**Michigan Melons**

The Michigan melons scenario was developed to represent an environment
in which melons are grown in an area where rainfall is high and soils
are more vulnerable to runoff than most places where melons are grown in
the state. The Michigan melon crops include cantaloupe, honeydew, and
watermelon. Based on the 2002 USDA National Agricultural Statistics
Summary, cantaloupe production accounted for approximately 70% of the
crop acreage for the above three melon crops (USDA, 2005). In 2002,
294,045 acres of melons were grown nationally. Michigan ranked 23^rd^ in
the nation in production of melons with 1,381 acres or 0.5% of the
national acreage.

Melons belong to the cucurbit family of plants, known as Cucurbitaceae,
which includes cucumbers, gourds, squash, and pumpkins. There are
several different genus names used in the family. Cantaloupes (*Cucumis
melo* L. var. *antalupensis*) and honeydews (*Cucumis melo* L. var.
*inodorus*) are classified in the same genus. Mixed melons, including
crenshaw, casaba, Santa Claus, Persian, Juan Canary, piel de sapo, and
other melon types are in this genus, while watermelons are in a
different genus *Citrullus lanatus* (Thunb.) Matsum & Nakai.

Melons in Michigan tend to be grown mostly in counties that are adjacent
to the Great Lakes in the southern portion of the state. Monroe County
has the largest melon production (236 acres) and is located in the
southeast corner of the state along Lake Erie. Unlike the other states
in the Midwest for which June is the wettest month, the wettest months
in Michigan are August and September.

  -------------- -------------------- ------------------ ------------------
  **Table 1.**                                           
  Candidate                                              
  Weather                                                
  Stations in                                            
  Michigan.                                              

  Station ID     Location             Annual Average     June Average
                                      Precipitation      Precipitation

  W14826         Flint, MI            31.6 in            3.1 in

  W14836         Lansing, MI          31.5 in            3.6 in

  W14840         Muskegon, MI         32.9 in            2.6 in

  W14847         Sault Ste. Marie, MI 34.7 in            3.0 in

  W14850         Traverse City, MI    33.5 in            3.3 in

  W94814         Houghton, MI         33.8 in            2.8 in

  **W94847\***   **Detroit, MI**      **32.9 in**        **3.6 in**

  W94849         Alpena, MI           28.4 in            2.6 in

  W94860         Grand Rapids, MI     37.1               3.7 in
  -------------- -------------------- ------------------ ------------------

\* The weather station selected for the Michigan melon scenario is
Detroit.

The candidate Michigan weather stations in the southern part of the
state include Muskegon, Lansing, Detroit and Grand Rapids (Table 1).
Since melons are mostly grown in counties adjacent to the Great Lakes,
it is reasonable to assume that proximity to the lakes is an important
consideration. Of these four cities, Muskegon is located directly on
Lake Michigan, and Detroit is located on Lake St. Clair, about 10 miles
north of Lake Erie. Both locations have nearly identical precipitation
with a mean annual precipitation of 32.9 inches. However, Detroit
receives somewhat more rainfall in the spring while precipitation in
Muskegon is greater in the fall. Since pesticide applications are more
prevalent around the time of planting rather than harvest, melon fields
near Detroit would be expected to generate more pesticide runoff than
those near Muskegon. For these reasons, Monroe County, located just
south of Detroit, was chosen as the site for the Michigan melon
scenario.

The site for this scenario is in MLRA L99, the Erie-Huron Lake Plain.
This area is a nearly level lake plain with a few scattered sandy
ridges, representing past shorelines and moraines. Soils in this area
have dominantly formed in till, moraines, and lake plains. (USDA, 2006).
Corn, soybeans, winter wheat and hay are the dominant crops in this
area. Monroe County is part of the Great Lakes Basin.

The soil selected for the scenario is the Selfridge loamy sand, which is
classified as loamy, mixed, active, mesic Aquic Arenic Hapludalf. The
Selfridge soil is a benchmark soil in Hydrologic Group B. Although Group
C soils are extensive in Monroe County, melons are not tolerant of
poorly drained soils, so a spatially extensive Group B soil was chosen
to represent a vulnerable soil that is used for melon agriculture in
this county. The Selfridge soil series description[^1] lists vegetables
among the crops grown on the series. The Selfridge soil covers 12.9% of
the land area in the county. Slopes range from 0 to 3% in this part of
the county.

