Soil water chemistry as affected by liming and N fertilization at two Swedish coniferous forest sites
1992
Nohrstedt, H.Oe. (Institutet foer Skogsfoerbaettring, Uppsala (Sweden))
Lime (1000 kg per ha), NH4NO3 (150 kg N per ha) or a combination of both, were added to plots in two middle-aged coniferous stands. Lysimeter studies were performed during four to six years after treatment. The concentration of inorganic N did not increase after addition of lime only. NH4NO3 fertilization, alone or in combination with lime, temporarily increased inorganic N, especially NO3. All treatments increased the acidity during the whole observation period when compared to the control. Addition of lime did not increase concentrations of Ca and Mg in the soil water. In contrast, N fertilization significantly increased the concentrations of both elements. The increases followed exactly the pattern of increases in NO3 concentrations. More research is needed to explain soil water acidification by a low lime dose. Application practices as regards placement within different parts of watersheds are an important subject to study. With our present knowledge, a low dose of lime cannot be recommended to counteract effects of acid deposition.
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