To investigate feasibility of applying mechanized cultivation mode to tomato product in Chinese solar greenhouses of Shanxi Province, a mechanized cultivation mode was developed to replace labor-intensive manual tasks involved in traditional product method．Under mechanized cultivation mode, mechanization level of solar greenhouses was increased from 38.5% to 73.3%．Labor consumption was saved by 113.10 working-day/hm²．The change in net present value was calculated as 29281 yuan/hm²．These findings demonstrated that it was feasible to apply mechanized cultivation mode to tomato product in solar greenhouses of Shanxi Province．Moreover, this mode could offer a potential solution to challenges arising from increased labor shortage and costs in future．

At present, important role of harvest mechanization technology is rapid growing in process of soybean production in our country, and it is of great significance to promote revitalization of soybean industry in China and protect safety of national grain and oils．Important role of harvest mechanization technology in process of soybean industry revitalization was systematically expounded, present situation and constraints of mechanized harvesting of soybeans were analyzed, developing trend was discussed, development countermeasures in China were put forward, which would provide a scientific basis for soybean harvest mechanization technology development, and had a certain reference value for soybean industry revitalization and sustainable development of soybean production in China．

In order to solve problem of header profiling in fresh corn harvester which reaping both corn stalk and spike, an adaptive profiling system for header of fresh corn harvester was developed based on principle of ultrasonic ranging．In this system, ultrasonic ranging sensor was installed in the front end of header divider, which was used to detect height difference between header divider and ground in real time．Height difference signal was transmitted to central control terminal of corn harvester, which issued corresponding adjustment instruction, controlled header adjusting hydraulic system to adjust header height, and realized adaptive profiling of corn harvester's header during operation．The 190 kW four-line all-harvesting fresh food corn harvester was used as a prototype, and adaptive profiling system of header was carried out to verify profiling system．Average operating speed of corn harvester was 4 km/h, rotation speed of cutting table was 400 r/min, and stubble height was from 90 mm to110 mm．Test results showed that in whole process of 8 hours of cumulative operation, header adjustment was stable and there was no contact with the ground．Experimental results verified effectiveness of header adaptive profiling system．

Aiming at difficulty of agricultural keyword extraction in domain text, an agricultural keyword extraction method was proposed, which combined new word discovery and improved TextRank algorithm．The algorithm calculated word formation probability of words in text through information entropy to find domain proper nouns and new words, and expanded word segmentation dictionary through manual audit．Based on word segmentation dictionary, calculation method of TextRank algorithm node value in the construction of word graph was improved, word position and part of speech weight were added, and comprehensive weight of words was used to extract text keywords．Through experimental comparison, F value of this algorithm was 7.5% higher than traditional TF-IDF algorithm on average, and 9.8% higher than TextRank algorithm on average．The algorithm had certain practicability．

A solution has been proposed for green heating in winter in plastic greenhouses with rear wall in the north．This system is a typical "internet plus" facility agriculture intelligent control system．Its network architecture consists of bottom sensor network layer, middle convergence layer and top service application layer, which can realize remote monitoring．The system used solar collectors to heat the air in daytime and transmit hot air to ground through pipeline circulating pump．It used heat exchange principle to make soil warm and store energy, and slowly released heat energy at night to solve problem of heating plastic greenhouse with rear wall in the north in winter．In case of continuous overcast days, late spring cold and other conditions, electric and geothermal auxiliary devices could be started to maintain temperature in the shed．Compared with existing greenhouse intelligent system in the north, this scheme has characteristics of green environmental protection, energy saving and consumption reduction．

With implementation of policies for national, local, and temporary storage of corn, planting area of corn has significantly increased, and yield of corn straw has also increased．Corn straw contains abundant crude fiber, organic matter, and nutrients such as nitrogen, phosphorus, magnesium, potassium, and calcium required for plant growth．Implementing straw returning to field can effectively enhance soil fertility, improve soil physical and chemical properties, promote black soil protection, promote sustainable land use, and promote sustainable agricultural development．Main methods of returning straw to field include direct return and indirect return．Selection of land return methods should be tailored to local conditions, and selecting appropriate land return methods based on soil conditions can effectively protect farmland environment．Characteristics of different straw returning methods were introduced, impact of straw returning on soil environment was analyzed．It could provide scientific basis for selecting straw returning methods according to local conditions and sustainable agricultural development paths．

