HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via ISI Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Stoddard, C. S. Articles by Thom, W. O. Search for Related Content PubMed PubMed Citation Articles by Stoddard, C. S. Articles by Thom, W. O. Agricola Articles by Stoddard, C. S. Articles by Thom, W. O. Related Collections Ground Water Quality Nutrients Pesticides Best Management Practices Infiltration Other Environmental Contamination

TECHNICAL REPORTS

Vadose Zone Processes and Chemical Transport

Fertilizer, Tillage, and Dairy Manure Contributions to Nitrate and Herbicide Leaching

^a University of California Cooperative Extension Service-Merced County, 2145 Wardrobe Avenue, Merced, CA 95340-6496
^b Department of Plant and Soil Sciences, N-122 Agricultural Science-North, University of Kentucky, Lexington, KY 40546-0091

^* Corresponding author (jgrove{at}uky.edu)

Received for publication June 10, 2004. Few studies have examined the water quality impact of manure use in no-tillage systems. A lysimeter study in continuous corn (Zea mays L.) was performed on Maury silt loam (fine, mixed, semiactive, mesic Typic Paleudalf) to evaluate the effect(s) of tillage (no-till [NT] and chisel-disk [CD]), nitrogen fertilizer rate (0 and 168 kg N ha^–1), and dairy manure application timing (none, spring, fall, or fall plus spring) on NO₃–N, atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine), and alachlor [2-chloro-2'-6'-diethyl-N-(methoxymethyl)acetanilide] concentrations in leachate collected at a 90-cm depth. Herbicides were highest immediately after application, declining to less than 4 µg L^–1 in about two months. Manure and manure timing by tillage interactions had little effect on leachate herbicides; rather, the data suggest that macropores rapidly transmitted atrazine and alachlor through the soil. Tillage usually did not significantly affect leachate NO₃–N, but no-tillage tended to cause higher NO₃–N. Manuring caused higher NO₃–N concentrations; spring manuring had more impact than fall, but fall manure contained about 78% of the N found in spring manure. Nitrate under spring "only fertilizer" treatment exceeded 10 mg L^–1 38% of the time, compared with 15% for spring only manure treatment. After three years, manured soil leachate NO₃–N exceeded that for soil receiving only N fertilizer. Soil profile (90 cm) NO₃–N after corn harvest exceeding 22 kg N ha^–1 was associated with winter leachate NO₃–N greater than 10 mg N L^–1. Manure can be used effectively in conservation tillage systems on this and similar soils. Accounting for all N inputs, including previous manure applications, will be important.

Abbreviations: CD, chisel-disk tillage • NT, no-till