Wood ash treatment affects seasonal N fluctuations in needles of adult Picea abies trees: a 15N-tracer study
Source: Trees, Volume 18, Number 1, January 2004 , pp. 54-60(7)
Abstract:A 15N-tracer experiment was carried out in a stand of adult spruce trees [Picea abies (L.) Karst.] located on the Swiss Plateau in order to investigate the effects of wood ash treatment on seasonal nitrogen fluctuations in fine roots and needles. Treatments included irrigation (W), liquid fertilization (LF) and wood ash (A) application. 15N fluctuation in fine roots and current to 3-year-old needles was studied after one 15N pulse for 2 consecutive years (1999, 2000). 15N tracer was rapidly incorporated into the fine roots of adult trees, and 15N values reached similar levels in all treatments 2 months after the pulse. In the needles, the largest increase in 15N was observed in those of the current year. Following the initial peak during spring growth, 15N values in needles of control trees showed an oscillating pattern through the season. This oscillation is attributed to the increased use of internal N sources, as soon as the roots can no longer meet the increased N demand during the sprouting phase. However, W-, LF- and A-treated trees no longer showed the oscillation in 15N. Additional water (W and LF) as well as fertilizer (A and LF) may have induced shifts in the microbial flora, thus increasing the unlabelled N release from the soil. The strongest dampening was observed for the A treatment, indicating sufficient N availability from the soil, and making intensive use of the internal N sources unnecessary. Treatment with wood ash thus resulted in a similar fertilizer response to liquid fertilization.
Document Type: Research Article
Affiliations: 1: Paul Scherrer Institut, 5232, Villigen PSI, Switzerland, 2: Paul Scherrer Institut, 5232, Villigen PSI, Switzerland, Email: email@example.com 3: Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, 8903, Birmensdorf, Switzerland, 4: Swiss Federal Research Station for Agroecology and Agriculture FAL Reckenholz, 8046, Zürich, Switzerland,
Publication date: January 1, 2004