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Nitrate-nitrogen is determined by adding 30 milliliters of calcium sulfate extracting solution to a 2 gram scoop of soil and shaken for 15 minutes. The nitrate level in the filtered extract is measured on a Lachat QuickChem 8500 Flow Injection Analyzer by the cadmium reduction method. The results are reported as pounds per acre of nitrate-nitrogen (NO3-N) in the top 2 feet of soil or as parts per million nitrate-nitrogen (NO3-N) in the soil for all other depths.