                                 |
| PRZM 3.12     |                   |                                 |
| Captina Silt  |                   |                                 |
| Loam Soil     |                   |                                 |
| Parameters    |                   |                                 |
| for Warren    |                   |                                 |
| County,       |                   |                                 |
| Tennessee --  |                   |                                 |
| Ornamental    |                   |                                 |
| Nurseries**   |                   |                                 |
+---------------+-------------------+---------------------------------+
| **Parameter** | **Value**         | **Source/Comments**             |
+---------------+-------------------+---------------------------------+
| Total Soil    | 152 cm            | NRCS Soil Data Mart (SDM)       |
| Depth (CORED) |                   | (htt                            |
|               |                   | p://soildatamart.nrcs.usda.gov) |
+---------------+-------------------+---------------------------------+
| Number of     | 4                 | NRCS Soil Data Mart (SDM)       |
| Horizons      |                   | ([http://soi                    |
| (NHORIZ)      |                   | ldatamart.nrcs.usda.gov](http:/ |
|               |                   | /soildatamart.nrcs.usda.gov/)). |
|               |                   | Top horizon spans scenario      |
|               |                   | horizons 1 and 2 in order to    |
|               |                   | conform to PRZM input           |
|               |                   | requirements. SDM horizons 3 &  |
|               |                   | 4 combined into 1 horizon for   |
|               |                   | simplicity. PRZM Scenario       |
|               |                   | Guidance (EPA, 2004).           |
+---------------+-------------------+---------------------------------+
| Horizon       | 10 cm (HORIZN =   | NRCS Soil Data Mart (SDM)       |
| Thickness     | 1)                | ([http://soi                    |
| (THKNS)       |                   | ldatamart.nrcs.usda.gov](http:/ |
|               | 13 cm (HORIZN =   | /soildatamart.nrcs.usda.gov/)). |
|               | 2)                | Top horizon spans scenario      |
|               |                   | horizons 1 and 2 in order to    |
|               | 38 cm (HORIZN =   | conform to PRZM input           |
|               | 3)                | requirements. PRZM Scenario     |
|               |                   | Guidance (EPA, 2004).           |
|               | 91 cm (HORIZN =   |                                 |
|               | 4)                |                                 |
+---------------+-------------------+---------------------------------+
| Bulk Density  | 1.35 g/cm^3^      | NRCS Soil Data Mart (SDM)       |
| (BD)          | (HORIZN = 1)      | ([http://soi                    |
|               |                   | ldatamart.nrcs.usda.gov](http:/ |
|               | 1.35 g/cm^3^      | /soildatamart.nrcs.usda.gov/)). |
|               | (HORIZN = 2)      | Midpoint of the reported range. |
|               |                   | PRZM Scenario Guidance (EPA,    |
|               | 1.45 g/cm^3^      | 2004).                          |
|               | (HORIZN = 3)      |                                 |
|               |                   |                                 |
|               | 1.53 g/cm^3^      |                                 |
|               | (HORIZN = 4)      |                                 |
+---------------+-------------------+---------------------------------+
| Initial Water | 0.25 cm^3^/cm^3^  | NRCS Soil Data Mart (SDM);      |
| Content       | (HORIZN =1)       | values are mean 1/3-bar water   |
| (THETO)       |                   | contents of Captina soils.      |
