Tuesday, November 6, 2007 - 10:15 AM
134-4

Effects of Soil Amendments on Aggregate Stability, Infiltration, and Glomalin in Eroded and Compacted Areas.

James Applewhite1, C.T. Hallmark1, and W.E. Fox III2. (1) Texas A&M University - Soil & Crop Sciences, Dept of Soil and Crop Sciences, 2474 TAMU, College Station, TX 77843-2474, (2) Texas Water Resources Institute, 2118 TAMU, College Station, TX 77843-2118

Fort Hood, located in central Texas, supports two full armored divisions requiring constant training and maneuvering exercises. As a result of heavy traffic the soils of Fort Hood have become increasingly compacted and denuded of vegetation. This destruction has led to excessive erosion and subsequent silting of local streams creating the potential for water quality problems both on and off-site. Reducing soil erosion could be accomplished by improving aggregate stability which would increase infiltration rates and provide a better medium for plant growth. In addition, glomalin, a recently discovered soil protein has been shown to increase aggregate stability among many soils. This study was conducted to determine what role different vegetation mixes and fertility treatments would play on aggregate stability, infiltration rates, and glomalin content. The vegetation mixes involve a variety of native grass species and the fertility treatments consist of inorganic fertilizers and organic compost from local concentrated animal feeding operations. Knowing how these soil properties respond to a gradient of vegetative mixes and fertility amendments would improve management decisions and delay the soil and water quality issues facing Fort Hood. Aggregate stability was determined using a wet sieving procedure and additionally by calculating the water dispersible clays. Infiltration rates were collected using a drip-type rainfall simulator, while total glomalin levels were extracted and quantified using a Bradford assay with a bovine serum albumin standard. Initial samples were collected to provide a base measure of soil properties with continued sampling for 2 years. The study area consisted of 8 treatment plots (930 m2/plot) each done in triplicate. Results from preliminary data will be presented.