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We present a unified model to describe the dynamics of optical frequency combs in quantum cascade lasers (QCLs), incorporating both ring and Fabry–Pérot (FP) cavity configurations. The model derives a modified complex Ginzburg–Landau equation (CGLE), leveraging an order parameter approach, and is capable of capturing the dynamics of both configurations, thus enabling a comparative analysis. This result demonstrates that FP QCLs, in addition to ring QCLs, belong to the same universality class of physical systems described by the CGLE, which includes, among others, systems in the fields of superconductivity and hydrodynamics. In the modified CGLE, a nonlinear integral term appears that is associated with the coupling between counterpropagating fields in the FP cavity and whose suppression yields the ring model, which is known to be properly described by a conventional CGLE. We show that this crucial term holds a key role in inhibiting the formation of harmonic frequency combs (HFCs), associated with multi-peaked localized structures, due to its anti-patterning effect. We provide support for a comprehensive campaign of numerical simulations in which we observe a higher occurrence of HFCs in the ring configuration compared to the FP case. Furthermore, the simulations demonstrate the model’s capability to reproduce experimental observations, including the coexistence of amplitude and frequency modulation, linear chirp, and typical dynamic scenarios observed in QCLs. Finally, we perform a linear stability analysis of the single-mode solution for the ring case, confirming its consistency with numerical simulations and highlighting its predictive power regarding the formation of harmonic combs.

Introduction In Europe, because of the high production levels of livestock farming in general and pig farming in particular, animal waste management has become increasingly important to comply with the required lowering of livestock farming environmental pressure. Usually manures undergo solid/liquid separation, which generates one clarified liquid fraction and one nutrient-rich solid fraction suitable for in farm composting (both raw and in mixture with other bulking agents). This can be used to produce soil amendments, whose management can be further improved by pelletization that, against technological and environmental advantages, has the disadvantage of requiring a quite high energy input. Results Four different pelleted organic fertilizer formulations made of swine manure solid fraction (SMSF) composted both by itself and with sawdust (SMSF-SD), wood chips (SMSF-WC) and wheat straw were tested to highlight differences in physico-chemical and land distribution features. They were compared with two pelleted organic fertilizers ordinarily available at retailers. Results show that, as far as physical and chemical features are concerned, the greatest difference from the reference products used in this study is found in pellet size distribution after spreading since the disintegrating action of the rotating vanes does not affect the tested formulation with the same intensity as the commercial products. Distribution tests showed that SMSF-SD was the formulation with better longitudinal and transverse distribution, while SMSF was the one showing good transverse but poor longitudinal distribution. Conclusions In farm pelletizing of SMSF composted with different organic waste materials as co-formulates can turn into organic fertilizer formulations comparable with pelleted organic fertilizers ordinarily available at retailers. SMSF-WC was the formulation with the best resistance to fragmentation induced by spreader vanes. SMSF-SD was the formulation showing better longitudinal and transverse distribution, while SMSF showed good transverse but poor longitudinal distribution. These promising results enhance the importance of co-composting as a way to increase livestock farming sustainability and produce better manure compost for wider agricultural uses.

Citrus is a subtropical fruit tree with high water requirements. This study aimed to determine the effects of water deficit on an orange orchard subjected to different water-saving strategies. The study was realised in an orange orchard in a semiarid area by adopting four different water management techniques: 100% crop evapotranspiration (control); SSDI—subsurface sustained deficit irrigation; RDI—regulated deficit irrigation; PRD—partial rootzone drying treatment during five growing seasons. The experimental design foresaw a randomised block design with six replicates per treatment (24 index plants). The results of the study showed that the water-saving strategies reduced irrigation water consumption by 25% (SSDI), 33% (RDI), and 49% (PRD) compared to the fully irrigated treatment without yield reduction, thus increasing water use efficiency. Mineral nutrition of the trees was slightly affected by irrigation treatments; element concentration in leaves was generally in the optimal range; only potassium showed values below the recommended leaf concentrations. Regarding fruit quality parameters, the vitamin C concentration in RDI showed significant differences with a value of 62.7 mg 100 mL−1 compared to 58.5 mg 100 mL−1 in the control. Plants subjected to SSDI and PRD strategies showed increased levels of pulp colour index with significant values of 10 and 9.90, respectively, compared to the control (8.44). By implementing targeted water management, citrus growers could save water and increase the ascorbic acid and sugar concentration in the fruits; anthocyanins also increased but not significantly. These findings open new market opportunities for citrus growers in marginal areas, where they cannot rely solely on producing citrus fruits to remain competitive.

