Submitted to: Soil and Water Conservation Society Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 9/20/2000
Publication Date: 9/20/2000
Citation: HUBBARD, R.K., POTTER, T.L., BEDNARZ, C.W., GATES, R.N., HANNA, W.W. EFFECTIVENESS OF GRASS BUFFER SYSTEMS IN FILTERING DEFOLIANT RESIDUES IN SURFACE RUNOFF FROM LAND CROPPED TO COTTON. SOIL AND WATER CONSERVATION SOCIETY PROCEEDINGS.ABSTRACT #51, P. 51. 2000. Interpretive Summary:
Technical Abstract: Research is being conducted to determine the effectiveness of grass buffer systems in filtering the defoliants tribufos (DEF) and thidiazuron (DROPP) from surface runoff draining from land cropped to cotton (Gossypium hirsutum L.). Two different grasses, Coastal Bermudagrass (Cynodon dactylon L. Pers.) (Tifton 85) and Common Bermudagrass along with two different buffer lengths, 11.4 or 22.8 m, are being evaluated. There are three replicates per treatment including a control. The research is being conducted at a Research Farm located near Tifton, GA. The soil is a Tifton loamy sand (fine-loamy, silicious, thermic, Plinthic Kandiudult). During spring 2000 eighteen cotton- grass buffer plots were established. The plots are 45.6 m in length and 3.6 m in width and run up and downslope on approximately a 2 % slope. There is a 0.6 m alleyway between each of the plots. The sides are bounded by plastic barriers inserted 0.15 m into the soil and extending 0.15 m above ground. The purpose of the barriers is to cause all surface runoff exiting the area cropped to cotton to flow downslope through the buffer systems. Manual collection troughs are installed on each plot at the interface of the cotton and grass buffer (control treatment), or at 11.4 or 22.8 m downslope into the grass buffer from this interface. Surface runoff flows from the troughs into glass collection bottles through a 10:1 splitter. Excess water draining from the splitter leaves the sampler site through underground drain tile and exits completely offsite. Surface runoff samples have been collected since summer 2000. Data are available from runoff events wich occurred since defoliant application in 9/2000. Results showed that both grass buffer systems were highly effective in reducing concentrations of these active ingredients.