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- Abstract：In order to analyze the correlations between yield and energy-related quality traits of stems and leaves, 96 energy sorghum hybrids were taken as study object. Field experiments in complete random block design were conducted in two sites with distinct differences in environmental condition in North China. The coefficients of variation in the measured traits of the 96 hybrids ranged between 3. 7%-61. 3% and 4. 8%-60. 0% in Jiexiu and Zhuozhou, respectively. The coefficient of variation of stem and leaf yield and theoretical ethanol yield were the largest among the studied traits. The stem yield and leaf yield were positively correlated. Concerning the same energy-related quality traits, the majority of those traits were positively correlated, and the theoretical ethanol yield of stem and leaf were positively correlated. It indicates that yield and quality traits stem and leaf can be simultaneously improved to achieve high theoretical ethanol yield. The measured traits can be compressed into four principal components in both sites. The first two principal components are straw yield factor and stem carbohydrate factor in Jiexiu and Zhuozhou site. Overall, the straw yield factor and stem carbohydrate factor are the favorable traits that should be paid more attention to.Keywords：stem yield;leaf yield;theoretical ethanol yield;energy-related traits;correlation analysis2|9|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to define the high yield performance and adaptability of forage oat varieties in different regions, the experiment was conducted to identify and GGE-biplot was used to analyze 20 forage oats from home and abroad and 22 tests site in the main forage oat production areas of all the country from 2017 to 2019. The results showed that: These varieties were divided into four categories: high-yield varieties, high-yielding forage varieties, varieties with longer growing days and higher plant height, and varieties with poor correlation with the above traits. The correlation between the number of spikes per ear and the yield of forage grass is closer, and the correlation between 1 000-grain weight and the yield of grain is relatively closer. G1(‘Bayou 3')and G3(‘Bayan 6')are high-yield and stable product varieties of fresh grass, G11(‘Longyan 3')and G16(‘Caoyou 1')are high-yield for hay and stable. E13(Yanyuan County, Liangshan Yi Autonomous Prefecture, Sichuan Province)and E21(Qitai County, Changji Prefecture, Xinjiang Uygur Autonomous Region)are well represented tests. For the purpose of producing fresh grasses, the most suitable varieties for E1(Baicheng, Jilin Province)and E20(Harbin, Heilongjiang Province)is G2(‘Bayou 18'); the most suitable varieties for E17(Chifeng City, Inner Mongolia Autonomous Region)and E18(Chengde City, Hebei Province)is G14(‘Qingyin 2'); E3(Zhangbei County, Zhangjiakou City, Hebei Province), E6(Chayouqian County, Ulanqab City, Inner Mongolia Autonomous Region), E9(Kelan County, Xinzhou City, Shanxi Province)and E10(Haidong City, Qinghai Province), where the most suitable variety is G11; most suitable varieties is G3 for the other tests. For the purpose of hay production, the most suitable variety for E4(Wuchuan County, Hohhot, Inner Mongolia)is G10(‘GL381'); E3, E6, E9, E10 and E20, where the most suitable variety is G8(‘Yuanza 1'); E18, E14(Taizhou City, Jiangsu Province)and E15(Shannan City, Tibet Autonomous Region), where the most suitable variety is G9(‘Zhangyan 4'); E1, E2(Zhangjiakou City, Chongli district, Hebei Province), E13, E21, E22(Haiyan County, Haibei Tibetan Autonomous Prefecture, Qinghai Province), the most suitable variety is G16; E5(Ulanhot, Xingan League, Inner Mongolia), E8(Huairen City, Shanxi Province)and E19(Tongliao City, Inner Mongolia)do not have the most suitable varieties, and the better varieties are G16, G12(‘Dingyan 2')and G8. This study defined the high yield and adaptability of different 20 varieties in various regions, and provided the basis for the popularization and application of these varieties.Keywords：forage oats;SD-GGE biplot;classification of varieties;division of varieties6|10|5<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The aim of this study was to select suitable planting density for machine picked cotton in South Xinjiang. Cultivar ‘Zhongmiansuo 88' was applied as research material, and six planting densities 90 000(P1), 120 000(P2), 150 000(P3), 180 000(P4), 210 000(P5)and 240 000 plants/hm2(P6), were set in a randomized block experimental design. Different indicators of photosynthetic characteristics and yield were observed under different treatments. The results showed that: With the increase of planting density, the SPAD, Pn, Tr, Gs, Fo/Fm, Fv/Fm, PIabs and seed cotton yield of machine picked cotton displayed the trend of “first rise then fall”, while the Ci showed initially decreased