Cable-skidding operations in mountainous selective logging pose significant risks to residual stands due to the extraction of heavy and long stems/logs along steep skid trails. While the influence of trail design variables such as traffic intensity and slope gradient has been extensively studied, the impact of management practices, specifically operational layout and the expertise of forest workers, on residual stand damage remains less understood. This study examined the effects of management practices and skid trail design variables on the severity and healing of wounds inflicted on residual trees over a five-year period. Three decommissioned harvest units with similar characteristics but differing in trail variables and management practices were analyzed: university-managed operations (short-length logs handled by professional operators), mill-managed operations (long-length logs handled by semi-professional operators), and privately-managed operations (mixed-length logs handled by less-experienced operators). A two-stage inventory was conducted, beginning in 2016 with an assessment of mechanical injuries caused by a cut-to-length harvesting system involving multiple log lengths, followed by postharvest wound healing evaluation in 2021. Results revealed that damages rates ranged from 37% in university-managed blocks to 49% in mill-managed blocks. Gentle slopes accounted for 43% of the damage, while steep slopes contributed 53%. Traffic intensity further played a role, with damage rates of 40% in low-traffic areas, 46% in medium-traffic areas, and 51% in high-traffic areas. Over the five-year postharvest period, healing rates varied significantly: stands managed under university supervision showed a healing rate of 56%, compared to a lower rate of 35% for mill-management stands. Treatments on gentle slopes and in low-traffic areas showed an annual healing rate of 12% higher than those on steep slopes and in high traffic areas. These findings highlight the importance of management practices, particularly the use of short-length harvesting methods in mountainous mixedwood stands and the effective supervision of harvesting crews. Implementing such practices not only reduce the severity of damage to residual stands but also enhance more efficient wound healing over time.

To address the inefficiency and high cost of manual potato pickup in segmented harvesting, a dual-disc potato pickup and harvesting device was designed. The device utilizes counter-rotating dual discs to gather and preliminarily lift the potato-soil mixture, and combines it with an elevator chain to achieve potato-soil separation and transportation. Based on Hertz's collision theory, the impact of disc rotational speed on potato damage was analyzed, establishing a maximum speed limit (<= 62.56 r/min). Through kinematic analysis, the disc inclination angle (12-24 degrees) and operational parameters were optimized. Through coupled EDEM-RecurDyn simulations and Box-Behnken experimental design, the optimal parameter combination was determined with the potato loss rate and potato damage rate as evaluation indices: disc rotational speed of 50 r/min, disc inclination angle of 16 degrees, and machine forward speed of 0.6 m/s. Field validation tests revealed that the potato loss rate and potato damage rate were 1.53% and 2.45%, respectively, meeting the requirements of the DB64/T 1795-2021 standard. The research findings demonstrate that this device can efficiently replace manual potato picking, providing a reliable solution for the mechanized harvesting of potatoes.

The production of industrial hemp (Cannabis sativa L.) has expanded recently in the US. Limited agronomic knowledge and supply chain issues, however, stemming from a long-standing cultivation ban, pose a barrier to continued market expansion of hemp, which leads to the import of most hemp products. This review examines the most recent cultivation methods, fertilizer and nutrient requirements, soil management practices, environmental parameters, and post-harvest processing methods, particularly in the context of environmental benefits such as soil phytoremediation and CO2 sequestration. Details of the valorization of hemp biomass into sustainable products, such as fibers, papers, packaging, textiles, biocomposites, biofuels, biochar, and bioplastics, along with current limitations and scope for improvements, are explored. Finally, an overall summary of the life cycle and techno-economic analysis aimed at optimizing their environmental performance and economic feasibility are discussed with a focus on inter with the growing circular economy paradigm.

Underground winter bamboo shoots, prized for their high nutritional value and economic significance, face harvesting challenges owing to inefficient manual methods and the lack of specialized detection technologies. This review systematically evaluates current detection approaches, including manual harvesting, microwave detection, resistivity methods, and biomimetic techniques. While manual methods remain dominant, they suffer from labor shortages, low efficiency, and high damage rates. Microwave-based technologies demonstrate high accuracy and good depths but are hindered by high costs and soil moisture interference. Resistivity methods show feasibility in controlled environments but struggle with field complexity and low resolution. Biomimetic approaches, though innovative, face limitations in odor sensitivity and real-time data processing. Key challenges include heterogeneous soil conditions, performance loss, and a lack of standardized protocols. To address these, an integrated intelligent framework is proposed: (1) three-dimensional modeling via multi-sensor fusion for subsurface mapping; (2) artificial intelligence (AI)-driven harvesting robots with adaptive excavation arms and obstacle avoidance; (3) standardized cultivation systems to optimize soil conditions; (4) convolution neural network-transformer hybrid models for visual-aided radar image analysis; and (5) aeroponic AI systems for controlled growth monitoring. These advancements aim to enhance detection accuracy, reduce labor dependency, and increase yields. Future research should prioritize edge-computing solutions, cost-effective sensor networks, and cross-disciplinary collaborations to bridge technical and practical gaps. The integration of intelligent technologies is poised to transform traditional bamboo forestry into automated, sustainable smart forest farms, addressing global supply demands while preserving ecological integrity.

