Modelling the Effects of Soil Conditions on Olive Productivity in Mediterranean Hilly Areas

Abstract

The majority of olive (Olea europaea L.) production in Mediterranean environments is characterized by low external inputs and is practiced in hilly areas with shallow soils. This study aimed to study the yield and nutritional status for olive (cv. "Zeiti") trees in northwestern Syria and establish correlations between yield, on the one hand, and soil/land factors and tree nutrition, on the other hand, to determine the most yield-affecting factors. Land and soil fertility parameters (field slope, soil depth, and soil nutrients) and concentrations of leaf minerals were determined. As olive roots can go deep in the soil profile to extract nutrients, the total available nutrients per tree (over the whole profile) were estimated. Multiple regression analyses were performed to determine the model that best accounts for yield variability. Total available soil potassium amount ( 2 = 0.68), soil total N amount ( 2 = 0.59), and soil depth ( 2 = 0.56) had the highest correlations with olive fruit yields. Available soil potassium amount and soil depth explained together 77% of the yield variability observed. In addition to these two factors, adding leaf B and Fe concentrations to the model increased the variability explained to 83%. This paper is dedicated to the good memory of Mr. Malek Abdeen.

Management of Olive Tree Fertilization in Morocco

“…A study carried out in Syria revealed that the olive yield variability was explained at 68% by the amount of potassium available in the root zone, followed by total N with 58% and mineral N with 44% [5]. The same study showed the absence of correlation between yield and leaf N and P contents and a significant correlation (26%) between yield and leaf K content.…”

Technological Innovation in the Traditional Olive Orchard Management: Advances and Opportunities to the Northeastern Region of Portugal

“…This common practice contributes to increases in both biodiversity and soil conservation, preventing worrying rates of soil erosion. Indirectly, both natural and cultural heritage could be potentiated through agro-ecotourism [2,21,32,33].…”

“…Unlike many fruit tree crops, olive trees can be well established on calcareous soils; however, they can also thrive in moderately acidic soils, with pH levels varying between 5.5 and 8.5. However, olive trees benefit from near-neutrality values due to the increase in nutrient absorption capacity as a consequence of the higher soil microbial activity (i.e., accelerates the mineralization process) [4,32,50]. In terms of physical properties, the soil texture and depth are limiting factors of the olive tree's productive cycle, since they influence the soil water holding capacity, an effect that can be minimized through the implementation of cover crops and/or by adding organic matter.…”

Benefits of organic olive rainfed systems to control soil erosion and runoff and improve soil health restoration

“…In this study, the average olive yields for all experimental plots in 2015, 2016, 2017, and 2018 were 17.3, 5.5, 15.0, and 18.7 kg tree −1 , respectively. In this context, according to Tubeileh et al (2014), for rainfed plantations, the olive yield varied considerably from 6.0 to 65.0 kg tree −1 .…”