Soil samples representing six major forest soil series and two meadow unclassified types were collected from 17 locations on critical deer migration routes in the central Sierra Nevada, California. Nutrient tests were conducted in the greenhouse using soft chess (Bromus mollis) as an indicator species to determine deficiencies of nitrogen, phosphorus, and sulfur. These tests were carried out to assess fertilizer needs and the probability of field response to increased nutrient levels in the

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... for improvement of forage quality and quantity on deer migration routes. All soils were nitrogen deficient; the meadow soils were less so than the forest soils. In 94% of the soils samples, the addition of phosphorus (70%) or phosphorus and sulfur (24%) with nitrogen increased plant yields dramatically (as much as 26 times) compared with adding nitrogen alone. Addition of sulfur with nitrogen produced a yield response equal to that produced by phosphorus or phosphorus plus sulfur with nitrogen in three soils. Nitrogen was the nutrient most limiting for plant growth; phosphorus was next important and was essential for best response in most soils. Sulfur produced variable responses, usually increasing plant yields only after nitrogen and phosphorus deficiencies were corrected. Productivity of forage and browse species growing on these soils is determined by nutrient status; characteristics delineated at the series level, such as depth, texture, and structure; and moisture-temperature relations in specific years. Authors are range scientists, U.S. Dep. Agr., Agr. Res. Serv., Renewable Resource Center, University of Nevada, 920 Valley Road, Rem 89512 and Pacific Southwest Forest and Ranp Exp. %a., Forest Serv., Forest Sciences Laboratory, 208 I E. Sierra Avenue, Fresno, California 93710, respectively. This study is a contribution from the U.S. Dep. Agr., Forest Serv..