Climate model forecasts indicate a significant drop in annual rainfall in southern Spain by the end of the century, which would especially affect rainfed agricultural systems (IPCC 2021). Soil management has a marked influence on the use of water resources (Madejón et al., 2023). In this work, it has been evaluated whether conservation tillage techniques (no tillage and reduced tillage) increase resistance to drought in non-irrigated soils in the expected scenario of reduced rainfall compared to traditional tillage. Aspects related to the activity and diversity of soil biotic communities are studied. A rain manipulation experiment was established in rainfed soils of the Guadalquivir Valley. Agricultural production was monitored for two years (broad bean and wheat in rotation), and the main physicochemical properties, microbial activity, fungal and bacterial diversity, and soil nematodes were characterized. The experimental drought produced a decrease in the plant biomass of the broad bean crop, especially in reduced tillage, although not in its grain production. The exclusion of rain had a marginally significant effect on the organic carbon content of the superficial soils in the broad bean crop, which was slightly higher in the soils of the exclusion treatment, possibly due to an increase in the root:shoot ratio of the plants. Drought did not produce significant effects on various indices of microbial activity (soil respiration and enzymatic activities). However, tillage significantly influenced the amount of microbial biomass and the colonization patterns of broad bean plants by arbuscular mycorrhizal fungi (being higher in non-tillage), which was positively related to the levels of plant water potential. The nematode community was affected by the type of tillage, such that the maturity and structure indices were higher under the no-tillage system, reflecting the negative effect of tillage on the populations of the genera of nematodes more sensitive to disturbances. References IPCC (International Panel of Climate Change), 2021. IPCC, 2021: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. t al., (eds.)]. Cambridge University Press. In Press. Paula Madejón, Elena Fernández-Boy, Laura Morales-Salmerón, Carmen M. Navarro-Fernández, Engracia Madejón, María Teresa Domínguez. 2023. Could conservation tillage increase the resistance to drought in Mediterranean faba bean crops?. Agriculture, Ecosystems and Environment 349. 108449.

Funding US- 126062 (Programa Operativo FEDER, Universidad de Sevilla) and the Spanish Ministry of Science and Innovation (project PID2021–122628OB-I00 WASTE4DROUGHT)

Resumen del póster 14 en 1st International Agrienvironment Symposium – 1st IAS2023 in Salamanca, Spain, 17-18th July 2023.

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