Assessing the Impact of Six Years of Regenerative Agriculture on a Commercial Olive Orchard in Southern Spain

Olive is one of the most relevant crop in Mediterranean regions, in which regenerative agriculture (RA) might have a widespread potential impact providing environmental and economic benefits. However, research on its viability and actual impacts under specific local conditions remains limited. To address the effect of RA on soils and crops, an olive-farm in Southern Spain where regenerative practices have been implemented since 2019 was studied. These practices include no-till farming, the use of spontaneous cover crops, application of manure, biochar, and olive leaves to the soil, as well as directed grazing to manage the cover vegetation. Our study included two areas within the farm. In one area, the spontaneous cover crops were well-developed (RegG), while in the other, the soils were less favorable, and the cover crop had a poorer establishment (RegB). A forest area close-by the olive grove (Forest) served as a benchmark, alongside a neighboring farm with the same soil type, tree age, and planting framework but managed using conventional methods (Conv). Conventional management involved no spontaneous cover crops and the use of synthetic fertilizers and pesticides. Physical, chemical, and biological soil properties, along with the nutritional status of the trees were measured to compare the effect of RA on soil quality. The Forest soil had the highest organic matter content (13.5 %), followed by the regenerative olive groves, RegG and RegB (5.9 %), and finally, the conventional olive grove; Conv (4.7 %). RegB showed a need for further improvements in management practices to achieve the benefits seen in RegG. Regenerative practices also enhanced microbial activity and diversity (5.83 and 3.33, respectively), reaching levels comparable to the reference Forest soil (5.7 and 3.36, respectively), highlighting their effect in improving soil health. Globally, the regenerative practices contributed to improve soil quality, as determined by an increase in carbon and water storage, and biological activity, reaching values similar to those obtained in the natural ecosystems. Despite these promising results, long-term research is necessary to fully understand the effectiveness of RA across various soil types and planting frameworks, as well as its socioeconomic feasibility.

Acknowledgement: This work has been supported by the Projects “Monitoring, reporting and verification of soil carbon and greenhouse gases balance” (https://www.project-marvic.eu/) from HORIZON-MISS-2022-SOIL-01-05 (GA 101112942) and PID2020-114917RB-100 from Ministerio de Ciencia e Innovación, Spain.