County Scale Soil Permeability Maps for Herbicide Applications Online

 

Robert T. Paulsen¹,

ABSTRACT:

Monsanto Corporation and Zeneca Agricultural Products entered into an agreement with the U.S. Environmental Protection Agency to jointly support the registration of a new herbicide for use in corn.  Acetochlor is a low application rate herbicide designed to control weeds in corn.  As a voluntary measure to preserve ground water quality, the Acetochlor Registration Partnership (ARP) decided to produce county scale soil maps that would locate soils that may be sensitive to the vertical transport of acetochlor where the water table was less than 30 feet below the land surface.  These maps reside on the ARP Internet site and are accessible by farmers, chemical appliers, local, state, and federal regulators.  The web address is: WWW.ARPinfo.com  under "Level 4 County Maps".

 

Maps for more than 300 U.S. Counties were compiled manually and digitized for export to the web site. U.S. Department of Agricultural soil surveys for each county were obtained and the soils that failed specific absorption criteria were identified on individual air photos. A composite base map was created and digitized in two formats; 1) with the outlines of the airphotos and, 2) with roads, towns, and railroad locations.  Details on the preparation of the maps and real time web access will be presented.

 

KEY TERMS: Soils, GIS, Pesticides, ARP
 

INTRODUCTION

 

Problem

 

The Acetochlor Registration Partnership (ARP) composed of Monsanto Corporation and Zeneca Agricultural Products entered into an agreement with the U.S. Environmental Protection Agency (EPA)  to support the registration of acetochlor for use on corn.  As part of the registration, the Acetochlor Registration Partnership (ARP) manages and stewards all acetochlor-containing products with a unique program, which includes specific soil restrictions aimed at eliminating the potential for ground water contamination and extensive mapping of soils to clearly display where acetochlor products should and should not be used.

 

The ARP needed to produced county scale soil maps for major corn producing counties in the US  that provide guidance in locating coarse textured, low organic matter soils that might be susceptible to leaching.  The goal was to allow users of acetochlor to avoid areas where application may lead to groundwater contamination.

 

 

Approach

 

The ARP compiled a list of 325 counties that they would like to have soil maps for. The preferred solution to the problem would have been to use the US Department of Agriculture’s (USDA) county scale digital soil maps (SSURGO) however at the time of this project only a hand full counties were completed under the SSURGO program.  The approach consisted of the following steps.

 

1. Obtain copy of  county soil survey.
2. Using both STATSGO and the soil survey compile a list of soils that met the criteria:

 

Sand Texture with less than 3% organic matter.

Loamy Sand Texture with less than 2% organic matter.

      Sandy Loam Texture with less than 1% organic matter.

 

 

3. Review each soil map airphoto and color in polygons of target soils.
4. Transpose airphoto maps to base map included in the soil survey.
5. Digitize in Geographic Projection  the resulting soil map using ESRIâ ArcInfo V7.
6. Clean and Build soil polygons.
7. Using ESRI ArcViewâ V3 prepare Shape files and Layouts.
8. Export Layouts as WMF files.
9. Import to MS PowerPointâ (MS Office 95 version) files.
10. Ship to ARP.
11. ARP webmaster places PPT files on website.

 

We called this the “bloody knuckle” approach as it was rather intensive.

 

The resulting maps were placed as PowerPoint files on the ARP web server at:

 

WWW.ARPINFO.COM

 

Once there click on the Level 4 County Maps. The URL for the maps directly is:

 

www.arpinfo.com/co_maps/co_maps.htm

 

From there the user picks the state and county of interest.

 

 

 

Alternate Sources of County Scale Maps

 

 

SSURGO

 

Ideally, we would have liked to have used the USDA SSURGO data, these are digital county soils maps ready for import to ArcView.  However, at the time we started the project just 7 Florida counties were complete and could cost $500 each.  By the time we finished there were about 35 counties completed and cost only $50 each.  As of September 1999 there were almost 700 counties completed and downloadable for free from the USDA at:

 

www.ftw.nrcs.usda.gov/stssaid.html

 

Using The Online Maps

These maps are used by the farmer, the bulk pesticide dealer / applier and  regulators to evaluate the potential use of this herbicide.  The maps are to be used to key people in on where there may be the potential for this product to be used with caution.  The user should refer to the county soil survey or in-field soil samples to determine the ultimate suitability of the product.

 

         Ford County Kansas showing soils of concern and the air photo overlay grid.

 

 

      Ford County Kansas showing the soils of concern and the major roads and towns.

 

 

 

Ford County Kansas showing the soils of concern and roads from

 

SSURGO Data.

 

 

 

Although the SSURGO map offers more detail it takes a bit of processing to get the raw data into the form to display the selected soils.  There is also some difference in the above maps, due to a slight revision in soil data in SSURGO (1999) from the older published soil survey (US Department of Agriculture, 1965).

 

 

Summary

 

Monsanto Corporation and Zeneca Agricultural Products entered into an agreement with the U.S. Environmental Protection Agency to jointly support the registration of a new herbicide for use in corn.    As a voluntary measure to preserve ground water quality, the Acetochlor Registration Partnership (ARP) decided to produce county scale soil maps that would locate soils that may be sensitive to the vertical transport of acetochlor where the water table was less than 30 feet below the land surface.   The digital soils maps need to meet the stated goal were not publicly available.  USDA County Soil Surveys for 325 counties were obtained, reviewed, target soils identified, and their locations transposed to a babes map.  The base maps were digitized and stored in a format accessible over the internet. These maps reside on the ARP Internet site and are accessible by farmers, chemical appliers, local, state, and federal regulators.  The web address is: WWW.ARPinfo.com  under "Level 4 County Maps".

 

 

 

 

REFERENCE

 

US. Department of Agriculture. 1965. Soil Survey of Ford County, Kansas. USDA, Washington DC.   28p.  

(1) Director – The Paulsen Group, Inc.  13411 Tamarack Road  Silver Spring, MD 20904.  ph: 301-384-1838; rpaulsen@interserv.com