Transactions of the Chinese Society of Agricultural Engineering, the 1st in Agricultural Engineering, is supervised by China Association for Science and Technology, and sponsored by Chinese Society of Agricultural Engineering. It aims to introduce the latest scientific achievements and developing trends of Agricultural Engineering and provides the academic developments abroad and domestic of the discipline. The scope covers agricultural water-soil engineering, agricultural information and electrical technology, agricultural products processing engineering.
The journal is included in EI, JST, Pж(AJ), CA and CSCD.
Editor-in-Chief Zhu Ming
Deputy Editor-in-Chief Wei Xiuju Zhang Ruihong Xi Weimin Wang Liu Wang Yingkuan Li Pingping Ying Yibin Tong Jin Yun Wenju Zhao Chunjiang Kang Shaozhong
The banana stalks are rich in fiber, and the existing returning machines for banana straw and stubble crushed in China have generated a few problems such as overly severe cutting resistance, the fiber of banana straw winding crushing blade roller on the returning machine, working on the unstable condition and serious power consumption. In order to deal with the above problems which the existing choppers met with in the working process, with the help of theoretical study and the analysis on the planting model for banana in Hainan Province, this paper put forward a returning method that the moving knives on the front knife roller were used to crush banana straws and the flail knives on the back knife roller were used to break stubble under the earth. The rotational direction of stubble crushing roller in the returning machine was same to the forward direction of the machine providing power, while the rotational direction of straw crushing roller was contrary to that of stubble crushing roller. On the basis of establishing theoretical model and the analysis on the planting model for banana in southern China, the key shaped parameters of the sliding-cutting blade and the structural parameters of crushing blade rollers were determined respectively. Besides, the sliding-cutting and anti-twining returning device for banana straw was put forward. The overall structure and working principle of sliding-cutting and anti-twining returning device were described. The performance of crushing banana straw and the power consumption were evaluated by simulating the crushing operation of banana straw in farmland through a bench test driven by double electric motors. The machine is composed of electrical motors, a tractor powered by electricity, the frame of machines, the straw crushing device and the stubble crushing device. Through Design-Expert software, a quadratic orthogonal rotating experiment was performed. Based on the variance analysis and regression fitting, a multiple regression equation was gained, presenting the effects of the working speed of the returning device, the rotating speed of rotating roller of moving knives and the rotating speed of rotating shaft of stubble crushing on the qualified rate of straw crushing and power consumption. It can be seen that the rotating speed of rotating roller of moving knives has the most influential effect, followed by the rotating speed of rotating shaft of stubble crushing, and the working speed of the returning device has the least influence on the qualified rate of straw chopping. The operation condition was optimized by applying the response surface method. The optimum factors for straw and stubble crushing process are as follows. The rotating speed of rotating roller of moving knives is 1 600 r/min, the rotating speed of rotating shaft of stubble crushing is 500 r/min, and the working speed of the returning device is 1.39 m/s. Based on the theoretical analysis, the higher qualified rate of straw crushing was achieved under the faster rotating speed of rotating roller of moving knives. The smaller power consummation is obtained under the lower rotating speed of rotating roller of moving knives and the lower rotating speed of rotating shaft of stubble crushing. Under the optimal condition, the corresponding qualified rate of straw crushing and power consumption are 95.2%, and 4.96 kW, respectively. The differences between the experimental and the analytical values of the qualified rate of straw chopping and power consumption are 0.31 percentage points and 0.27%, respectively, which indicate that the software analytical value is in great agreement with the experimental value. And by field test, the qualified rate of straw crushing of machine proposed in this paper is higher by 1.94 percentage points and the power consumption is lower by 11.3%, compared with vertical flail banana stalk crushing machine. Its successful implementation can greatly improve the production efficiency for crushing banana straw and stubble on one hand, and on the other hand prevent the pollution brought by deserted banana straw putridity.
