Pneumatic centralized seeding technology has the advantages of high seeding efficiency, wide adaptability and low seed damage. In the study, it was found that the type and structural parameters of the seed distributor had a great influence on the seeding uniformity of the pneumatic centralized seeding system. In this study, M-type, T-type and Y-type seed distributors were proposed respectively, and the overall structure and working principle of the pneumatic collection system were expounded. Taking wheat as the research object, the force and motion analysis of the seed particle group in the distributor under the action of airflow was carried out. Based on the CFD-DEM gas-solid coupling method, the simulation models of wheat seeds and distributors were established respectively. Taking the coefficient of variation of the uniformity of each row displacement as the index, the simulation test of the influence of different outlet types on the performance of the distributor was carried out, and the M-type seed distributor was determined as the optimal structure. On this basis, the influence of different outlet pipe inclination angles, top cover cone angles, inlet diameters, fillet radius and airflow velocity on the uniformity of the internal flow field of an M-type seed distributor was studied by single factor experiment, and the significant factors and their horizontal range were determined. The orthogonal test of three factors and three levels was carried out with the factors of outlet pipe inclination angle, top cover cone angle and fillet radius. The optimal structural parameters of the M-type seed distributor were determined by response surface analysis with the variation coefficient of uniformity of each row displacement as the index. The bench and field verification tests were carried out on the experimental farm of Northwest A & F University. The simulation and experimental results show that compared with the T-type and Y-type seed distributors, the M-type seed distributor significantly improves the seeding quality of wheat seeds, and the coefficient of variation of seeding uniformity is reduced by 7.41% and 3.72%, respectively. When the cone angle of the top cover is 117.03° and the angle of the outlet pipe is 59.50°, the corner radius is 69.46 mm, the uniformity of the seed distributor is the best, and the coefficient of variation of the uniformity of each row is 6.05%. The absolute errors between the simulation results of the M-type seed distributor and the bench and field test results were 1.00% and 1.55%, respectively. The research provides reference and technical support for the design of a pneumatic collecting and discharging system.

Agricultural robot is one of the hottest topics in the field of agricultural machineries. Domestic and foreign research on robot mobile platforms for greenhouse/farmland/orchard operations (weeding, fertilization, spraying, picking, etc.) has achieved preliminary results, but mobile robotic system for soil sampling is still seldom found in literatures. Undisturbed soil sampling is an important basis for analyzing soil mechanical properties. If the original state of the soil sample cannot be guaranteed, it will be difficult to obtain accurate research results through subsequent laboratory physical and mechanical testing and analysis. To address this issue, we developed a farmland soil collection robot mobile platform with compact structure, strong pass ability, good soil extraction quality, and high soil extraction efficiency, put forward the design scheme of the mechanical system and control system and carried out preliminary field trial research. The main contents of this research are as follows: First, the design of robotic mobile platform was conducted, by determining differential steering mode, fulfilling mechanical design, selecting hardware components, and building control software framework. The wheelbase and track width of the platform were 960 mm and 600 mm, respectively. The power of the in-wheel motor was 1 000 W. The movement of the platform could be controlled through both speed control knob and remote-control handle. Second, an on-board layer soil sampling equipment was developed, which worked in a hydraulic screw-in mode. The main structure parameters of the sampler were determined based on theoretical analysis, which were validated with a finite element analysis software-ANSYS. Third, field tests were also conducted to test the mobility and soil sampling performances of the robot system. The maximum obstacle crossing height and climbing slope of the robot were 80 mm and 35°, respectively. Based on the shear strength testing results of soil samples in depth 0 to 200 mm, we knew that the internal friction angle of the soil samples, which came from the proposed new system, had no significant differences compared to those coming from cutting ring sampling, with a P-value of 0.866 at the confidence level of 0.05. Similarly, for the soil samples in depth 0 to 100 mm and 100 to 200 mm, the variances of soil cohesion from our new system also had no significant differences compared to those from cutting ring sampling, with P-values of 0.145 and 0.717 at the confidence level of 0.05, respectively. The soil extraction efficiency comparison test results showed that the soil extraction device only took 3 to 5 minutes to complete one soil extraction.