|               | 0.25 cm^3^/cm^3^  | Horizon 4 is mean of SDM        |
|               | (HORIZN =2)       | horizons 3 & 4 weighted by      |
|               |                   | horizon thickness. (EPA, 2004). |
|               | 0.29 cm^3^/cm^3^  |                                 |
|               | (HORIZN =3)       |                                 |
|               |                   |                                 |
|               | 0.24 cm^3^/cm^3^  |                                 |
|               | (HORIZN =4)       |                                 |
+---------------+-------------------+---------------------------------+
| Compartment   | 0.1 cm (HORIZN =  | NRCS Soil Data Mart (SDM)       |
| Thickness     | 1)                | ([http://soi                    |
| (DPN)         |                   | ldatamart.nrcs.usda.gov](http:/ |
|               | 1.0 cm (HORIZN =  | /soildatamart.nrcs.usda.gov/)). |
|               | 2)                | PRZM Scenario Guidance (EPA,    |
|               |                   | 2004).                          |
|               | 2.0 cm (HORIZN =  |                                 |
|               | 3)                |                                 |
|               |                   |                                 |
|               | 1.0 cm (HORIZN =  |                                 |
|               | 4)                |                                 |
+---------------+-------------------+---------------------------------+
| Field         | 0.25 cm^3^/cm^3^  | NRCS Soil Data Mart (SDM);      |
| Capacity      | (HORIZN =1)       | values are mean 1/3-bar water   |
| (THEFC)       |                   | contents of Captina soils.      |
|               | 0.25 cm^3^/cm^3^  | Horizon 4 is mean of SDM        |
|               | (HORIZN =2)       | horizons 3 & 4 weighted by      |
|               |                   | horizon thickness. PRZM         |
|               | 0.29 cm^3^/cm^3^  | Scenario Guidance (EPA, 2004).  |
|               | (HORIZN =3)       |                                 |
|               |                   |                                 |
|               | 0.24 cm^3^/cm^3^  |                                 |
|               | (HORIZN =4)       |                                 |
+---------------+-------------------+---------------------------------+
| Wilting Point | 0.10 cm^3^/cm^3^  | NRCS Soil Data Mart (SDM);      |
| (THEWP)       | (HORIZN =1)       | values are mean 15-bar water    |
|               |                   | contents of Captina soils.      |
|               | 0.10 cm^3^/cm^3^  | Horizon 4 is mean of SDM        |
|               | (HORIZN =2)       | horizons 3 & 4 weighted by      |
|               |                   | horizon thickness. PRZM         |
|               | 0.14 cm^3^/cm^3^  | Scenario Guidance (EPA, 2004).  |
|               | (HORIZN =3)       |                                 |
|               |                   |                                 |
|               | 0.14 cm^3^/cm^3^  |                                 |
|               | (HORIZN =4)       |                                 |
+---------------+-------------------+---------------------------------+
| Organic       | 1.2% (HORIZN = 1) | NRCS SDM; values for horizons 1 |
| Carbon        |                   | to 3 = mean %OM / 1.724. PRZM   |
| Content (OC)  | 1.2% (HORIZN = 2) | Scenario Guidance (EPA, 2004).  |
|               |                   |                                 |
|               | 0.15% (HORIZN =   |                                 |
|               | 3)                |                                 |
|               |                   |                                 |
|               | 0.15% (HORIZN =   |                                 |
|               | 4)                |                                 |
+---------------+-------------------+---------------------------------+