Using cow manure as main raw material, kitchen waste, corn stalk, vegetable waste, and vegetable waste fermentation sieve residue as auxiliary materials for mixing, a self-made fermentation reactor was used for forced aeration aerobic fermentation to compare impact of different excipients on quality change and composting effect of dairy manure fermentation process．A total of 6 treatments were set up in experiment: CK was cow manure, T₁ was cow manure+sieve residue, T₂ was cow manure+kitchen waste, T₃ was cow manure+kitchen waste+sieve residue, T₄ was cow manure+vegetable waste, T₅ was cow manure+corn stalk．Results showed that duration of high temperature period above 55 °C for CK, T₁, T₄, and T₅ reached 5 days, meeting requirements of aerobic fermentation for number of days of high temperature period, while T₂ and T₃ were less than 5 days, of which T₃ did not reach a high temperature above 55 °C, and average temperature of T₅ during high temperature period was 62.8 °C．After fermentation finished, water content loss rate of material was from 27.08% to 47.39%, and T₄ treatment had the highest loss rate．The pH range was from 8.15 to 8.84, and only the pH of CK and T₃ treatments was less than 8.5．Organic matter loss rate ranges from 9.19% to 17.28%, with T₅ being the highest．Total nitrogen, total phosphorus, and total potassium of each treatment were higher than initial content, and T₁ and T₄ could significantly improve total nutrient content of material．Contents of heavy metals As, Pb, and Cd after fermentation were lower than those before fermentation, while contents of Hg and Cr were on the contrary．Especially, attention should be paid to excessive Cr content after fermentation of cow manure．Mixed fermentation of cow manure and corn straw/vegetable waste could effectively improve quality of compost．

Used the minimum temperature data from April to May of 1960 to 2022 of Zhidan weather station and temperature observation data of regional weather station and orchard weather station from October 2021 to May 2022, field investigation, mathematical statistics, random forest regression, and natural breakpoint method were used for temperature statistical analysis and Zhidan apple flowering freezing damage risk zoning．Results showed that apple freezing damage in Zhidan mainly appeared on April 11-17, 24-26 and May 13-15, and appeared the most frequently on April 11-17．Average freezing weather was about two years．Extreme minimum temperature of apple flowering period was low in the 1960s, 1970s, 2000s and 2010s, and freezing damage was serious, while extreme minimum temperature of apple flowering period was highed in the 1980s and 1990s, and freezing damage was light．Valley land, due to accumulation of cold air, low temperature, and high risk of freezing damage, was not suitable for planting apples．When altitude was from 1200 to 1430 m, temperature changed sharply, and risk areas of heavy, medium, and light coexisted．When altitude was above 1430 m, and risk of freezing damage was relatively low．At present, about 67.2% of orchards in Zhidan were light risk areas, 25.3% were medium risk areas and 7.5% were heavy risk areas．Planting structure of orchards in heavy risk area should be adjusted, and orchards in medium risk area should strengthen prevention of freezing injury．

Under support of information technology, great changes have taken place in agricultural production．With information technology, agricultural production has gradually realized development of intensification, high efficiency and intelligence．Based on this background, a long-stroke integrated water and fertilizer spraying device driven by intelligent tracked vehicle was designed, which included intelligent motor, flox coupling, support plate, sprinkler head, speed sensor and other components．At the same time, an efficient control system was designed．The whole system included homepage system interface, monitoring system interface, data display interface, real-time parameter interface and other parts．And real-time monitoring of GPS, fertilizer EC value, pH value and other information, real-time monitoring of surrounding environment changes, at the same time will be transmitted to control terminal real-time data, to achieve purpose of remote control．Through control system, constantly adjusted fertilizer ratio and spraying speed according to environment, to make growth of entire crop mechanized and intelligent．

In order to alleviate contradiction between supply and demand of Isatis indigotica planting water resources in Hexi Oasis, solve problem of extensive irrigation decision-making in irrigation process, and improve efficiency of irrigation water use, by referring to Jensen model, water balance equation, etc., according to environmental characteristics of drought and little rain in the Hexi Oasis and growth law of different water consumption intensity in each growth period of Isatis indigotica, an irrigation decision-making model of Isatis indigotica was constructed and genetic algorithm was used to solve reasonable allocation of limited water resources in Isatis indigotica irrigation．At the same time, considering constraints of irrigation water volume, effective precipitation, irrigation cost, yield and other factors in each growth period, under guidance of insufficient irrigation theory, genetic algorithm was used to optimize irrigation decision with existing Isatis indigotica planting data to achieve goal of water saving, high efficiency and high yield．Optimization results showed that slight water deficit of fleshy roots could significantly improve efficiency of irrigation water use, which was consistent with actual planting irrigation situation．

