Monthly variation of soil chemical properties In the mixed beech-hornbeam stand

Base cation leaching as a process affecting nutrient transport، has a key role in preventing of soil macro element loss (especially in poor soil) that varies result in interaction relations of soil، climate and biological activity over time. So the objective of this study was to investigate monthly variation of base cations (calcium، magnesium، sodium and potassium) of shallow (0-10 cm) and deep (10-50 cm) soil leaching in the mixed beech-hornbeam stand located in district one of Shastkolate forest، Golestan province. Samples of different layers of soil leaching were taken after each rain from 2008/12/21 to 2009/12/21 and were studied in the laboratory. To investigate the monthly variation of base cation leaching، we used one way variance analysis and for mean comparison we used Duncan''s test at the 95% level confidence. Result showed amounts of base cation leaching of soil layers in various months were different significantly. The least leached cation in shallow (in October) and deep soil (September، October and November) was for magnesium. Also the most leached cation in shallow soil was for potassium in August (8. 54 kg ha) and in deep soil was for calcium in December (6. 39 kg ha).