***Sensitive Parameter Uncertainties***

[Meteorological File]{.underline}

As characterized above, Metfile W13882 (Chattanooga TN) is the closest
metfile to Warren County, which was used to represent this scenario. The
metfile is located approximately 60 miles from Warren County and is
generally representative of the area. However, the terrain is
mountainous and elevations vary widely. Rainfall in eastern TN and
western NC may be over or underestimated due to terrain and orographic
effects. A sensitivity analysis of meteorological stations in the
surrounding region would reduce uncertainty in the PRZM results.

[]{.mark}

[Slope]{.underline}

The scenario USLELS value was calculated with the Haan and Barfield
equation (1978) using a 2% slope and an assumed 400-foot slope length,
as per PRZM scenario development guidance (EPA, 2004). A slope of 2% was
selected because it is midpoint of the range for Captina soils according
to USDA (USDA 2006b). This value is also supported by (Halcomb 2002)
which indicates nurseries should not be located on steep slopes and by
Craig Adkins (Area Specialized Agent, North Carolina Cooperative
Extension Service, personal communication) who indicated that slopes may
range from 0-6%. This scenario may underestimate runoff for nurseries
located on slopes greater than 2%

[]{.mark}

[USLE C Factor and Manning's N Value]{.underline}

[]{.mark}

The RUSLE Project does not include data for ornamental nursery crops.
Therefore, USLE C Factor and Manning's N values were selected from data
on North Carolina orchards with cover in the alleyways, due to the
similarities between conditions. Halcomb (2002) suggests that up to 40%
of nursery fields can be covered in roads, wooded areas, field borders,
and areas to steep to grow, leaving 60% available for production. Roads,
travel lanes, waterways, etc. should be covered in fescue (Halcomb,
2002) or other permanent ground cover/cover crop adhering to Nursery
Crop Best Management Practices for field nurseries (Craig Adkins,
personal communication). Of the available locations, Asheville North
Carolina has the most similar meteorological conditions and cover in
alley ways as this scenario.

[]{.mark}

[Soil Data]{.underline}

No geospatial data were available to determine the exact locations and
geographic extent of nurseries in the region. The USGS National Land
Cover Data set includes a nurseries classification; however it indicates
that no nurseries are present in Warren County, even though it is the
"nursery capital of the world". This is likely due to the resolution of
the data (30 m) and age of the data set (based on 1970's and 80's
imagery). As a result, soils were selected based on soil recommendations
listed in Halcomb (2002), the geographic extent of the listed soils in
the area, the drainage group, slope, and erodibility. The soil selected
is a hydrologic group C soil; however there is some evidence that
nurseries in the region are located primarily on hydrologic group B
soils (Craig Adkins, personal communication). Better geographic herefore
runoff and erosion may be potentially overestimated

[]{.mark}

[Crop Parameters]{.underline}

Outdoor ornamental nurseries are highly diverse in the numbers, sizes,
and types of plants grown. Ornamental nurseries also vary in the
cultivation methods which can range from potted plants (container
operations) to field nurseries that may harvest and package plants as
bare root or balled and burlapped. This scenario has been parameterized
to be representative of the most "typical" nursery plants in the area
(see description above).

[Curve Number]{.underline}

The curve number is the most sensitive parameter in PRZM scenarios. The
curve number for this scenario was based on TR-55 (Table 2-2c). Up to
40% of nursery field can be covered in roads, wooded areas, field
borders, and areas to steep to grow, leaving 60% available for
production (Halcomb 2002). Therefore the land use type closest to this
scenario was the value for a hydrologic group C soil representative of
farmsteads, buildings, lanes, driveways, and surrounding lots. Runoff
and erosion may be under or over-estimated for alternative nursery
operations and model validation has high value in this regard. Based on
preliminary investigation, no runoff data are available for validating
runoff from outdoor nursery operations in this geographic area.

![](media/image1.png){width="9.129166666666666in"
height="5.352083333333334in"}

**Figure 1. TR-55 (USDA, 1986) Farmstead curve number used for scenario
development relative to other available cover types, soil treatments,
and conditions.**

