The compatibility between the morphological characteristics (MCs) of rapeseed bare-root seedlings and transplanters directly affects planting quality. To improve the adaptability of transplanters to the MCs of different rapeseed cultivars, this study focused on six winter rapeseed cultivars (A1: Huyou 17, A2: Huayouza 9, A3: Fengyou 520, A4: Zhongyou 108, A5: Zheyou 50, and A6: Huayouza 62). Five MCs—root length (RL), seedling height (SH), root diameter (RD), stem thickness (ST), and seedling width (SW)—were measured during the seedling ages (25-40 d). Multiple comparisons were conducted to identify cultivars with no significant differences (NSD, α=0.05) in MCs, while skewness and kurtosis were analyzed to assess temporal variations in MC distributions. Quadratic polynomial regression was employed to model the growth trends of MCs for each cultivar. The results showed that the skewness and kurtosis ranges of MCs were –0.65 to 1.16 and 1.62 to 6.28, respectively, indicating significant variability in growth symmetry and concentration both within and among cultivars. As seedling age increased, the number of cultivars with NSD in MCs progressively decreased (25 d: 5; 30 d: 4; 35 d: 3; 40 d: 2), but A3, A5, and A6 maintained consistent stability before 35 d. Based on MC statistical analysis, the key design parameters for the transplanter were determined as follows: flat belt width was 180 mm, positioning bar spacing was 70 mm, flexible belt width was 150 mm, clamping distance was 8 mm, seedling drop height was 180 mm, and planting depth was 40 mm. Field tests demonstrated that the transplanter exhibited superior compatibility with cultivars A3, A5, and A6, achieving seedling delivery success rates of 93.75% (A3), 93.23% (A5), and 92.71% (A6), along with significantly higher planting success rates compared to the control group (A1, A2, A4). This study provides a theoretical basis for optimizing the compatibility between transplanters and rapeseed bare-root seedlings, as well as guiding the structural design of transplanting machinery.

Microgreen cultivation is often required for the precise sowing due to the small size and sensitivity of the seeds. However, it is still lacking in the equipment for the multi-row parallel mechanized seeding. Manual sowing is also confined to the uniform distribution during operations, due to the high risk of seed damage. In this study, a pneumatic needle suction device was developed for precision seed metering. A kinetic model was established to analyze the seed adsorption via the suction needles in the seeding device. Computational Fluid Dynamics simulations were conducted to optimize the airflow patterns and pressure distribution around the needles, in order to realize the efficient seed pickup and release. The key mechanical components were determined with their operational parameters, including a vibratory seed-feeding device, a pivoting air cylinder for needle movement, a seed tray conveyance, and a tray stacking mechanism. A systematic experiment was employed to identify the optimal combination of the operational parameters. The critical factors were determined, such as the vacuum pressure level, the orifice diameter of the suction needles, and the vibration frequency of the pneumatic vibrator in the feeding system. Firstly, single-factor experiments were performed to determine the approximate effective ranges for each factor. Two representative microgreen seeds were selected: the Toona sinensis and Medicago sativa. The results indicated that for Toona sinensis seeds, the superior seeding performance was achieved within the following ranges: the suction orifice diameters between 0.6 and 1.2 mm, vibration frequencies from 10.5 to 11.5 Hz, and vacuum pressures ranging from 6 to 11 kPa. In the smaller Alfalfa seeds, the effective parameters were a slightly broader orifice diameter range of 0.5 to 0.7 mm, but a narrower vibration frequency band of 9 to 10.5 Hz and a lower vacuum pressure requirement of 5 to 9 kPa. Subsequently, a quadratic orthogonal rotation combination was implemented to determine the optimal parameter and factor interactions. This advanced statistical analysis revealed that the optimal seeding performance for the Toona sinensis was obtained at a vibration frequency of 12 Hz, a suction needle orifice diameter of 0.9 mm, and a vacuum pressure of 7.5 kPa. In the Alfalfa seeds, the optimal combination of the parameters was a vibration frequency of 10 Hz, an orifice diameter of 0.6 mm, and a vacuum pressure of 5 kPa. Bench tests were finally conducted to validate the performance under these optimal parameters. The results demonstrated that there was a highly qualified seed index of 95.48% and a very low miss-seeding index of merely 1.70% for the Toona sinensis. In Alfalfa, the excellent performance was also obtained with a qualified index of 92.10% and a miss-seeding index of 2.30%. The pneumatic seeding device fully met the agronomic requirements for the precision sowing of the microgreen seeds. In conclusion, a pneumatic seed metering device was successfully optimized for the microgreen seed sowing. The theoretical modeling, CFD simulation, and experiment were combined to determine the optimal parameters for the different seed types. The crucial guidance was provided for the operational adjustment of such equipment. The findings can offer valuable insights and a solid reference for future structural optimization of the high-performance seeding devices in the emerging microgreen industry. A technological gap can be effectively bridged for the high efficiency of microgreen production in small-scale precision agriculture.

