Phosphorus Response of Western Hemlock Seedlings on Pacific Coastal Soils from Washington1
- Paul E. Heilman and
- Gorden Ekuan2
This study showed that poor growth in the greenhouse of western hemlock seedlings (Tsuga heterophylla Raf. Sarg.) on two pedons from Pacific coastal hemlock forests in Washington is, due primarily to deficiency of P. Without P treatment, seedlings on three horizons of two pedons of the Vesta series contained from 0.03 to 0.09% P in their foliage. Addition of P at the rate of 300 kg P/ha raised the foliar P level to 0.09 to 0.18%. Mean seedling height at 9 months on soil with P added was 184% and dry weight was 233% of the corresponding values without P. Addition of forest floor material to the pots at a 1:2 (volume) ratio to soil increased seedling growth and concentration of P in foliage and reduced the growth response to P treatment. Phosphorus treatment reduced foliar N levels whereas the effect of forest floor on foliar N was inconclusive.
Soil P data from analysis of 38 coastal hemlock pedons showed that pedon samples used in the greenhouse study were average to below average for the area in status of P.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © .