Nutrient testing of soils to determine fertilizer needs on central sierra nevada california usa deer cattle ranges
Evans, R.A.; Neal, D.L.
Journal of Range Management 35(2): 159-162
Soil samples representing 6 major forest soil series and 2 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 N, P and S. These tests were carried out to assess fertilizer needs and the probability of field response to increased nutrient levels in the soil for improvement of forage quality and quantity on deer migration routes. All soils were N deficient; the meadow soils were less so than the forest soils. In 94% of the soils samples, the addition of P (70%) or P and S (24%) with N increased plant yields dramatically (as much as 26 times) compared with adding N alone. Addition of S with N produced a yield response equal to that produced by P or P + S with N in 3 soils. N was the nutrient most limiting for plant growth; P was next important and was essential for best response in most soils. S produced variable responses, usually increasing plant yields only after N and P 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.