There is a problem that subsoiling shovel tips are poor in wear resistance and lose effectiveness frequently. In order to solve the problems of poor wear resistance and frequent failure, Fe-Cr-Ni alloy coating was prepared on 45 steel substrate using flame spray welding process. And the spray welding coating has been quenched using the specimen residual temperature. The quenching temperature was 800 °C. The microstructure, composition and phase of alloy coating were analyzed by scanning electron microscope, energy dispersive spectrometer, and X-ray diffraction. The microhardness was tested by microhardness tester. The wear properties were tested by soil abrasive wear testing machine. The results sho that the coating zone, binding zone and substrate zone are obvious, metal interpenetration phenomenon is found in binding zone, and metallurgical bonding can be achieved between the coating and substrate. The good metallurgical bonding can be obtained between the coating and iron substrate. The alloy coating consists of carbide Cr
7C
3 and Cr
23C
6, boride Fe
2B, (Cr,Fe)
7C
3 and solid solution γ-Fe(Cr,Ni,C,Si) and (Fe,Ni). On the effect of oxygen and acetylene hot resource, the Fe and Cr elements in the alloy are heated to molten state, and then Fe, Cr and C, B are combined to form carbide and boride. As the role of the austenite stable element Ni, there is γ-Fe(Cr, Ni, C, Si) solid solution formed in the coating, which is helpful to reduce the brittleness of the spray welding layer. Compared with the unquenched coating, the microstructure of quenched coating is refined, and the hard phase is shown as rectangular block, lozenge block and ball block, whose size is from 5 to 20 μm. The microhardness of the quenched coating can reach up to 900 HV, and the average microhardness is about 800 HV, increased by about 100 HV compared with the unquenched coating. The contrast tests were carried out between quenched coating, unquenched coating and 65Mn subsoiling shovel tip. The average wear loss of quenched coating is about 0.30 g, that of the unquenched coating is about 0.35 g, and the average wear loss of 65Mn subsoiling shovel tip is about 0.50 g, about 2 times as much as the quenched coating. After carrying out field test, the wear loss of subsoiling shovel tip with quenched coating is 32 g, and 65Mn subsoiling shovel tip is 70 g. As shock cooling effect of quenching, alloy elements transfer is difficult, which is not conducive to the growth of carbide. As a result, the carbides are refined. Furthermore, the supersaturated solid solution of carbon is formed owing to diffusion failure of some carbon elements. The supersaturated solid solution leads to the increase of dislocation density, the lattice distortion, and the hardness increase. The dispersion distribution of hard phase Cr
7C
3, (Cr,Fe)
7C
3, Cr
23C
6 and Fe
2B is obtained on the softer substrate. The hard phase plays a role of increasing the energy consumption of the abrasive, and reducing the cutting and ploughing effect of abrasive grains on the coating surface. The hard phase, supersaturated solid solution and Fe, Ni are fused together, showing alternate distribution. The substrate metal with good toughness has good bonding effect on hard phase. There is good wear resistance for quenched coating. The spray welding coating is quenched using the coating residual temperature successfully. The cost of quenching process is low and the efficiency is high. The process is convenient and flexible, which can meet the needs of the subsoiling shovel surface strengthening and practical application.
