Impacts of Erosion on the Sustainability of Organic Olive Groves: A Case Study (Estepa Region, Southwestern Spain)

Abstract

Spain has more than 2.5 M ha of olive groves, with 60% of this area (i.e., 1.5 M ha) concentrated in the region of Andalusia (Southern Spain). Assuming the socio-ecological characteristics of these crops, of which their contribution to ecosystemic services (ES) is fundamental for society, it is highly relevant to direct their management towards practices that guarantee their durability. Organic management of olive groves constitutes a multifunctional model that contributes to ensuring its sustainability and represents 2.4–3.5% of the olive grove area in Spain. Taking the Protected Designation of Origin (PDO) Estepa (Southwestern Spain) as a study model, where organic olive groves are novel, a study of the impacts of erosion on the economic, social, and environmental factors associated with this management was carried out in addition to estimating its impacts. The results showed how organic management promotes edaphic fertility, keeping the levels of diffuse pollution under the legislative limits. Although the increase in erosion has negative effects on the sustainability/durability of agricultural holdings, organic management consolidates a sustainable model that satisfies farmers’ demands. Therefore, organic farming is a model that focuses on the correct use of natural resources associated with the geographical region of study, and contributes to increasing the sustainability of olive groves.

Mapping and quantifying medium-term soil loss rates in mountain olive groves using unmanned aerial vehicle technology

“…A wide variety of methods, differing in accuracy, equipment and costs, can be used to calculate soil loss rates in agricultural areas. These methods include generic erosion models such as the Universal Soil Loss Equation (USLE), both the original version and its updates [1] , [2] , [3] , [4] , and direct measurements in the field using experimental plots with water and sediment collection equipment [5 , 6] . Both approaches present certain deficiencies: the first is often limited by a lack of field observations, and even if these are available, they may produce unsatisfactory results [7] ; in the second case, direct measurements only provide limited spatio-temporal information [8] , especially when obtained from runoff plots.…”

“…Overall, this approach was found to be practical and effective. The method includes the following steps: [1] measure the current relief using UAV technology; [2] reconstruct the historical relief from field measurements; [3] calculate soil truncation (h) and obtain a soil erosion rate map; [4] determine the erosive dynamics of the slope and establish the relation between tree truncation, slope and mounds. The method we describe presents the following advantages: it quantifies soil losses by reference to existing tree mounds; it is straightforward to apply; its application enhances the calibration of erosion models.…”