|OLIVIERA JR, R|
Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/20/1998
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.