The application of municipal sewage sludge as fertilizer in the production of non-food energy crops is an environmentally and economically sustainable approach to sewage sludge management. In addition, the application of municipal sewage sludge to energy crops such as Miscanthus x giganteus is an alternative form of recycling nutrients and organic material from waste. Municipal sewage sludge is a potential source of heavy metals in the soil, some of which can be removed by growing energy crops that are also remediation agents. Therefore, the objective of the research was to investigate the effect of municipal sewage sludge applied at three different rates of 1.66, 3.22 and 6.44 t/ha on the production of Miscanthus. Based on the analyses conducted on the biomass of Miscanthus fertilized with sludge from the wastewater treatment plant in three fertilization treatments, it can be concluded that the biomass of Miscanthus is a good feedstock for the process of direct combustion. Moreover, the application of the largest amount of municipal sewage sludge during cultivation had no negative effect on the properties of Miscanthus biomass. Moreover, the cellulose and hemicellulose content of Miscanthus is ideal for the production of second-generation liquid biofuels. Fertilizer treatments had no effect on the content of cellulose and lignin, while a significant statistical difference was found for hemicellulose.

Contemporary knowledge on climate change has given rise to a group of advocates who suggest global veganism as an adaptive means of mitigating the threat of climate change. Livestock farming is accused of contributing massively to greenhouse gas (GHG) emissions. Some studies suggest that eliminating meat from the diet (i.e., moving to a vegan diet) can reduce GHG emissions globally, while other studies suggest that livestock farming may make a smaller contribution to GHG emissions compared to previous estimates. A paradigm shift in agricultural production is expected to have direct impacts on natural resources, biodiversity, and economies. However, crop-only production and an exclusively vegan diet may lead to the loss of important plant and animal genetic materials, increase pressure on land and water resources, and exacerbate problems with agricultural crop residues. This “all in one basket” approach may affect the global meat trade, change the dynamics of some economies, and threaten food security in the event of pest and disease pandemics. This review found that crop-based ideology would make a huge contribution to reducing GHG emissions, while the integrity of land and water resources could be threatened in the future. Agricultural policies need to develop appropriate instruments to ensure food security, consumer preferences, and environmental protection and to provide a fair income for farmers worldwide. Global stakeholders in the agri-food sector, from policy makers to farmers, need to be engaged in a coherent policy to reduce the C footprint in our diets, protecting the (agri)environment and securing incomes.

Wastewater treatment plants are facilities where wastewater is treated by technological processes. A byproduct of a wastewater treatment plant is sewage sludge, which can be both a good soil conditioner and a source of nutrients for the crops to which it is applied. Energy crops are non-food plants that can cleanse the soil of heavy metals through their ability to phytoremediate. The purpose of this study is to determine the effects of different amounts of sewage sludge on soil and plants. In the experiment Virginia mallow (Sida hermaphrodita L.) was used and the influence of stabilized sewage sludge in the amounts of 1.66, 3.32 and 6.64 t/ha dry matter on the energy composition and biomass yield was observed.The obtained results showed a yield of 8.85 t/ha at the maximum amount of sewage sludge used. Hemicellulose content was 20.20% in the application of 6.64 t/ha of sewage sludge and 19.70% in the control, while lignin content was 17.97% in the control and 16.77% in the maximum amount of sewage sludge. The heavy metals molybdenum and nickel did not differ significantly under the influence of larger amounts of sewage sludge, while manganese increased from 23.66 to 35.82 mg/kg.

Current and upcoming Sun-Induced chlorophyll Fluorescence (SIF) satellite products (e.g., GOME, TROPOMI, OCO, FLEX) have medium-to-coarse spatial resolutions (i.e., 0.3–80 km) and integrate radiances from different sources into a single ground surface unit (i.e., pixel). However, intrapixel heterogeneity, i.e., different soil and vegetation fractional cover and/or different chlorophyll content or vegetation structure in a fluorescence pixel, increases the challenge in retrieving and quantifying SIF. High spatial resolution Sentinel-2 (S2) data (20 m) can be used to better characterize the intrapixel heterogeneity of SIF and potentially extend the application of satellite-derived SIF to heterogeneous areas. In the context of the COST Action Optical synergies for spatiotemporal SENsing of Scalable ECOphysiological traits (SENSECO), in which this study was conducted, we proposed direct (i.e., spatial heterogeneity coefficient, standard deviation, normalized entropy, ensemble decision trees) and patch mosaic (i.e., local Moran’s I) approaches to characterize the spatial heterogeneity of SIF collected at 760 and 687 nm (SIF₇₆₀ and SIF₆₈₇, respectively) and to correlate it with the spatial heterogeneity of selected S2 derivatives. We used HyPlant airborne imagery acquired over an agricultural area in Braccagni (Italy) to emulate S2-like top-of-the-canopy reflectance and SIF imagery at different spatial resolutions (i.e., 300, 20, and 5 m). The ensemble decision trees method characterized FLEX intrapixel heterogeneity best (R² > 0.9 for all predictors with respect to SIF₇₆₀ and SIF₆₈₇). Nevertheless, the standard deviation and spatial heterogeneity coefficient using k-means clustering scene classification also provided acceptable results. In particular, the near-infrared reflectance of terrestrial vegetation (NIRv) index accounted for most of the spatial heterogeneity of SIF₇₆₀ in all applied methods (R² = 0.76 with the standard deviation method; R² = 0.63 with the spatial heterogeneity coefficient method using a scene classification map with 15 classes). The models developed for SIF₆₈₇ did not perform as well as those for SIF₇₆₀, possibly due to the uncertainties in fluorescence retrieval at 687 nm and the low signal-to-noise ratio in the red spectral region. Our study shows the potential of the proposed methods to be implemented as part of the FLEX ground segment processing chain to quantify the intrapixel heterogeneity of a FLEX pixel and/or as a quality flag to determine the reliability of the retrieved fluorescence.

Reducing costs in livestock farming can be achieved by stockpiling. Stockpiling is managing a pasture or hay to accumulate forage produced during the growing season to be grazed at a later time. The objective of this study was to identify stockpile initiation dates and N fertilization rates that optimize stockpile yield and quality of semi-natural mountain grassland in Croatia. A randomized complete block design with four replications was applied. Stockpile initiation dates were 15 June, 1 July, 15 July and 1 August. Nitrogen fertilization treatments were 0, 35, or 70 kg*ha-1 applied as ammonium nitrate on the date of stockpile initiation for each treatment. In late fall before snowy period were determined dry matter yield (DM), botanical composition, crude protein (CP), neutral (NDF) and acid detergent fibre (ADF) content. Stockpile forage DM yield was generally greater from earlier stockpile initiation dates (2.91, 2.18, 2.05 and 1.44 t DM*ha-1 for 15 June, 1 July, 15 July and 1 August stockpile initiation dates, respectively; LSD at 0.05 = 0.24). Stockpile forage DM yield was the greatest with 70 kg N*ha-1 and the lowest with 0 N fertilization, averaging 1.78, 2.23 and 2.43 t DM*ha-1 (LSD at 0.05 = 0.14) for 0, 35, and 70 kg N*ha-1, respectively, when averaged across stockpile initiation dates and years. Crude protein tended to increase and neutral detergent fiber tended to decrease as stockpile initiation was later in the season. These results indicate that initiating stockpiling of seminatural mountain grassland about first half of July with 35 kg N*ha-1 optimizes stockpiled grassland in the North-West region of Croatia.