Vegetative barriers as a nature-based solution for agricultural landscapes diversification: design and management of this green infrastructure in a Mediterranean climate.

Agricultural intensification has used technological advances to raise food production, but it has also created environmental imbalances. Environmental degradation, e.g. soil loss and offsite contamination, and loss of biodiversity, related to the expansion and intensification of agriculture, have been documented internationally^[1][2]. Since the 1980s, with the Single European Act^[3] as a legal basis, different attempts have been made to address this threat at European level through better focused environmental policies. For instance since the CAP reform in 1992, environmental sustainability of agriculture has been constantly ongoing. In fact, the latest reform post-2021 shows more ambitious objectives with the introduction of eco-regimes. Other key initiatives like the Green Infrastructure Strategies and the EU Mission: A Soil Deal for Europe have emerged^[4][5][6] being focused on recovering natural capital as a source of ecosystem services.

In this context, ALIve^[7], SCALE^[8] and ECOMED^[9] projects and the Rural Landscape Diversification Program of the Córdoba Countryside^[10] aim to provide scientific and technical knowledge for the sustainable intensification of agriculture in Mediterranean areas, in particular southern Spain, through nature-based solutions.

Although vegetative barriers are one of the key instruments to manage agricultural landscapes towards sustainable intensification, detailed empirical information on how to implement them still scarce. This communication presents an experiment on different alternatives on how to stablish a vegetative barrier combining fifty-two herbaceous and woody species adapted for Mediterranean conditions. This experiment explores seventeen different strategies, combining different irrigation, mulching and tillage combinations. In these plots, growth, survival and phytosanitary status of the plants, and soil moisture at the end of each hydrological year were monitored since its implantation in February 2021. This communication presents results from the first year of implementation, as well as a costs analysis of the different strategies evaluated. This information can be valuable for practitioners and planners interested in these nature-based solutions.

After the first year, it was observed that all the treatments presented a remarkable survival rate, above 48% (CoT4), albeit this increases with better management reaching 100% with better tillage, mulching and drip irrigation. Plant growth also responded to best management ranging from 14.1 cm in height (CoT4) and 11.8 cm in diameter (CoT3) to 46.7 cm in height (CoT9) and 58.8 cm in diameter (CoT9). The cost of implementation ranged from 1.7 €/m² (CoT4) to 6.0 €/m² (CoT9). Among the most successful individual operations is mulching with a fabric film, which despite having the highest implementation cost 2.5 €/m² results in the lowest maintenance cost 0.4 €/m².

Acknowledgements: ALIve (PID2019-105793RB-I00), SCALE (Nº 862695) and ECOMED (PR.AVA23.INV202301.035).

References:

[1] MITECO, «Plan estratégico estatal del patrimonio natural y de la biodiversidad a 2030». 2022.
[2] European Commission, «EU Biodiversity Strategy for 2030». 2020.
[3] European Economic Community, «Single European Act». 1987.
[4] European Commission, «Green Infrastructure (GI) — Enhancing Europe’s Natural Capital». 2013.
[5] MITECO, «Estrategia Nacional de Infraestructura Verde y de la Conectividad y Restauración Ecológicas». 2021.
[6] European Commission, «EU Mission: A Soil Deal for Europe». 2023.
[7] https://alive.csic.es/
[8] https://ejpsoil.eu/soil-research/scale/
[9] https://www.juntadeandalucia.es/agriculturaypesca/ifapa/web/node/60947
[10] https://www.jardinbotanicodecordoba.com/investigacion/diversificacion-del-paisaje-agrario/