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In orogenic gold deposits, the mechanism by which a hydrothermal fluid precipitates gold in laminated quartz veins remains elusive. The Kanowna Belle deposit hosts gold mineralization in structurally controlled quartz-pyrite laminated veins that cut volcano-sedimentary and granitic rocks of the Kalgoorlie terrane, Australia. Veins show microtextural evidence for multiphased emplacement, corresponding to three distinct pyrite growth zones in which Au enrichment in the pyrite is attributed to high fluid influx. To monitor the chemical and isotopic evolution of the auriferous fluid leading to gold precipitation, we combine in situ multiple sulfur isotope analyses with trace element composition of gold-bearing pyrite growth zones: cores (Au ≤149 ppm; δ34S –3.3 to +4.2‰; As ≤2.5 wt %; Ni ≤4,022 ppm; Te ≤416 ppm), Au-rich oscillatory zoned mantles (Au ≤2,251 ppm; δ34S –8.4 to +0.1‰; As ≤4.5 wt %; Ni ≤1,111 ppm; Te ≤829 ppm), and rims (Au ≤264 ppm; δ34S –6.0 to +2.8‰; As ≤1.4 wt %; Ni ≤2,113 ppm; Te ≤229 ppm). The positive and consistent Δ33S of each zone (Δ33S = +0.3 ± 0.2‰; n = 160) indicates that one single reservoir was tapped during the evolution of the mineralizing system. The gold-rich pyrite mantle zones precipitated from a fluid undergoing SO42−/H2S fluctuations associated with phase separation due to rapid and repeated releases in fluid pressure. This study demonstrates that the “fault-valve” process applies a first-order control on the precipitation of gold from a single auriferous fluid reservoir.

The European Green Deal has set a concrete strategic plan to increase farm sustainability. At the same time, the current global challenges, due to climate change and fuels and commodity market crises, combined with the COVID-19 pandemic and the ongoing war in Ukraine, affect the need for quality food and necessitate the reduction of negative external effects of agricultural production, with fair remuneration for the farmers. In response, precision agriculture has great potential to contribute to sustainable development. Precision agriculture is a farming management system that provides a holistic approach to managing the spatial and temporal crop and soil variability within a field to improve the farm’s performance and sustainability. However, farmers are still hesitant to adopt it. On these premises, the study aims to evaluate the impacts of precision agriculture technologies on farm economic, agronomic, and environmental management by farmers adopting (or not) these technologies, using the case study method. In detail, the work focuses on the period 2014–2022 for two farms that cultivate durum wheat in central Italy. The results suggest that the implementation of precision technologies can guarantee economic and agri-environmental efficiency. The results could serve as a basis for developing a program to start training in farms as well as to suggest policy strategies.

We present results from high-pressure, high-temperature experiments that generate incipient carbonate melts at mantle conditions (~90km depth and temperatures between 900 - 1050℃). We show that these melts can effectively sequester sulfur, in its oxidised form of sulfate, platinum group elements, and first-row transition metals from mantle lithologies of peridotite and pyroxenite. These primitive oxidised melts may be effective agents to dissolve, redistribute and concentrate sulfur as well as chalcophile metals within the mantle, and from the mantle to shallower regions within the Earth, where localised dynamic physio-chemical processes can lead to ore genesis at various crustal depths. It is proposed that these carbonate-sulfur rich melts may be more widespread than previously thought, and may play a first order role in the metallogenic enhancement of localised and predictable lithospheric domains.

This paper focuses on a nanoscale study of nano- and micrometer-size Os-rich mineral particles hosted in a Ni-Fe-Cu sulfide globule found in an olivine megacryst from the Udachnaya pipe (Yakutia, Russia). These platinum-group element mineral particles and their host sulfide matrices were investigated using a combination of techniques, including field emission gun electron probe microanalyzer, field emission scanning electron microscopy, and focused ion beam and high-resolution transmission electron microscopy. The sulfide globule is of mantle origin, as it is hosted in primitive olivine (Fo90–93), very likely derived from the crystallization of Ni-Fe-Cu sulfide melt droplets segregated by liquid immiscibility from a basaltic melt in a volume of depleted subcontinental lithospheric mantle. Microscopic observations by means of field emission scanning electron microscopy and single-spot analysis and mapping by field emission gun electron probe microanalyzer reveal that the sulfide globule comprises a core of pyrrhotite with flame-like exsolutions (usually 1100 °C, which later decomposed into pyrrhotite and the pentlandite flame-like exsolutions upon cooling at

