Monday, November 5, 2007 - 2:05 PM
110-4
Assessment of the Impact of Sugarcane Residue Management Techniques on the Forms of Carbon Export in Surface Water Runoff.
Theophilus Udeigwe, School of Plant Environmental and Soil Sciences, Louisiana State University, 104 M.B. Sturgis Hall, Baton Rouge, LA 70803, Jim Wang, School of Plant,Environmental&Soil Sciences, Louisiana State University, 313 M.B. Sturgis Hall, Louisiana State University, Baton Rouge, LA 70803, Lewis Gaston, 104 Sturgis Hall, Louisiana State University, Louisiana State University, School of Plant, Environmental and Soil Sciences, Baton Rouge, LA 70803-2110, and Sonny Viator, Iberia Research Station, Louisiana State University AgCenter, 603 Bridge Road, Jeanerette, LA 70544.
Carbon export from agricultural fields is not given much attention as nitrogen or phosphorus export. Organic carbon plays a major role in contaminant transport from soil to receiving surface waters. It is also a major source of microbial substrate in surface waters, leading to increased microbial population and thus, increased oxygen demand in receiving water bodies. This study would evaluate the impact of three sugarcane residue management techniques: ground burning (burn), residue shredding (shred) and residue retaining (residue) on the proportion of total organic carbon (TOC), dissolve organic carbon (DOC), and particulate organic carbon (POC) exported in surface runoff. The results indicate that TOC accounted for 92-99% of TC in all surface water samples from the three treatments, with POC accounting for 65, 67 and 76% of TOC for residue, shred and burn treatment respectively. Evaluation of the relationships among measured variables shows that total suspended solids (TSS) and turbidity measurements each explained about 80% of the variability associated with POC, and 55% for TOC. The pattern of distribution of TOC and DOC over the sampling period was similar for the three treatments evaluated.