Sowing is critical for successful crop establishment and productivity, particularly in precision agriculture management strategies. However, topsoil characteristics directly affect agribusiness maximization (i.e., crop-yield increase, machinery efficiency, operating-cost reduction) even in the most advanced farming management techniques. The excessive presence of coarse fractions or stones in arable soil layers prevents modern machinery from reaching optimal efficiency. This work focuses on sowing to verify whether the vibration and noise arising during this operation significantly change with varying soil conditions according to the stoniness degree of disturbance on soil workability. To make this assessment, an experimental sowing activity was carried out on four soil plots with two different disturbance degrees. The results confirmed that the noise and acceleration of the sowing machine significantly correlated with the soil disturbance degree and related workability profile.

Trichoderma spp. are widely reported to regulate plant growth by improving nutrient uptake, photosynthesis, and abiotic stress tolerance. However, their possible application for bedding plants is little explored, especially when comparing different growing media. Considering that coconut coir dust is finding broader application in the ornamental plants sector as a peat substitute, this work was aimed to test the combination of Trichoderma atroviride AT10 and coconut coir dust on Impatiens walleriana plants. Four treatments were tested as a mix of: (i) two growing media (70:30), peat:perlite or coconut coir dust:perlite; and (ii) the absence or presence of a T. atroviride treatment. At the end of the production cycle, the biomass and ornamental parameters, leaf pigments, nutrient content of the plant tissues, and Trichoderma abundance were assessed. The results revealed that T. atroviride can readily colonize coir, and the same positive effects of inoculum were found in plants grown on both substrates. The biostimulant effect of T. atroviride was observed as an increase in the aboveground biomass, number and weight of flowers, pigments and nutrient concentration, thereby improving the commercial quality of I. walleriana. Thus, T. atroviride has shown its potential in making bedding plant cultivation more sustainable and improving the yield and aesthetic parameters of plants grown on peat and coconut coir dust substrates.

Automation reduces the impact of farming on climate change and helps farmers adapt to its financial impact. Automatic feeding systems (AFSs) increase the ruminant’s feeding precision and ease operators’ workload. Such systems exist on a spectrum, requiring varied levels of operator support and installation complexity. A recent survey on farmers pointed out that those already running an AFS and those willing to buy one appreciate its ease of use, the resulting animal welfare, and the resulting overall benefits (increased production, farm profitability, and reduced feed waste). Whether technologically complex or not, studies have confirmed the benefits that farmers perceive to be underlying the remarkable reduction in the environmental impact of feeding operations (AFSs are electrically powered), the increase in animal welfare resulting from reduced conflicts around accessing the feed bunk, and the constant availability of fresh feed. However, their introduction should follow accurate and holistic structural and economic planning for existing and newly built facilities. The availability of public subsidies plays an essential role in pushing farmers to adopt the most modern digital technologies, whose benefits may even increase when farmers couple them with interconnected sensors to monitor animals’ physiological states.

Propagation of photoexcited modes provides important information for novel quantum state. Here, the authors reveal the propagation of sub-diffractional hyperbolic phonon-polariton modes influenced by the Dirac plasmons in topological insulators.

Simulation systems have become essential tools for both researchers and virtual laboratory experiments. In the Agri-food-chain, SimAgri, a driving simulator for tractors and operating machines, has been developed for precision agriculture (PA) research and to train professional farm drivers. Using the virtual environment of the simulator, the influence and fine-tuning of PA operations logic may be evaluated by simulating existing systems, or designing new ones, in specially compared scenarios and setups. Current configurations include an agricultural tractor carrying or towing farm equipment such as sprayers, seeders and fertilizer, embedded sensors, human–machine interfaces that may be configured like a joystick, console and touchscreen, and four virtual environment monitors. The study describes the design choices that have made it possible to create a simulator aimed at precision agriculture, keeping auto guidance, geolocation, and operations with ISOBUS implements as pillars. This research aims to use a unique purpose-designed simulation platform, installed on a driver-in-the-loop simulator to provide data to objectify the benefits of PA criteria. Numerical and experimental data have been compared to ensure results reliability.