This study aimed to establish, calibrate and verify a discrete element method (DEM) particle model of rototilled soil particles for investigating the particle migration and machine soil interaction mechanism when forming micro-ridge seed beds by the rapeseed direct seeding machine. The soil type was rototilled yellow-brown soil, which is widely distributed in the mid-lower Yangtze River. The study consisted of two parts: parameter calibration and application verification. The parameter calibration followed these steps: (1) testing the soil plastic limit and selecting the contact model accordingly; (2) measuring the basic parameters, such as the soil particle size distribution and repose angle after rototilling; (3) using the EDEM particle filling and particle factory function to reproduce the particle bed based on the particle size distribution; (4) solving the optimal contact parameter combination by using factorial design, steepest ascent method, and quadratic orthogonal rotation regression method. The application verification test used two sets of structural parameters of a rotary-cutting micro-ridge seedbed preparation device (RMSD, which is the key device of rapeseed direct seeding machine to forming micro-ridge seed beds) to conduct DEM simulation and field tests, and compared the particles migration patterns and the landform after operation. A soil plastic limit tester was used to determine the plastic limit of the soil. The plastic limit of the sampled soil was 24.79%, which is close to the upper limit of the moisture content for rototiller operation. Hence, the Hertze-Mindlin (no slip) contact model was selected. The particle size range and mass ratio of the rototilled soil particles from the rapeseed direct seeding machine were sieved and counted. The rototilled soil particles of each particle size range were scanned and modelled using the EinScan-Pro 3D scanner. Based on the 3D models of the soil particles, the EDEM particle filling function was used to reconstruct the particles with different particle sizes and mass ratios. The soil particles bed was re-generated in EDEM according to the particles` mass ratio. The contact parameter calibration test includes a two-level factorization test, steepest ascent test, and quadratic orthogonal regression test, respectively, to perform a preliminary analysis of test factors and eliminate non-significant tone system, narrow down the range of factors, and solve the combination of contact parameters. The contact parameter calibration test uses the repose angle as an indicator. The two-level factorization test showed that the impact restitution coefficient had no significant effect on the repose angle; the rolling friction coefficient, static friction coefficient, and the interaction term of the two significantly affected the repose angle. The steepest ascent test was designed based on the model regression equation from a two-level factorization test. The steepest ascent test reduced the range of factors tested 0.20-0.60 (static friction coefficient) and 0.05-0.40 (rolling friction coefficient) to 0.32-0.51 and 0.11-0.27, a reduction of greater than 50%, providing effective support for obtaining accurate regression models. Since the restitution coefficient had an insignificant effect on the repose angle, the impact recovery coefficient was set to an intermediate level of 0.350 for the quadratic orthogonal regression test. The calibrations resulted in restitution, static friction and rolling friction coefficients of 0.350, 0.351 and 0.257, respectively. The verification consists of simulations and field tests conducted on the RMSD with two structural parameters. The field verification test used the PIVlab tool and the Trimble TX8 3D laser scanner to obtain the soil particles` velocity and the landform. The simulation of 2 structural parameters was consistent with field experiments. The error of micro-ridge distance is 8.25%, which increases with the number of vanes of RMSD. The calibration parameters are accurate. This paper provides fundamentals for the DEM simulation and structural improvement for rapeseed micro-ridge seedbed preparation device.

