Strategic Tillage in the Mediterranean: No Universal Gains, Only Contextual Outcomes

Abstract

In Mediterranean drylands, where year-to-year climatic variability and soil con-straints (e.g., compaction or shallow profiles) often limit the feasibility of strict no-tillage (NT), strategic tillage (ST) has emerged as a pragmatic support tool within conservation agriculture. To evaluate its short-term effects, multi-country field trials were established in Morocco, Tunisia, Türkiye, and Spain across a rainfall gradient (250–580 mm). We assessed soil water content (SWC), crop biomass, and yield under ST compared with NT systems. Results were context- dependent. SWC responses varied: largely unchanged in Morocco and Tunisia, slightly increased in Morocco in 2023, and significantly reduced in Spain in 2022. Biomass generally showed no significant change, with modest decreases in Morocco and modest increases in Tunisia. Yield effects were more pronounced: pooled data from Morocco indicated a significant reduction under ST, and Tunisia showed a significant yield loss in 2021. Türkiye exhibited non-significant declines in both SWC and yield, while Spain experienced yield-neutral but SWC-reducing outcomes. Overall, ST did not have negative effects across sites. Instead, its impacts were strongly conditioned by local soils, rainfall distribution, and crop context. These findings highlight that ST can be considered as a pragmatic tool to overcome some of the agronomic difficulties in the Mediterranean region with little or no negative effects on productivity of soil moisture.