In order to explore comprehensive impact of drought occurrence and development process on photosynthetic characteristics and water use efficiency of cotton at the leaf scale under mulch drip irrigation in the key period of cotton, five drought simulation experiments with different water gradients were carried out to analyze effects of drought occurrence and development with different intensities on cotton photosynthetic characteristics and water use efficiency．Results showed that photosynthetic characteristic parameters（net photosynthetic rate, stomatal conductance, transpiration rate, intercellular CO₂ concentration）of leaves increased first and then decreased with advance of growth process．After 9 days of gradient water control, each treatment entered a different drought development process, and photosynthetic characteristic parameters of each treatment decreased in turn．Drought stress did not change trend of water use efficiency of cotton leaves．Water use efficiency of cotton leaves under five different gradient water treatments showed an upward trend during flowering and boll stage, but its change was not regular．Research results could provide theoretical basis for accurate evaluation of cotton drought degree and dynamic monitoring of drought occurrence and development．

In order to reveal effects of natural factors and their interaction on temporal and spatial changes of vegetation in Kaidu River Basin, using NDVI as research index, combined with 11 natural factors, using linear regression analysis method and geographic detector model, temporal and spatial variation and its driving forces of NDVI in the Kaidu River Basin from 2001 to 2020 were analyzed．Results showed that NDVI in study areas showed an increasing trend, middle and high vegetation cover areas improved significantly from 2001 to 2020．The NDVI was high in the west and low in the east, transformation of low and middle vegetation cover to middle and high vegetation cover was obvious．DEM had the highest explanatory power（40.3%）, it dominated spatio-temporal pattern of NDVI． Natural factors had interactive effects on NDVI, especially interaction between soil type and slope had the strongest influence．The mode of interaction was dominated by bivariate enhancement and nonlinear enhancement effects．Range and type of factors suitable for vegetation growth in the study area was analyzed, which could provide useful reference for local vegetation restoration measures．

In order to understand pollution of soil heavy metals in agricultural land in mountainous areas and identify pollution sources of eight kinds of heavy metals, 1311 samples of soil surface（0-20 cm）were collected in the study area, and pH, As, Cd, Cr, Cu, Hg, Ni, Pb, Zn were tested and analyzed．Nemerow comprehensive index method, geostatistics method, correlation analysis, one-way analysis of variance and positive definite matrix（PMF）model were used to study characteristics and possible pollution sources of heavy metal pollution in agricultural land in mountainous areas．Results showed that contents of eight heavy metals in the soil of study area were significantly higher than background value of soil in Chongqing．Except for heavy pollution in some areas, soil in the study area was generally clean or slightly polluted, and main polluting element was Cd．PMF model results showed that there were three main sources of soil heavy metal pollution in the study area, namely natural parent material source（Cd, Cr, Cu, Ni, Pb, Zn）, mining activity source（As, Cr, Hg, Pb, Zn ）, source of agricultural activities（As, Cd , Cr, Hg ）．

In order to solve problems of low efficiency and high cost of Codonopsis pilosula manual excavation, a four-bar mechanism Codonopsis pilosula excavation device was designed based on human simulation．Simplified model of soil- Codonopsis pilosula excavation device was established by means of Proe, simplified model of soil- Codonopsis pilosula - excavation device was established by means of discrete element simulation software EDEM and multi-body dynamics software Adams．Through ADAMS_ EDEM conducts simulation excavation experiments, range of rotational speed and soil entry angle was determined when resistance was low．SAS software was used to carry out optimum balance random design test for rotational speed and soil entry angle, and soil trench excavation test was verified．Simulation results showed that the better range of earth angle was from 75° to 80°．The optimum speed range was from 60 r/min to 90 r/min．Excavation test results showed that when the best combination was 70 r/min and 75° by final analysis, loosing rate of codonopsis pilosula was 97.94%, damage rate was 4.52%．The next was 60 r/min and 75°, loosening rate was 96.62% and damage rate was 5.7% ．

In order to improve utilization rate of crop straw, a kind of straw picking and crushing machine was designed which was suitable for multiple regions, especially for straw returning or collecting in the northwest arid region．The all-in-one machine included picking up device, crushing device and conveying device．Three devices installed on the same frame to improve stability of whole machine．SolidWorks software was used for solid modeling, ADAMS software was used for kinematic simulation of the model, by controlling pick up speed ratio to change movement trajectory of pick up roller, so as to obtain speed range of pick up roller with the best effect．EDEM software was used to establish straw-soil-machine interaction discrete element simulation system, and optimal speed of picking roller was deduced by comparing forward resistance of cutter roller in multiple simulation groups．Results showed that when forward speed of implement was 1 m/s and speed of knife roller was 1140 r/min, picking speed ratio was 15.73 and straw picking rate was α= 92.14%, at this time, resistance encountered by swinging knife during forward process was the smallest, and the machine has the best picking effect on scattered straw, with the lowest work energy consumption．