The shovel type seedbed preparation machine is suitable for the preparation of rapeseed seedbeds in the rice-oil rotation area in the mid-lower Yangtze River. It can complete the functions of soil plowing, soil leveling, straw burying, and furrow opening in one operation. However, the unit had large vibration and noise during idling and field operations, which can easily cause wear and tear of key components, reduce work reliability and trouble-free working time, and affect the health and comfort of the driver. In order to solve the problem of large vibration during unit operation, this paper analyzed the theoretical excitation frequency of the main vibration source during the operation of the tractor coupling unit through theoretical calculation, and the vibration acceleration of the unit under idle speed and field operation conditions was tested by using Coco-80 dynamic signal Test and analysis system. By using time-domain analysis and frequency-domain analysis, the vibration acceleration at different measuring points under two working conditions was determined, and the main excitation source of the unit was the movement of the shovel type tillage and soil preparation device. Based on the results of the vibration test, a scheme to reduce the vibration of the shovel type seed bed preparation machine was proposed by optimizing the arrangement of the crank phase angle to reduce the combined inertial force and inertia moment of the machine. According to the mass substitution method and kinematics analysis, the inertial force variation trend of a single group of shovel tillage and land preparation devices was obtained. Base on the calculation results, it was further clarified that the inertial force on the whole machine can be reduced by rationally designing the crank phase angle arrangement of the ten groups of mechanisms of the unit. Based on the calculated inertia force on a single group of mechanisms and combined with the crank phase angle of the existing machine tools arrangement, the inertial force and inertial moment force models of ten sets of crank-rocker mechanisms of the whole machine were established, and the arrangement of the crank phase angle that minimizes the total inertial force and inertial moment of the whole machine was obtained by using MATLAB software. Under this crank phase angle arrangement, the total inertial force of the whole machine was basically balanced, and the average absolute value of the total inertia moment in the x and y axes were reduced by 37.40% and 30.09% respectively. In order to verify the vibration reduction effect of changing the crank arrangement on the unit, the acceleration time domain signal was collected from the improved unit at the place where the vibration was relatively large. Compared with the unit before improvement, the total vibration of the measuring points after the improvement was respectively reduced by 36.42% and 31.97% under the conditions of idle speed and field operation. This research can provide reference for the inertia force balance design of planar linkage mechanisms and the research on vibration reduction of agricultural machinery based on planar linkage mechanism groups.

Direct seeding has been one of the most efficient cultivation modes for a wide range of plants, such as rapeseed. Among them, the existing ditching device cannot fully meet the practical direct seeding in recent years, due to the low stability of the furrow shape and the seedbeds on both sides of the furrow. In this study, a propeller-type ditching device was designed to actively open the furrows at high speed (≥10 km/h) and simultaneously distribute the soil in the middle and lower reaches of the Yangtze River. A quasi-propeller ditching blade was then proposed, according to the working mode of propellers. The blade arrangement was determined using kinematic and dynamic analysis. The critical parameters (the pitch and edge structures) were also determined to reduce the cutting resistance. A simulation experiment of the blade cutting was carried out using the discrete element model of the blade cutter-soil system. The simulation results indicated that the cutting resistance first decreased and then increased with the increase of the pitch angle, whereas, the rear grinding edge reduced the soil cutting resistance. The quasi-propeller blade group with the optimal combination of pitch angle and edge structure achieved a resistance torque of 176.6 N·m and a traction resistance reduction of 447.7 N, compared with the straight spoon-blade group with a travel speed of 12 km/h and rotation speed of 810 r/min. The dynamic analysis was implemented to determine the curved structure parameters of the soil homogenizing plate. Furthermore, a soil-distributing simulation experiment was carried out using the ditching cutter-soil distributing plate-soil interaction model. The better performance of soil distributing was achieved, when the camber of the left and right distributing plates was 0.19 and the down-inclination angle was 10° and 7°, respectively. The field experiment indicated that the work quality of the overall device fully met the requirements of direct rapeseed seeding when operating at a high speed of 9-12 km/h. An optimal combination was achieved: the furrow depth was 169.1-188.6 mm, the furrow depth stability coefficient was 92.5%-95.6%, the flatness of the furrow surface was 22.2-23.0 mm, the coefficient of variation of soil distributing on both sides was 14.3% and 17.2%, and the stubble burying rate was 81.96%-87.46%, the operating power consumption at the operating speed of 12 km/h was 66.84 kW. This finding can provide a strong reference for the high-speed no-tillage, ditching, and high-quality seedbed preparation for rapeseed in the rice-oil rotation areas of the mid-lower Yangtze River.

