A Perspective on Optimizing the Productive and Environmental Performance in Southern Italian Olive Groves: Analyzing the Impact of Organic Fertilizers and Seasonal Irrigation Management on Yield, Water Footprint, and Water Efficiency

This study investigates the impact of various irrigation regimes and organic fertilizers on olive cultivation productivity and environmental sustainability. Experimental results showed that olive trees fertilized with biochar yielded an average of 2640 kg ha-1, while those fertilized with a commercial product based on dry blood resulted in lower yields of 1820 kg ha-1. Significant productivity gains were observed under irrigation, particularly with the fully watered regime, which nearly doubled yields compared to non-irrigated trees. The study also highlighted the influence of irrigation on water use efficiency, with water consumption metrics varying notably among different fertilization treatments. The water footprint analysis indicated that the most sustainable option, characterized by the lowest water footprint, did not consistently align with productivity gains, emphasizing the need for integrated management strategies. An analysis of marginal irrigation use efficiency revealed that optimizing irrigation volumes improved productivity while providing substantial water savings. A scoring system was employed to standardize various parameters, enabling direct comparisons of irrigation and fertilization treatments. Ultimately, the results suggested that biochar, in combination with deficit irrigation strategies, could enhance both productivity and sustainability in olive farming, with the strategy of ceasing irrigation at the pit hardening phase achieving the highest aggregated score for management effectiveness. These findings underscore the importance of optimizing irrigation and fertilization practices to promote environmentally sustainable agricultural systems in Mediterranean climates.