Scientific, technological and large-scale afforestation is one of the ways to effectively curb desertification, and the tree planting equipment in current market has a single function, is too large, and wastes a lot of manpower and material resources．In order to solve this problem, a desert independent tree planting and watering equipment based on SolidWorks 3D software was designed, and mechanical part of equipment used Ansys Workbench software to perform static simulation analysis of equipment frame when water tank was fully loaded and unloaded, and motion simulation of film cutting device using Adams software to ensure rationality of the design．Control part used C language programming and STM32 F103ZET6 microcontroller to develop and establish a complete control system of the equipment．On this basis, the use of mechanical manufacturing, 3D printing and other technologies to complete processing of parts of each device, and build desert independent tree planting and watering equipment．The equipment could independently complete drilling, seedlings, watering and film laying process．Results showed that equipment has good performance and complete functions, and planting efficiency could reach 65 saplings with height from 30 cm to 40 cm and diameter from 1.5 cm to 3.0 cm．

Press roll is a key part of counterroll granulating machine, and shape of its teeth has a direct influence on its performance．Aiming at problems of insufficient material extrusion and poor forming effect of connected gear type of counterroll granulating machine, an improved scheme of broken gear type of press roll structure was proposed．Simulation test of pelletizing process under two kinds of press rollers was carried out by using discrete element software．Results showed that thextrusion effect of broken gear press roller was better than that of continuous gear press roller．The optimal speed range was from 20 rad/s to 25 rad/s through simulation analysis of speed of broken gear counterroll granulating machine．Discrete element was coupled with finite element to analyze stress and deformation of press roller with broken gear under extrusion speed of 25 rad/s, and then nCode software was used to predict stress fatigue of press roller．Results showed that the maximum stress of press roll was 72.279 MPa and the maximum deformation was 0.835 mm, both of which met design requirements of strength and stiffness．The life of die hole was the smallest when gap between two press rolls was the smallest, and fatigue damage was more likely to occur．

At present, cassava mainly relies on manual peeling, which is labor-intensive and inefficient, and can easily cause cassava to spoil．In order to overcome this obstacle, a clamping type cassava peeler was developed by comprehensively considering working principles and structural design of relevant mechanisms, and taking into account characteristics of cassava tubers themselves．Transmission system was designed through design parameters and requirements, a simplified model was established, and force analysis and calculation of clamping mechanism and peeling mechanism were carried out based on relevant theories．At the same time, a static analysis was conducted on key components of peeling machine to ensure that stability and safety of peeling machine meet design requirements．

Restricted by type of schools, agricultural and forestry graduates often have some difficulties in finding jobs, such as few job choices and low employment quality．Smart car competitions can help students master professional knowledge and skills．As a national competition integrating technological innovation and theoretical innovation, smart car competition can effectively improve employment level and competitiveness of students by participating in smart car competition．In order to promote students' good employment and employment through smart car competitions, it needs joint efforts of students, universities and society．It also need to actively carry out innovation and entrepreneurship education, strengthen ideological and political theory construction and accelerate construction of competition platforms in daily teaching．

With development of science and technology, especially development of computer technology, it is possible to use computers as tools to study characteristics of real systems．Development of hydraulic simulation technology provides a good technical means for practice of the course "Hydraulic and Pneumatic Transmission"．Taking hydraulic system of harvester header as an example, application of AMESim simulation technology in practice of hydraulic and pneumatic transmission courses was introduced through header system analysis, hydraulic circuit design, AMESim modeling, and header lifting process simulation．This could provide a new method for practical reform of hydraulic and pneumatic transmission courses．

Academic self-efficacy could reflect learning and psychological state of college students, it is an effective indicator to predict and has influence to academic achievement and competence quality of undergraduate students．Developing strategies to enhance academic self-efficacy according to characteristics of different majors is more effective than general cultivating methods．Unique characteristics of agricultural engineering majors were analyzed, then academic self-efficacy enhancement strategies and specific measures were formulated, and effectiveness of these measures were finally verified through teaching practice．It could provide reference for cultivation of academic self-efficacy among students majoring in agricultural engineering．

Crop cultivation is a comprehensive and practical applied discipline, and it is the most basic and most important part of agricultural science．Under background of rural revitalization strategy, problems and contradictions existing in "Crop Cultivation" course in higher vocational colleges were analyzed, and teaching reform goals and methods of crop cultivation course was proposed．It aims to cultivate a group of high-quality and skilled agricultural talents for society and help rural revitalization．