Air-assisted centralized metering devices cannot fully meet the large-scale seed supply during high-speed operations in recent years. It is high demand for better compatibility in the seeding rate and size of rice, wheat, and rapeseed, particularly on the high flowability of rice and wheat. In this study, a type-hole wheel was proposed to specifically design for the compatible mode with rice, wheat, and rapeseed. The number and rotational speed of the hole wheels were rapidly adjusted to allow for the flexible seeding rate in the seeding system, leading to the simultaneous use of rice, wheat, and rapeseed. The spiral arrangement of the hole wheels was used to increase the mobility of seeds within the seed-filling area. Thereby, the stability of seed supply was improved during high-speed seed feeding operations. Mechanical analysis was also carried out on the seed filling, seed carrying, and seed falling stages during the seed supply process. The type-hole structure parameters were determined using the physical characteristics of rice and wheat seeds. A hole wall curve was designed using brachistochrone. EDEM simulation experiments were conducted to analyze the population motion states under different rotational speed conditions at the filling, carrying, and falling stages. The variation curves were derived for the number of seeds that were supplied in the spiral and linear arrangement of the hole wheel with time. The peaks, valleys, and periods of the curves were statistically analyzed. The EDEM simulation experiments show that better performance was achieved at 40 r/min for the rice, wheat, and rapeseed supply stages. There was more outstanding behavior of the dragging and bouncing during the seed-filling stage at 80 r/min. Some seeds cannot fully enter the mold hole during the initial stage of seed carrying. But the seeds were moved down the side wall of the mold hole for the secondary seed filling, as the mold hole wheel rotated. All seeds were fed in a timely manner without any "seed sticking" phenomenon during the seed-feeding stage. Once the number of holes was determined, the pulsation period was inversely proportional to the speed of the hole wheel. The adjacent holes were sequentially misaligned on the hole wheel, when the hole wheel was spirally arranged. The continuous seed filling and feeding performance were improved to reduce the pulsation, indicating a more stable seed supply. Furthermore, the fluctuation range was reduced by more than 30 grains in the spiral arrangement of the shaped hole wheel for the rice and wheat seeds under the same rotational speed conditions, compared with the linear arrangement. The bench test was carried out to determine the rotation speed range with the better seed supply rate and stability. The regression model of seed supply rate was constructed for the rice, wheat, and rapeseed. Therefore, the coefficient of variation was less than 1% for the stability of the seed supply rate, and the seed supply rates were 1 050.62-1 535.87, and 4 171.82-5 073.76 g/min, respectively, for the hybrid rice and wheat seeds, when the number of type-hole wheels was 16, and the speed of seed supply ranges were 30-50, and 50-70 r/min, respectively. In rapeseed, the coefficient of variation was less than 0.5% for the seed supply rate stability, and the range of rapeseed supply rate was 160.42-227.45 g/min, when the number of type-hole wheels was 1, and the rotational speed of seed supply was 20-30 r/min. Moreover, there was a relative error of less than 2% between the regression model and the experimental value of the seed supply rate of rice, wheat, and rape. The field seeding experiment showed that the stability coefficients were 1.32%, 1.16%, and 1.07% for the variation of the total displacement in the collector for the rice, wheat, and rapeseed, respectively when the operating speed was 8-10 km/h. The seeding system fully met the high requirements for the multi-crop seeding operations with the rice, wheat, and rapeseed. This finding can provide a strong reference to optimize the structural parameters of the air-assisted centralized metering device for multiple crops.