and then increased trend. The SPAD, Pn, Tr, Gs and Fv/Fm of leaves were the highest in P4 treatment at full budding and full flowering stage. The SPAD, Pn, Tr and Gs of leaves were the highest in P3 treatment at full boll stage. The Fv/Fm was highest at P4 treatment. The Fo/Fm was highest in P3 treatment at full bud stage, and was highest in P4 treatment at full flowering and full boll stage. The PIabs sustained the highest in P3 treatment at full budding, full flowering and full boll stage. With the increase of planting density, the boll number per plant decreased significantly. The boll weight per plant and the yield of seed cotton presented a “first increase and then decrease” trend. The yield of seed cotton in P5 treatment was the highest and reached 6 272. 79 kg/hm2, which was 28. 54%, 18. 61%, 3. 87%, 2. 95% and 12. 78% higher than that of P1, P2, P3, P4 and P6 treatment respectively. There was no significant difference with P3 and P4 treatment(P>0. 05). Considering the physiological indexes and yield, it was concluded that the planting density should be reduced appropriately, and the planting density should be controlled within the range from 150 000 to 180 000 plants/hm2.Keywords：plant density;machine picked cotton;photosynthetic characteristics;fluorescence parameters;yield2|9|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to search for the trapping crops that can stimulate the seed germination of Phelipanche aegyptiaca, ethanol extracts were firstly obtained by soaking different plants with different concentrations of ethanol. The ethanol extracts were then extracted by n-hexane, chloroform and ethyl acetate in turn to obtain the n-hexane extract, chloroform extract and ethyl acetate extract, respectively. Seed germination experiments were conducted to determine and evaluate the effect of different plant extracts on the germination of P. aegyptiaca seeds. The results showed that Artemisia dracunculus, Torilis scabra, Artemisia rupestris, Vernonia anthelmintica, and Dracocephalum moldavica can be used as trap crops to stimulate the seed the suicide germination of P. aegyptiaca. The chloroform extracts had the highest germination activity, followed by n-hexane and ethyl acetate. Among all the tested plants, the chloroform extracts of A. dracunculus induced high levels of germination of the seeds(99. 20%)at the concentration of 2. 20×10-2 μg/mL, demonstrating that A. dracunculus is a promising trap crop candidate for P. aegyptiaca.Keywords：Artemisia dracunculus;plant extract;Phelipanche aegyptiaca;seed germination;trap crop1|9|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To evaluate the level of heavy metal pollution in soil and the dietary health risk of melon fruit in a melon producing area, 41 soil samples and corresponding 41 melon fruit samples were taken. ICP-MS was used to analyze the soil, melon fruit and 5 kinds of heavy metal content of Cu, Cd, As, Cr and Ni. Single factor pollution index method and comprehensive pollution index method were applied to investigate the Nemero heavy metal pollution characteristics. The Target Hazard Quotient(THQ)and Total non-carcinogenic risk index(HI)were adopted to investigate the heavy metals in melon fruit for dietary health risks evaluation. The results showed that: The maximum values of Cr, Ni, Cd and Cu in 41 soil samples were all lower than the screening value of agricultural soil pollution risk. The average content of As was 2. 75 times of the risk screening value. The arsenic pollution of 32% of the samples reached the moderate pollution level. The pollution index of Cd maximum value was close to the critical value of mild pollution. The comprehensive pollution degree of all samples was moderate, and the THQ and HI of melon fruit were far less than 1. In conclusion, the soil heavy metal pollution existed in the assessment area, and the main pollution heavy metals were As and Cd. The effects of the five heavy metals on the dietary safety of melon fruits were not high.Keywords：melon;heavy metal;pollution level;health risk1|11|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to analyze the genotype of one Tibetan yak-derived Pasteurella multocida strain isolated and preserved in our laboratory and the biological characteristics of the protein encoded by the rpoE gene, 16S rDNA gene, specific gene. capsule typing, lipopolysaccharide typing, and rpoE gene amplification and other molecular biological and bioinformatics methods were used. The results showed that the genotype of the P. multocida strain from yak was B∶L2∶ST44. The similarity of rpoE gene between the isolate and that from Indian cattle was 100%. The molecular weight of the rpoE protein was 22. 0 ku and the theoretical pI was 4. 86. The protein was unstable without transmembrane structure and signal peptide, and had conservative domain and potential phosphorylation function for intracellular hydrophilic. The secondary structure of α-helix accounted for 67. 