|He, B - SOUTHWEST AG. UNIV. CHINA|
|HUANG, CHI HUA|
Submitted to: North Central Weed Science Society US Proceedings
Publication Type: Proceedings
Publication Acceptance Date: January 15, 1999
Publication Date: N/A
Technical Abstract: The introduction of erosion reducing soil amendments to existing crop production systems may alter the activity and mobility of soil applied herbicides. Laboratory trials using rainfall simulation and packed (1.05 g.cm3) soil boxes were conducted to evaluate the effect of various soil amendments on soil erosion. This system also documented the effect of erosion controlling soil amendments on the movement of soil applied herbicides in runoff water, with sediments and through leaching into the soil profile. Soil amendments included synthetic gypsum (5 Mg/ha), polyacrylamide (20 kg/ha), and ammonium lauryl sulfate and ammonium laureth sulfate (0.31 kg/ha). Soil was treated with a tank mix of atrazine and metolachlor herbicides at 1.12 and 2.24 kg ai/ha, respectively. Simulated rainfall was applied using deionized water at 60 mm/hr for 2 hours followed in 24 hr. by 30 mm/hr for 1 hour. Runoff and sediment samples were collected periodically during the rainfall, and bulk soil samples were taken following the second rain event. Synthetic gypsum and polyacrylamide delayed the onset of runoff for both events, reduced the average runoff volume and reduced atrazine loss in runoff water. Ammonium lauryl and laureth sulfate increased herbicide losses in runoff. Amendments did not reduce sediment losses, but synthetic gypsum reduced the sediment associated herbicide losses. Synthetic gypsum and polyacrylamide increased atrazine and metolachlor leaching. The successful inclusion of erosion reducing amendments into crop production systems will require attention to the various potential interactions.