<table>
<colgroup>
<col style="width: 18%" />
<col style="width: 6%" />
<col style="width: 7%" />
<col style="width: 10%" />
<col style="width: 10%" />
<col style="width: 6%" />
<col style="width: 7%" />
<col style="width: 7%" />
<col style="width: 8%" />
<col style="width: 9%" />
<col style="width: 7%" />
</colgroup>
<tbody>
<tr class="odd">
<td colspan="11"><strong>Table 5. Soils of Warren County, TN Ranked by
Area<sup>a,b</sup>.</strong></td>
</tr>
<tr class="even">
<td><strong>Soil</strong></td>
<td><strong>Total Acres</strong></td>
<td><strong>% Area</strong></td>
<td><strong>Hydrologic Group</strong></td>
<td><strong>Erodibility</strong></td>
<td><strong>Slope</strong></td>
<td><strong>pH</strong></td>
<td><strong>OM</strong></td>
<td><strong>Sand</strong></td>
<td><strong>Siltv</strong></td>
<td><strong>Clay</strong></td>
</tr>
<tr class="odd">
<td>WAYNESBORO</td>
<td>61090</td>
<td>22.0%</td>
<td>B</td>
<td>0-0.28</td>
<td>0-12</td>
<td>0-5</td>
<td>0-2</td>
<td>0-66</td>
<td>0-37.9</td>
<td>0-20</td>
</tr>
<tr class="even">
<td>MOUNTVIEW</td>
<td>26769</td>
<td>9.6%</td>
<td>B</td>
<td>0.43</td>
<td>2-12</td>
<td>5</td>
<td>0.75-2</td>
<td>6.9-11.4</td>
<td>68.1-68.6</td>
<td>20-25</td>
</tr>
<tr class="odd">
<td>BAXTER</td>
<td>21505</td>
<td>7.7%</td>
<td>B</td>
<td>0.28-0.37</td>
<td>12-50</td>
<td>5-5.5</td>
<td>0.75-2</td>
<td>18.1-42.1</td>
<td>37.9-53.8</td>
<td>19.5-31</td>
</tr>
<tr class="even">
<td>DICKSON</td>
<td>20843</td>
<td>7.5%</td>
<td>C</td>
<td>0.43</td>
<td>1-4</td>
<td>5</td>
<td>2</td>
<td>14</td>
<td>71</td>
<td>15</td>
</tr>
<tr class="odd">
<td>ROCKLAND</td>
<td>19464</td>
<td>7.0%</td>
<td>D</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
</tr>
<tr class="even">
<td>STONY</td>
<td>17780</td>
<td>6.4%</td>
<td>B</td>
<td>0.28</td>
<td>5-30</td>
<td>5</td>
<td>2</td>
<td>44.3</td>
<td>40.7</td>
<td>15</td>
</tr>
<tr class="odd">
<td>CHRISTIAN</td>
<td>16167</td>
<td>5.8%</td>
<td>C</td>
<td>0.37-0.43</td>
<td>1-20</td>
<td>4.6-5.5</td>
<td>0.5-2</td>
<td>14.2-20.5</td>
<td>49-71.8</td>
<td>14-33.5</td>
</tr>
<tr class="even">
<td>HUNTINGTON</td>
<td>15270</td>
<td>5.5%</td>
<td>B</td>
<td>0.28-0.32</td>
<td>0-2</td>
<td>6.7</td>
<td>2.5</td>
<td>11.3-22.4</td>
<td>67.7-67.7</td>
<td>21-22.5</td>
</tr>
<tr class="odd">
<td>CUMBERLAND</td>
<td>9257</td>
<td>3.3%</td>
<td>B</td>
<td>0.32-0.37</td>
<td>0-12</td>
<td>5.6</td>
<td>0.75-2.5</td>
<td>18.1-22.4</td>
<td>50.9-55.1</td>
<td>22.5-31</td>