02%, the tertiary structure was rod-shaped micro bending model, there were multiple antigen epitopes, the predicted interaction with 10 proteins. In conclusion, this study conducted genotyping and bioinformatic analysis of rpoE gene of a P. multocida strain from Tibetan yaks, which provided references for further understanding the genotype of P. multocida from Tibetan yaks and exploring the biological characteristics of RpoE protein.Keywords：Yak;Pasteurella multocida;genotyping;rpoE;gene;bioinformatics analysis3|15|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The aim of this study was to analyze the whole genome sequence and its functional genes of Lactobacillus plantarum SWUN5815 from yak. Based on PacBio RSII sequencing platform, the whole genome of Lactobacillus SWUN5815 was sequenced and the basic functions of GO, KEGG, COG and NR databases were annotated. The results showed that: 1)The genome size of Lactobacillus plantarum SWUN5815 was 3. 27 Mb, and GC content was 44. 59%; 2)A total of 3 258 coding genes were predicted, with 2 814 147 bp length in total and an average length of 864 bp; 3)According to annotation of the basic functions and metabolic pathway genes on the genome of SWUN5815 through the functional database, there were five genes involved in the antioxidant activity process and two genes involved in immune process in the genome of SWUN5815. The genome contained metabolic processes such as antibiotics and biodegradation. The pathways that can regulate immunity and inflammation were related. There are 18 known genes in the genome and 4 functional sequences of ABC type bacteriocin transport system. In conclusion, the whole genome sequencing of SWUN5815 and the analysis of its specific functional genes were helpful to study its probiotic characteristics, which provided important reference for probiotics as antibiotic substitutes and feed additives.Keywords：Yak;Lactobacillus plantarum;whole-genome sequencing;gene function annotation;bacteriocin2|8|6<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to understand the microbial pollution in the nipple watering system in the layer farms in winter and spring, the bacterial contents in the pipe water and the V-trough on different tiers of the layer house with 8 overlap tiers were continuously monitored to compare the bacterial contamination and its association with laying performance and egg quality traits. The total copy number of bacterial genome 16S rDNA was detected by quantitative real-time PCR. The results showed that there was no significant difference in the 16S rDNA copy number in pipe water among tiers, while the 16S rDNA copy numbers in V-trough were slightly higher in the 3rd and 7th tier compared to the 1st and 5thtier(P>0. 05). The 16S rDNA copy number in the V-trough was 575. 44-32 130. 51 times higher than that in the pipe water(P<0. 01)on each tier throughout the experiment. The laying rate, albumen height, and Haugh unit of chickens were higher in the 1st and 5thtier compared to that in the 3rd and 7th tier, and there was no significant difference in other egg quality traits among tiers. The 16S rDNA copy number of bacteria in the pipe water was weakly and positively correlated with that in the V-trough on different tiers in both winter and spring(correlation coefficient, r=0. 223, r=0. 225). The bacterial content in V-trough was weakly and positively correlated with temperature and air bacterial content, and had significant positive correlation with humidity in winter(r=0. 325). The bacterial content in V-trough was weakly negatively correlated with laying rate and egg quality traits, and had significant negative correlation with Haugh unit and albumen height in spring(r=-0. 348, r=-0. 479). In conclusion, the bacteria content in the V-trough was much higher than that in the pipe water in both winter and spring, and had much higher correlation with environmental temperature, humidity and air quality, which indicated higher potential negative impacts on the laying performance and egg quality of laying hens. It is necessary to strengthen the monitoring of pollution and the control of safety inside V-trough during production.Keywords：layer house;nipple watering system;V-trough;bacteria content;laying performance2|10|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore the pathogenicity of nonreplicating Toxoplasma in mice, nonreplicating Toxoplasma uracil auxotrophs(NRTUAs)were constructed by CRISPR-Cas9. The positive strains were selected by drugs and fluorescence, and identified by PCR. The phenotype of NRTUAs was identified by plaque assay. Mice were acutely infected with NRTUAs. Mice treated with△KU80 strains were used as infection control, while mice treated with PBS were utilized as blank control. The death of mice was recorded daily and the organs were analyzed by histopathology. The