In order to solve the problems of grain loss, breakage and impurity in sorghum harvest, the influence of maturity and mechanical harvest rate on the effect of combined harvest was studied. Taking Jinza No.22 sorghum as the research object, the plot experiment scheme was adopted, and three mechanical harvesting rates were set at the milk ripening stage, wax ripening stage and complete ripening stage, respectively, and the mechanical harvesting rates were set at 0.5 m/s, 1.0 m/s and 1.5 m/s, and the indexes such as crushing rate, impurity content, total loss rate and moisture content were measured, so as to obtain the influence rules of mature stage and mechanical harvesting rate on the harvesting effect. The results showed that the maturity stage and mechanical harvest rate had significant effects on the harvest indexes of sorghum, such as impurity content, crushing rate and total loss rate, and the most influential factors on the three harvest indexes were maturity stage. The best results can be achieved when the wax is ripe and the mechanical harvest rate is 1.0 m/s, when the grain moisture content is from 14.756% to 15.746%, the impurity content is 0.14%, the crushing rate is 0.29%and the total loss rate is 5.48%. This study obtained the influence law of mature period and mechanical harvest rate on sorghum harvest effect, which can provide theoretical basis for reasonable selection of mature period and popularization of harvesting technology of sorghum mechanization.

China is a major producer and consumer of fruits, with output and area consistently ranking first in the world. However, China's orchards have long faced complex environments, with traditional manual operations facing high costs, labor shortages, and low efficiency. With the establishment of standardized and large-scale orchards, traditional models are no longer suitable for the development of modern orchards. The multi-functional operation technology platform integrates the functions of picking, ditching, fertilization, spray, transportation, etc., effectively improves the efficiency of orchard operations, saves costs, and becomes the key tool for the efficient development of modern forestry and fruit industry. This article introduces the structural composition and working principle of a multifunctional homework platform, mainly introducing the two key parts of the lifting structure and chassis system, and provide an overview of the development trends of standardized orchard operation platforms at home and abroad, from simple mobile platforms to scalable platforms, followed by a series of improvements such as navigation and automatic leveling systems. By comparing the characteristics and advantages of different types of orchard operation platforms, clarify the shortcomings of domestic multi-functional operation platforms, and summarize and analyze the main research focus of multifunctional operation platforms at home and abroad, focusing on automatic leveling technology In terms of general chassis technology, navigation obstacle avoidance technology, lifting technology, chassis passability technology, power system coordination and management technology, and system quality improvement technology, this paper explores the bottlenecks faced by the development of multifunctional work platforms in China, such as insufficient intelligence and informatization, and relatively lagging policy support. Finally, suggestions are proposed to address the development gap between China's homework platforms and foreign homework platforms, such as promoting standardization and standardization of orchard planting, and developing towards intelligence and informatization, in order to provide development ideas for high-quality mechanized operations in China's orchards.

Intelligent plant protection machinery in large fields is an important means to improve pesticide utilization, enhance the quality of agricultural products, and ensure the sustainable development of agriculture. In order to understand the research status of intelligent plant protection technology and clarify the future development direction, this article focused on three main directions of intelligent operation of high-clearance plant protection machinery: prescription application in large-scale farmland, target spraying on a small scale in land parcels, and variable-speed spraying. From the aspects of perception, analysis, decision-making, and control, the article elaborates on the technical principles of prescription map construction, spatial coordinate transformation methods, and prescription recognition that integrate high-precision satellite positioning, the current level of key technologies for target spraying technology routes and weed recognition, and believed that high-precision spraying based on online prescriptions must be the focus of future research. The article carried out a comparative analysis of the advantages and disadvantages of four speed measurement modes for variable-speed spraying and believed that with the widespread application of satellite positioning in agricultural machinery, satellite-based speed measurement will become the main method of high-precision speed measurement due to its greater versatility, convenience, and accuracy. To explore the current development status of variable spraying control, the article summarized two control methods and implementation methods for pressure-controlled variable spraying. From a comprehensive perspective, pipeline cut-off flow control is the main way to achieve variable spraying, and three control algorithms of segmented control, pulse width modulation, and PID control of flow control were analyzed from the perspective of technical principles, implementation processes, and optimized applications. After the discussion, it is believed that PID control based on machine learning will be an important direction to improve traffic control performance. With the continuous development of artificial intelligence technology, plant protection robots that integrate intelligent perception, analysis and decision-making and autonomous operation capabilities will become the mainstream development direction of plant protection machinery in the future.

