Optimizing Water Resources use and Yield Stability in Mediterranean Cotton cropping systems: A Regenerative Agriculture Approach

Southern Italy offers the ideal environment for cotton, yet its production must face the critical constraint of water scarcity while transitioning toward sustainable and regenerative models. This study evaluates the agronomic effects of regenerative agriculture practices applied to cotton in Southern Italy, assessing whether transitioning to low-impact systems can balance yield stability and water savings under different soil management strategies. The field trials were conducted during the 2024 and 2025 seasons in experimental fields of CREA in Rutigliano (BA), on a clay-loam soil (Luvisol/Vertic Cambisol) with a low organic matter content. The typical Mediterranean climate of the area is characterized by hot, dry summers, which were monitored via an on-site weather station to compute soil water balance. The effects of (i) two irrigation water regimes [full irrigation (I100, 100% ET) and deficit irrigation (I50, 50% ET), started one month after sowing)], (ii) three soil management [conventional tillage (CT, plowing at 30 cm and hoeing), minimum tillage (MT, within 10–15 cm, preceded by a vetch cover crop), and no-tillage (NT, direct seeding, preceded by a vetch cover crop)] and (iii) three genotypes [ST402, Armonia, and Hybrid HA1432, to evaluate their specific adaptability to regenerative protocols] were evaluated under the field trials. The factorial experiment was arranged in a split-split plot experimental design with three replicates, considering irrigation water regime as main plot factor, soil management as sub-plot factor and variety as sub-sub plot factor. Soil water content (SWC) was continuously monitored using capacitive probes (at depths of 0.2 and 0.4 m) connected to GPRS dataloggers. Seasonal water consumption amounted to 352 mm for I100 and 222 mm for I50 in the 2024 season, and 322mm for I100 and 205 mm for I50 in 2025, highlighting the water savings achieved through the deficit irrigation strategy. SWC showed that the CT under the I50 regime frequently dropped below the readily available water threshold. This indicated water stress in both years compared to the alternative soil management systems, establishing the basis for higher water use efficiency. In the 2024 season, the highest yields were recorded under MT, (2.89 t/ha) and, among genotypes, by the hybrid HA1432 (2.99 t/ha). In addition, under deficit I50, the MT strategy resulted in significantly higher production, whereas no differences emerged among soil management systems under the I100 regime. During the 2025 season, crop yield and WUE were significantly affected by the interaction among irrigation, soil management, and genotype. Interestingly, the varietal choice produced a significant difference only under I100 combined with NT. In this scenario, the hybrid HA1432 outperformed the others, reaching the highest yield (5.60 t/ha) and the best WUE. Under I50 or in tilled plots (CT and MT), no statistical differences were observed among the genotypes, which showed comparable yield stability and water efficiency. In conclusion, combining regenerative soil management (particularly MT) with rational irrigation optimizes water resources use, alleviates stress within the soil-plant system, and stabilizes crop yields, confirming the sustainability of this supply chain in Mediterranean environments.