Determination of nutrition status of olive (Olea europaea L.) orchards in Gümülci̇ne (Greece) by means of leaf samples

In this study, analyses of olive (Olea europaea L.) leaves were conducted from 25 different olive orchards in the Gümülcine region of Western Thrace, Greece, with the assistance of GPS. The aim of the study was to assess the current plant nutrition status of the orchards by analyzing the levels of N, P, K, Ca, Mg, Fe, Mn, Zn, and Cu in olive leaves. The average nitrogen (N) value of the olive leaves was determined as 1.75%, falling into the "sufficient" category. When considering the average values of macronutrients, phosphorus (P) was found to be 1,06%, potassium (K) 4,32%, calcium (Ca) 12,92%, and magnesium (Mg) 1,06%, all of which were classified as "very high." Looking at the average values of micronutrients, iron (Fe) was found to be 0,77 mg kg⁻¹, copper (Cu) 0,12 mg kg⁻¹, zinc (Zn) 0,14 mg kg⁻¹, and manganese (Mn) 0,27 mg kg⁻¹, all of which were at "very low" levels. The fact that olive orchards in the research area are generally rich in macronutrients but poor in micronutrients indicates a focus on macronutrients in fertilization. It is of utmost importance that future fertilization programs include micronutrients as well.