Proximal soil sensors are receiving strong attention from several disciplinary fields, and this has led to a rise in their availability in the market in the last two decades. The aim of this work was to validate agronomically a zone management delineation procedure from electromagnetic induction (EMI) maps applied to two different rainfed durum wheat fields. The k-means algorithm was applied based on the gap statistic index for the identification of the optimal number of management zones and their positions. Traditional statistical analysis was performed to detect significant differences in soil characteristics and crop response of each management zones. The procedure showed the presence of two management zones at both two sites under analysis, and it was agronomically validated by the significant difference in soil texture (+24.17%), bulk density (+6.46%), organic matter (+39.29%), organic carbon (+39.4%), total carbonates (+25.34%), total nitrogen (+30.14%), protein (+1.50%) and yield data (+1.07 t ha−1). Moreover, six unmanned aerial vehicle (UAV) flight missions were performed to investigate the relationship between five vegetation indexes and the EMI maps. The results suggest performing the multispectral images acquisition during the flowering phenological stages to attribute the crop spatial variability to different soil proprieties.&nbsp

In Mediterranean cropping systems, it is important to utilise marginal lands for the cultivation of native food crops. Previous research on Crithmum maritimum L., a species native to southern Europe, has focused on its alimentary and chemical parameters. The aim of the present study was to identify the effects of irrigation and fertigation systems on C. maritimum in Mediterranean cropping systems. We planted C. maritimum seeds in an organic farm in Italy, and we carried out three experiments (fertigation, irrigation, and control) with three replications each. We evaluated plant phenological development and biomass production. We found that these treatments significantly influenced plant phenology and biomass parameters. Even with low irrigation and fertigation, this species showed a significant difference in the Bundesanstalt, Bundessortenamt, CHemischeIndustrie (BBCH) phase at harvest: in fact, there were 39 and 35 leaves on the main stem in the irrigation and fertigation treatments, respectively, while there were 29 leaves on the main stem in the rainfed unfertilised control. Biomass production also showed the same significant difference: 1.8 and 2.0 t ha−1 of total dry biomass in the irrigation and fertigation treatments, respectively, and 1.2 t ha−1 of total dry biomass in the rainfed unfertilised control. In conclusion, we recommend the use of C. maritimum for food production in Mediterranean organic cropping systems.

The agricultural sector is required to produce food at the same pace as population growth, while accounting for pollution and costs. For this reason, conservative agricultural practices have been employed worldwide. Attenuated Total Reflectance–Fourier Transform Infrared (ATR-FTIR) spectroscopy has the ability to provide a snapshot of the macromolecular composition of a sample in a timely and cost-effective way and it has been widely applied in the field of agriculture to assess food quality. The aim of this study was to exploit ATR-FTIR spectroscopy to assess the impact of different soil tillage methods (conventional tillage, CT, minimum tillage, MT, and no tillage, NT) and nitrogen fertilization levels (0, 90 and 180 kg N ha−1) on the macromolecular composition of leaves and caryopses of durum wheat (Triticum turgidum subsp. durum). The analysis of the spectral data revealed that the quality of durum wheat, in terms of protein content, grown on soil with no tillage was not reduced. Indeed, with regards to caryopses, the different tillage methods influenced only the lipid and hemicellulose content, whereas the macromolecular composition of leaves was sensitive to tillage methods mostly during the early stage of growth. Moreover, no relevant effects were found in leaves and caryopses when different fertilizer concentrations were used. These results provide important knowledge supporting the adoption of both no-tillage soil treatments and reduced fertilization dosage for the development of durum wheat management strategies and support the use of spectroscopy for conservative agriculture practices.

