Impact of organic fertilization on soil properties, plant physiology and yield in two newly planted olive (Olea europaea L.) cultivars under Mediterranean conditions

Abstract

The aim of the present research was to investigate the effect of two commercial organic fertilizers (Activit and Agrobiosol) on two newly planted olive cultivars for two successive years. Two cultivars were used, ‘Koroneiki’ an olive oil cultivar and “Konservolia” a table olive one. The organic fertilizers were combined with inorganic fertilizers which when used alone served as control. Organic fertilizer application resulted in lower soil pH values (8.0–8.15 compared to 8.46 in control) and higher cation exchange capacity (up to 19.6meq 100g−1 compared to 17.1meq 100g−1 in control). Soil N, K, Mn and Zn concentration were higher under the combined application of Activit plus inorganic fertilizer. A significant increase of leaf area index was observed when organic fertilizers were used. Nutrient concentrations of the leaves were in all treatments within the adequacy range. Carbon assimilation rate also increased under organic fertilization in ‘Koroneiki’ in summer (17.4–18.7μmolm−2s−1) compared to control (14.9μmolm−2s−1). Yield of ‘Koroneiki’ trees during the second year (the only cultivar bearing fruits) was higher under both organic fertilizers application, reaching almost 55% increase compared to the use of only inorganic fertilizer.