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Introduction: The use of treated municipal wastewater (TWW) represents a relevant opportunity for irrigation of agricultural crops in semi-arid regions to counter the increasing water scarcity. Pharmaceutically active compounds (PhACs) are often detected in treated wastewater, posing a risk to humans and the environment. PhACs can accumulate in soils and translocate into different plant tissues, reaching, in some cases, edible organs and entering the food chain. Methods: This study evaluated the uptake and translocation processes of 10 PhACs by olive trees irrigated with TWW, investigating their accumulation in different plant organs. The experiment was conducted in southern Italy, in 2-year-old plants irrigated with three different types of water: freshwater (FW), TWW spiked with 10 PhACs at a concentration of 200 µg L-1 (1× TWW), and at a triple dose (3× TWW), from July to October 2021. The concentration of PhACs in soil and plant organs was assessed, collecting samples of root, stem, shoot, leaf, fruit, and kernel at 0 (T0), 50 (T1), and 107 (T2) days of irrigation. PhACs extraction from soil and plant organs was carried out using the QuEChERS method, and their concentrations were determined by high-resolution mass spectrometry coupled with liquid chromatography. Results: Results of uptake factors (UF) showed a different behavior between compounds according to their physicochemical properties, highlighting PhACs accumulation and translocation in different plant organs (also edible part) in 1× TWW and 3× TWW compared to FW. Two PhACs, carbamazepine and fluconazole, showed interactions with the soil-plant system, translocating also in the aerial part of the plant, with a translocation factor (TF) greater than 1, which indicates high root-to-leaf translocation. Discussion: Findings highlight that only few PhACs among the selected compounds can be uptaken by woody plants and accumulated in edible parts at low concentration. No effects of PhACs exposure on plant growth have been detected. Despite the attention to be paid to the few compounds that translocate into edible organs, these results are promising for adapting wastewater irrigation in crops. Increasing knowledge about PhACs behavior in woody plants can be important for developing optimized wastewater irrigation and soil management strategies to reduce PhACs accumulation and translocation in plants. [ABSTRACT FROM AUTHOR]

Kiwifruit vine decline syndrome (KVDS) is an emerging challenge related to various factors, including water stagnation, soil compaction, root hypoxia, imbalanced soil redox potential, soil nutrient imbalance and fungal pathogens, yet its definitive causes remain unconfirmed. This study compared soils and roots of healthy plants (CTRL group) and plants affected by KVDS (KVDS group) at a kiwifruit orchard (Actinidia chinensis cv. 'Zesy002') in Sermoneta (Lazio region), Italy. Our findings indicate that soil redox potential, a parameter related to soil oxidation, and soil macroporosity were significantly lower in the KVDS soils. The water table was also found to be higher in the KVDS block of the orchard, demonstrating a higher soil water content. This suggests less aeration and more water content in KVDS‐affected soils compared to the control. Root analyses showed that KVDS led to browning and decomposition of rhizodermis, decay of the central stele, detachment of the cortex, reduced cell size and the presence of starch granules in the parenchyma, with significant variations in root morphometric parameters. To mitigate KVDS, sustainable agronomic practices, including precision irrigation, green manure, compost addition and water drainage root pruning, were carried out on some KVDS‐symptomatic vines (SUST group). Molecular analyses revealed the presence of 10 fungal species from treated root plants, with Paraphaeosphaeria michotii, Fusarium oxysporum and Ilyonectria vredenhoekensis being frequently isolated from symptomatic KVDS‐affected plants but less from SUST plants. Also, Beauveria bassiana and Bacillus amyloliquefaciens, showed an effect against I. vredenhoekensis and P. michotii, and may be suitable candidates as biocontrol agents. The adoption of sustainable agronomic practices resulted in significantly more healthy plants (46% increase) by the end of the trial, demonstrating that a sustainable soil use and water management at kiwifruit orchards can mitigate KVDS through restoration of natural growth conditions. [ABSTRACT FROM AUTHOR]

Background: Beneficial bacteria-plant interactions play an important role in agriculture, positively affecting plant status and improving product quality. Bacterial endophytes contribute to host plant protection and survival. Aim: This study characterised the bacterial communities present in soil, leaf surface and xylem sap of olive trees, and investigated their response under a sustainable (Smng) or a conventional (Cmng) management system in an olive grove located in southern Italy. The aims are: (a) to understand if soil bacteria enter xylem and reach leaves and (b) to verify if the bacterial communities in the two management systems deeply differ due to the different agronomic practices applied in Smng and in Cmng. Methods: Therefore, a metagenomic approach was used to detect microorganisms, in order to estimate bacterial diversity and abundance, and to identify the bacterial taxa in the three analysed compartments in plants subjected to Smng and Cmng systems. Results: Bacterial communities came from the soil and reached aerial plant parts through xylem sap. The application of different agronomic practices influenced the composition of soil bacterial communities. Conclusions: The potential benefits of the specific bacterial taxa detected under the Smng system could improve plant growth protection and provide a higher crop quality in fruit plants. [ABSTRACT FROM AUTHOR]

