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Foliage samples were secured from the upper‐one third of the crowns of Douglas fir (Pseudotsuga taxifoliaP.), lodgepole pine. (Pinus contortaD.), and western hemlock (Tsuga heterophyllaR.) trees. Needles of the 1961, 1962, and 1963 growth were obtained with the exception of western hemlock samples at Gold River where only the current growth was collected. The needles were analyzed for the micronutrients B, Cl, Co, Cu, Fe, Mn, Mo, and Zn and for the apparently nonessential elements Al and Si. The ranges in concentration of B, Cl, Co, Cu, Fe, Mn, Mo, Zn, Al, and Si encountered in the various needle samples were: 2.5–17.0, 73–170, 0.05–0.46, 2.1–5.6, 38.6–68.3, 293–1982, < 0.5–0.10, 3.0–52.3, 175–787, and <467–8700 ppm in the dry matter, respectively. Manganese occurred in greater amounts than any of the other 7 micronutrients. Concentration of Fe, Mn, Al, and Si generally increased with age of needles. Levels of Mn, and Al tended to be higher in needles of western hemlock than in Douglas fir. Western hemlock needles contained much less Si than Douglas fir needles.

Pellets containing 15 mg of P prepared from each of the following salts: KH2PO4(MKP), NH4H2PO4(MAP), (NH4)2HPO4(DAP), Ca(H2PO4)2·H2O (MCP), and CaHPO4·2H2O (DCPD) were placed in cavities in the surface of Bradwell very fine sandy loam (pH = 7.8) and Monroe silt loam (pH = 5.8). The treated soils were stored at 5, 20, and 35C. Extent of dissolution of fertilizer pellets and development of soil‐fertilizer reaction zones were measured during the first 14 days of storage. At the end of 2, 7, 14, 28, and 56 days the soil‐fertilizer reaction zones were sampled and the concentration of water‐soluble P and the percentage of fertilizer P soluble in the reaction zones were determined. Rate of dissolution of the water‐soluble P fertilizers increased markedly as temperature increased. Some pellets were incompletely dissolved at the end of 14 days at 5C, whereas, at 35C dissolution was usually complete in less than 4 days. For each 15C increase in temperature there was about a 33% reduction in concentration of water‐soluble P and the proportion of fertilizer P soluble in water. During the first 14 days after adding the water soluble fertilizers there was a rapid decrease in concentration of water‐soluble P and proportion of dissolved fertilizer P while after 14 to 28 days the changes were much samller. Extraction of water‐soluble P decreased in the order MKP>MAP = DAP>MCP>DCPD>check. Differences among sources became smaller with increased time of contact with soil. DCPD was more soluble in the acid Monroe soil than in the calcareous Bradwell soil.

Shoots of the 1960, 1961, and 1962 growth were removed from two fertilized plus trees and two unfertilized adjacent check trees in April 1963. Each plus tree received 80 pounds of 16‐20‐0 ammonium phosphate sulphate fertilizer in April 1961, and 40 pounds of the same fertilizer in April 1962. The length of the shoots was measured and needle production was determined. Needles from each of the 3 years of growth were analyzed for N, P, K, Ca, Mg and S. Fertilization increased the length of the 1962 shoots. Diameter of the shoots also appeared to be increased. Needles from the fertilized trees seemed to be larger and darker green in color. Weight of needles produced in 1962 was greatly increased by fertilization. Concentration and weight of N in needles was markedly increased by fertilization, particularly in the 1962 growth. Phosphorus concentration was slightly reduced by fertilization. However, the weight of P in the 1962 needles was increased by fertilization. The N/P ratios in all needle samples from the fertilized trees were much greater than those in the unfertilized check trees. Although K concentration was reduced in the foliage from fertilized trees, weight of K was not influenced by fertilization. Potassium percentage tended to be lowest in the oldest tissue, and highest in the youngest tissue of all trees. Concentration and weight of Ca was highest in foliage from the fertilized trees. Calcium concentration increased with age of all foliage samples. Fertilization resulted in an increase in concentration and weight of Mg. Concentration and weight of S was highest in the foliage from fertilized trees. Older needles appeared to have a higher S concentration than the younger needles.