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

This Article Abstract 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 Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Williams, C. F. Articles by Farmer, W. J. Search for Related Content PubMed Articles by Williams, C. F. Articles by Farmer, W. J. Agricola Articles by Williams, C. F. Articles by Farmer, W. J. Related Collections Fate Pesticides Organic Compounds

Estimating the Potential for Facilitated Transport of Napropamide by Dissolved Organic Matter

^a USDA-ARS, U.S. Water Conservation Lab., 4331 E. Broadway Rd., Phoenix, AZ 85040-8832
^b Dep. of Environmental Sci., Univ. of California, Riverside, CA 92521-0424

View larger version (16K): [in a new window]   Fig. 1. Liner relationship between the ratio of the K1/K2 solution Kd's for each treatment and soil organic matter. Closed symbols are for treatments where napropamide was applied in acetone and allowed to dry. Open symbols are for treatments where napropamide was applied in water and allowed to dry. Regression lines are computed based on pooling all treatments where napropamide was applied in acetone (solid line) and all treatments where napropamide was applied in water (broken line).

View larger version (16K): [in a new window]   Fig. 2. Relationship between soil organic matter content (closed symbols) and the ratio of the K1/K2 solution Kd's (open symbols) and for each treatment and fraction of applied napropamide leached in the first 30 mL of effluent. Napropamide was applied to soil allowed to dry and a 5-cm treated soil layer was placed over a 10-cm untreated layer and irrigated with a constant head. Error bars are ±1 standard error of the mean. In some cases error bars are smaller than the symbols.

View larger version (11K): [in a new window]   Fig. 3. Relationship between the soil organic matter content for each soil and the fraction of applied napropamide retained in the treated layer following 100 mL of cumulative leachate and draining. Napropamide was applied to soil allowed to dry and a 5-cm treated soil layer was placed over a 10-cm untreated layer and irrigated with a constant head. Error bars are ± 1 standard error of the mean. In some cases error bars are smaller than the symbols.

View larger version (12K): [in a new window]   Fig. 4. Relationship between the K1 distribution coefficient for each soil and the fraction of applied napropamide retained in the treated layer following 100 mL of cumulative leachate and draining. Napropamide was applied to soil allowed to dry and a 5-cm treated soil layer was placed over a 10-cm untreated layer and irrigated with a constant head. Error bars are ± 1 standard error of the mean. In some cases error bars are smaller than the symbols.

View larger version (23K): [in a new window]   Fig. 5. Final distribution of napropamide in soil columns following irrigation treatments. Distribution represents the readsorption of napropamide desorbed from the treated layer onto the untreated soil below. Error bars are ± 1 standard error of the mean. In some cases error bars are smaller than the symbols.