My Account: Log In | Join | Renew
Search
Author
Title
Vol.
Issue
Year
1st Page

Abstract

 

This article in JEQ

  1. Vol. 28 No. 1, p. 11-24
     
    Received: Jan 23, 1998
    Published: Jan, 1999


    * Corresponding author(s): hatfield@nstl.gov
 View
 Download
 Alerts
 Permissions
 Share

doi:10.2134/jeq1999.00472425002800010002x

Water Quality in Walnut Creek Watershed: Setting and Farming Practices

  1. J. L. Hatfield *,
  2. D. B. Jaynes,
  3. M. R. Burkart,
  4. C. A. Cambardella,
  5. T. B. Moorman,
  6. J. H. Prueger and
  7. M. A. Smith
  1. Iowa State Univ., Hardin County Ext. Office, 524 Lawler St., Iowa Falls, IA 50126-8000.

Abstract

Abstract

Nonpoint-source pollution has been linked to agricultural practices; however, there is a need for quantitative information describing the effect of specific farming practices on ground and surface water quality. Lack of information at the watershed scale limits our ability to make decisions about the effect of potential changes in either farming practices or landscape management that would enhance water quality. A multidisciplinary study was designed to evaluate the effect of farming practices on subsurface drainage, surface runoff, stream discharge, groundwater, volatilization, and soil processes that influence water quality. Walnut Creek watershed is a 5130-ha intensively cropped area in central Iowa on the Des Moines Lobe landform region. Soils within the watershed are in the Clarion-Nicollet-Webster (Typic Hapludoll-Aquic Hapludoll-Typic Haplaquoll) soil association, and the underlying surficial material is glacial till. Land use is predominantly corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] rotation. Fertilizer use, herbicide application, tillage practices, and crop selection were obtained through surveys of each field operator. Atrazine [6-chloro-N-ethyl-N′-(1-methylethyl)-1,3,5-triazine-2,4-diamine], cyanazine [2-[[4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl]amino]-2-methylpropanenitrile], EPTC [S-ethyl dipropyl carbamothioatel, and metolachlor [2-chloro-N-(2-ethyl-6-methyiphenyl)-N-(2-methoxy-1-methylethyl)acetamide] are the primary herbicides used within the watershed at rates similar to those for the state. Nitrogen fertilizer was applied as anhydrous ammonia on 60% of the corn fields at an average rate of 153 kg ha−1 for the 1991–1994 period, but the frequency of corn fields receiving <112 kg ha−1 has increased.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © .