Effects of nitrogen on growth properties and phenology of silver birch (Betula pendula Roth)

Abstract

Effects of stress caused by differentiated inputs of nitrogen after the application of ammonium nitrate (NH4NO3) on silver birch (Betula pendula Roth) were monitored in a greenhouse. The applied ammonium nitrate did not affect pH values but increased differently the content of nitrogen in soil and leaves. With increased inputs of nitrogen the height and diameter increment of birch also decreased, budbreak was delayed and the autumn leaf-fall slowed down. Frost heaving of shoots occurred particularly in the lower half of the birch stem. With the increasing content of nitrogen in leaves the content of phosphorus decreased and the level of potassium increased.

Keywords

• nitrogen
• silver birch
• stress
• phenology of budbreak
• leaf-fall
• frost heaving