results indicated that: 1)NRTUAs were resistant to pyrimidine and chloramphenicol, and the PCR identification of upstream and downstream of the recombinant homologous arm was positive, while the PCR identification of endogenous gene deletion was negative; 2)NRTUAs could grow and produce plaques in the medium containing uracil, but could not grow and produce plaques in the medium lacking uracil; 3)After NRTUAs infection, all the mice survived, and the histological morphology was the same as the PBS group. All the mice in △KU80 group died, and the organs showed serious pathological changes. In summary, NRTUAs strains were successfully constructed in this study, which was not fatal to mice and had no pathological changes in various organs of mice. This study laid a theoretical foundation for the application of NRTUAs as candidate strains of Toxoplasma gondii vaccine in livestock breeding.0|8|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to understand the research advances of regional agricultural ecosystem under the framework of rural revitalization strategy and promote the research and practice of rural revitalization, this study searched WOS and CNKI databases with “agro-ecosystem” as the keyword, and sorted out and analyzed 28 039 English publications from 1996 to 2020 and 11 036 Chinese papers from 1981 to 2020, respectively. The results show that promoting ecological agriculture based on ecological civilization is a hot spot. The focus of relevant research on agricultural ecosystem is deepening constantly by going from macro to micro dimensions, from system as whole to specific elements, and by coupling subsystems together, especially investigating the coordinated development between the agricultural ecological environment system and agricultural economy system. Researches are focused on the combination between system specific elements, which can bring the circulation change of the energy and information. Especially in the agricultural operation mode reviewing, the comprehensive benefits after farmland transfer are reviewed by paying attention to the well-being issues related to the livelihood of farmers on the basis of economic benefits, and studying the ecological benefits of traditional agriculture, e. g. intercropping and three-dimensional agriculture. Finally, the future research development trend of regional agricultural ecosystem is suggested in this study. The regional ecological agricultural management system should be based on ecological agriculture. Macro policy guidance and micro management should be integrated for strengthening the coupling research of production intensification and the ecological intensification of agricultural ecosystem.5|9|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Based on the factor-process-function analysis within the cultivated land system, the framework of the cultivated land health of demand-function-dimension was established and a cultivated land health evaluation index system was built. The comprehensive index method, “1+X” accumulation model and the minimum factor method were applied to evaluate the health status of cultivated land by taking Daxing District as an example for verification. The results indicated that: Firstly, the connotation of cultivated land health was put forward and the cultivated land health evaluation index system was constructed from four dimensions, e. g. potential productivity, cultivated land resilience, production environment and product quality. Secondly, the potential productivity, cultivated land resilience and production environment index of cultivated land in Daxing District ranged from 1 135. 81 to 2 807. 23, 63. 95 to 94. 67 and 0. 40 to 1. 0, respectively. The product quality index of the four dimensions were 100. Lastly, the cultivated land health grades included healthy, sub-healthy and morbidity in the region and no unhealthy cultivated land. Moreover, the cultivated land areas at above three levels were 4 726. 51, 19 333. 12 and 16 754. 94 hm2, respectively. The cultivated land health evaluation results were proved the different across regions. In conclusion, the cultivated land health evaluation index system established in this study can better reflect the actual situation of the region and provide references for the sustainable utilization of cultivated land resources.Keywords：cultivated land health;evaluation;index system;Daxing District3|11|12<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：By using the Penman-Monteith method recommended by FAO and the sensitive curve analysis method, the reference crop evapotranspiration, change law of meteorological factors and contribution of meteorological factors to the change of reference crop evapotranspiration over from 1968 to 2018 of Minqin Station in Gansu National Ground Station were studied. The results showed that: 1)In Minqin Station, the variation characteristics of ET0 in a year showed a parabolic form, which increases from January to May, decreased from August to December, and reached the maximum value of 5. 