At the CREA research facility of Treviglio (Bergamo, Italy), to provide farmers with valuable hints for the transition from conventional to precision agriculture, information on crop production dynamics (Maize and Triticale) has been obtained using real-time soil mapping (resistivity technique) and production quality and quantity monitoring with a commercial yield mapping apparatus. The geostatistical processing of data resulted in the same zoning for Triticale, meaning that the characteristics of soil influenced crop behavior more than the variability resulting from other factors, which suggests that improvements in product yields can be planned and achieved acting, for instance, on variable rate distribution of fertilizers. The importance of the acquired data can help farmers to manage factors that are external to their plots of land.

Soil amendments (e.g., compost) require uniform incorporation in the soil profile to benefit plants. However, machines may not mix them uniformly throughout the upper soil layer commonly explored by plant roots. The study focuses on using image texture analysis to determine the level of mixing uniformity in the soil following the passage of two kinds of harrows. A 12.3-megapixel DX-format digital camera acquired images of soil/expanded polystyrene (in the laboratory) and soil/compost mixtures (in field conditions). In the laboratory, pictures captured the soil before and during the simulated progressive mixing of expanded polystyrene particles. In field conditions, images captured the exposed superficial horizons of compost-amended soil after the passage of a combined spike-tooth–disc harrow and a disc harrow. Image texture analysis based on the gray-level co-occurrence matrix calculated the sums of dissimilarity, contrast, entropy, and uniformity metrics. In the laboratory conditions, the progressive mixing resulted in increased image dissimilarity (from 1.15 ± 0.74 × 106 to 1.65 ± 0.52 × 106) and contrast values (from 2.69 ± 2.06 × 106 to 5.67 ± × 1.93 106), almost constant entropy (3.50 ± 0.25 × 106), and decreased image uniformity (from 6.65 ± 0.31 × 105 to 4.49 ± 1.36 × 105). Using a tooth-disc harrow in the open field resulted in higher dissimilarity, contrast, entropy (+73.3%, +62.8%, +16.3%), and lower image uniformity (−50.6%) than the disc harrow, suggesting enhanced mixing in the superficial layer.

Near-field imaging techniques, at terahertz frequencies (1–10 THz), conventionally rely on bulky laser sources and detectors. Here, we employ a semiconductor heterostructure laser as a THz source and, simultaneously, as a phase-sensitive detector, exploiting optical feedback interferometry combined with scattering near-field nanoscopy. We analyze the amplitude and phase sensitivity of the proposed technique as a function of the laser driving current and of the feedback attenuation, discussing the operational conditions ideal to optimize the nano-imaging contrast and the phase sensitivity. As a targeted nanomaterial, we exploit a thin (39 nm) flake of Bi2Te2.2Se0.8, a topological insulator having infrared active optical phonon modes. The self-mixing interference fringes are analyzed within the Lang–Kobayashi formalism to rationalize the observed variations as a function of Acket’s parameter C in the full range of weak feedback (C < 1).

The optimization of energy input on agricultural farms, such as through improved fuel consumption, is currently under investigation in agricultural mechanization research with the aim of achieving economic and environmental goals. In previous research, we developed a simplified algorithm focused on defining the most efficient tractor–implement combination considering the factors that most influence this aspect. The ASABE (American Society of Agricultural and Biological Engineers) equation for calculating the drawbar pull force was adopted to fit the results to the soil conditions. Agricultural tires of different sizes were tested at different pressure settings under field conditions to assess differences in drawbar force. The resulting algorithm underwent a linear regression analysis to achieve a simplified equation for assessing the optimal wheel-slip, mass, engine power, and tire pull force properties during drawbar works that result in optimal fuel consumption with a minimal tractor efficiency impairment. Using a specific probability density function, the Monte Carlo Simulation method introduced randomness into the input and runs a sufficiently large number of trials to identify the most probable output. The result is a simplified algorithm that can be used to investigate the effects of certain parameters on fuel consumption; however, it can be adapted to evaluate the effects of different implements, tires, engine settings, or fleet management methods on fuel consumption.