Transplanting offers several advantages, such as alleviating the conflict of crop rotation, shortening the growth cycle of rapeseed, and increasing the unit yield of rapeseed. However, in the rice-rapeseed planting pattern, the growth period of rapeseed is short, manual transplanting is labor-intensive, and there is a lack of mechanized transplanting technology and equipment for rapeseed bare-root seedlings. To address these issues, this study proposed a mechanical transplanting process scheme of "leveling the ridge surface + furrowing and soil gathering + aligning and placing seedlings + soil covering and compacting" based on the agronomic requirements for rapeseed transplanting and the morphological characteristics of rapeseed bare-root seedlings. Meanwhile, a transplanter for rapeseed bare-root seedlings had been developed. The structure and working principle of the transplanter were elaborated. Structural design and theoretical analysis were carried out for key components such as the spiral soil homogenizer, trenching soil aggregating device, row-aligned seedling placement device, and soil covering and compaction device. According to the degree of freedom constraints during the conveying process of rapeseed bare-root seedlings, morphological characteristics, compatibility analysis with each key component, and the quality requirements for each transplanting operation, the key structural and working parameters of the transplanter were determined. The spiral soil homogenizer, with a pitch of 180 mm, a pitch angle of 64°, and a blade diameter of 200 mm was designed. When the furrowing disc inclination angle, center distance, and penetration depth were 42.1°, 350 mm, and 70 mm respectively, the requirements for preparing a seedling furrow with a width of 170 mm can be met, and at this time, the height of the gathered soil in the middle was 107.2 mm. A mechanical and kinematic model for the lateral sequential feeding and vertical flexible clamping conveying process of rapeseed bare-root seedlings was established. The conditions for stable seedling feeding and "zero-speed seedling dropping" were analyzed. The internal spacing of the partition, initial clamping spacing, clamping conveying inclination angle, and seedling dropping height were determined to be 45 mm, 30 mm, 70°, and 165 mm respectively. The rotational speeds of the first and second driving pulleys were 15-32 mm/s and 155-230 mm/s respectively. The covering disc inclination angle and soil turning depth were analyzed and determined to be 40° and 160 mm respectively, and the compaction wheel thickness and installation inclination angle were 60 mm and 10° respectively. A method for field tests and performance evaluation was proposed, and field transplanting performance tests had been completed. The results of the field tests showed that when the machine advances at a speed of 0.80-1.20 km/h, the inclination angles of the furrowing disc and covering disc were 42° and 40° respectively, and the rotational speeds of the first and second driving pulleys were 20 and 160 r/min respectively, there was no missed transplanting during the transplanting operation. The seedling placement success rate was 93.63%, the seedling injury rate was 3.21%, the planting qualification rate was 90.25%, and the coefficient of variation of plant spacing was 9.01%. All key components of the transplanter operated stably and can completed functions such as ridge surface leveling, seedbed preparation, seedlings alignment and placement, and soil covering and compaction in a single pass. All operational performance indicators met the basic requirements for the mechanized transplanting of rapeseed bare-root seedlings. The growth of rapeseed after transplanting was tracked. The survival rate was counted three days after transplanting and reached 96.52%. This study provided a new approach for the development of mechanized transplanting equipment for bare-root seedlings of leafy and stem vegetables. The findings and the developed transplanter could potentially enhance the efficiency and quality of rapeseed transplanting operations, contributing to agricultural productivity and sustainability in regions where the rice-rapeseed planting pattern is prevalent.