29 mm/d in July. The annual change of ET0 displayed a trend of fluctuation and increase. 2)Correlation analysis and principal component analysis showed that ET0 had the greatest correlation with Tmax and VPD. By using partial correlation analysis, it was found that the correlation between ET0 and U, Rn-G is the smallest, and the partial correlation between ET0 and U, Rn-G was relatively large, indicating that the relation between ET0 and U, Rn-G was greatly affected by other meteorological factors. 3)The variation trend of meteorological factors was similar to that of the sensitivity coefficient of meteorological factors. The sensitivity coefficient of ET0 to Rn-G was not large. However, due to the large growth range of Rn-G itself, the contribution rate of ET0 to Rn-G was the largest. T and VPD also contributed to the growth of ET0. U had a large negative contribution to the growth of ET0.1|10|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to reveal the influence of rainfall intensity and rock layer tendency on the loss of nitrogen and phosphorus in Karst Trough Valley, a simulation experiment was conducted using artificial rainfall devices and variable slope steel channels. The designed slope was 25°, rock exposed rate was 15%, rock layer dip angle was 30°, and the underground hole fissure degree was 3%. The rainfall intensities were respectively 30, 60, and 90 mm/h, and the rainfall duration time is 1 h. The results showed: 1)The runoff increased with the increase of rainfall intensity. The surface runoffs in descending order was bare slope>bedding slope>reverse slope, and the underground runoffs were reverse slope>bedding slope>bare slope. 2)The concentration of total nitrogen in runoff was the highest under the condition of 30 mm/h rain intensity. The concentration of ammonium and nitrate nitrogen was the highest under the condition of rain intensity of 60 mm/h, while the phosphorus concentration decreased with the increase of rainfall intensity. The concentration of nitrogen and phosphorus reached the highest in the runoff of the slope. 3)The amount of nitrogen and phosphorus loss increased with the increase of rainfall intensity, and the amount of underground loss was higher than that of above-ground loss; under the conditions of different rock formations, the above-ground performances of nitrogen and phosphorus loss in descending order was slope>bedding slope>inverted slope. The performance is inverted layer slope>bedding slope> bare slope; The loss of nitrogen is the most in the inverted layer slope, and the phosphorus loss is the most in the bedding slope. In conclusion, different schemes should be put forward for different rock slopes in terms of water and soil conservation measures and soil quality improvement in Karst Trough Vally.Keywords：Karst Trough Valley;rainfall intensity;bare slope;bedding slope;reverse slope;nitrogen and phosphorus loss4|9|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to research the high-quality agricultural development at a smaller scale, based on the county-level panel data, an evaluation index system was constructed from the five dimensions, e. g. green development, product quality, industrial benefit, production efficiency and scale management. Taking the Yellow River Basin in Shaanxi Province as the research area, the spatio-temporal evolutionary characteristics and impact mechanism of high-quality agricultural development were investigated by comprehensively use AHP-entropy combination weighting method, TOPSIS method and Geodetector. The results showed that: 1)The level of high-quality agricultural development in the Yellow River Basin of Shaanxi Province has increased by more than 5 times from 2003 to 2017, and production efficiency and industrial benefit have been greatly improved, but the level of green development has dropped significantly; 2)The county-level differentiation and pattern change of high-quality agricultural development level are obvious, and its spatial evolution unfolds along the main stream and tributaries of the Yellow River. The high-level areas are located on the periphery of the Xi'an metropolitan area, and expand along the Weihe and Luohe River, then become a whole area in the Guanzhong Plain Region. The low-level area moves inward from main stream of the Yellow River in northern Shaanxi and tends to be dispersed; 3)The spatio-temporal evolution of high-quality agricultural development level in the basin is the result of the interaction of multiple factors. The main influencing factors for the differentiation of development level are per capita arable land, total investment in fixed assets, transportation superiority, urbanization rate and water resources. In conclusion, the high-quality agricultural development should be