Remote sensing has become a cornerstone of modern agricultural monitoring, addressing the dual challenges of increasing production while ensuring environmental sustainability. Based on a conceptual framework developed over the past decade, key application areas include yield estimation, phenology, stress assessment (e.g., drought), crop mapping, and land-use change detection. In Central Europe, regionally specific conditions such as fragmented land ownership, small and irregular plots, and high climate variability shape these applications. Annual field crops, such as cereals, oilseeds, maize, and forage crops dominate production and represent the primary focus of monitoring efforts. Optical data from Sentinel-2 are effective for mapping crop types and analyzing phenology, especially when dense time series are available. However, persistent cloud cover during critical growth phases limits the effectiveness of optical approaches, prompting the integration of radar data from Sentinel-1. Multi-sensor strategies increase the robustness of classification and temporal continuity, supporting monitoring under adverse conditions. Reliable reference data from systems such as the Land Parcel Identification System enables parcel-level validation and facilitates object-oriented analyses in line with management needs. Future developments will increasingly rely on advanced time-series analysis, machine learning, and the integration of agrometeorological and crop model data. As climate change intensifies drought frequency and yield variability, remote sensing will play a pivotal role in enabling near-real-time monitoring and decision support within the evolving landscape of digital agriculture ecosystems. The aim of this review article is to provide an overview of crop monitoring in the Central European region over approximately the past fifteen years, emphasizing trends in subsequent technological and procedural developments.
The paper concerns a study of drying and the creation of a statistical model for measuring the relative humidity of the drying environment in a belt dryer, as well as the moisture content of hop heads, stems, and bracts. The SAAZ variety was used, which is widely cultivated in the Czech Republic, and the data from harvesting seasons since 2017 were recorded. The findings demonstrated the influence and dependence of the moisture content of hop cones and their parts on the relative humidity of the drying environment in a belt dryer of hops. This dependence was confirmed by a statistical analysis of the measured values. Furthermore, a quadratic model was developed based on measurements taken over three harvest seasons. The model is applicable to predict the moisture content of the hops at a given location based on the relative humidity of the drying environment in the belt dryer and could be useful for developing an automatic hop-drying system.
This article examines the reuse of waste polyurethane foam (PUF) as a material in line with circular economy principles. The main objective was to evaluate how crushed polyurethane filler of different bulk densities—35 kg·m−3 (PUF35), 60 kg·m−3 (PUF60), and their blends at 1–5 wt%—affects the mechanical behaviour and structural integrity of hybrid composite systems and bonded laminated joints. An epoxy resin matrix was combined with 3D-printed polylactide (PLA) honeycomb structures, with rectangular and hexagonal core geometries. Static tensile tests showed that the blended filler (PUF35/60) preserves tensile strength and increases the modulus of elasticity for both core geometries, reaching maximum values at 4 wt% (3.8 GPa for rectangular, 3.6 GPa for hexagonal cores). In bonded lap joints, 1 wt% PUF35 resulted in the highest tensile adhesive bond strength (13.3 MPa). SEM confirmed a high-quality phase interface and continuous adhesive contact between the epoxy matrix and the 3D-printed PLA surface, with dominant cohesive failure and effective mechanical anchoring of foam particles, even near local printing defects. The results confirm mechanically recycled PUF as a promising filler for advanced sandwich structures and adhesive systems.
Ground‑mounted photovoltaics, including agrivoltaic concepts, are increasingly deployed on agricultural land. In practice, damaged modules from repowering modules are sometimes stored on‑site for prolonged periods, creating localized vegetation suppression and land‑stewardship concerns that are rarely quantified. We present two anonymized case studies from Czechia (nominal capacities of 0.861 and 1.109 MWp; commissioned 2010 and 2009; repowered 2022 and 2021), where cracked backsheets and/or broken front‑glass modules were stacked and stored directly on grasslands within PV parcels. Using GIS delineation on orthophotos supported by field photographs, we quantified the land area (19,560 and 22,100 m²), PV panel area (plan‑ view; 4,960 and 5,080 m²), and stored PV module area (plan‑ view storage footprint; 109 and 100 m²). Stored module counts were estimated from visible stacks (≈1800 and ≈2000 modules). Using a conservative mass range of 18–25 kg/module, the stored masses were ~32–45 t and ~36–50 t, respectively. Although the storage footprints constitute <1% of the land area, they create persistent “dead zones” on agricultural land and concentrate tens of tonnes of material directly on the soil. We discuss regulatory and economic barriers to timely removal in the context of circular‑economic goals and propose practical reporting indicators for repowering projects on agricultural land: Astore (m²), Nstore (pcs), Mstore (t), storage duration, condition class, and storage interface.