Response of Douglas-Fir Seedlings to Nitrogen, Sulfur, and Phosphorus Fertilizers

摘要

Effects of fertilizers on growth and nutrient content of seedlings potted in Grove and Bunker forest soils were determined. Growth was primarily stimulated with nitrogen in the Grove soil and with phosphorus in the Bunker soil. Fertilization influenced nutrient levels in the seedlings. Growth results agree with observed response of Douglas-fir to fertilization in the field. Data also suggest that low phosphorus and/or high nitrogen may be responsible for lack of positive growth response of Douglas-fir to nitrogen.