Accurate estimates of canopy cover (CC) are central for a wide range of forestry studies. As direct measurements are impractical, indirect optical methods have often been used to estimate CC from the complement of gap fraction measurements obtained with restricted-view sensors. In this short note we evaluated the influence of the image pixel resolution (ground sampling distance; GSD) on CC estimation in poplar plantations obtained from field (cover photography; GSD < 1 cm), unmanned aerial (UAV; GSD

Fruit harvesting trucks are used to easy and speed-up the work of agricultural operators. These vehicles are provided with a moving cargo bed, which can be raised up to 3 meters from the ground so that workers are closer to the plants top. Due to factors like height of centre of gravity and operation on soft and irregular soil, these vehicles present several safety issues. This research, carried out inside a project funded by INAIL (Italian National Institute for Insurance against Accidents at Work), analysed the stability of fruit harvesting trucks with particular focus on rollover risk. Experimental tests were carried out to characterise the response of these vehicles. Multibody models of two trucks were then developed and used to determine the rollover angle along a generic direction considering the effect of vehicle configuration and of tire-soil stiffness.

Sturgeon caviar quality relies not only on the perfect dosage of the ingredients but also on the long sturgeon breeding cycle (about 12–15 years) and the exact timing of the egg extraction. For the improvement and the promotion of Italian caviar, the development of an analytical system dedicated to fish products, and caviar, in particular, is fundamental. The use of near-infrared spectrometry (NIRS) technology is auspicious. The aquaphotomics approach proved to be an adequate analytical tool to highlight, in real-time, the differences in caviar quality stored with, or without, borax as a preservative. Seventy-five sturgeon caviar (Acipenser transmontanus) samples underwent spectral NIR characterization using a microNIR1700 in the 900–1700 nm range. Data processing was carried out according to the literature. Tenderometric and sensory analyses were also carried out in parallel. The results suggest that a process line under strict control and monitoring can result in high-quality caviar without any other preservative than salt. The challenge of producing caviar without any potentially-toxic preservatives could now be a reality. NIR spectroscopy and aquaphotomics can be, in the future, non-invasive methods to monitor the whole production chain.

In this retrospective compendium, we attempt to draw a “fil rouge” along fifteen years of our research in the field of optical feedback interferometry aimed at guiding the readers to the verge of new developments in the field. The general reader will be moved at appreciating the versatility and the still largely uncovered potential of the optical feedback interferometry, for both sensing and imaging applications. By discovering the broad range of available wavelengths (0.4–120 μm), the different types of suitable semiconductor lasers (Fabry–Perot, distributed feedback, vertical-cavity, quantum-cascade), and a number of unconventional tenders in multi-axis displacement, ablation front progression, self-referenced measurements, multispectral, structured light feedback imaging and compressive sensing, the specialist also could find inspirational suggestions to expand his field of research.

Irrigation with wastewater can strongly contribute to the reduction of water abstraction in agriculture with an especial interest in arid and semiarid areas. However, its use can have drawbacks to both soil and micro-irrigation systems, especially when the total solids in the wastewater are high, such as in digestate liquid fractions (DLF) from plant material. The aim of this study was thus to evaluate the performances of a serpentine shaped micro-emitter injected with a hydrocyclone filtered DLF (HF-DLF) from corn + barley biomass and evaluate the traits of the liquid released within a 8-h irrigation cycle. HF-DLF was injected at 10%, 25%, and 50% dilution compared to tap water (at pH = 7.84) and the system performances were measured. No clogging was found, which likely depended on both the shape of the emitter and the high-pressure head (200 kPa). HF-DLF dilution at 10%, 25%, and 50% consisted in +1.9%, +3.5, and −4.9% amount of liquid released compared to the control. Fluid temperature during irrigation (from 9:00 to 17:00) did not explain the difference in the released amounts of liquid. In 10% HF-DLF % and 25% HF-DLF, a pH difference of + 0.321 ± 0.014 pH units compared to the control was found, and such difference was constant for both dilutions and at increasing the time. In contrast, 50% HF-DLF increased pH by around a half point and such difference increased with time. Similar differences among treatments were found for the total solids in the liquid. These results indicate that 50% HF-DLF was accumulating materials in the serpentine. These results suggest that a low diluted HF-DLF could directly be injected in irrigation systems with few drawbacks for the irrigation system and contribute to water conservation since such wastewater are available from the late spring to the early fall, when water requirements are high.

