Effect of Spatial Variability on Fertiliser Requirement of Olive Orchard Cultivated for Oil Production

Abstract

Aim of this research is to determine effect of spatial variability of soil texture, pH, salt, and plant nutrient contents of soil and leaves on fertiliser requirement of an oil olive orchard which has 102 olive trees. Soil and leaf samples were taken from 29 locations to determine spatial variability. Soil texture, pH, salt, lime, organic matter, nitrogen (N), phosphorous (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), copper (Cu), zinc (Zn) and manganese (Mn) amounts were determined from soil samples that were taken from 0-30 cm and 30-60 cm soil depths. N, P, K, Ca, Mg, Fe, Cu and Mn were determined from leaf samples. When results were evaluated, N, P, K, Ca and Cu contents had optimum values, but Fe, Mn and Zn were found in deficiency levels. Fertiliser requirements for variable rate fertilisation were between 0-0.76 kg/tree for N, 0-0.192 kg/tree for P, and 0-5.22 kg/tree for K. Fertiliser requirement for fixed rate was determined 0.75 kg/tree for nitrogen, 0.275 kg/tree for phosphorous and 1.5 kg/tree for potassium. Required N, P and K values converted to commercial fertiliser forms as urea, ammonium nitrate, and potassium sulphate and triple super phosphate.