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- Abstract：In view of how to more scientifically and accurately detect transgenic plants, a comparative research method is used to study the detection methods and standardization of transgenic plants in China and abroad. The results show that: 1)There are three detection aspects for transgenic plants and their products, which including component detection, environmental safety detection and food safety detection; 2)At present, the detection methods of transgenic plants in China and abroad are at an advanced level. However, it still needs to be updated with the continuous emergence of transgenic plants and products; 3)In order to ensure the long-term effective safety supervision of transgenic plants and their products in China, it is necessary to coordinate the detection methods development of transgenic plants with its standardization and safety management. In conclusion, the detection technology and standardization of transgenic plant still need to be continuously developed and innovated to provide more powerful technical guarantee for the national safety supervision of transgenic products.Keywords：transgenic plants;detection approach;standardization9|9|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Biotech/GM crops have always been a social controversy topic from the scientific debate of scholars to the safety concerns of general public. Based on the data of ISAAA, the development of global biotech/GM crops was summarized systematically from the aspects of field trial, approved for commercialization, commercial cultivation and GM product import, and so on, in order to show objectively the development of global biotech/GM crops in the past decades and provide an all-round overview of the development of global biotech/GM crops. A large number of field trials and strict approvals of biotech/GM crops indicated the cautious attitude and biosafety system of different countries. The increasing of biotech/GM crops in areas, varieties, traits and countries accepting GM products showed that the development of biotech/GM crops and GM products has become an irresistible trend. In the future, with the improvement of biosafety system and the correct popularization of biotech/GM knowledge, the awareness environment for the development of biotech/GM crops will be improved, and more people accepting biotech/GM crops will become a common phenomenon.Keywords：biotech/GM crops;field trials;commercialized;crop traits6|11|6<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to study the differences of physiological indexes and quality characters in the progenies of soybean green retarded mutant, the mutagenic progenies M6 of soybean stay-green mutant ‘Z-94320' induced by 60Co-γ were used as test materials to measure and analyze the chlorophyll content in different stages, photosynthesis during the seed-filling period, protein and fat of soybeans with different seed coat color and cotyledon color. The results showed that the average content of chlorophyll of stay-green progenies in the senescence stage was 41. 76±0. 93, and the average rate of change was(12. 27±0. 70)%, which was significantly higher than that of the common progenies. The stomatal conductance of green seed coat progeny was inhibited, but there was no significant difference in photosynthetic parameters among different groups. The quality of the stay-green progenies was significantly higher than that of the common progenies, and the change rate of chlorophyll had a extremely significant positive correlation with protein content and fat content. In stay-green group, the protein content and fat content of light green seed coat and green cotyledon soybean were(44. 35±0. 16)and(21. 57±0. 03)g/100 g higher than those of green seed coat and cotyledon soybean, respectively.Keywords：soybean;stay-green mutant;chlorophyll content;photosynthesis;quality analysis0|9|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore the molecular basis of the differences in cold resistance among peach varieties, wild peach(Prunus persica)and 17 peach varieties and lines were used as test materials. The PpCBF2 gene was cloned by PCR and RT-PCR. The expression characteristics of PpCBF2 at low temperature in ‘Zaohongxia' and ‘Okubo' leaves were analyzed by qRT-PCR. The results showed that: 1)the full-length DNA and cDNA sequences of PpCBF2 gene were 894 bp, the open reading frame was 690 bp, encoding the 229 amino acids and containing the AP2/EREBP domain of the CBF family; 2)The full-length nucleotide sequence and the number of encoded amino acids of the PpCBF2 gene of the strain were the same as those of the Prunus persica, but there were 1-2 amino acid site mutations in 9 varieties: The mutations of ‘Baimangpantao', ‘81715', and ‘Okubo' occurred at N-myristoylation site or the phosphorylation site of casein kinase II; mutations in ‘Italia3', ‘Hanlu', and ‘B6832'occurred in the AP2/EREBP domain; 3)PpCBF2 of ‘Zaohongxia' and ‘Okubo' were induced by low temperature, and there were significant differences in expression levels. In conclusion, PpCBF2 gene was relatively conservative among peach varieties, but a few varieties had mutations in gene functional sites; this gene was significantly induced by low temperature and was related to cold resistance.2|8|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to assess the inheritance and expression stability of exogenous genes in the long-term subcultuted transgenic apple lines, the GFP transgenic apple tissue culture plantlets of 7 lines cultured for 9 years were used as test materials. The genetic and expression stability of GFP gene were analyzed at the levels of resistance, DNA, transcription and post transcription. The results showed that GFP gene could be detected in the tissue culture seedlings of 7 