After years of exploration, fertilizer reduction technology in dry farming area of Yuzhong County, Gansu Province has gradually matured, and has been demonstrated and promoted in major crops, providing scientific data support and precise and strong technical support for fertilizer reduction and efficiency improvement in Yuzhong County．From balanced regulation of nitrogen, phosphorus, and potassium fertilizers to precise formula fertilization according to demand, and then to integration of fertilizer reduction and efficiency enhancement technology through increasing application of organic fertilizers to replace（reduce）fertilizers and improving traditional fertilization methods, from 2018 to 2022, cumulative promotion area in major crops such as vegetables, corn, potatoes, wheat, lilies, and traditional Chinese medicine was 866700 hm², with an additional net income of 1.283 billion yuan．Through experiments with different amounts of organic fertilizer for Songhua vegetable, results showed that yield of Songhua vegetable increased with increase of commercial organic fertilizer usage, and commodity rate increased from 46.73% to 50.33%．Through experiments with different amounts of bio organic fertilizer for cabbage results showed that after using bio organic fertilizer and reducing amount of fertilizer by 20%, total phosphorus, dietary fiber, and calcium content of commercial cabbage decreased significantly compared to control, while vitamin C content increased in all treatments．This indicated that cabbage has a more fragrant taste, richer nutrition, and improved quality．The recommended optimal amount of bio organic fertilizer was 3 t/hm², with a maximum reduction of 20% in chemical fertilizer．

To explore practical application of wood vinegar in biological control of plant diseases and its impact on respiratory function of pathogenic fungi, experiment used mycelial growth rate method to determine its antibacterial activity against 7 plant pathogenic fungi, and studied its impact on key enzymes of tricarboxylic acid cycle and energy metabolism of sensitive strain Fusarium culmorum tested．Results showed that wood vinegar had a certain inhibitory effect on 7 kinds of plant pathogenic fungi tested, among which Fusarium culmorum, a sensitive strain, showed the most significant inhibitory effect．Its EC₅₀ value was 4.98 μL/mL, and when concentration was 5.5 μL/mL, inhibition rates of spore germination and biomass by wood vinegar were 90.09% and 95.22%, respectively．After wood vinegar treatment, respiration rate of Fusarium culmorum was inhibited, activities of SDH and MDH decreased, content of ATP decreased, ADP and AMP increased first and then decreased, and energy charge level decreased, indicating that wood vinegar inhibited respiration and metabolism of Fusarium culmorum．It hindered normal operation of tricarboxylic acid cycle, interfered with its energy metabolism, and led to dysfunction of fungal somatic cells．It has been preliminarily proved that wood vinegar ccould achieve its antifungal effect mainly by destroying respiration and metabolism of fungi．

Dense planting of apple orchards with dwarf rootstocks has become world apple cultivation development trend．However, apple root system under such planting pattern is shallow and the trees are easy to fall down．Trellis（struts）are needed to stabilize the tree．In addition, during process from flowering to ripening, hail often occurs, which seriously affects yield and quality of apples．Building hailstone proof nets is an effective hail prevention measure．An improved " integrated supporting and hail proof net " system was designed, which combined trellis and hailstone proof net．Structure, construction materials, erection, maintenance and cost of new trellis system were briefly analyzed in order to provide reference for design and construction, cost saving, system management and maintenance of "trellis–hailstone proof net " in apple orchard．

Taking selenium rich tea industry in Ankang City, Shaanxi Province as research object, current development status of selenium rich tea industry in Ankang City was introduced from five aspects: industrial scale, private economy, brand value, scientific research and development, and tea tourism integration．SWOT analysis method was used to comprehensively analyze market competition conditions and environment of selenium rich tea industry in Ankang City from four dimensions: policy support, economic foundation, social background, and technological strength．And countermeasures and suggestions for technological, branding, market-oriented, and sustainable development of selenium rich tea industry in Ankang City were proposed from three levels: government, industry, and enterprise．

Influencing factors of agricultural modernization development in Shaanxi Province were analyzed, and an indicator system was constructed based on actual development of agricultural modernization in Shaanxi Province from 2001 to 2020．It was found that development of agricultural modernization in Shaanxi Province was mainly affected by two major components: agricultural input and output and rural development（FAC₁）and agricultural governance（FAC₂）, and they had a significant impact on the farmers' net income per capita（Y₁）and the Engel coefficient of rural households（Y₂）, which were related indicators of agricultural modernization development．Marginal effect of FAC₁ on Y₁ and Y₂ was constant, while marginal effect of FAC₂ on Y₁ and Y₂ increased first and then decreased．And suggestions were put forward to promote development of agricultural modernization in Shaanxi Province．