Protected horticulture is a high energy-consuming sector in which the optimization of energy use and cost for heating facilities is strategic in achieving high environmental and economic sustainability of production. The main aim of the project was to evaluate the use of a heat pump for basal heating as an alternative technology to grow crops with reduced canopies, such as basil. During the test, an area of the greenhouse contained two systems of coaxial pipes circulating warm water from a heat pump and a condensing boiler. These pipes were placed above the growing media. At the same time, a separate area of the same greenhouse contained a traditional heating system consisting of an air heater, the solution commonly used to heat greenhouses. Microclimatic conditions and energy consumption were analyzed for the three heating technologies. The energy analysis of the three experimental heating options showed that all of them could ensure suitable thermal conditions for cultivation in the winter period. Overall, the results confirmed the energy saving resulting from the adoption of the heat pump, underlining the importance of this device in terms of the support that the energy-saving goal receives.

We study the nonlinear dynamics of a quantum cascade laser (QCL) with a strong reinjection provided by the feedback from two external targets in a double cavity configuration. The nonlinear coupling of interferometric signals from the two targets allows us to propose a displacement sensor with nanometric resolution. The system exploits the ultra-stability of QCLs in self-mixing configuration to access the intrinsic nonlinearity of the laser, described by the Lang–Kobayashi model, and it relies on a stroboscopic-like effect in the voltage signal registered at the QCL terminals that relates the “slow” target motion to the “fast” target one.

The phytotoxicity of four different composts obtained from pig slurry solid fraction composted by itself (SSFC) and mixed with sawdust (SC), woodchips (WCC) and wheat straw (WSC) was tested with bioassay methods. For each compost type, the effect of water extracts of compost on seed germination and primary root growth of cress (Lepidium Sativum L.) was investigated. Composts were also chemically analysed for total nitrogen, ammonium, electrical conductivity and heavy metal (Cu and Zn). The chemicals were correlated to phytotoxicity indices. The mean values of the germination index (GI) obtained were 160.7, 187.9, 200.9 and 264.4 for WSC, WCC, SC and SSFC, respectively. Growth index (GrI) ranged from the 229.4%, the highest value, for SSFC, followed by 201.9% for SC, and 193.1% for WCC, to the lowest value, 121.4%, for WSC. Electrical conductivity showed a significant and negative correlation with relative seed germination at the 50% and 75% concentrations. A strong positive correlation was found for water-extractable Cu with relative root growth and germination index at the 10% concentration. Water-extractable Zn showed a significant positive correlation with relative root growth and GI at the 10% concentration. These results highlighted that the four composts could be used for organic pellet production and subsequently distributed as a soil amendment with positive effects on seed germination and plant growth (GI > 80%).

Self-propelled fruit harvesters (SPFHs) are agricultural machines designed to facilitate fruit picking and other tasks requiring operators to stay close to the foliage or to the upper part of the canopy. They generally consist of a chassis with a variable height working platform that can be equipped with lateral extending platforms. The positioning of additional masses (operators, fruit bins) and the maximum height of the platform (up to three meters above the ground) strongly affect machine stability. Since there are no specific studies on the lateral stability of SPFHs, this study aimed to develop a specific test procedure to fill this gap. A survey of the Italian market found 20 firms manufacturing 110 different models of vehicles. Observation and monitoring of SPFHs under real operational conditions revealed the variables mostly likely to affect lateral stability: the position and mass of the operators and the fruit bin on the platform. Two SPFHs were tested in the laboratory to determine their centre of gravity and lateral stability in four different settings reproducing operational conditions. The test setting was found to affect the stability angle. Lastly, the study identified two specific settings reproducing real operational conditions most likely to affect the lateral stability of SPFHs: these should be used as standard, reproducible settings to enable a comparison of results.