transgenic apple lines which could grow normally on the culture medium containing 50 mg/L kanamycin; Absolute quantitative qRT-PCR analysis showed that the copy numbers of GFP gene were different in each transformed lines, and the expression levels of GFP mRNA in 7 transgenic lines were significantly different by relative quantitative qRT-PCR detection. At the same time, the green fluorescence intensity of each transformed line was significantly different under the fluorescence microscope. There was no significant correlation between GFP gene copy number and GFP mRNA expression in 7 transgenic lines by SPSS software. In conclusion, the exogenous gene could remain stability in long-term cultured transgenic apple plantlets. However, there were significant differences of the expression of foreign genes in different transformation strains, and their expressions were not significantly related to the copy number, which might be related to the insertion site of exogenous genes in the plant genome.Keywords：apple;GFP;gene;real-time fluorescent quantitative PCR;genetic stability;gene expression4|9|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To investigate the effects of grazing supplementary feeding on growth performance and blood indexes of Simmental calves, sixteen grazing Simmental calves in Chifeng grassland were divided into grazing group and grazing plus feeding group, respectively. Body weight, body size and other growth performance indicators were measured. Total protein(TP), urea nitrogen(BUN), glucose(GLU), interleukin 1(IL-1)and interleukin 2(IL-2)in serum were detected by ELISA. The results showed that: 1)There was no significant difference in daily weight gain between two groups of calves at 0-30 d in the formal trial period(P>0. 05). However, the daily weight gain of calves in the grazing plus feeding group was significantly higher than that those calves in the grazing group at 31-60 d(P<0. 05). In the whole experimental stage, except for the heart girth, the body size in grazing and supplementary feeding group were higher than that in grazing group, but the differences were not significant(P>0. 05). 2)The contents of urea nitrogen(BUN)and glucose(GLU)in serum of calves were significantly increased by grazing and supplementary feeding(P<0. 05). There was no significant difference in total protein(TP)and glycertin trilaurate(TG)content. 3)The levels of immunoglobulin G(Ig G)and interleukin 1(IL-1)calves were significantly increased by grazing and supplementary feeding(P<0. 05). The contents of triiodothyronine(T3), thyroid hormone(T4), growth hormone(GH)and interleukin 2(IL-2)were higher than those in grazing group, but their differences were not significant(P>0. 05). In conclusion, the supplementary feeding can improve the growth performance of grazing Simmental calves, the blood biochemical index, serum hormones level and immune level of Simmental calves.Keywords：Simmental calves;grazing and supplementary feeding;growth performance;serum indexes2|9|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To improve the production efficiency and fine management level of large-scale sheep farms, an intelligent equipment for rapid measurement of the sheep weight and flock classification management was designed and developed. By taking a programmable logical controller as core, the sheep weighing and grouping system, which was an intelligent electromechanical equipment system driven by pneumatic power, was designed. Moreover, the system used the optical electrical sensor to detect the moving position of sheep. Real-time reading sheep's identity data was stored in wireless electronic ear tags, the sheep's weight data was obtained instantly and the sheep was quickly divided into groups. The field test results showed that the system was stable and reliable. The system was tested on 15 different sheep, there was no significant difference between the actual value and the measured value of the weight data(P>0. 05). The maximum weighing relative error of the system was 1. 2%, the average relative error was 0. 71%, and the weighing and grouping efficiency was 3 sheep per minute. Therefore, the intelligent weighting system can be applied to large-scale farms.Keywords：sheep farm;programmable logic controller;intelligent weighing;sheep grouping1|8|3<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To establish a detection system for isolation, culture and identification of myoblasts from broiler in vitro, eleven-day-old broiler embryos were digested with type I collagenase and isolated via differential adhesio, followed by the optimization of cultivation conditions. The isolated cells were then identified by cell morphology observation and myogenic differentiation marker gene expression and induced to myogenic differentiation in a 2% horse serum. The results showed that the myoblasts were spindle-shaped, and the cell proliferation rate was significantly higher at 39. 5 ℃ than that at 37. 0 ℃(P<0. 05). Real-time quantitative PCR analysis showed that the myoblast-specific marker genes myogenic differentiation marker 1(MyoD)and myogenic factor 5(Myf5)were expressed at both the proliferation and differentiation stages. And the expression of myogenin(MyoG)and muscle regulatory factor(MRF4)in the differentiated myoblasts was significantly higher than that in the proliferation phase(P<0. 05). In addition, the cells were positive for desmin at proliferation stage and myosin heavy chain(MyHC)antibody at differentiation stage by immunofluorescence assay. In conclusion, the broiler primary myoblasts were successfully isolated and had better proliferation ability at 39. 