</tr>
<tr class="even">
<td>HARTSELLS</td>
<td>7767</td>
<td>2.8%</td>
<td>B</td>
<td>0.28</td>
<td>4-9</td>
<td>4.6</td>
<td>1.5</td>
<td>44.8</td>
<td>41.2</td>
<td>14</td>
</tr>
<tr class="odd">
<td>RAMSEY</td>
<td>5659</td>
<td>2.0%</td>
<td>D</td>
<td>0-0.2</td>
<td>0-20</td>
<td>0-5</td>
<td>0-1</td>
<td>0-64.8</td>
<td>0-40</td>
<td>0-16.5</td>
</tr>
<tr class="even">
<td>CAPTINA<sup>c</sup></td>
<td>5305</td>
<td>1.9%</td>
<td>C</td>
<td>0.43</td>
<td>1-3</td>
<td>5.5</td>
<td>2</td>
<td>14.2</td>
<td>71.8</td>
<td>14</td>
</tr>
<tr class="odd">
<td>GUTHRIE</td>
<td>5254</td>
<td>1.9%</td>
<td>D</td>
<td>0.43</td>
<td>0-2</td>
<td>4.6</td>
<td>1.5</td>
<td>13.6</td>
<td>68.9</td>
<td>17.5</td>
</tr>
<tr class="even">
<td>ETOWAH</td>
<td>5125</td>
<td>1.8%</td>
<td>B</td>
<td>0.37-0.37</td>
<td>0-30</td>
<td>4.3-5</td>
<td>2-3.5</td>
<td>11.4-26.3</td>
<td>52.7-68.6</td>
<td>20-21</td>
</tr>
<tr class="odd">
<td>LINDSIDE</td>
<td>4655</td>
<td>1.7%</td>
<td>C</td>
<td>0.32</td>
<td>0-2</td>
<td>6.5</td>
<td>2.5</td>
<td>11.3</td>
<td>67.7</td>
<td>21</td>
</tr>
<tr class="even">
<td>LAWRENCE</td>
<td>4250</td>
<td>1.5%</td>
<td>C</td>
<td>0.43</td>
<td>0-2</td>
<td>5.5</td>
<td>2</td>
<td>14</td>
<td>71</td>
<td>15</td>
</tr>
<tr class="odd">
<td>SEQUATCHIE</td>
<td>3732</td>
<td>1.3%</td>
<td>B</td>
<td>0.32</td>
<td>0-12</td>
<td>5</td>
<td>2-2.5</td>
<td>41.1-43</td>
<td>36.9-39.5</td>
<td>17.5-22</td>
</tr>
<tr class="even">
<td>RAMSEY-JEFFERSON</td>
<td>3623</td>
<td>1.3%</td>
<td>D</td>
<td>0.2</td>
<td>20-45</td>
<td>5</td>
<td>1</td>
<td>64.8</td>
<td>18.7</td>
<td>16.5</td>
</tr>
<tr class="odd">
<td>TALBOTT</td>
<td>3505</td>
<td>1.3%</td>
<td>C</td>
<td>0.32-0.37</td>
<td>5-20</td>
<td>5.6</td>
<td>1.25</td>
<td>17.9-20.5</td>
<td>50.1-54.5</td>
<td>25-32</td>
</tr>
<tr class="even">
<td>ALLEN</td>
<td>3293</td>
<td>1.2%</td>
<td>B</td>
<td>0.2-0.28</td>
<td>2-30</td>
<td>5</td>
<td>0.5-1.75</td>
<td>34-43</td>
<td>37-38.5</td>
<td>18.5-29</td>
</tr>
<tr class="odd">
<td>JEFFERSON</td>
<td>2671</td>
<td>1.0%</td>
<td>B</td>
<td>0.24-0.28</td>
<td>0-20</td>
<td>5-6.7</td>
<td>2-2.5</td>
<td>11.3-67.2</td>
<td>15.3-67.7</td>
<td>15-21</td>
</tr>
<tr class="even">
<td>LINKER</td>
<td>2432</td>
<td>0.9%</td>
<td>B</td>
<td>0.37</td>
<td>2-12</td>
<td>5</td>
<td>2</td>
<td>42.1</td>
<td>37.9</td>
<td>20</td>
</tr>
<tr class="odd">
<td>SANGO</td>
<td>2264</td>
<td>0.8%</td>
<td>C</td>
<td>0.43</td>
<td>0-2</td>
<td>5</td>