driven by the high-quality green agriculture, construction of new infrastructure, new urbanization and major projects, precise regional evaluation and countermeasures.Keywords：high-quality agricultural development;the Yellow River Basin in Shaanxi Province;evaluation index system;spatio-temporal evolution;geodetector0|8|17<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to tackle the problem of time-consuming and labor-intensive training samples labelling in deep learning, a semi-supervised image labeling method based on deep learning for edible mushroom was designed. The method effectively combines the object detection model with iterative image labeling, and realizes the semi-supervised image labeling through the iterative operations of “detection model training-automatic object detection-manual labels correction-detection model updating”. Based on this method, a semi-supervised image labeling system was constructed and the performance of the system was tested and analyzed in the experiments. The experimental results show that the detection precision, recall and average precision of the model after iteratively updated achieves 98. 1%, 88. 5% and 88. 3% on the test set, respectively. Using the constructed semi-supervised image labeling system, the labeling speed achieves 15 seconds per image and the labeling time of a single image is only 2. 5% of that of pure manual labeling, which greatly reduces the time cost. The research achievement provided an efficient labeling method and tool for training samples labeling in deep learning study, which is helpful to improve the efficiency of image labeling and reduce labor cost.Keywords：image labeling;deep learning;object detection;edible mushroom;semi-supervised4|57|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Aiming at the problems of small ventilation and low energy efficiency ratio of agricultural axial fans, ATK48HS3P1H agricultural axial fan was taken as the research object. The influence of diffuser angle(φ), length(L), air volume(Q0)and energy efficiency ratio(N)were investigated by means of wind chamber test, reverse modeling and CFD numerical simulation. The results show that: 1)The static pressure recovery coefficient(CP)of diffuser first increases and then decreases with the increase of φ. The wind speed distribution uniformity(γ)of diffuser fluctuates up and down with the increase of φ. The optimized air volume(τ)first increases and then decreases slowly with the increase of φ. The trend of N curve is consistent with that of τ. CP, γ, τ, and N reach larger values at φ=12°. 2)When L=575 mm and φ is between 3° and 25°, τ and N first increase and then decrease with the increase of φ, and better performance is achieved at φ=12°. When φ=12° and L is between 485 and 665 mm, τ and N increase first and then decrease with the increase of L, and reach the maximum at 575 mm. 3)Finally, cross simulation is used to verify that φ=12° and L=575 mm are the optimal parameters of the diffuser. The fan air volume increases by 6. 11% and the energy efficiency ratio increases by 7. 83%. The research shows that the evaluation of diffuser performance should be comprehensively analyzed from four aspects: static pressure recovery coefficient, wind speed distribution uniformity, air volume optimization and energy efficiency ratio.Keywords：agricultural axial fan;diffuser;optimized design;numerical simulation1|9|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to solve the problems that the feed pellets were easy to be broken, easy to have residual remaining, and there was large fluctuation of feeding mass in the feeding bowl during the conveying process, and to improve the throughput of the spring screw feeder, this study analyzed the stress state and conveying mechanism of the feed pellets during the conveying process of the spring screw feeder. Taking the length of the fixed connecting shaft for screw at the inlet feed, the clearance between the screw pipe and the screw blade, the rotation speed as influencing factors, and the feed particle crushing rate, residual rate in the pipe, the throughput and the feeding stability as evaluation indicators, the combined orthogonal tests were carried out on a self-designed spring screw feeder test platform in this study. The results showed that: 1)Screw clearance had a significant influence on the crushing rate, residual rate, throughput and feeding stability(P<0. 05), while the rotation speed and feed shaft length only had a significant influence on throughput(P<0. 05); 2)With the increase of clearance, the crushing rate and residual rate decreased significantly, the throughput and the feeding stability increased significantly; As the speed increased and the shaft length decreased, the throughput was significantly increased. 3)The optimized parameter combination of the spring screw feeder was that the length of the fixed connecting shaft for screw 180 mm, the clearance 4. 