The influence of a shift from conventional to organic olive farming on soil management and erosion risk in southern Spain

Abstract

Natural resource conservation should be fundamental to organic agriculture, including the prevention of soil erosion. Soil erosion in the olive orchards of southern Spain is recognized as a serious problem causing environmental, economic and social repercussions, both on and off-site. This study describes the changes in soil management practices that accompanied a shift from conventional to organic olive farming and the corresponding effect of those management practices on erosion risk in the province of Córdoba, Andalusia. Interviews with 107 farmers were carried out in two different geographic areas to assess the socio-economic factors influencing farm management decision-making, and on-farm erosion risk evaluations and soil data (organic matter, aggregate stability, infiltration and vegetative ground cover) were taken on 25 farms to assess the effects of those decisions on soil erosion risk. Results from this study show that the shift to organic farming in olive orchards in the province of Córdoba has been accompanied by increased protection of the soil and lowered erosion risk. The most important changes in soil management practices associated with the transition from conventional to organic agriculture were the reduction in tillage and the increase in management systems that incorporate a vegetative cover controlled either by grazing livestock or mowing. However, the shift to organic farming has had more impact in the south of the province than in the north where farm management systems have historically led to less erosion.

From experimental research to an on‐farm tool for participatory monitoring and evaluation: an assessment of soil erosion risk in organic olive orchards

“…Before the final version was complete, the work was submitted to a second process of farmer revision in the form of group meetings and individual farmer collaboration to ensure easy comprehension and technical adequacy of the field manual. The assessment was evaluated on 25 organic olive orchards in the province of Córdoba (in which the majority of the organic olive orchards of Andalusia are located), where detailed field measurements were taken of soil properties, topography, climate and soil management practices (Milgroom et al, 2006). Finally, six workshops and seminars were held with organic olive farmers and three with technicians and researchers to test the applicability and validity of the field manual with the future users.…”

“…The field manual has two parts: the first part is an assessment of the erosion risk of the particular farm, and the second part offers corresponding soil management recommendations for addressing the problems of soil erosion identified in a field survey of organic olive orchards (Milgroom et al, 2006). The manual was designed combining a visual assessment of erosion symptoms in the field inspired by Morgan (1986) with an adapted and simplified version of the Revised Universal Soil Loss Equation (RUSLE) (Renard et al, 1997) calibrated previously for the soils and the management typical in olive orchards of Andalusia (Gómez et al, 2003).…”

Methodological considerations in discriminating olive-orchard management type using olive-canopy arthropod fauna at the level of order

“…Currently, this crop occupies the largest surface area in Andalusia (Alonso, 2011). The natural and semi-natural vegetation in this region continues to be eliminated to increase the area for olive-orchard cultivation, and therefore the original landscape has been reduced and fragmented (Parra & Calatrava, 2006;Milgroom et al, 2007). This trend has impoverished the arthropod fauna in the olive-orchard agroecosystem (Guzmán & Alonso, 2004b;Ruano et al, 2004;Santos et al, 2007a;Scalercio et al, 2012;Paredes et al, 2013).…”

Farming practices and policy measures for agricultural soil conservation in semi‐arid Mediterranean areas: The case of the Guadalentín basin in southeast Spain

“…Reduced tillage can significantly reduce erosion rates (Milgroom et al, 2007). No-tillage seems to provide a buffering of crop productivity in the driest years (Gómez et al, 1999;Ordóñez-Fernández et al, 2007).…”