+-----------------+----------+-----------------------------------------+
| **Table 2.**    |          |                                         |
| PRZM 3.12.2     |          |                                         |
| Climate and     |          |                                         |
| Time Parameters |          |                                         |
| for Monroe      |          |                                         |
| County, MI      |          |                                         |
| Melon Scenario. |          |                                         |
+-----------------+----------+-----------------------------------------+
| Parameter       | Value    | Source/Comments                         |
+-----------------+----------+-----------------------------------------+
| Starting Date   | Jan. 1,  | Meteorological File from Detroit, MI    |
|                 | 1961     | (W94847)                                |
+-----------------+----------+-----------------------------------------+
| Ending Date     | Dec. 31, | Meteorological File from Detroit, MI    |
|                 | 1990     | (W94847)                                |
+-----------------+----------+-----------------------------------------+
| Pan Evaporation | 0.77     | PRZM Manual Figure 5.1. (USEPA, 2006)   |
| Factor (PFAC)   |          |                                         |
+-----------------+----------+-----------------------------------------+
| Snowmelt Factor | 0.36 cm  | Maximum value of minimum range of PRZM  |
| (SFAC)          | °C^-1^   | Manual Table 5.1 (USEPA, 2006)          |
+-----------------+----------+-----------------------------------------+
| Minimum Depth   | 17.5 cm  | PRZM Manual (USEPA 2006) Average of     |
| of              |          | 15-20 cm                                |
|                 |          |                                         |
| Evaporation     |          |                                         |
| (ANETD)         |          |                                         |
+-----------------+----------+-----------------------------------------+
| Pan Factor Flag | 0        | Pan Factor Flag set to read from        |
| (IPEIND)        |          | weather data as per guidance (USEPA,    |
|                 |          | 2004)                                   |
+-----------------+----------+-----------------------------------------+

USLE C factor and Manning's N values are from a RUSLE assessment for
mulch tilled strawberries (RUSLE Project; LA2STSTN) using weather data
from Grand Rapids. This set of values was chosen as it was in the same
region of the country and the data set generated using strawberries was
the most similar crop available for this area of the country.

+-----------------+----------+-----------------------------------------+
| **Table 3.**    |          |                                         |
| PRZM 3.12.2     |          |                                         |
| Erosion and     |          |                                         |
| Landscape       |          |                                         |
| Parameters for  |          |                                         |
| Monroe County,  |          |                                         |
| MI Melon        |          |                                         |
| Scenario.       |          |                                         |
+=================+==========+=========================================+
| Parameter       | Value    | Source/Comments                         |
+-----------------+----------+-----------------------------------------+
| Method to       | 4 (MUSS) | PRZM Manual (USEPA, 2006)               |
| Calculate       |          |                                         |
| Erosion         |          |                                         |
| (ERFLAG)        |          |                                         |
+-----------------+----------+-----------------------------------------+
| USLE K Factor   | 0.17     | USDA NRCS Soil Data Mart                |
| (USLEK)         | tons     | (http://soildatamart.nrcs.usda.gov/)    |
|                 | EI^-1\*^ |                                         |
+-----------------+----------+-----------------------------------------+
| USLE LS Factor  | 0.25     | Value listed for 1.5% slope at 400 feet |
| (USLELS)        |          | using equation in Hann and Barfield     |
|                 |          | (1978)                                  |
+-----------------+----------+-----------------------------------------+
| USLE P Factor   | 1        | No contouring(USEPA, 2006)              |
| (USLEP)         |          |                                         |
+-----------------+----------+-----------------------------------------+
| Field Area      | 172 ha   | Area of Shipman Reservoir watershed     |
| (AFIELD)        |          | (EPA, 1999)                             |
+-----------------+----------+-----------------------------------------+
| NRCS Hyetograph | 3        | PRZM Manual Figure 5.8 (USEPA, 2006)    |
| (IREG)          |          |                                         |
|                 |          | Type 2, IREG=3                          |
+-----------------+----------+-----------------------------------------+
| Slope (SLP)     | 1.5%     | Mean value for Selfridge loamy sand,    |
|                 |          | weighted for acreage                    |
+-----------------+----------+-----------------------------------------+
| Hydraulic       | 600 m    | Shipman Reservoir (EPA, 1999)           |
| Length (HL)     |          |                                         |
+-----------------+----------+-----------------------------------------+
| Irrigation Flag | 0        | Irrigation off                          |
| (IRFLAG)        |          |                                         |
+-----------------+----------+-----------------------------------------+
| \* EI = 100     |          |                                         |
| ft-tons \* in/  |          |                                         |
| acre\*hr        |          |                                         |
+-----------------+----------+-----------------------------------------+

+-----------------+----------+-----------------------------------------+
| **Table 4.**    |          |                                         |
| PRZM 3.12.2     |          |                                         |
| Crop Parameters |          |                                         |
| for Monroe      |          |                                         |
| County, MI      |          |                                         |
| Melon Scenario. |          |                                         |
+=================+==========+=========================================+
| Parameter       | Value    | Source/Comments                         |
+-----------------+----------+-----------------------------------------+
| Initial Crop    | 1        | Set to 1 for all crops (EPA, 2004).     |
| (INICRP)        |          |                                         |
+-----------------+----------+-----------------------------------------+
| Initial Surface | 1        | 1= fallow; default parameter is ignored |
| Condition       |          | as ERFLAG \> 0.                         |
|                 |          |                                         |
| (ISCOND)        |          |                                         |
+-----------------+----------+-----------------------------------------+
| Number of       | 1        | Set to number of crops in simulation.   |
| Different Crops |          |                                         |
| (NDC)           |          |                                         |
+-----------------+----------+-----------------------------------------+
| Number of       | 30       | Set to weather data in meteorological   |
| Cropping        |          | file: Detroit, MI (W94847).             |
| Periods (NCPDS) |          |                                         |
+-----------------+----------+-----------------------------------------+
| Maximum         | 0.25 cm  | Moderate to heavy canopy PRZM table     |
| Rainfall        |          | 5-4. Value consistent with TX melons    |
| Interception    |          | (EPA, 2004).                            |
| Storage of Crop |          |                                         |
| (CINTCP)        |          |                                         |
+-----------------+----------+-----------------------------------------+
| Maximum Active  | 46 cm    | Kemble JK. Basics of crop irrigation.   |
| Root Depth      |          | Alabama cooperative extension system.   |
| (AMXDR)         |          | ANR-1169 April 2000                     |
+-----------------+----------+-----------------------------------------+
| Maximum Canopy  | 100%     | Value consistent with TX melons (EPA,   |
| Coverage        |          | 2004).                                  |
| (COVMAX)        |          |                                         |
+-----------------+----------+-----------------------------------------+
| Soil Surface    | 3        | 3 = residue. Melons are picked and      |
| Condition After |          | packed directly from the vines in the   |
| Harvest (ICNAH) |          | field (USDA, 1998).                     |
+-----------------+----------+-----------------------------------------+
| Date of Crop    | 30/04/61 | USDA Crop Profile for cantaloupes in IN |
| Emergence       |          | (1998). Plant seedlings, so emergence = |
|                 |          | planting.                               |
| (EMD, EMM,      |          |                                         |
| IYREM)          |          |                                         |
+-----------------+----------+-----------------------------------------+
| Date of Crop    | 25/06/61 | USDA Crop Profile for cantaloupes in IN |
| Maturity        |          | (1998)                                  |
|                 |          |                                         |
| (MAD, MAM,      |          |                                         |
| IYRMAT)         |          |                                         |
+-----------------+----------+-----------------------------------------+
| Date of Crop    | 15/08/61 | USDA Crop Profile for cantaloupes in IN |
| Harvest (HAD,   |          | (1998)                                  |
| HAM, IYRHAR)    |          |                                         |
+-----------------+----------+-----------------------------------------+
| Maximum Dry     | 0.0      | Not used in scenario                    |
| Weight (WFMAX)  |          |                                         |
+-----------------+----------+-----------------------------------------+
| Maximum Crop    | 25 cm    | Value consistent with TX melons (EPA,   |
| Height (HTMAX)  |          | 2004).                                  |
+-----------------+----------+-----------------------------------------+
| SCS Curve       | 86, 79,  | PRZM Table 5.10, B Soil, fallow, and    |
| Number (CN)     | 86       | row crop, contoured, poor condition     |
+-----------------+----------+-----------------------------------------+
| Manning's N     | 0.040    | RUSLE Project; LA2STSTN; strawberries,  |
| Value (MNGN)    |          | Grand Rapids weather station; mulch     |
|                 |          | tillage(USDA, 2000)., dates adjusted to |
|                 |          | match planting and harvest              |
+-----------------+----------+-----------------------------------------+
| USLE C Factor   | 0.0      | RUSLE Project; LA2STSTN; strawberries,  |
| (USLEC)         | 11-0.038 | Grand Rapids weather station; mulch     |
|                 |          | tillage(USDA, 2000). dates adjusted to  |
|                 |          | match planting and harvest              |
+-----------------+----------+-----------------------------------------+