5 ℃. This study provided cellular foundation for exploring the mechanism of muscle development and its nutritional regulation.Keywords：broiler;myoblast;identification;culture temperature;myogenic differentiation7|7|3<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To study the application and research progress of bee colony behavior monitoring at home and abroad, literatures from 2005 to 2019 were searched by using “bee monitoring”, “automation” and “behavior” as keywords. The literatures were summarized from two aspects, e. g. nest monitoring and out nest monitoring. The results showed that: 1)The monitoring and application of image, sound, temperature, humidity, weight and other information in the hive at home and abroad greatly improved the efficiency of beekeeping and reduce the burden of beekeeping. 2)Monitoring the number of bees in the gate area of the beehive and the number of bees in and out of the beehive improved the convenience of practical application, and reduced the dependence on sensors during development process. 3)Computer vision based out nest monitoring became a new research hotspot. At the same time, studies were mainly single information analysis with insufficient use of environmental data and insufficient aquaculture auxiliary information. Future studies should focus on collaborative analysis of multiple types of monitoring information, using different monitoring information and environmental information correlation analysis, and discover a variety of auxiliary breeding strategies to assist the development of apiculture.Keywords：the behavior of the bees;automatic monitoring;in hive;out of hive0|14|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to have an overall understanding of the research in plastic mulching film, this study takes the data of 1 895 papers collected from the Web of Science database from 2000 to 2019 as the data source, based on the method of bibliometrics, combined with the software such as Excel and VOSviewer, the number of published papers in plastic mulching film research, major countries and institutions where issued the publications, research topics and research frontiers were analysis. The results showed that: there was an increasing trend on the number of published papers in this field. Since 2013, the number of publications has been increasing rapidly. From the perspective of national research abilities, China, the United States and Italy contributed most of publications, Chinese research institutions contributed the highest number of papers in this field, as Northwest A&F University, Chinese Academy of Sciences and China Agricultural University; The research directions in this field include the application of plastic mulching film in agriculture(including the influence of film on agricultural output, soil moisture, temperature, etc. ), polymer material analysis of mulching film, development and application of biodegradable mulching film, biodegradation of mulching film and influences of plastic residual film on soil environment and ecological environment. From the perspective of research trends, as large residual of mulching film remains in soil, the future hotspots of the frontier may be biased towards the impacts of plastic film residual on the ecological environment and soil quality. Especially the effects of plasticizer and microplastics on soil food chain safety, ecosystems, and human health deserve further investigation. At the same time, it is important to develop biodegradable mulch films to replace traditional plastic mulch films, evaluate the effects of agricultural applications in time, and promote the biodegradable mulch films on a large scale as soon as possible.Keywords：plastic mulching film;Web of Science;bibliometrics;agriculture5|11|12<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to find out the distribution regularities of threshed mixtures and study the influence of working parameters effect the distribution of threshed mixtures by longitudinal axial flow flexible threshing and separating device in harvester, a single factor test was designed. Experiments were conducted on a self-developed test platform for studying the changes in the axial and radial distribution of the mixtures from the longitudinal axial flow flexible threshing device using the drum rotation speed, threshing clearance, feeding amount and baffle angle as test factors. The results showed that: 1)When the working parameters changed, the distribution of the threshed mixtures did not change significantly in the axial and radial directions; 2)The axial mixtures and grain distribution of the flexible thresher conformed to the exponential function, the distribution regularities of pods and light debris conformed to the cubic function; 3)The distribution regularities of radial mixtures, grains, pods and light debris conformed to polynomials with different coefficients.Keywords：soybean;flexible threshing;harvester;distribution regularities;threshed mixtures0|8|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Aiming at the low accuracy of image segmentation and geometric parameter measurement of apple leaves by traditional methods, a new automatic image segmentation algorithm of apple leaves based on deep learning and guided filtering technology is proposed. Deep learning method is firstly adopted in this study. BiseNet convolutional neural network is used to automatically segment the image of apple leaves to obtain the main contour of apple leaves. The color apple leaf image is then used as the guide image to conduct the guiding filtering processing on the main body contour to enhance the detail feature information such as sawtooth edge. Finally, the outline of the main body and the detailed feature information were combined to segment to obtain complete and accurate information of apple leaves. The results of 8184 apple leaf image data sets containing 174 kinds of apple leaves show that the accuracy of apple leaf segmentation and IoU ratio of the proposed algorithm are 98. 