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uniform root system with depth so a weighted salinity of the root zone is based on the plants root growth patterns. Alfalfa typically has a majority of its roots in the top 60 inches of the soil profile(Lindenmayer et al. 2011). The average root zone salinity can then be calculated by weighting each depth increment assuming alfalfa has the following rooting pattern (Ayers and Westcot, 1985):  40% of the roots in the top quarter (0 to 18 inches)  30% of the roots in the second quarter(18 to 36 inches)  20% of the roots in the third quarter(36 to 54 inches)  10% of the roots in the bottom quarter(54 to 72 inches) Alfalfa yields are generally expected to be decreased when soil salinity increases to greater than 2.0 dS/m. However research indicates that when the soil contains appreciable levelsof gypsum, such as the soils at the New Horizon Mine, alfalfa can tolerate soil ECe concentrations up to 4.0 dS/ without yield reductions (Ogle and St. John, 2009). This is due to the solubility of gypsum in the saturated paste extract conditions compared to in-situ field conditions (Ayers and Westcot, 1985). In general, when the average root zone soil salinity begins to decrease crop yields, the soil salinity can be decreased by the use of agronomic leaching. Agronomic leaching is a well- established method for removing salts from the soil root zone. Agronomic leaching is achieved by applying irrigation water in excess of crop demand to remove salts from the crop rooting zone. The soil salinity increase in the soil stockpiles is expected to be handled through agronomic leaching. Agronomic leaching is a process to manage root zone soil salinity. It is important to note that none of the average soil salinity observed in the soil stockpiles was greater than alfalfa’s soil salinity tolerance threshold levels in soils that contain measurable quantities of gypsum. In soils with measurable quantities of gypsum the salinity threshold that it effects alfalfa production is 4.0 dS/m in thesoil root zone(Maas and Hoffman, 1977; Ogle and St. John, 2009; and USDA, 2013). If agronomic leaching is required to decrease the soil salinity concentration in the water sources, CC ditch and natural precipitation, are ideally suited. Water quality data from the CC ditch (the intended source of irrigation water for the Morgan property) indicate that the electrical conductivity is less than 500dS/m throughout most of the irrigation season. In addition,it is safe to assume that the salinity of naturalprecipitation is equal to or less than the salinity of the CC ditch water. Water with low salinity is considered to be very aggressive (corrosive) at removing soluble salts from the soil matrix(Ayers and Westcot, 1985). The reason for the aggressive nature of low salinity water is that the applied water has to be in equilibrium with the exchange phase of the soil(Robarge, 1998). Low salinity water must accept a large concentration of ions (salts) to achieve this equilibrium. As the low salinity applied water percolates through the soil matrix the salinity ions will move out of the soil root zone. 11 {00136879.1 }