Ozolinčius, R., Varnagirytė, I., Armolaitis, K. and Karltun, E. 2005. Initial Effects of Wood Ash Fertilization on Soil, Needle and Litterfall Chemistry in a Scots Pine (Pinus sylvestris L.) Stand. Baltic Forestry, 11 (2): 59-67

Initial effects of wood ash and/or N fertilization were investigated in a field experiment located in a 38-year-old Scots pine stand on a Haplic Arenosol in Kačerginė, Lithuania. There were in total six treatments, three levels of wood ash addition (1.25, 2.5 and 5.0 t ha^-1), one level of N addition (180 kg N ha^-1), one combined treatment (2.5 t ha^-1 of wood ash and 180 kg N ha^-1) and one untreated control. The treatments were repeated in four blocks. The pH_CaCl2 of the O horizon increased from 3.45 (control) to 6.15 for t he highest ash dose and exchangeable Ca²⁺ and Mg²⁺ increased significantly (p<0.001). There were no changes in the mineral topsoil (0-5 cm) for the acidity but exchangeable Ca²⁺ and Mg²⁺ increased significantly (p<0.05) compared to the control for the highest ash treatment. Soil solution concentrations of Ca²⁺, Mg²⁺ and K⁺ increased at 20 cm depth as a result of the ash treatment but at 50 cm depth only Mg²⁺ concentration was higher than the control. Leaching of NO^3- and NH⁴⁺ increased in the N treatment compared to the control but no effect of the ash treatment was observed. The wood ash increased the concentration of Ca in the current year but not one-year-old needles 6 months after the application. N concentration in the current and one-year-old needles and even litterfall increased as a result of the N treatment. Ca uptake seemed to be stimulated by high N availability as indicated by high Ca concentrations in needles from the N treatment. There were no other indications of interactions between the ash and N treatments.

Key words: wood ash, Scots pine, Arenosols, soil solution, needles, litterfall, chemical composition.