Due to climate change, the application of water saving strategies is of particular interest. The aim of this study was to evaluate the effects of deficit irrigation (DI) and partial root-zone drying (PRD) techniques on the crop water stress index (CWSI), water use efficiency (WUE), and quality parameters in processing tomatoes grown in open field conditions in a Mediterranean climate. Two cultivars were grown for two growing seasons under four irrigation regimes as follows: (i) IR₁₀₀: full irrigation by restoring 100% of the maximum tomato evapotranspiration (ET_c); (ii) IR_70DI: 70% of the amount of water given to the IR₁₀₀; (iii) IR_70PRD: 70% of the amount of water given to the IR₁₀₀ by applying partial root-zone drying and (iv) IR₀: irrigation only at transplanting and during fertigation. During the flowering period, the first growing season was characterized by an absence of rainfall and by higher temperatures also showing a higher CWSI. Despite, under IR_70PRD, the CWSI was significantly higher than under IR_70DI, the marketable yield obtained was significantly higher. Both IR_70DI and IR_70PRD regimes received approximately 24% less water than IR₁₀₀, but the yield reduction with relation to the optimum regime was equal to 16.2% under IR_70DI, and only 7.6% under IR_70PRD. The WUE increment of IR_70PRD with respect to IR₁₀₀ was equal to 27% in the first growing season and to 17% in the second one, showing that the positive effect of PRD on the WUE is more evident in the more stressed year. Finally, the results from the principal component analysis (PCA) showed that the two cultivars had different qualitative responses in the two extreme regimes (IR₁₀₀ and IR₀) but not under PRD and DI regimes.

Water deficit and high temperatures are the main environmental factors which affect both wheat yield and technological quality in the Mediterranean climate. The aim of the study was to evaluate the variation in the gluten protein assembly of four durum wheat genotypes in relation to growing seasons and different nitrogen levels. The genotypes, Marco Aurelio, Quadrato, Pietrafitta and Redidenari, were grown under three nitrogen levels (36, 90 and 120 kg ha⁻¹) during two growing seasons in Southern Italy. Significant lower yield and a higher protein concentration were observed in the year characterized by a higher temperature at the end of the crop cycle. The effect of the high temperatures on protein assembly was different for the genotypes in relation to their earliness. Based on PCA, in the warmer year, only the medium-early genotype Quadrato showed positive values along the “protein polymerization degree” factor, while the medium and medium-late genotypes, Marco Aurelio and Pietrafitta showed negative values along the “proteins assembly” factor. No clear separation along the two factors was observed for the early genotype Redidenari. The variation in gluten protein assembly observed in the four genotypes in relation to the growing season might help breeding programs to select genotypes suitable for facing the ongoing climate changes in Mediterranean area.

Industrial and municipal wastewaters are often used for irrigating agricultural fields in arid and semi-arid countries, representing the most attractive option to alleviate pressure on fresh-water resources. However, the wastewater may contain various potentially toxic elements and organic matters with highly harmful effects on human and animal health. During two growing seasons of globe artichoke, the effects of irrigation with secondary (SWW) and tertiary (TWW) municipal wastewater on heavy metal soil and plant content were evaluated, together with the consequent human risk from artichoke head consumption. The heavy metal contents (i.e., Al, Cd, Co, Cr, Cu, Fe, Ni, Pb, Zn, and Mn) of the irrigation water, soil, plant, and yield were analyzed. Total and extractable heavy metals were quantified to determine the bioaccumulation factors, and the health risks to adults and children were determined according to hazard indices. The heavy metal contents of the artichoke heads harvested after SWW and TWW irrigation were lower than the international threshold values, and low bioaccumulation factors suggested that these heavy metals did not accumulate in the edible part of the artichoke crop. The hazard indices that were based on the consumption of the artichoke heads remained <1.0 for both adults and children, thus indicating that the health risks involving the different heavy metals are not significant.