<td>2</td>
<td>14.3</td>
<td>72.7</td>
<td>13</td>
</tr>
<tr class="even">
<td>WHITWELL</td>
<td>1488</td>
<td>0.5%</td>
<td>C</td>
<td>0.24</td>
<td>0-2</td>
<td>5.3</td>
<td>2</td>
<td>43</td>
<td>39.5</td>
<td>17.5</td>
</tr>
<tr class="odd">
<td>STASER</td>
<td>1413</td>
<td>0.5%</td>
<td>B</td>
<td>0.32</td>
<td>0-25</td>
<td>5.9-6.5</td>
<td>3</td>
<td>65.6-66.5</td>
<td>14.9-15</td>
<td>18.5-19</td>
</tr>
<tr class="even">
<td>MELVIN</td>
<td>1263</td>
<td>&lt;0.5%</td>
<td>D</td>
<td>0.43</td>
<td>0-2</td>
<td>6.7</td>
<td>2</td>
<td>14.1</td>
<td>71.4</td>
<td>14.5</td>
</tr>
<tr class="odd">
<td>GULLIED</td>
<td>860</td>
<td>&lt;0.5%</td>
<td> </td>
<td>0</td>
<td>0-0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
</tr>
<tr class="even">
<td>MINVALE</td>
<td>720</td>
<td>&lt;0.5%</td>
<td>B</td>
<td>0.37</td>
<td>2-12</td>
<td>5</td>
<td>2</td>
<td>22.4</td>
<td>55.1</td>
<td>22.5</td>
</tr>
<tr class="odd">
<td>SWAIM</td>
<td>570</td>
<td>&lt;0.5%</td>
<td>D</td>
<td>0.32</td>
<td>3-10</td>
<td>5.5</td>
<td>1.25</td>
<td>17</td>
<td>57</td>
<td>26</td>
</tr>
<tr class="even">
<td>COBBLY</td>
<td>442</td>
<td>&lt;0.5%</td>
<td>B</td>
<td>0.28</td>
<td>0-5</td>
<td>5</td>
<td>2</td>
<td>66.8</td>
<td>19.2</td>
<td>14</td>
</tr>
<tr class="odd">
<td>BRUNO</td>
<td>431</td>
<td>&lt;0.5%</td>
<td>A</td>
<td>0.15</td>
<td>1-3</td>
<td>6.8</td>
<td>1.25</td>
<td>77.7</td>
<td>16.3</td>
<td>6</td>
</tr>
<tr class="even">
<td>BODINE</td>
<td>268</td>
<td>&lt;0.5%</td>
<td>B</td>
<td>0.37</td>
<td>20-45</td>
<td>4.6</td>
<td>1.5</td>
<td>30.4</td>
<td>55.6</td>
<td>14</td>
</tr>
<tr class="odd">
<td>ELKINS</td>
<td>242</td>
<td>&lt;0.5%</td>
<td>D</td>
<td>0.37</td>
<td>0-2</td>
<td>4.3</td>
<td>3.5</td>
<td>11.4</td>
<td>68.6</td>
<td>20</td>
</tr>
<tr class="even">
<td>DUNNING</td>
<td>177</td>
<td>&lt;0.5%</td>
<td>D</td>
<td>0.32</td>
<td>0-2</td>
<td>6.7</td>
<td>3.5</td>
<td>19</td>
<td>45</td>
<td>36</td>
</tr>
<tr class="odd">
<td>LIMESTONE</td>
<td>0</td>
<td>&lt;0.5%</td>
<td>C</td>
<td>0.43</td>
<td>0-2</td>
<td>5.5</td>
<td>2</td>
<td>14</td>
<td>71</td>
<td>15</td>
</tr>
<tr class="even">
<td colspan="11"><p>Notes:</p>
<p><sup>a</sup> pH, OM, Sand, Silt, and Clay are based on representative
values from USDA Soil Data Mart.</p>
<p><sup>b</sup> Table excludes areas for mines and water</p>
<p><sup>c</sup> Captina soils are the most extensive benchmark soil in
hydrologic group C.</p></td>
</tr>
</tbody>
</table>

