Status of Macro and Micro Nutrients of Olive Orchard in Northern Iran

Abstract

Gilan Province, located in the north of Iran, is from among the main centres and critical poles of olive production in Iran. The average yield of Gilan Province olive orchards are about 2200 kg per hectare which is slightly higher than the average of global yield, but it is considerably lower than the European countries or the desired status. One reason is the nutritional disorders. The index of deviation from optimum percentage is a simple way to diagnose the orchards’ nutritional disorders. This index indicates the nutritional status of plant or shortage and/or surplus of nutritional elements and can be used for prioritizing the plant’s need to nutrients. This study was conducted aiming at investigating the nutritional balance of olive orchard using the deviation from optimum percentage (DOP). To conduct this research, more than 80 olive orchards with strong, moderate and weak yields in Gilan Province were selected. The mean concentration of nutrients (reference numbers) in the leaves of orchards with relative strong yield for N, P and K were obtained 1.54, 0.12 and 1.36, respectively and for Fe, Mn, Zn, Cu and Br obtained 128.31, 44.79, 22.31, 4.95 and 27.05 mg/kg. The reference numbers obtained in this study can be evaluated in each olive orchard of the province. On the basis of index of deviation from optimum percentage, the need to nutrients were in this order: N > Zn > B > K > Fe > Mn > P > Cu.