Volatilization of alachlor and atrazine as influenced by surface litter

A basic knowledge of how herbicide volatilization is influenced by agronomic practices is necessary if long-term detrimental impacts from herbicides are to be minimized. We measured cumulative herbicide volatilization losses in glass agroecosystem chambers to assess how surface residue conditions, simulated rainfall, temperature, and herbicide formulation affect volatilization of atrazine and alachlor. Research results demonstrated that herbicide volatilization before water application was greater under mulched conditions, but decreased dramatically after the first irrigation. As a result, after 35 d cumulative volatilization of atrazine from a mulched soil surface was less than half that from bare soil for both formulations. Plant litter on the soil surface and encapsulated herbicides may be viable alternatives for reducing volatilization of some herbicides in humid regions.