The effects of land use change of forests on chemical properties of soil

This study was performed، in 2007at Lahijan basin، to investigate the effect of land use change from forest to agricultural land. Four land use types were selected، including forest، blackberry-tea orchard، 40 year -and 50 year- tea orchards. For each treatment six samples were harvested using auger from the depths of 0-30 cm and 30-60cm and used for measuring organic carbon content، total N، pH، Lime، phosphorous and absorbable potassium. The results revealed that by changing land use from forest to other use types the amounts of lime، organic carbon content، total N and pH have decreased in the first layer، more obviously in 50-year old tea-orchard. In this layer، absorbable potassium has increased while absorbable phosphorous remained intact. In the second layer (30-60 cm)، organic matters، pH، lime and total N have diminished، respectively in blackberry-tea orchard، 40 year tea-orchards and 50 year- tea orchards، whereas no significant differences have been for other factors estimated.