For the estimation of the soil organic carbon stocks, bulk density (BD) is a fundamental parameter but measured data are usually not available especially when dealing with legacy soil data. It is possible to estimate BD by applying pedotransfer function (PTF). We applied different estimation methods with the aim to define a suitable PTF for BD of arable land for the Mediterranean Basin, which has peculiar climate features that may influence the soil carbon sequestration. To improve the existing BD estimation methods, we used a set of public climatic and topographic data along with the soil texture and organic carbon data. The present work consisted of the following steps: i) development of three PTFs models separately for top (0–0.4 m) and subsoil (0.4–1.2 m), ii) a 10-fold cross-validation, iii) model transferability using an external dataset derived from published data. The development of the new PTFs was based on the training dataset consisting of World Soil Information Service (WoSIS) soil profile data, climatic data from WorldClim at 1 km spatial resolution and Shuttle Radar Topography Mission (SRTM) digital elevation model at 30 m spatial resolution. The three PTFs models were developed using: Multiple Linear Regression stepwise (MLR-S), Multiple Linear Regression backward stepwise (MLR-BS), and Artificial Neural Network (ANN). The predictions of the newly developed PTFs were compared with the BD calculated using the PTF proposed by Manrique and Jones (MJ) and the modelled BD derived from the global SoilGrids dataset. For the topsoil training dataset (N = 129), MLR-S, MLR-BS and ANN had a R2 0.35, 0.58 and 0.86, respectively. For the model transferability, the three PTFs applied to the external topsoil dataset (N = 59), achieved R2 values of 0.06, 0.03 and 0.41. For the subsoil training dataset (N = 180), MLR-S, MLR-BS and ANN the R2 values were 0.36, 0.46 and 0.83, respectively. When applied to the external subsoil dataset (N = 29), the R2 values were 0.05, 0.06 and 0.41. The cross-validation for both top and subsoil dataset, resulted in an intermediate performance compared to calibration and validation with the external dataset. The new ANN PTF outperformed MLR-S, MLR-BS, MJ and SoilGrids approaches for estimating BD. Further improvements may be achieved by additionally considering the time of sampling, agricultural soil management and cultivation practices in predictive models.

Combining remote and proximal sensing in agriculture is essential to monitor crop spatial-temporal variability and to provide high-quality prescription maps for the precision agriculture applications. The study showed how different combinations of soil management (no tillage&mdash, NT vs. conventional tillage&mdash, CT) and nitrogen (N) fertilization levels (0.90 and 180 kg N ha&minus, 1) can affect the durum wheat nutritional status and development through vegetation indices computation and proximal sensing tool application. Chlorophyll and N crop content were measured, in addition a proximal sensing tool and multispectral imagery equipped on unmanned aerial vehicle were used. The N input is the key driver for durum wheat development (4.5 &plusmn, 0.92 t ha&minus, 1 on average), but when it was not provided the NT performed better than CT (2.51 &plusmn, 0.22 vs. 1.46 &plusmn, 0.28 t ha&minus, 1 respectively) in terms of grain yield. This is due to the greater content of organic matter and N availability which characterizes the NT system. The near infrared (NIR) band-based vegetation indices can well detect the durum wheat nutritional status (R2 = 0.70 on average). The showed results can provide an important contribution in the implementation of ago-environmental policies aimed at environmental impact of cereal-based-cropping systems reduction.

In Mediterranean cropping systems, it is important to utilize marginal lands for the cultivation of non-food crops. Spontaneous thistle genera such as Cynara cardunculus L. and Onopordum tauricum Willd. are native to southern Europe. Previous research has focused on their spontaneous growth in the environment or ability to supply biofuel. The aim of this study was to identify the effect of two different planting densities on the flower differentiation, vegetable rennet production and weed control of O. tauricum Willd. and C. cardunculus L. in rainfed unfertilized Mediterranean cropping systems. The results showed that plant density influenced most of the biomass parameters for O. tauricum Willd. but no significant differences were observed for C. cardunculus L. Higher densities of both species were beneficial for weed control. We recommend the use of C. cardunculus L. and O. tauricum Willd. as suitable species for vegetable rennet production in Mediterranean organic cropping systems.

Handheld chlorophyll meters as Soil Plant Analysis Development (SPAD) have proven to be useful tools for rapid, no-destructive assessment of chlorophyll and nitrogen status in various crops. This method is used to diagnose the need of nitrogen fertilization to improve the efficiency of the agricultural system and to minimize nitrogen losses and deficiency. The objective of this study is to evaluate the effect of repeated conservative agriculture practices on the SPAD readings, leaves chlorophyll concentration and Nitrogen Nutrition Index (NNI) relationships in durum wheat under Mediterranean conditions. The experimental site is a part of a long-term-experiment established in 1994 and is still on-going where three tillage managements and three nitrogen fertilizer treatments were repeated in the same plots every year. We observed a linear relationship between the SPAD readings performed in the central and distal portion of the leaf (R2 = 0.96). In fertilized durum wheat, we found all positive exponential relationships between SPAD readings, chlorophyll leaves concentration (R2 = 0.85) and NNI (R2 = 0.89). In the unfertilized treatment, the SPAD has a good attitude to estimate leaves chlorophyll concentration (R2 = 0.74) and NNI (R2 = 0.77) only in crop grow a soil with relative high content of soil organic matter and nitrogen availability, as observed in the no tilled plots. The results show that the SPAD can be used for a correct assessment of chlorophyll and nitrogen status in durum wheat but also to evaluate indirectly the content of soil organic matter and nitrogen availability during different growth stages of the crop cycle.