Cumin (Cuminum cyminum L.) is a globally important spice crop, particularly significant in Xinjiang, China, where it is extensively cultivated in cotton-cumin intercropping systems. This review concentrates on the serious bottleneck hindering the development of the cumin industry: the low level of harvesting mechanization. Traditional manual harvesting methods are labor-intensive, inefficient, and result in high yield losses. This paper fully explores the prospects and challenges of mechanizing cumin harvesting in accordance with the particular biological characteristics of cumin plants and the complexity of intercropping systems. We review the current status of research in the following domains: (1) cumin biological traits and intercropping models; (2) grain loss and stalk damage patterns in stripper harvesting of similar crops; (3) factors influencing root-soil interaction during mechanical extraction; (4) uprooting-conveying harvesting techniques and row division/plant singulation methods applicable to root and tuber crops; and (5) cumin-threshing and -cleaning technologies. This review highlights the inadequacy of current grain-harvesting machinery for cumin and underscores the urgent need for specialized, low-loss harvesting technologies tailored to cumin's delicate nature and intercropping context. Finally, we propose future research directions to overcome these mechanization challenges and promote the sustainable development of the cumin industry.

The study investigates the mechanical requirements for harvesting coriander (Coriandrum sativum L.) by analyzing static and dynamic cutting forces for three distinct varieties: SIMCO, GCr1, and GCr2. Through controlled laboratory experiments, the static cutting force was measured using a texture analyzer across variations in blade speed (2, 4, 6, 8, and 10 mm/s), stem number (1-5), cutting height (50, 75, 100, 125, and 150 mm), and moisture content (23 %, 30 %, and 37 %). The static cutting force for SIMCO was found to be the highest (151.6 N), followed by GCr1 (145.68 N) and GCr2 (140.48 N), primarily due to stem structure and diameter differences. The dynamic cutting force was also measured in the indoor soil bin using a reciprocating cutter bar by simulating the field conditions at varied forward speeds (0.3, 0.6, 0.9, and 1.2 m/s), cutter bar speeds (2, 8, 14, and 20 strokes/s), and cutting heights (50, 75, 100, 125, and 150 mm). For dynamic cutting, the SIMCO variety required an average maximum force of 33.14 N, which was 6.85 % and 7.06 % higher than GCr1 and GCr2 respectively. The dynamic cutting forces were influenced most significantly by cutter bar speed and forward speed, with optimal cutting achieved at 20 strokes/s cutter bar speed and 0.3 m/s forward speed. Response Surface Methodology (RSM) models with R2 values above 0.99 effectively predicted both static and dynamic cutting forces, indicating strong model adequacy and providing detailed insights into the interactions between parameters. The analysis revealed that the number of stems and blade speed were the primary influencers on static cutting force, while the dynamic force was most affected by cutter bar speed and forward speed. This study highlights the importance of customized parameter settings to enhance harvester efficiency, reduce energy consumption, and minimize seed damage during harvest.

The Discrete Element Method (DEM) is an innovative numerical computational approach. This method is employed to study and resolve the motion patterns of particles within discrete systems, contact mechanics properties, mechanisms of separation processes, and the relationships between contact forces and energy. Agricultural machinery involves the interactions between machinery and soil, crops, and other systems. Designing agricultural machinery can be equivalent to solving problems in discrete systems. The DEM has been widely applied in research on agricultural machinery design and mechanized harvesting of crops. It has also provided an important theoretical research approach for the design and selection of operating parameters, as well as the structural optimization of potato harvesting machinery. This review first analyzes and summarizes the current global potato industry situation, planting scale, and yield. Subsequently, it analyzes the challenges facing the development of the potato industry. The results show that breeding is the key to improving potato varieties, harvesting is the main stage where potato damage occurs, and reprocessing is the main process associated with potato waste. Second, an overview of the basic principles of DEM, contact models, and mechanical parameters is provided, along with an introduction to the simulation process using the EDEM software. Third, the application of the DEM to mechanized digging, transportation, collection, and separation of potatoes from the soil is reviewed. The accuracy of constructing potato and soil particle models and the rationality of the contact model selection are found to be the main factors affecting the results of discrete element simulations. Finally, the challenges of using the DEM for research on potato harvesting machinery are presented, and a summary and outlook for the future development of the DEM are provided.

