The impact of buckwheat and paulownia (Paulownia elongata × P. fortunei) intercropping on beekeeping value and buckwheat yield.

Increasing crop diversity is a way for agriculture to transition towards a more sustainable and biodiversity-friendly system. Growing buckwheat intercropped with paulownia can contribute not only to mitigating climate change but can also enrich the environment with species of agricultural importance, without causing a decline in pollinators, since buckwheat is pollinated mainly by the honeybee. In a field experiment comparing growing buckwheat with paulownia against a monoculture crop, we investigated differences in flower visitation and beekeeping value, as well as the associated impact on crop yields. We analysed the effect of intercropping on the beekeeping value of buckwheat in terms of bee population size and the sugar mass in buckwheat flowers, nectar mass in buckwheat flowers, the quality of the delivered raw sugar and biometric characteristics. We found significant differences in the number of branches on the main shoot and the total number of branches. Significantly higher parameters were obtained in sites with buckwheat monoculture. The cultivation method variant did not cause differentiation in either the structure elements or the yield itself. Yields ranged from 0.39 (2021) to 1.59 (2023) t·ha-1. The average yield in intercropping was slightly lower (0.02 t·ha-1) than in the monoculture system of buckwheat (0.93 t·ha-1). More flowers per plant per day of observation and more flowers in millions of flowers per hectare per day of observation were observed in the intercropping of buckwheat with paulownia. Based on our experiment, we concluded that growing buckwheat in monoculture significantly increased the number of flowers, resulting in an increase in pollinator density and an increased number of pollinators per unit area.

Qualitative and Quantitative Assessment of Buckwheat Husks as a Material for Use in Therapeutic Mattresses.

Buckwheat husks are used in many therapeutic products such as pillows, mattresses, seats, etc. This material is proposed by producers for example for discopathy, back pain and head vasomotor disorders. Our studies evaluated the impact of using cotton mattresses with buckwheat husk fillings on people's health condition. The main research was carried out on the group of 60 people divided into 3 groups (1-people with skeletal system problems, 2-people spending a lot of time lying with the probability of pressure ulcer formation and 3-healthy people). In addition, different tests have been carried out on the possibility of colonization of mattresses by fungi, bacteria and arthropod pests, and rheological, chemical and flammability tests. The research material in the form of buckwheat husks was tested in a diverse way. All tests indicate high usefulness of husks for therapeutic activity. This material was contaminated with fungi, bacteria and pests at a very low level, related to the natural colonization of buckwheat nuts during harvest and storage. The quality of the husks was also confirmed in rheological, chemical and flammability studies. Finally, this has also been confirmed in surveys conducted on people with health problems. The analyses show that the buckwheat husk is an excellent material that can be used to fill prophylactic mattresses. This has been confirmed by the results of laboratory tests and opinions of respondents using mattresses filled with buckwheat husk.

Oxytree Pruned Biomass Torrefaction: Process Kinetics.

Oxytree is a fast-growing energy crop with C4 photosynthesis. In this research, for the first time, the torrefaction kinetic parameters of pruned Oxytree biomass (Paulownia clon in Vitro 112) were determined. The influence of the Oxytree cultivation method and soil class on the kinetic parameters of the torrefaction was also investigated. Oxytree pruned biomass from a first-year plantation was subjected to torrefaction within temperature range from 200 to 300 °C and under anaerobic conditions in the laboratory-scale batch reactor. The mass loss was measured continuously during the process. The relative mass loss increased from 1.22% to 19.56% with the increase of the process temperature. The first-order constant rate reaction (k) values increased from 1.26 × 10-5 s-1 to 7.69 × 10-5 s-1 with the increase in temperature. The average activation energy for the pruned biomass of Oxytree torrefaction was 36.5 kJ∙mol-1. Statistical analysis showed no significant (p < 0.05) effect of the Oxytree cultivation method and soil class on the k value. The results of this research could be useful for the valorization of energy crops such as Oxytree and optimization of waste-to-carbon and waste-to-energy processes.

Oxytree Pruned Biomass Torrefaction: Mathematical Models of the Influence of Temperature and Residence Time on Fuel Properties Improvement.

Biowaste generated in the process of Oxytree cultivation and logging represents a potential source of energy. Torrefaction (a.k.a. low-temperature pyrolysis) is one of the methods proposed for the valorization of woody biomass. Still, energy is required for the torrefaction process during which the raw biomass becomes torrefied biomass with fuel properties similar to those of lignite coal. In this work, models describing the influence of torrefaction temperature and residence time on the resulting fuel properties (mass and energy yields, energy densification ratio, organic matter and ash content, combustible parts, lower and higher heating values, CHONS content, H:C and O:C ratios) were proposed according to the Akaike criterion. The degree of the models' parameters matching the raw data expressed as the determination coefficient (R2) ranged from 0.52 to 0.92. Each model parameter was statistically significant (p < 0.05). Estimations of the value and quantity of the produced torrefied biomass from 1 Mg of biomass residues were made based on two models and a set of simple assumptions. The value of torrefied biomass (€123.4·Mg-1) was estimated based on the price of commercially available coal fuel and its lower heating value (LHV) for biomass moisture content of 50%, torrefaction for 20 min at 200 °C. This research could be useful to inform techno-economic analyses and decision-making process pertaining to the valorization of pruned biomass residues.