VOLATILIZATION OF ALACHLOR AND ATRAZINE AS INFLUENCED BY SURFACE LITTER

A basic knowledge of how herbicide volatilization is influenced by agr onomic practices is necessary if long-term detrimental impacts from he rbicides are to be minimized. We measured cumulative herbicide volatil ization losses in glass agroecosystem chambers to assess how surface r esidue conditions, simulated rainfall, temperature, and herbicide form ulation affect volatilization of atrazine and alachlor. Research resul ts demonstrated that herbicide volatilization before water application was greater under mulched conditions, but decreased dramatically afte r the first irrigation. As a result, after 35 d cumulative volatilizat ion of atrazine from a mulched soil surface was less than half that fr om bare soil for both formulations. Plant litter on the soil surface a nd encapsulated herbicides may be viable alternatives far reducing vol atilization of some herbicides in humid regions.