Precision Farming is nowadays an important challenge aiming to improve environmental quality in rural areas, giving more sustainability to agricultural operations by improving the quality of fieldworks and increasing the food safety and security for social life. To these purposes, the setting up of specific methodologies, for precision Farming Management System (FMS), is required the use of sensors and Geomatics techniques and optimization of field operation with the aim to build a precision Farming Management System (FMS) enhancing the agricultural performance and ability to predict and mitigate environmental risks. The research activities here presented belong to a multidisciplinary project named “PFRLab: Setting of a Precision Farming Robotic Laboratory for cropping system sustainability and food safety and security” founded by the Universita Politecnica delle Marche during the period 2017–2020. The main goal of the research is to design a database for data management based on agriculture ontology, using as case study the experimental farm of Universita Politecnica delle Marche. To solved this task, many data have been connected by advanced technologies like Unmanned (UAV), Internet of Things (IoT), Remote Sensing and field sensors. In the future, the big amount of field data allow building a Decision Support System to increase the performances of precision farming experimental trials and making farm’s decision potentially more productive and efficient.

The acceleration of Digital Agriculture is evident through the increased adoption of digital technologies on farms including smart machines, sensors and cloud computing. In this paper we present the preliminary results of the research project funded by Università Politecnica delle Marche in 2018 “PFRLab: Setting of a precision farming robotic laboratory for cropping system sustainability and food safety and security”, which is still underway. In this context, as first result, an interdepartmental Research and Services Center called “Smart Farming” has been set up with the aim to strengthen multidisciplinary collaborations in the fields of Agriculture and Forestry, Geomatics, ICT and Robotics. Regarding field activities the SPAD 502 as well as Normalized Difference Vegetation Index (NDVI) provide a good estimate of the Chlorophylla+b content in durum wheat leaves so can be used to predict in a quickly and non-destructively way, the crop greenness status and to identify any nutritional deficiencies in real time. Future research activities are certainly needed to fully explore the potentialities of conservation agriculture and precision farming, and to drive the transition process from conventional agriculture to modern conservation agriculture and precision farming techniques. In-depth studies are planned on the combined effect of nitrogen fertilization and soil management on the main production variables of durum wheat in order to evaluate whether specific tools for precision agriculture applications can find significant diffusion even in Mediterranean cereal based cropping systems.

Ancient lavas reveal the presence of deep mantle reservoirs with anomalously light oxygen signatures. These lavas fingerprint heterogeneous mantle domains in early Earth that may have since been mixed away.

International audience; On Earth, high temperature mafic to ultramafic lava flows, such as komatiites and ferropicrites of the Archean and Proterozic eons, can be hosts to Ni-Cu-PGE sulphide mineralisation. Mechanical/thermo-mechanical erosion and assimilation of sulphur-rich crustal rocks is ascribed as the principal mechanism that leads to sulphide supersaturation, batch segregation and subsequent accumulation of metal-enriched magmatic sulphides (e.g., Bekker et al., Science, 2009). In order to investigate the likelihood of the occurrence of similar sulphide mineralisation in extraterrestrial magmatic systems, we numerically modelled erosion and assimilation during the turbulent emplacement of Martian lavas, some of which display chemical and rheological analogies with terrestrial komatiites and ferropicrites, on a variety of consolidated sedimentary sulphate-rich substrates. The modelling approach relies on the integration of i) mathematical lava erosion models for turbulent flows (Williams et al., J. Geophys. Res., 1998), ii) thermodynamic volatile degassing models (Gaillard et al., Space Sci. Rev., 2013), and iii) formulations on the stability of sulphides (Fortin et al., Geochim. Cosmochim. Acta, 2015). A series of scenarios are examined in which various Martian mafic to ultramafic mantle-derived melts emplace over, and assimilate consolidated sulphate-rich substrates, such as the sedimentary lithologies (i.e., conglomerates, sandstones and mudstones) recently discovered at the Gale Crater landing site. Our modellings show that lavas emplacing over consolidated sedimentary substrate rather than stiff basaltic crust, are governed by relatively high cooling and substrate erosion rates. The rapid assimilation of sulphate, which serves as a strongly oxidising agent, could result in dramatic sulphur loss due to increased volatile degassing rates at fO2 ≳QFM-1. This effect is further enhanced with increased temperature. Nevertheless, sulphide supersaturation in the way of sulphate assimilation can be achieved in relatively reduced (i.e., fO2