Existing micro-ridge seedbed preparation devices can often be equipped with conventional rotary tillage. However, the shallow tillage depth has been confined to the suboptimal operational efficiency. Particularly, the rapeseed cannot resist extremely adverse climates during optimal sowing and seedling in the current cultivation. In this study, a shallow plow was proposed with the high-speed micro-ridge direct seeding for rapeseed. Three sequential functions were integrated: 1) high-speed strip shallow tillage. A "lift-first and throw-later" mechanism was utilized to rapidly form the ridges using directional soil throwing; 2) micro-ridge seedbed shaping. The geometric configuration of the ridges was optimized to enhance the soil structure, and 3) sowing on ridge tops and furrows. The moisture was regulated to improve the stress resilience and yield stability of the rapeseed in the micro-ridge system. According to the operational requirements of the high-speed strip shallow tillage, a directional soil-throwing shallow plow was developed for the soil displacement at high speed. The micro-ridge morphology was analyzed for the curved surface of a variable-pitch twisted spiral plow body. The plowshare parameters were then determined: a cutting-edge angle of 120°, an entry angle of 30°, and a plowshare width of 120 mm. A mathematical model was established for the shallow plow guide curve. A kinematic analysis was also conducted on the soil lifting and throwing. Single-factor experiments were performed using EDEM software. A systematic investigation was also made on the effects of the shallow plow height, shallow plow opening, and end helix angle on the directional soil-throwing performance. A central composite design (CCD) with two factors (shallow plow opening and end helix angle) and five levels was implemented to determine their interactions on the directional soil-throwing performance. The optimal combination of the parameters was identified after iterative simulation and optimization: the shallow plow height of 375 mm, shallow plow opening of 200 mm, and end helix angle of 40°. Field experiments were conducted on the sandy clay loam and loam soil. The shallow plow achieved better soil-throwing performance at the high speed (12 km/h), compared with the conventional speed (4 km/h). Furthermore, the directional soil throwing was enhanced under the high-speed operation. There were well-defined furrows and strip-shaped soil accumulation in ridging zones. Key metrics included a soil flow back ridge-furrow ratio of 26.18%, a soil-directed migration ratio of 57.42%, and a soil throw accumulation height of 160.60 mm. The better operational passage of the machined to the stable ridge with a ridge height of 148.64 mm and a ridge width of 349.6 mm. The coefficients of variation were less than 5% for the ridge height and width. The high stability was also achieved in the directional soil throwing position, soil quantity, and throwing accumulation height, thus fully meeting the micro-ridge requirements. Furthermore, directional soil-throwing with the shallow plow can be expected for optimal operational passage in the high-speed micro-ridge seedbed preparation. Seedling emergence validated that the micro-ridge seedbed configuration fully met the agronomic requirements for the rapeseed direct-seeding. These findings can provide a viable technical pathway to develop high-quality rapeseed seedbeds for micro-ridge direct seeding.

Soil-engaging components of agricultural machinery can exert a direct influence on the operational efficiency, energy consumption dynamics, and pedological health. In this present study, a bibliometrics analysis was conducted on both English and Chinese literature and invention patent data of the agricultural machinery soil-engaging components in the period from 2000 to 2024. Multidisciplinary databases were also employed for the global coverage, including the Web of Science Core Collection, China National Knowledge Infrastructure (CNKI), Espacenet (European Patent Office), and the China National Intellectual Property Administration (CNIPA). Advanced scientometric visualization tools—CiteSpace and VOSviewer—the research performed was utilized to realize the multidimensional analysis, including the publication volume chronologies, geographical distributions of the contributing nations, structural mappings of the institutional and author collaborative networks, the highly cited seminal works, and keyword co-occurrence/clustering diagnostics. Thereby, the current research landscape evolved on the thematic concentrations and prospective trajectories. Empirical findings demonstrated that the global academic output exhibited an upward trajectory from 2000, and then a plateau phase from post-2017, indicating a fundamental research. Subsequently, the People’s Republic of China emerged as the predominant research in both quantitative output volume and aggregate academic influence in the field. High-impact research entities—institutions and authors—were observed in the themes: the functional optimization on the components with the adaptability to diverse regional soil tillage (e.g., geometric profiling for the draft force mitigation and residue disposal), advanced material strengthening techniques (including wear-resistant surface engineering and composite material integration), tillage regime compatibility (design paradigms tailored for conservation, conventional, or reduced-tillage systems), and intelligent perception integration (sensor-enabled components in real-time load diagnostics and operational monitoring). Collectively, there was an interconnected framework driving the technological progression. Contemporary research hotspots were focused mainly on the conservation tillage (components optimization for the minimal soil disturbance and the maximum residue retention), energy-efficient and anti-adhesive design (innovative component to reduce the energy consumption and soil adhesion), high-fidelity discrete element method (DEM) modeling of the soil-tool interaction mechanics, and smart technology applications (entailing IoT integration, embedded sensing architectures, and adaptive control systems). Some technological challenges were still remained, including the insufficient material performance and inadequate multi-objective optimization (reflecting unresolved tensions between wear resistance, fracture toughness, mass reduction, and cost efficiency), underdeveloped modular system dynamic coupling (evidenced by limited integration and interaction analysis between modular components under operational stresses), and deficient environmental robustness of intelligent sensing (as the vulnerability to extreme field conditions, including moisture ingress, particulate contamination, mechanical vibration, and impact loads). Consequently, the future breakthroughs were concentrated on the novel material innovation (smart materials, nano-composites, and functionally graded structures), systemic intelligent upgrading (AI-driven predictive maintenance and autonomous adjustment algorithms), eco-sustainable development pathways (low-carbon manufacturing, recyclability, and soil health preservation), and multifunctional modular architectures (interchangeable, scalable components for the versatile field operations); These priorities were addressed to promote the soil-engaging components toward the high operational efficiency, quality metrics, and intelligence levels with the low energy intensity. A technological evolution can also provide a strong reference for the sustainable intensification and high-quality production in precision agriculture.

