Soil Properties in Sloping and Flat Olive Orchards in Rainfed Mediterranean Conditions

Abstract

Olives have traditionally been grown for years in northwest Turkey on sloping areas where the use of mechanization is difficult. However, in recent years, it has been encouraged to spread olives in flat areas that are more suitable for mechanization. This study was conducted to determine the soil properties of two traditional olive orchards with no-tillage on the sloping and tillage on the flat for two years. The results showed that the bulk density and penetration resistance of flat orchard at 30–40 cm were 1.70 g cm−3 and 2.10 MPa, and the corresponding values for sloping were 1.24 and 1.56, while the values were lower between 0 and 20 cm soil depths of both orchards. Oxygen diffusion rate remained at threshold level in all soil depths in two orchards, but it was found higher with 110.25 µg m−2 s−1 in sloping compared to 85.50 µg m−2 s−1 in flat. All nutrients were found to be generally insufficient in both orchards. Over the average of two years, N remained below the threshold level for flat and sloping with 1198.15 and 1004.50 mg kg−1, respectively, while the corresponding values of 11.56 and 10.86 mg kg−1 for P were found to be within normal ranges. Overall, at the regional scale where olives represent a very high proportion of agricultural land, the use of no-tillage practices seems promising, which means the sustainability of the olive.