6 mm(the inner diameter of the screw tube 46 mm), and the speed 169 r/min. Compared with the conveying performance of the existing spring screw feeder, the overall conveying performance of the optimized spring screw feeder is as follows: the crushing rate was reduced by 84. 7%, the residual rate was reduced by 3. 9%, the conveying capacity was increased by 30. 7%, and the feeding stability was increased by 27. 1%.Keywords：screw feeder;conveying performance;crushing rate;residual rate;throughput;feeding stability5|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Aiming at the problems that laying hens in the rearing period are greatly affected by the environment, easy to get sick, and their body temperatures are difficult to be detected in free-range state, the infrared thermal imaging technology and multiple regression analysis are used to analyze the relationship between the body surface temperature and the under-wing temperature, and to establish a temperature prediction model. The environmental temperature and humidity affect the measurement of the body surface temperature. Therefore, to make sure the body surface temperature collected by the infrared camera can accurately reflect the true temperature of the body, synchronous measurement is carried out to measure the temperatures under the wings and the body surface of laying hens temperature, and the temperature and humidity in the breeding environmentare are also collected. Through analyzing the correlation between the variables, it is found that the variables that can reflect the true temperature of the body, and can be introduced to establish an optimal temperature prediction model. The results show that: 1)The temperature of the feather-covered area and the ambient temperature of the laying hens in the free-range state are collinearity; 2)The average relative error of the multiple linear temperature prediction model is 0. 38%; 3)The average of the multiple nonlinear temperature prediction model, and the relative error is 0. 17%. Inconclusion, the infrared thermal imaging camera can be used to detect the body temperature of laying hens, and the results of the multivariate nonlinear temperature prediction model are more accurate.Keywords：laying hens;multiple regression;infrared thermography;temperature prediction model0|9|3<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To investigates the impact of China's market-oriented grain procurement and storage system reform on the interests of grain processing enterprises, the survey date of 176 grain processing enterprise in China during 2013 to 2016 are analyzed. The results show that: the diversity of market participants have significantly impacted grain processing enterprise operation revenue by raising grain price. Under the impact, the profits of state-owned enterprise are higher than those of private companies, among which the medium-sized enterprise who lose the most interest. In conclusion, the floor price policy should be continued and improved. Meanwhile, the change of the enterprise's operating procedure and deepen reform of China's market-oriented grain procurement and storage system could stimulate the market's vitality.Keywords：grain procurement and storage system reform;grain processing enterprise;operation revenue;two-tier stochastic frontier model0|8|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Based on the improved polygon area method and Thiel index, this study analyzed the mechanization level of staple food grain production(MLSFGP)of China and the level differentiation in eastern, central and western areas from 2003 to 2017. By using quadrant diagram and panel data model, the study also analyzed the spatial-temporal evolution and the driving mechanism of MLSFGP of the 31 provinces in Mainland China. The results showed that: 1)From 2003 to 2017, the comprehensive mechanization rate of staple food grain production increased from 38. 03% to 74. 61% and showed the characteristic of wheat>corn>paddy rice. Wheat had a relative balanced development in its three links of tractor ploughing, mechanical sowing and mechanical harvesting. However, the weak link of mechanization of corn production was mechanical harvesting, and the weak link of mechanization of paddy rice production was mechanical sowing. 2)Intraregional difference among the eastern, central and western areas contributed 71. 28% to the overall disparity of MLSFGP in China, and the difference among the provinces in the western area was much bigger than that of the central and eastern areas. At the same time, the MLSFGP of the western area was far lower than that of the central and eastern areas. 