Plant and soil samples were collected from mequite dunes sites which had not been irrigated (control) or had been irrigated (treatment) with water. Soil samples were collected (hand augered) under mesquite (Prosopis glandulosa) trees to three depths, 0-50 and 50-100, and 100-150cm. Soil samples were placed in plastic bags, tied, and stored in portable coolers. Soil samples were analyzed for zinc , cupper, iron, and manganese. Plant tissue was analyzed for total nitrogen and total phosphorous. This study has been completed.