Research Articles

The biogas slurry (BS) generated through the anaerobic fermentation of biogas in pig farms is extensively employed as an organic fertilizer in Northeast China. BS is often used in large amounts because of fragmented farmland ownership resulting from previous local policies. In this work, 20 m³ · 667m^-2 of BS was applied to black soil twice and to aeolian sandy soil once to explore microbial-driven nutrient cycling. The results indicated that BS increased organic carbon, total nitrogen, and total phosphorus contents in black soil. The activities of C-cycling and P-cycling enzymes in black soil were enhanced, while the activities of P-cycling enzymes in aeolian sandy soil were reduced. The BS application increased the abundance ratio of fungi to bacteria in both soil types. Total carbon, total nitrogen, and total phosphorus primarily influenced the microbial community structure in black soil, while pH was the key factor in aeolian sandy soil. However, the excessive increase of heavy metals in black soil treated twice BS posed a potential risk to the environment. Utilizing BS as fertilizer is a viable strategy applicable for Northeastern China’s agriculture, and application dosages must be adjusted according to experimental results.

Although chemical fertilizers increase crop productivity, they have undesirable effects on the environment, soil fertility, and negatively influence fruit shelf life and quality. Therefore, the application of plant biostimulants and biostimulant-like substances has become necessary to improve the availability and absorption of nutrients, enhance growth, yield, quality, and tolerance to abiotic and biotic stresses, and serve as an alternative to mineral fertilizers. Therefore, this study investigated the influence of zeolite, kaolin (KL), and chitosan (Cs) in alleviating abiotic stress and improving productivity and quality of strawberry plants. Strawberry plants were soil fertilized by zeolite at 0, 2, and 3 kg and then they were sprayed with 2% g/L KL + 500 ppm Cs, 4% KL + 1000 ppm Cs, and 6% KL + 1500 ppm Cs. The individual application of zeolite improved the performance of strawberry plants, and its influence greatly increased with the combination spraying of different combinations from KL + Cs. The highest increments resulted from the application of 3 and 2 kg of zeolite combined with the spraying of 4% KL + 1000 ppm Cs and 6% KL + 1500 ppm Cs compared to non-treated plants.

Longitudinal tensile, longitudinal compressive, and flexural tests of bamboo from different regions were carried out, and the values of strength and elastic modulus were obtained. The probability distribution models of mechanical properties of bamboo in different regions were studied based on the data. The effects of no waterproofing treatment, tung oil treatment, and wood wax oil treatment on mechanical property degradation of bamboo were studied in response to 7 days of soaking. The main conclusions include: the mechanical properties of bamboo produced in Yunnan Province were the highest, followed by Jiangxi Province, and the lowest in Zhejiang Province. The Weibull distribution model achieved a good fit for all mechanical properties. With the increase of soaking time, the mechanical properties of bamboo were degraded. Degradation in the control group was the highest, followed by the wood wax oil group, and tung oil group was the lowest. On the 7^th day, the average mechanical properties of the control group had decreased by 32.0%, the tung oil group by 14.5%, and the wood wax oil group by 25.6%. Through comprehensive comparison, it was evident that tung oil treatment provided the best waterproofing effect for bamboo.

The monitoring of forest biomass stock volumes in larger operations is typically conducted irregularly, either by tracking cargo arrivals or by using simple manual measurement methods. The objective of this study was to assess the accuracy of smart methods based on laser scanning technology, integrated into mobile phones and a handheld laser scanner, for measuring smaller piles of forest chips. For the experiment, a total of 50 m³ of fiberwood logs were chipped and distributed into four piles. The smart solutions selected for laser scanning of forest biomass in this study were the Stonex Geoslam X120 GO handheld laser scanner and the iPhone 14 Pro Max equipped with a LiDAR sensor. The results were influenced by the selected conversion coefficient and the exclusion of small scattered fragments of forest chips around the piles, which were not included in the final volume calculation. The smallest discrepancy identified by the smart solutions was 3 m³ (6%) of woody mass. The findings demonstrated that the smart solutions utilizing LiDAR technology offer good affordability, ease of use, and satisfactory accuracy. They are user-friendly and provide quick results.

Aperture plugging is a phenomenon that limits both the capacity and efficiency of pulp screens, which are critical components of the papermaking process. An understanding of how plugs are created and how they can be avoided can enhance the manufacture of paper products, providing energy savings, increased productivity, improved product quality, and higher levels of paper recycling. This work considers the creation and dispersion of plugs in a small, industrial screen. Flow resistance provides a means of assessing the presence of plugs and their evolution through creation and dispersion. A structured means of plug dispersion was formulated, from which floc strength could be inferred. These novel measurements provide insight not only into the factors that control plug creation, but into their character. Long-fiber (softwood) plugs were found to form and consolidate quickly and to achieve high strength. Their low porosity limited flow through the slot soon after creation. Short-fiber (hardwood) plugs formed more slowly, and they were more porous and weaker.