3)Provinces of the leading type and the slowing type of MLSFGP were mainly located in the plain region and the scarcely populated region in western area with abundant croplands, while provinces of the developing type and the lagging type of MLSFGP were mostly located in the mountain region in southwest China and the hilly region of the central and eastern area. As to the mountain region in southwest China, it had both the lowest level and the slowest development speed in mechanization of staple food grain production. 4)The factor of topographic relief had the greatest positive influence on MLSFGP, increasing the plant proportion of wheat and corn could also have an evident positive effect on MLSFGP, while enhancing peasants' income and enlarging their cropland area had relatively weaker positive effect. The labor amount per farmer household had an obvious negative effect on MLSFGP.Keywords：staple food grain;agricultural mechanization;spatial-temporal evolution;regional difference1|9|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore the method of determining crop income insurance premium rate under small sample size, this study constructs a two-dimension information diffusion model with non-uniform distributionm, and the method and steps of calculating income insurance premium rate are designed by using information diffusion technology, and the estimation efficiency of the two-dimension information diffusion model is verified by using Monte Carlo simulation method. The results show that: In the case of small sample size, the two-dimension information diffusion model with non-uniform distribution has better estimation efficiency, and can improve the estimation accuracy of income insurance rate. Taking the corn income insurance in Hebei Province as an example, the net premium rate is 8. 29% by using the two-dimension information diffusion model. In conclusion, the method proposed in this study is helpful to improve the accuracy of rate determination of crop income insurance in the case of small sample size, and is conducive to the high-quality development of income insurance.Keywords：revenue insurance;two-dimension information diffusion model;premium rate calculation1|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The aim of this study is to explore the impact mechanism of consumer perceived value and satisfaction, and their behavior intention to purchase featured agricultural products. From the perspective of consumer behavior of featured agricultural products, this study constructs a structural equation model and mediating effects testing model based on the evidence of donkey meat consumption of urban residents in Shandong and Hebei Provinces. and empirically analyzes the relationship between the perceived value, satisfaction and behavior intention. The results show that: Both the perceived value and satisfaction can significantly promote the purchase behavior intention of consumer featured agricultural products. The emotional value, social value, regional value and green value in perceived value can affect behavioral intention directly, while the functional value acts indirectly on behavioral intention through satisfaction. In conclusion, according to the difference in the impacts of the perceived value on consumer's behavior intention, a diversified propaganda and marketing model should be constructed to stimulate the market demand of consumer featured agricultural products and promote the development of characteristic agriculture.Keywords：featured agricultural products;mediating effect;perceived value;structural equation modeling method7|9|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to clarify the price transmission in the mutton sheep industry chain, based on the monthly data of product prices in the upstream, middlestream and downstream links of mutton sheep industry chain, a vector autoregressive model is constructed in this study. The impact of external shocks on the transmission of the price system of mutton sheep industry chain is analyzed by using impulse response functions and variance decomposition. The results of Granger causality test confirm that feed and live sheep price fluctuation are the cause of mutton price fluctuation rather than vice versa. From the impulse response diagram, under the disturbance of mutton price, feed price, and live sheep price, the response of mutton price reaches the maximum in the current, second period and third period, and then is gradually weakened. The results of the forecast variance show that the live sheep price and mutton price contribute more to the change in the mutton price. At the end of this study, policy recommendations are put forward to improve the existing mutton sheep price emergency mechanism from the perspective of the industry chain, improve the mutton sheep market circulation mechanism, improve the efficiency of price transmission, promote moderately large-scale sheep breeding and promote the vertical integration of the mutton sheep industry chain.Keywords：external shock;mutton price;industry chain;price transmission;VAR model2|8|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