To promote farmers’ participation in rural residential land consolidation, the research of discussing the mechanism of farmers’ participation in rural residential land consolidation and identifying the factors affecting farmers’ participation behavior should be carried out urgently. Specific mechanisms of some influence factors causing farmers’ different participation behaviors could not be explained well, when farmers’ different participation behaviors in different consolidation stages were considered as an entire party. Therefore, based on rural residential land consolidation stages, farmers’ participation behaviors were divided into four types in this paper: general participation, decision-making participation, construction participation and late management and protection participation. The questionnaire was designed to investigate farmer basic information, farmers’ different participation behaviors, and the environment of the villages. To guarantee the representativeness of the sample, three to four resettlement areas, in which land consolidation had been completed, were chosen in every district/county. The total number of valid farmer questionnaires was 531 from two cities in northern and southern Jiangsu Province, which involved 25 villages in five districts/counties. From June to August in 2016, face-to-face investigations were conducted with farmers by random sampling. Based on the micro-survey data, binary logistic regression models by Stata 12.0 software were used to explore the influence factors of farmers’ different participation behaviors in different rural residential land consolidation stages. The results indicated that: 1) Farmers’ cognition of consolidation content, health condition, government support and local economic level had significant impacts on farmers’ general participation, while the factors like gender, education years, cognition of participation ability and social identity, which should significantly affect farmers’ participation behaviors theoretically, exerted no significant influence in the model. 2) There were significant differences between the factors that significantly affected farmers’ participation in different rural residential land consolidation stages. And factors such as gender, social identity and social relation network had significant effects on farmers’ particular participation behavior, but the effects were counteracted at general participation level. It was the reason why they had no significant effect on farmers’ general participation behavior. This finding fully demonstrated the necessity of analyzing farmers’ participation in different stages. 3) Despite factors affecting farmers’ participation behavior in different stages differed, farmers’ cognition of consolidation content, cognition of participation ability and government support influenced most types of farmers’ participation behaviors significantly. 4) Family income and education years had no significant impact on any type of farmers’ participation behavior. It implies that constraints brought by low family income and educational level are no more the key factors that reduce farmers’ participation motivation. Consciousness of rights will be the new incentive instead. And the awakening of consciousness of rights depends on the construction of the external systems and policies. According to these results, it is suggested that differential policies should be made to encourage farmers participating in the entire consolidation process. Enhancing farmers’ ability to participate, improving participation process and constructing external institutional environment should be the priorities of policy-making in the foreseeable future. This study can provide a more comprehensive and accurate guidance for promoting farmers’ participation in rural residential land consolidation.
The study on spatial heterogeneity of the early-warning status of cultivated land system security (CLSS) and its driving factors at county level plays an important role in accurately identifying the early-warning status of the CLSS and scientifically formulating the protection plan of cultivated land system. The purpose of this study was to explore and identify spatial heterogeneity characteristics of the early-warning status of the CLSS and its driving factors in Heilongjiang Province, which is located in main grain producing area of Northeast China. In the paper, exploratory spatial data analysis (ESDA) was used to identify spatial heterogeneity characteristics of the early-warning status of CLSS in 72 counties of Heilongjiang Province, and ordinary least squares (OLS) and geographical weighted regression (GWR) method were employed for exploring driving factors of the spatial heterogeneity of the early-warning status. The results were as follows. 1) The early-warning level of CLSS was relatively high in the counties of Heilongjiang Province on the whole. Of the 72 counties, 69 counties were in the early-warning status, and 28, 32, and 9 counties were low-level warning, medium-level warning and severe-level warning, respectively. 2) The spatial distribution of the early-warning status showed obvious heterogeneity and agglomeration characteristics in the study area. The severe-level warning areas were mainly found in the southeast and west of the region, while the secure and relatively secure areas were mainly concentrated in the north-south axis belt areas. The counties with positive spatial autocorrelation (high-high type and low-low type) emerged with the “clusters” and had a powerful agglomeration. The counties with negative spatial autocorrelation (high-low type and low-high type) were few and showed sporadic distribution. 3) Twelve variables were preliminarily selected for exploring the driving factors of the early-warning status by OLS model, and nine variables, including three natural-ecological factors (slope, elevation, and average annual temperature) and 6 socioeconomic factors [per capita GDP (gross domestic product), urbanization level, investment in agricultural fixed assets, water–soil coordination degree, agricultural waste index, and road network density] were determined for further analysis by the GWR model. The regression results by GWR model and ArcGIS spatial analysis showed the natural-ecological factors, including terrain and climate, and socioeconomic factors, including the land input-output, land-water resources allocation, had significant effect on the early-warning status of the CLSS. Moreover, the regression coefficients of these driving factors showed the significant spatial heterogeneity characteristics. In conclusion, the study on spatial heterogeneity of the early-warning status of the CLSS provides a reference for accurately identifying the spatial distribution of the early-warning status in Heilongjiang Province. Compared with OLS model, the GWR model visualizes the non-stationary characteristics of driving factors of the spatial heterogeneity of the early-warning status of the CLSS, which can be more intuitive and in-depth to explore the spatial difference of the effect of each driving factor on the early-warning status, and provide a scientific basis for formulating appropriate measures to mitigate future threats of the cultivated land system.