**Literature Cited**

EPA. 1998. Carsel, R.F., J.C. Imhoff, P.R. Hummel, J.M. Cheplick, and
A.S. Donigian, Jr. PRZM-3, A Model for Predicting Pesticide and Nitrogen
Fate in the Crop Root and Unsaturated Soil Zones: Users Manual for
Release 3.0. National Exposure Research Laboratory, Office of Research
and Development, U.S. Environmental Protection Agency, Athens, GA.

EPA. 1999. Jones, R.D., J. Breithaupt, J. Carleton, L. Libelo, J. Lin,
R. Matzner, and R. Parker. Guidance for Use of the Index Reservoir in
Drinking Water Exposure Assessments. Environmental Fate and Effects
Division, Office of Pesticide Programs, U.S. Environmental Protection
Agency, Washington, DC.

EPA. 2004. Abel, S.A. Procedure for Conducting Quality Assurance and
Quality Control of Existing and New PRZM Field and Orchard Crop Standard
Scenarios. Environmental Fate and Effects Division, Office of Pesticide
Programs, U.S. Environmental Protection Agency, Washington, DC. Revised
2004.

Haan, C.T. and B.J. Barfield. 1978. Hydrology and Sedimentology of
Surface Mined Lands. Office of Continuing Education and Extension,
College of Engineering, University of Kentucky, Lexington KY 40506. pp
286.

Halcomb, M. 2002. Nursery Field Production. University of Tennessee
Agricultural extension Service. Online at:
[www.utextension.utk.edu/hbin/Field Prod rev w
equip.pdf](http://www.utextension.utk.edu/hbin/Field Prod rev w equip.pdf).

NOAA. 2006. Climate Normals at Major Weather Observing Stations in all
50 States, Puerto Rico, and Pacific Islands. National Oceanic and
Atmospheric Administration (NOAA), Environmental Satellite, Data, and
Information Service. Online at:
[http://www1.ncdc.noaa.gov/pub/data/ccd-data](http://www1.ncdc.noaa.gov/pub/data/ccd-data/).

USDA. 1986. Urban Hydrology for Small Watersheds. United States
Department of Agriculture, Natural Resources Conversation Service.
Technical Release 55.

USDA. 2000. Revised Universal Soil Loss Equation (RUSLE) EPA Pesticide
Project. U.S. Department of Agriculture, National Resources Conservation
Service (NRCS) and Agricultural Research Service (ARS).

USDA. 2002a. 2002 Census of Agriculture. U.S. Department of Agriculture,
National Agricultural Statistics Service (NASS). Online at:
<http://www.nass.usda.gov/census/census02/preliminary/2002censusdates.htm>.

USDA. 2002b Census of Agriculture County Profile for Warren County,
Tennessee. United States Department of Agriculture, Tennessee
Agricultural Statistics Service. Online at:
<http://www.nass.usda.gov/census/census02/profiles/tn/cp47177.PDF>

USDA. 2006a. Official Series Description -- CAPTINA Series. U.S.
Department of Agriculture, Natural Resources Conservation Service
(NRCS). October. 2006. Online at:
<http://ortho.ftw.nrcs.usda.gov/cgi-bin/osd/osdname.cgi?-P>.

USDA. 2006b. Soil Survey Areas of Warren County, Tennessee. U.S.
Department of Agriculture, Natural Resources Conservation Service
(NRCS), Soil Data Mart. October. 2, 2006. Online at:
[http://soildatamart.nrcs.usda.gov](http://soildatamart.nrcs.usda.gov/).

**Contacts**

**Craig R. Adkins**

Area Specialized Agent\
North Carolina Cooperative Extension Service

120 Hospital Avenue, NE Suite 1

Lenoir, NC

Phone: 828-757-1290

Email: <Craig_Adkins@ncsu.edu>

**Marcus A. Halcomb**

Extension Area Specialist Nursery Production

University of Tennessee

201 Locust Street, Suite 10

McMinneville, TN

Phone: 931-473-8484

Email: <mhalcomb@tennessee.edu>