Effekte von Holzasche- und Flüssigdüngung auf die Nährstoffsituation und das Wachstum von Fichten ( Picea abies (L.) Karst.)

Summary: : We examined the effects of wood ash and liquid fertilizer on the nutritional status and growth of Norway spruce (Picea abies (L.) Karst.) in a 70-year-old, managed forest in the Swiss Central Plateau. Four treatments with four replications were applied over three years during the vegetation period: treatment I - irrigation with liquid fertilizer (mean: N 87, P 16, K 77 kg yr-1 ha-1, with 1.5 mm/d water) with the 'steady state fertilization' approach; treatment II - wood ash (4000 kg yr-1 ha-1); treatment III - irrigation only (1.5 mm/d); treatment IV - control. Growth was determined by analyses of tree rings, shoot length, needle weight and needle area. For the nutritional status, thirteen chemical elements were analyzed on 136 trees. The investigations showed increased growth of Norway spruce due to liquid-fertilization and wood ash input, but indicated no major shifts of nutrient contents and ratios in needles