Evaluation of Tarom Olive Orchards Nutritional Status Using the Deviation from Optimum Percentage Method (DOP)

There are many problems in yield, quality and and persistence regular bearing in olive trees, one of these problems is nutritional imbalances. This study carried out in order to evaluate nutritional status of olive orchards in Tarom region of Zanjan province. Samples of soil and leaf were taken from 79 olive orchards in June 2012 and 2013 and were analyzed by using appropriate laboratory methods. Deviation from optimum percentage (DOP) for each nutrient was calculated. The optimum concentration of nutrients in leaves of orchards with high yield for nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg), 1.8, 0.1, 1.2, 1 and 0.275 %, respectively and for manganese (Mn), zinc (Zn), copper (Cu) and boron (B), 20, 25, 4 and 30 mg/kg, respectively. The results showed that the average order of nutrients requirement according to DOP in the orchards is B>Mg>K>N>Zn>Mn>P>Ca>Cu. On the other hand all orchards with low yield, in terms of nutrient is in unbalanced status and nitrogen deficiency in 36%, potassium in 84%, magnesium in 93%, zinc in 35% and boron in 95% is predictable.