Fertilization in Icelandic Afforestation: Evaluation of Results

Limited research has been done on nutrient application to trees in Iceland, and little attention has been given to its possible role in alleviating plantation establishment problems. High mortality and poor growth of seedlings has been observed at many sites. Since 1995, fertilization trials have been established, addressing forest survival and initial growth. Results from trials established in 1995 revealed positive effects of fertilizer application both to survival and growth. Both, slow-release fertilizer and easily soluble fertilizers (N, NP or NPK) had a positive effect. Application of large doses of N (5.6 g N/plant), either alone or in combination with P and K resulted in increased mortality in the first growth period. N and P in combination were essential for successful establishment. Liming, K and P alone, showed no significant effect on survival or growth. Future research needs are discussed.