+----------------------+-------------------+--------------------------+
| **Table 5.** PRZM    |                   |                          |
| 3.12.2 Selfridge     |                   |                          |
| loamy sand Soil      |                   |                          |
| Parameters for       |                   |                          |
| Monroe County, MI    |                   |                          |
| Melon Scenario.      |                   |                          |
+----------------------+-------------------+--------------------------+
| Parameter            | Value             | Source/Comments          |
+----------------------+-------------------+--------------------------+
| Total Soil Depth     | 151 cm            | NRCS Soil Data Mart      |
| (CORED)              |                   | (SDM)                    |
|                      |                   | (http://soi              |
|                      |                   | ldatamart.nrcs.usda.gov) |
+----------------------+-------------------+--------------------------+
| Number of Horizons   | 5                 | NRCS Soil Data Mart      |
| (NHORIZ)             |                   | (SDM)                    |
+----------------------+-------------------+--------------------------+
| Horizon Thickness    | 10 cm (HORIZN =   | NRCS Soil Data Mart      |
| (THKNS)              | 1)                | (SDM). The top horizon   |
|                      |                   | was split into two       |
|                      | 10 cm (HORIZN =   | horizons as per. PRZM    |
|                      | 2)                | Scenario Guidance (EPA,  |
|                      |                   | 2004).                   |
|                      | 44 cm (HORIZN =   |                          |
|                      | 3)                |                          |
|                      |                   |                          |
|                      | 9 cm (HORIZN = 4) |                          |
|                      |                   |                          |
|                      | 78 cm (HORIZN =   |                          |
|                      | 5)                |                          |
+----------------------+-------------------+--------------------------+
| Bulk Density (BD)    | 1.32 g/cm^3^      | NRCS Soil Data Mart      |
|                      | (HORIZN = 1)      | (SDM)                    |
|                      |                   | ([                       |
|                      | 1.32 g/cm^3^      | http://soildatamart.nrcs |
|                      | (HORIZN = 2)      | .usda.gov](http://soilda |
|                      |                   | tamart.nrcs.usda.gov/)). |
|                      | 1.45 g/cm^3^      | Midpoint of the reported |
|                      | (HORIZN = 3)      | range. PRZM Scenario     |
|                      |                   | Guidance (USEPA, 2004).  |
|                      | 1.40 g/cm^3^      |                          |
|                      | (HORIZN = 4)      |                          |
|                      |                   |                          |
|                      | 1.60 g/cm^3^      |                          |
|                      | (HORIZN = 5)      |                          |
+----------------------+-------------------+--------------------------+
| Initial Water        | 0.159 cm^3^/cm^3^ | NRCS Soil Data Mart      |
| Content (THETO)      | (HORIZN =1)       | (SDM); values are mean   |
|                      |                   | available water plus the |
|                      | 0.159 cm^3^/cm^3^ | wilting point water      |
|                      | (HORIZN =2)       | content of Selfridge     |
|                      |                   | loamy sand soils         |
|                      | 0.139 cm^3^/cm^3^ |                          |
|                      | (HORIZN = 3)      |                          |
|                      |                   |                          |
|                      | 0.179 cm^3^/cm^3^ |                          |
|                      | (HORIZN = 4)      |                          |
|                      |                   |                          |
|                      | 0.148 cm^3^/cm^3^ |                          |
|                      | (HORIZN = 5)      |                          |
+----------------------+-------------------+--------------------------+
| Compartment          | 0.1 cm (HORIZN =  | NRCS Soil Data Mart      |
| Thickness (DPN)      | 1)                | (SDM)                    |
|                      |                   | ([                       |
|                      | 2 cm (HORIZN = 2) | http://soildatamart.nrcs |
|                      |                   | .usda.gov](http://soilda |
|                      | 2 cm (HORIZN = 3) | tamart.nrcs.usda.gov/)). |
|                      |                   | PRZM Scenario Guidance   |
|                      | 3 cm (HORIZN = 4) | (USEPA, 2004).           |
|                      |                   |                          |
|                      | 3 cm (HORIZN = 5) |                          |
+----------------------+-------------------+--------------------------+
| Field Capacity       | 0.159 cm^3^/cm^3^ | NRCS Soil Data Mart      |
| (THEFC)              | (HORIZN =1)       | (SDM); values are mean   |
|                      |                   | available water plus the |
|                      | 0.159 cm^3^/cm^3^ | wilting point water      |
|                      | (HORIZN =2)       | content of Selfridge     |
|                      |                   | loamy sand soils.        |
|                      | 0.139 cm^3^/cm^3^ |                          |
|                      | (HORIZN = 3)      |                          |
|                      |                   |                          |
|                      | 0.179 cm^3^/cm^3^ |                          |
|                      | (HORIZN = 4)      |                          |
|                      |                   |                          |
|                      | 0.148 cm^3^/cm^3^ |                          |
|                      | (HORIZN = 5)      |                          |
+----------------------+-------------------+--------------------------+
| Wilting Point        | 0.049 cm^3^/cm^3^ | NRCS Soil Data Mart      |
| (THEWP)              | (HORIZN =1)       | (SDM) Soil               |
|                      |                   | Characterization data;   |
|                      | 0.049 cm^3^/cm^3^ | values are mean 15-bar   |
|                      | (HORIZN =2)       | water contents of        |
|                      |                   | Selfridge loamy sand     |
|                      | 0.049 cm^3^/cm^3^ | soils.                   |
|                      | (HORIZN = 3)      |                          |
|                      |                   |                          |
|                      | 0.042 cm^3^/cm^3^ |                          |
|                      | (HORIZN = 4)      |                          |
|                      |                   |                          |
|                      | 0.018 cm^3^/cm^3^ |                          |
|                      | (HORIZN = 5)      |                          |
+----------------------+-------------------+--------------------------+
| Organic Carbon       | 1.16% (HORIZN =   | NRCS SDM; values for     |
| Content (OC)         | 1)                | horizons 1 to 3 = mean   |
|                      |                   | %OM / 1.724. PRZM        |
|                      | 1.16% (HORIZN =   | Scenario Guidance        |
|                      | 2)                | (USEPA, 2004).           |
|                      |                   |                          |
|                      | 0.145% (HORIZN =  |                          |
|                      | 3)                |                          |
|                      |                   |                          |
|                      | 0.145% (HORIZN =  |                          |
|                      | 4)                |                          |
|                      |                   |                          |
|                      | 0.145% (HORIZN =  |                          |
|                      | 5)                |                          |
+----------------------+-------------------+--------------------------+

**References**

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.

USDA. 1998. Crop Profile for Cantaloupes in Indiana. U.S. Department of
Agriculture, Pest Management Centers. October 1999. Online at:
<http://www.ipmcenters.org/CropProfiles/docs/Incantaloupes.pdf>

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. 2005. 2002 Census of Agriculture. U.S. Department of Agriculture,
National Agricultural Statistics Service (NASS). Online at:
<http://www.nass.usda.gov/index.asp>.

USDA. 2003. Official Series Description -- Selfridge Series. U.S.
Department of Agriculture, Natural Resources Conservation Service
(NRCS). Dec. 2006. Online at:
<http://ortho.ftw.nrcs.usda.gov/osd/dat/S/SELFRIDGE.html>

USEPA. 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.

USEPA. 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.

USEPA. 2006. 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 3.12.2*. National Exposure Research Laboratory, Office of
Research and Development, U.S. Environmental Protection Agency, Athens,
GA.

[^1]: <http://www2.ftw.nrcs.usda.gov/osd/dat/S/SELFRIDGE.html>