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United States Department of Agriculture

Agricultural Research Service

Title: Spatial Variability of Alachlor Sorption-Desorption in Soil

Authors
item Oliviera Jr, R - UNIV DE VICOSA BRAZIL
item Koskinen, William
item Ferreira, F - UNIV DE VICOSA BRAZIL
item Khakural, B - UNIVERSITY OF MINNESOTA
item Mulla, D - UNIVERSITY OF MINNESOTA
item Robert, P - UNIVERSITY OF MINNESOTA

Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 20, 1998
Publication Date: N/A

Technical Abstract: Use of site-specific rates for soil-applied herbicides based on sorption spatial variability is one possibility to reduce offsite movement. Spatial variability of alachlor sorption was determined for a 30-ha field in southern Minnesota, which ranged in pH from 4.9 to 7.6, clay content from 25 to 65 percent, and organic carbon (OC) from 1.5 to 5.8 percent. OC was the most important single property influencing alachlor sorption. Sorption was also concentration dependent. Significant hysteretic desorption from soil was observed and hysteresis was dependent on OC content. Based on empirical equations describing sorption as a function of soil OC content, which can be easily determined by routine soil analysis, criteria for differential rates of alachlor for this field are proposed.

Last Modified: 4/23/2014