In conventional olive growing, frequent soil tillage strongly reduces the complexity and diversity of the agro-ecosystem. Here, a metabolomic analysis was carried out on the xylem sap (XS) of olive plants (Olea europaea L.) from a grove located in Southern Italy (Basilicata region). The orchard has been divided in two plots that have been managed for 18 years with two different systems: a) 'sustainable management' (S mng), with no-tillage, fertigation and internal C-inputs (spontaneous weeds and pruning residues), and b) an adjacent rainfed 'conventional management' (C mng), that included soil tillage and mineral fertilization. The XS was extracted from olive shoots in two sampling times (ST1: May; ST2: October) using a Sholander pressure chamber, and its metabolome analyzed by ultra-high performance liquid chromatography (UHPLC) coupled to a hybrid quadrupole-time-of-flight mass spectrometer (QTOF-MS). The discriminating compounds were 94 at ST1 and 119 at ST2, and 35 of them were in common between the two sampling times. The majority of the discriminating metabolites (73 on 94 at ST1, and 109 on 119 at ST2) were found at higher concentration in the XS of S mng plants, compared to that of C mng ones. Most of the discriminating metabolites found in XS (about 80%, both at ST1 and ST2) were involved in plant secondary metabolism, mainly for plant chemical defense, growth regulation and signal transduction. The most prevailing class of compounds included terpenoids, phytohormones, alkaloids, sterols/steroids, retinols/retinoids, tocopherols and carotenoids. For the first time, we have demonstrated that the XS of a tree crop significantly responds to a shift of soil management. Generally, the plants of the S mng plot showed an up-regulated secondary metabolism. The results of our study encourage the use of a set of sustainable agricultural practices in a productive orchard, in order to enhance plant physiological status, increase yield quantity/quality, safeguard the environment and ameliorate human health. • Olive plants were managed by a sustainable (S mng) or a conventional (C mng) system. • A metabolomic analysis (UHPLC/QTOF-MS) of extracted xylem sap was conducted. • Deep differences in xylem sap composition were observed between S mng and C mng. • The plants from the S mng showed an up-regulated secondary metabolism. • The xylem sap of olive trees responded to a shift of soil management. [ABSTRACT FROM AUTHOR]

Field trials were conducted at traditional Mediterranean olive agro-ecosystems grown at two locations (Italy –IT, Greece –GR). Groves were managed for many years using sustainable (S , cover crops, compost application, mulching of pruning biomass) or conventional (C) practices (e.g., soil tillage, burning of pruning residuals). The IT grove was rainfed (rain) while the GR was irrigated (IRR). This study examined the seasonal variation of soil CO 2 emission (R s) to explore the effect of the management options (C, S) on R s at both sites. The second aim was to test the hypothesis that the seasonal R s is differentially modulated by soil temperature and moisture, namely that (i) soil moisture limits R s when it is below the lower limit of the readily available water (RAW LLim) and (ii) soil temperature above a threshold (max_T) reduces R s even if soil moisture is non limiting. On the whole-season basis, the mean R s rate at the rainfed site was 2.17 ± 0.06 (SE) at C rain and 2.32 ± 0.06 μmol CO 2 m−2 s–1 at S rain plot, while at the irrigated site R s was about 3.64 ± 0.11 (C IRR) and 4.05 ± 0.15 μmol CO 2 m−2 s–1 (S IRR). The seasonal oscillation of R s was consistent across locations and partitionable in three periods according to DOY (Day of Year) interval: Phase I (DOY 20–103 –GR; 20–118 -IT), Phase II (DOY 141÷257, GR; 142–257, IT) and Phase III (DOY 291–357, GR; 286–350, -IT). Pooling all the R s data across sites and managements, max_T was ∼ 20 °C discriminating a differential response of R s when soil moisture was < or > RAW LLim. These differential modulations exerted by temperature and moisture were integrated into a conditional model developed with a repeated random subsampling cross-validation procedure to effectively (R 2 = 0.84) predict R s. This paper mechanistically describes the interaction of the environment (soil moisture and temperature) and the management options (S , C) under various moisture conditions on R s and would support carbon flux accounting procedures (e.g., regulating ecosystem services) tailored to the estimation of sink/source capability of traditional olive agro-ecosystem within environmental-friendly agricultural domains. • Management and water supply options influenced the CO 2 soil emissions (R s). • Seasonal R s was partitioned in 3 phases based on soil temperature and moisture. • Temperature and moisture differentially modulated R s based on threshold values. • Sustainable plots showed high R s on most sampling dates. • The R s model was effective (R 2 =0.84) in rainfed and irrigated European sites. [ABSTRACT FROM AUTHOR]

Under suitable conditions, low-quality, treated urban wastewater (TWW) is an additional water resource for irrigation in water-scarce environments but its use in agriculture requires a careful monitoring of a range of hygiene parameters, including human pathogenic bacteria (HPB). DNA-based microbiological analyses on soil, xylem sap, and leaves surface (phyllosphere) were carried out in an olive (Olea europaea L.) grove located in Southern Italy (Basilicata region). The experimental grove has been managed in two plots for 18 years. The experimental plot (WW tr ) was drip irrigated daily with TWW (2800 m 3  ha -1  year -1 ), while the control plot (RF tr ) was rainfed. The results of the 16S-rRNA-based metagenomic analysis demonstrated that the phyllosphere had the lowest number of potential HPB (6), compared to soil (22) and xylem (26) compartments. Gammaproteobacteria, including potential HPB, like Pseudomonas and Acinetobacter spp., were significantly higher in WW tr soil and xylem sap, compared to RF tr . A similar trend was observed for Burkholderia spp. (Betaproteobacteria) and Mycobacterium spp. (Actinobacteria). The Firmicutes Enterococcus, Staphylococcus and Streptococcus spp. were more abundant in WW tr xylem sap. The pathogenic Clostridium perfringens was found higher on WW tr leaves (relative abundance 7.17 in WW tr and 1.33 in RF tr ) and Enterococcus faecalis in WW tr xylem sap (93.22 in WW tr and 7.08 in RF tr ). On the basis of the results obtained, the irrigation with TWW can be considered a realistic and safe agronomic practice in Mediterranean orchards, and an opportunity for farmers and consumers., (Copyright © 2018 Elsevier B.V. All rights reserved.)