In recent years, the improvement of living standards in rural areas of developing countries and the continuous upgrading of rural industrial economy have led to increasingly serious rural sewage discharge. The rural sewage from production and domestic wastewater, agricultural tailwater, and aquaculture wastewater seriously damages the ecological environment, affecting residents' well-being and economic development. This paper points out the limitations of traditional ecological methods and biological treatment methods, such as long treatment cycles, significant environmental impact, and secondary pollution. Furthermore, it further discusses the advantages of plasma technology in treating rural sewage, including its wide application range, high treatment efficiency, and absence of secondary pollution, filling the gap in the application of plasma technology in agricultural wastewater treatment. Although some reaction mechanisms of plasma are still unclear, and the requirements for equipment are relatively high, which still need to be continuously improved. However, in the future, by combining with other technologies, the efficiency and application range of plasma technology can be further improved, enabling it to play a greater role in optimizing and improving the comprehensive treatment process of rural sewage in developing countries.

Fertilizer directly affects crop yield by regulating plant growth and development, and it is an important factor in promoting modern intensive agriculture for high yield and quality of crops. However, urea and urea containing compound fertilizers are prone to produce byproducts such as biuret. Currently, the high content of biuret in fertilizers causes crop toxicity in farmland, which cannot be ignored. Therefore, it is of practical significance to establish an efficient method for detecting biuret in fertilizers, ensuring the safety of fertilizer production and promoting the green and high-quality development of agriculture in China. This research is based on the urgent demand for high-quality fertilizers in the development of modern agriculture in China, and a sensitive electrochemical sensing interface based on carbon-based structural materials is constructed to achieve online and rapid evaluation of biuret in fertilizers and effectively overcomes the shortcomings of liquid chromatography and UV spectrophotometry, such as cumbersome sample pretreatment, high analysis cost, and large sample turbidity interference. During the electrochemical assay, a graphene-nanogold composite is firstly prepared as a sensing interface modification material, which combines the surface characteristics of carbon-based structure with the excellent conductivity of nanogold; Secondly, based on the inhibitory effect of biuret on electrochemical signal of copper ions, a linear regression equation is established for the response current of copper ions with the variation of biuret concentration. With the help of a smartphone obtaining electrochemical signal, rapid electrochemical analysis of biuret is achieved. The experimental results demonstrate that there is a good linear relationship between the response current generated by copper ions and the concentration of biuret in the range of 1-80 mmol/L, with a detection limit of 0.50 mmol/L (S/N=3); The electrochemical sensing system is used for the analysis of biuret in fertilizer samples, and the relative errors between the detection results and those by high-performance liquid chromatography do not exceed 6.9%. Overall, this electrochemical method is applied to the online detection of biuret in fertilizers with high portability, reliability, and accuracy, aiming for technological innovation empowering crops with high yield and quality.

With the large-scale and intensive development of China's aquaculture industry, the discharge of livestock and poultry manure has increased significantly, causing serious pollution to the surrounding atmosphere, soil, water, etc., affecting the survival and health of human beings, and hindering the sustainable development of aquaculture industry. China has issued a series of policies to protect environment and encourage the use of organic fertilizers, encourage the use of livestock and poultry waste to produce organic fertilizers, and replace chemical fertilizers with organic fertilizers. In response to the requirements of national environmental protection policies and solve the problem of livestock and poultry manure treatment, a horizontal fermentation drum for livestock and poultry manure was developed. The drum is helpful for livestock and poultry manure to complete the aerobic fermentation process and achieve the purpose of harmless treatment by mixing livestock and poultry manure with fermentation strains and other auxiliary materials, assistance in heating, aeration and stirring, monitoring the temperature of the material in real time, and the setting of electric heating, the start and stop of the drum and the running time. The structure, working principle and main technical parameters of the roller were described. The technological process of aerobic fermentation of cow manure was designed according to the principle and precautions of aerobic fermentation, and the fermentation performance test of manure horizontal fermentation roller was completed according to the process. The results showed that the organic matter content was 5.2% and the total nutrient (N+P₂O₅+K₂O) content was 5.1%, all of which exceeded the standard values of NY525—2012《Organic fertilizer》. The mortality rate of ascaris eggs and the number of coliform bacteria were both within the standard range of NY884—2012《Microbial organic fertilizers》. The horizontal fermentation roller has the advantages of simple structure, good manure treatment effects, short treatment period, simple operation and economical applicability, and it can meet the harmless treatment and resource utilization of livestock and poultry manure in small and medium-sized breeding enterprises.