As an advanced non-invasive imaging technology, CT technology combines X-ray and computer reconstruction algorithms, which can accurately reveal the internal structure of objects. It has great application prospects in the field of agricultural engineering research and has gradually become one of the important technologies to promote the intelligence and precision of agricultural engineering. In order to systematically summarize the application status of CT technology in the field of agricultural engineering and analyze the future development trend of this technology, this paper summarizes the basic principles of CT technology, including equipment structure, workflow, image reconstruction post-processing technology, etc. By comparing with other non-destructive testing technologies, the significant advantages of CT technology in high resolution and strong penetration are highlighted. This paper reviews the application examples of CT technology in many fields of agricultural engineering research. For example, in the quality detection of fruits and vegetables, CT technology can non-destructively detect internal defects of fruits and vegetables, such as internal browning, voids, fibrous tissue, etc., and perform quality classification, which improves the detection efficiency and accuracy. In terms of grain evaluation, CT technology can accurately measure key parameters such as grain size, shape, internal tissue structure, and density, which can be used to evaluate grain quality and predict yield, and provide a scientific basis for breeding and planting management. In terms of stem analysis, CT technology can reveal the microstructure and physiological characteristics of stems, and provide a new perspective for studying the growth and development, lodging resistance, and mechanical strength of stems. In terms of root analysis, CT technology can track the growth process of roots, analyze the effects of roots on soil structure, porosity, and water transport, and provide important data for studying plant-soil interaction and improving soil management. In terms of soil pore analysis, CT technology can obtain three-dimensional pore structure images of soil, and analyze the geometric characteristics and spatial distribution of pores, which can be used to study the permeability, water retention, and permeability of soil, and provide scientific guidance for soil improvement and management. However, the application of CT technology still faces the problems of complex equipment operation processes, high image processing difficulty, detection resolution limitation, high equipment cost, and radiation safety. The operation process of CT equipment is relatively complex, involving multiple steps such as scanning parameter setting, image reconstruction, and post-processing. Moreover, image processing relies on professional software and algorithms, which requires a high technical level and professional knowledge of operators. The resolution of CT equipment has limitations in the application of small-volume agricultural product detection. The high cost of CT equipment and the radiation risk of X-rays to the human body have certain requirements for the installation and use environment, which limits its application in the field of agricultural engineering. In view of the above problems, this paper puts forward the development trend of CT technology applications, including enriching research objects, enhancing application effects, and optimizing technical links. CT technology is applied to the fields of agricultural machinery design, intelligent agricultural platforms, and agricultural education to develop new application scenarios. The development of multimodal imaging technology and low-dose imaging technology improves the level of intelligence and combines with artificial intelligence algorithms such as deep learning to achieve automatic image analysis. The purpose of this paper is to provide a reference for the further application and development of CT technology in the field of agricultural engineering, so as to promote the deep integration of CT technology and agricultural engineering research and its application in related research.