The temperature, humidity, and indoor airborne fungi were evaluated at 24 wooden cultural heritage sites (WCHs) (5 from field surveys and 19 from previous studies). Surface contaminating fungi was present year-round in the indoor space of WCHs. Wood decay fungi float only in summer and fall when relative humidity is high. The internal conditions of WCHs, such as an average temperature of 20 °C and a relative humidity of 75% or more, persisted for at least 4 weeks and up to 8 weeks of the year. Accordingly, the growth of surface contaminating fungi and wood decay fungi on wood and Hanji (Korea paper) surfaces was evaluated for 12 weeks. There was no growth at relative humidity of 95% or less. The maximum average relative humidity of 24 WCHs nationwide was 90% or less, which makes it impossible for most wood decay fungi to germinate and grow, and the period when it remained above 95% was very short. Therefore, the indoor space of WCHs is unlikely to be damaged by surface contaminating fungi and wood decay fungi in all periods of the year, as the environment suitable for germination and growth is not created for a long period.

Efficient and rapid identification of corn mildew levels is essential for proper storage and transportation. This study utilized surface-enhanced Raman spectroscopy (SERS) to obtain Raman spectral fingerprints of moldy corn, combined with multi-class support vector machines (SVM) for rapid detection. Spectral data were preprocessed using the Savitzky-Golay smoothing method, and principal component analysis (PCA) was applied to extract the top five components. Feature peaks were identified using partial least squares discriminant analysis (PLS-DA) regression coefficients, supplemented by manual selection, resulting in eight characteristic wavenumber peaks (482, 878, 1046, 1082, 1220, 1276, 1452, and 1590 cm^–¹). These features were used for clustering analysis, followed by SVM classification to distinguish mildew levels. The model achieved a 100% recognition rate, validated by cross-validation and confusion matrix analysis. The findings demonstrate that SERS combined with SVM enables precise differentiation of mildew levels, providing reliable support for Raman spectroscopy in fungal detection and grain safety monitoring.

The objective of this study was to synthesize flame-retardant wax by nano-sizing a previously developed flame-retardant with favorable performance characteristics. Additionally, this study assessed the leaching resistance of wood treated with flame-retardant wax. The findings revealed that wood treated with flame-retardant wax demonstrated no notable change in the weight loss rate before and after weathering treatments. In contrast, wood treated exclusively with flame retardants exhibited a discernible increase in the extent of weight loss. Furthermore, the leached phosphorus content was measured during the weathering process, revealing that the amount extracted from wood treated with flame-retardant wax was approximately 1/20 times of that extracted from wood treated with flame-retardant agents. Therefore, that wood treated with flame-retardant wax demonstrated superior flame-retardant performance before and after weathering treatments.

Preserving global rapeseed production against water shortages requires innovative strategies to enhance crop resistance. Despite its importance, rapeseed remains a water-intensive crop, making traditional irrigation practices unsustainable. Recent studies have explored methods to improve water use efficiency, and this study focuses on applying bioregulators to increase rapeseed yield under water-limited conditions, thereby contributing to food security and sustainability. A field experiment was conducted at the Agricultural Research Farm of Lovely Professional University during the 2021–2022 and 2022–2023 rabi seasons. The experiment, arranged in a split-plot design with 24 treatments, involved gypsum, bentonite sulphur, and elemental sulphur as various sulphur sources in main plots and hydrogel (2.5 kg/ha) and salicylic acid (150 ppm) applications at flowering and pod formation stages in subplots treatments. Gypsum (S1) notably seed yield, root length, and root dry weight. Additionally, hydrogel and salicylic acid applied during 50% flowering and 50% pod development (A6) produced the highest seed yield, root length, and root dry weight. This treatment also enhanced siliqua length and seed count, indicating the potential of gypsum and bioregulators in improving Brassica napus L. production under water-limited conditions.

Plastic products generally have excellent thermal plasticity and water resistance. However, their adverse environmental effects have become a severe problem. To overcome these problems, a 100% plant-derived plastic substitute material was developed by mixing wood powder, hydroxypropyl methylcellulose (HPMC), and citric acid solution, followed by vacuum extrusion and heating to insolubilize the HPMC. In this study, the effect of heating on physical properties was investigated. The extruded wood powder sheets were heated under a wide range from 0.5 to 5 h at 150 to 210 °C, which covers the conditions required for esterification between HPMC and citric acid. Water absorption, tensile strength, puncture resistance, and wettability were then tested. The sheet became tolerant of water and developed slightly higher tensile strength upon adequate heating, although it was more easily punctured when rewetted. Excessive heating at 210 °C was found to damage the sheet. The overall activation energy, calculated from the weight loss during heating, was as low as 46 kJ/mol, indicating that the dehydration and crosslinking of HPMC could occur easily. The curing process improved the water resistance and did not considerably worsen other physical properties; therefore, the possibility of using wood powder/HPMC/citric acid composite sheets has potential.