To address the inadequacies of mechanized potato-harvesting equipment on challenging terrains like hills, mountains, and small fields, a lightweight and simple self-propelled crawler potato combine harvester was developed based on the agronomic and harvesting requirements of potato cultivation. The machine consists of key components including a depth-limited soil-crushing device, an auxiliary feeding device, an excavation device, a rubber rod separation device, and a ton bag sorting device. It offers technical advantages such as a lightweight structure, auxiliary feeding and conveying, and manual assistance in sorting ton bags. The key components, such as the auxiliary feeding device, depth-limiting soil-crushing device, and rubber rod separation device, were analyzed theoretically to determine the relevant structures and parameters. Through initial harvesting performance tests, the separation screen line speed, vibration frequency, and device inclination angle were identified as the experimental factors. Evaluation indicators such as potato bruise rate, skin breakage rate, loss rate, and impurity content were chosen, and a three-factor, three-level Box-Behnken optimization test was conducted. The results indicated that with a separation screen line speed of 1 m/s, vibration frequency of 8 Hz, and device inclination angle of 30 degrees, the potato damage rate during harvesting was 1.318%, the skin breakage rate was 1.825%, the loss rate was 2.815%, and the impurity rate was 2.736%. Field tests with the same parameters showed that the potato damage rate, skin breakage rate, loss rate, and impurity rate of the harvester were 1.357%, 1.853%, 2.86%, and 2.748%, respectively, meeting relevant industry technical standards. This research can serve as a reference for enhancing the harvesting performance of potato combine harvesters and ton bag sorting technology.

With the advancement of technology and the national effort to promote the development of agricultural mechanization, sweet potato harvester technology is continuously evolving. To solve the problems related to high skin breakage rates and high damage rates during sweet potato harvesting, it is necessary to develop a conveying and separation mechanism that facilitates low skin breakage rates, low injury rates, good potato-soil separation, and smooth transport. This paper elaborates on the working modes of mechanized sweet potato harvesting, focusing on the current state of research on the conveying and separating mechanisms of sweet potato harvesters both in China and elsewhere. The functions of different types of conveying chains are summarized, the conveying and separating technologies used for the mechanized harvesting of other root crops that can be applied to sweet potato harvesters are analyzed, and an outlook on the development trends regarding sweet potato harvesters is provided.

To improve soil clod removal and reduce potato damage in potato combine harvesters, this study investigates the processes involved in soil clod removal and potato collisions within the bar-lift chain separation device of the harvester. It outlines the structure and working principles of the machine, theoretically analyzes the key dimensions of the digging device and potato-soil separation components, and derives specific structural parameters. A dynamic mathematical model of the bar-lift chain is established, from which the dynamic equations are formulated. The analysis identifies factors that influence the dynamic characteristics of the bar-lift chain. This study examines the working principles and separation performance of the potato-soil separation device, with a focus on the collision characteristics between potatoes and both the screen surface and the bars. Key factors such as the separation screen's line speed, the harvester's forward speed, and the tilt angle of the separation screen are considered. Simulations are performed using a coupling method based on the Discrete Element Method (DEM) and Multi-Body Dynamics (MBD). Through simulation experiments, the optimal parameter combinations for the potato-soil separation device are determined. The optimal working parameters are identified as a separation screen line speed of 1.25 m/s, a forward speed of 0.83 m/s, and a tilt angle of 25 degrees. Field harvesting experiments indicate a potato loss rate of 1.8%, a damage rate of 1.2%, an impurity rate of 1.9%, a skin breakage rate of 2.1%, and a yield of 0.15-0.21 ha/h. All results meet national and industry standards. The findings of this research provide valuable theoretical references for simulating potato-soil separation in combine harvesters and optimizing the parameters of these devices. Future potential research will consider the automatic regulation of the excavation volume of the potato-soil mixture, aiming to achieve intelligent control of the potato-soil separation operation.