Operator exposure to high levels of whole-body vibration (WBV) presents risks to health and safety and it is reported to worsen or even cause back injuries. Work activities resulting in operator exposure to whole-body vibration have a common onset in off-road work such as farming. Despite the wide variability of agricultural surface profiles, studies have shown that with changing soil profile and tractor speed, the accelerations resulting from ground input present similar spectral trends. While on the one hand such studies confirmed that tractor WBV emission levels are very dependent upon the nature of the operation performed, on the other, irrespective of the wide range of conditions characterizing agricultural operations, they led researchers to set up a possible and realistic simplification and standardization of tractor driver comfort testing activities. The studies presented herewith indicate the usefulness, and the possibility, of developing simplified procedures to determine agricultural tractor vibration comfort. The results obtained could be used effectively to compare tractors of the same category or a given tractor when equipped with different seats, suspension, tyres, etc.

Woody Biomasses (from agriculture and forestry activities) are among the most promising renewable energy sources. Current literature describes woody biomass feedstock supply chains supporting biofuels and utilities industries: the potentially productive land area overheads required for biomass production may results in a complex logistic within the whole chain. Its effective enhancement requires significant changes in the logistics environment of energy plants for sustainable energy production and the sequence-dependent procurement chains for biomasses furthermore complicate these changes. According to this, optimizing harvesting and supplying operations turns out to be strategic within the framework of the current energy policy. In this work we present a case study carried out monitoring 57 short rotation forestry (SRF) production sites placed in Emilia Romagna Region, Northern Italy, all supplying the harvested biomass to the same biomass power plant placed in the province of Ravenna (Italy). The overall average yield of these sites was 55 t/ha, the site surfaces ranged from 0.3 to 20 hectares and the distance from the power plant ranged between 8.2 to 102 km with one production site only within 10 km from the power plant. Harvest and transport costs were calculated according to two different harvesting scenarios: i) single phase harvesting (one cutting/chopping machine + tractors and trailers); ii) double phase harvesting (cutting/mowing machine followed after 80 days by chopping machine + tractors and trailers). Results show that, according to the first scenario, at increasing distances overall harvesting and transport costs ranged from 8.9 to 21.0 ± 1.3 􀀍/t (average ± standard deviation), while, with reference to the second scenario, they increased from 10.3 to 23.8 ± 1.5 􀀍/t with the transportation costs accounting from 16 to almost 70% of the total costs.

Extensification has recently become an important option in Western European agriculture, driven both by economic considerations (product surpluses together with the fact that developed countries cropping systems have been heavily relying on fossil energy) and growing public concern on the possible adverse effects of intensive farming on the environment and human health. The adoption of rational fodder crop rotations, with the rediscovery of the beneficial effect of the meadow, is viewed as a possible mean to reduce the impact of farming systems in the lowlands of Northern Italy, characterised by highly intensive cropping and animal husbandry. For this reason our study examines the effects of crop rotation on the energy balance during 1985-2007 period in a long-term crop rotation trial in Northern Italy comparing five fodder crop systems, different in the degree of crop intensification and for the presence or absence of the meadow: a 1-year continuous cereal double cropping (R1); a 3-year rotation (R3); a 6-year rotation (R6); a permanent meadow (PM); and a continuous grain maize cropping (CM). Each rotation was subjected to two input treatments, defined as high (mostly used in lowlands of northern Italy) and low (input reduction of ca. 30%) respectively, in terms of nutrient levels, herbicide doses, and soil tillage methods. The crop rotations exerted a marked influence on the energy balance. The most efficient rotations in terms of net energy production energy efficiency have been characterized by reduced length and presence of maize and catch-crops.