The gradual reduction of water reserves for irrigation has become a worldwide concern. To improve the irrigation of processing tomato, we conducted a study to evaluate a system that monitors both plant water status and soil moisture levels (PlaSoMan) compared to an evapotraspirometric method (IrriMan) and an empirical farmer’s management (FarMan) in a two-year field trial. The results showed that PlaSoMan saved around 30% and 7.5% of water, with a yield loss of only 10% and 2.5% compared to FarMan and IrriMan, respectively. Thus, PlaSoMan showed satisfactory irrigation water use efficiency (IWUE) over the two years. Moreover, IrriMan and PlaSoMan had lower blue water requirement (BWR) values than FarMan. Finally, PlaSoMan reached the highest value of the yield quality indicator, which combined total yield and brix degree. Thus, the new system, which assesses both plant water status and soil moisture levels, appears to be associated with high-quality and water-friendly tomato production representing an efficient solution for areas with limited water resources.

The viability of co-composting of olive mill pomace added to sewage sludge with other organic residues was evaluated and the agronomic use of the final composts was investigated. Two composting piles at different carbon-nitrogen ratios were performed, in which olive mill pomace (OMP), sewage sludge from vegetable processing (SS), fresh residues from artichoke processing residues (AR), and wheat straw (WS) were used. The two composting piles were placed inside a specially built greenhouse and a turning machine pulled by a tractor was used for turning and shredding the organic matrix (every 6 days) during the process. The humidity and temperature of organic matrices have been monitored and controlled during the entire composting process, which lasted 90 days. The process was also monitored to evaluate the microbiological safety of the final compost. The humidity of both piles was always kept just above 50% until the end of the thermophilic phase and the maximum temperature was about 50 °C during the thermophilic phase. The carbon-nitrogen ratio decreased from 21.4 and 28.2, respectively (initial value at day 1 in Pile A and B), to values ranging from 12.9 to 15.1, both composts that originated from the two different piles were microbiologically safe. During a two-year period, the effects of different types of compost on the main qualitative parameters of processing tomato and durum wheat was evaluated. Five fertilization treatments were evaluated for tomato and durum wheat crops: unfertilized control (TR₁); compost A (TR₂); compost B (TR₃); ½ mineral and ½ compost A (TR₄); and mineral fertilizer commonly used for the two crops (TR₅). Concerning the processing tomato yield, TR₅ and TR₄ showed the best results (2.73 and 2.51 kg, respectively). The same trend was observed considering the marketable yield per plant. The only difference was related to the treatments that included the compost (2.32, 1.77, and 1.73 kg/plant for TR₄, TR₃, and TR₂, respectively). As regards the qualitative parameters of tomato, the highest average weight of the fruits was found in the TR₅, TR₄, and TR₃ treatments (respectively, 73.67 g, 70.34 g, and 68.10 g). For durum wheat, only the protein component was differentiated between treatments. Furthermore, wheat grain yield parameters generally increased by combined application of mineral fertilizer and compost.

Organic farming systems are often constrained by limited soil nitrogen (N) availability. Here we evaluated the effect of foliar organic N and sulphur (S), and selenium (Se) application on durum wheat, considering N uptake, utilization efficiency (NUtE), grain yield, and protein concentration as target variables. Field trials were conducted in 2018 and 2019 on two old (Cappelli and old Saragolla) and two modern (Marco Aurelio and Nadif) Italian durum wheat varieties. Four organic fertilization strategies were evaluated, i.e., the control (CTR, dry blood meal at sowing), the application of foliar N (CTR + N) and S (CTR + S), and their joint use (CTR + NS). Furthermore, a foliar application of sodium selenate was evaluated. Three factors—variety, fertilization strategies and selenium application—were arranged in a split-split-plot design and tested in two growing seasons. The modern variety Marco Aurelio led to the highest NUtE and grain yield in both seasons. S and N applications had a positive synergic effect, especially under drought conditions, on pre-anthesis N uptake, N translocation, NUtE, and grain yield. Se treatment improved post-anthesis N uptake and NUtE, leading to 17% yield increase in the old variety Cappelli, and to 13% and 14% yield increase in Marco Aurelio and Nadif, mainly attributed to NUtE increase. This study demonstrated that the synergistic effect of foliar applications could improve organic durum wheat yields in Mediterranean environments, especially on modern varieties.