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We have developed ways to utilize discarded tires for erosion control structures, bank stabilization and slope stabilization and erosion control in the form of engineered structures for each of these applications. This paper also describes and illustrates a channel erosion control structure made entirely from individual tires used to form side walls, wing walls and aprons for the structure. In this case the individual tires were bound together with nylon rope to form a flexible structure. This structure was built in a ephemeral wash (gully) on a local ranch near Tucson, AZ and has been in place for over ten years.

This study was initiated to develop and assess the management of the application of animal waste and compost to an oat/corn rotation in Arizona. Unlike many Eastern states, Arizona uses nitrogen as the limiting nutrient in animal waste applications. In this project, nutrient analysis for nitrogen, phosphorus and electroconductivity were conducted on soil, manure/compost, and plant samples. There were three treatments replicated four times in this study. Treatment 1: inorganic nitrogen sources; Treatment 2: manure; Treatment 3: composted manure. All management decisions are made to maximize yield while assuring that the amount of nitrogen applied was equivalent to the nitrogen removed in the crop. In the first year, there was little or no difference in crop yields. In the second year, yield differences began to show. The soil nitrate-N content was remaining relatively low and equal between treatments. However soil phosphorus content has significantly increased in the manure and compost plots. According to the ruling, if the level of P becomes high enough, then P will become the limiting nutrient. Thus far, we have not reached that point; however, P levels are being monitored closely.

This study was initiated to determine the biological and nutrient impacts of manure and compost applications on an oat/corn rotation in Central Arizona. Bacterial analysis for E.Coli, Listeria and coliphage and nutrient analysis for nitrogen, phosphorus and electroconductivity were conducted on soil, manure/compost, irrigation water, drainage water and plant samples. The presence of endocrine disruptors was also tested on the irrigation and drainage water. After a single season of oats, there doesn't appear to be any significant increase in the presence of bacteria in the soil-water- plant environment. Endocrine disruptors were detected in drainage and irrigation water samples. Nitrate leaching is occurring but at relatively low rates. Oat forage yields between treatments were all over 10,000 kg/ha and there was no statistically significant difference between them.