99% and 98. 82% respectively. In conclusion, the area and circumference of apple leaves can be measured accurately and quickly by using the new algorithm established in this study. This study provides a new method for the geometric parameter measurements of apple leavesKeywords：apple leaves;image segmentation;deep learning;guided filtering12|10|3<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to understand the change characteristics of soil microbial biomass under the disturbance of grazing, this study took the grazing control test plot of Xilin Gol in Inner Mongolia as the research platform, and the content soil microbial biomass carbon(MBC), microbial biomass nitrogen(MBN)and microbial biomass phosphorus(MBP)were investigated under different grazing intensities between 2014 and 2017. The results showed that: 1)There were no significant annual changes in MBC and MBN content under different grazing intensities for four consecutive years(P>0. 05). The annual average values were 306. 00 and 55. 98 μg/g, respectively. The annual change of MBP content was significant(P<0. 001). The soil MBP content in the first year of grazing was 40. 99 μg/g on average. After the second year, the soil MBP content decreased by 50. 38%-79. 97%. 2)Under different grazing intensities, the contents of soil MBC, MBN and MBP reached the maximum under G8 treatment, and were higher than those under non-grazing treatment(G0); 3)Soil MBC∶N ratio remained relatively stable, and MBC∶P ratio was consistent with the control under moderate grazing intensity(G8). Therefore, the effect of grazing on soil microbial biomass, especially MBP content, is not only related to grazing intensity, but also related to grazing times. However, continuous grazing for 4 years displayed no significantly impact on the content of soil MBC and MBN in this area, but its impact on MBP content was obviouse. The moderate grazing intensity(G8)was the most suitable for microbial survival, which improved soil microbial biomass, maintained a reasonable ratio of microbial biomass carbon to nitrogen and phosphorus, and was conductive to maintain soil microbial biomass and the stability of grassland community and improve the productivity of grassland community.Keywords：Inner Mongolia;typical grassland;grazing;soil microbial biomass5|10|7<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Aiming at the status of sustainable utilization of water resources and problem of water pressure in Jilin Province, an ecological footprint model was adopted to analyze the ecological footprint of water resources in Jilin Province from the perspective of time and space. The results showed that: In terms of time, the ecological footprint of water resources in Jilin Province showed an upward trend and then a downward trend from 2004 to 2018; The ecological carrying capacity of water resources was affected by annual precipitation, and the fluctuations were obvious; The province's overall water resource utilization efficiency increased year by year. However, the main form of agricultural water use was still in a dangerous state of the water environment. From the spatial point of view, regions with higher water resources ecological footprint in Jilin Province on 2017 were concentrated in mid-western cities, and the regions with higher water resources ecological carrying capacity were mainly eastern cities; Among these cities, Baicheng City had serious water resource ecological losses and poor water ecological security status. Baishan City and Yanbian area had sufficient water resources reserves and large development potential. The overall situation of the province's water environment security is good, but interregional water environmental conditions vary greatly. In conclusion, there is a shortage of water resources in Jilin Province, and the government should take into account the actual situation of their own development and make corresponding measures in terms of water use in agriculture, industry and ecological environment in order to achieve the sustainable development and utilization of water resources in Jilin Province.Keywords：water resources ecological footprint;water resources ecological carrying capacity;spatial distribution;sustainable utilization;Jilin Province2|7|12<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Aiming at the problem of changes in precipitation, climate and soil moisture transfer process in different locations under photovoltaic panels after the photovoltaic power station in the steppe region was put into use, a typical grassland photovoltaic power plant in central Inner Mongolia was taken as the research object. Field observation experiments were conducted to quantify the impact of photovoltaic panels on rain redistribution in a single precipitation event. The soil volumetric water content at different depths of the soil layer under the photovoltaic panel, the evapotranspiration of soil moisture at various positions under the panel, and the atmospheric temperature and humidity were measured daily. Through the correlation analysis and linear regression equation, the response process of soil moisture and soil evapotranspiration under photovoltaic panels to precipitation events were obtained, and the coupling relationship was determined. The results show that: 1)Photovoltaic panels redistributed the ground moisture collection. Under the effect of pooling water under the front eaves of photovoltaic panels, the precipitation under the front edge of the photovoltaic panel increased by an average of 111. 33 mm. The precipitation below the panel was significantly lower than the area without the panel; 2)The volumetric water content of each soil layer under the photovoltaic panel was generally higher than the soil volumetric water content of the area where the panel is not erected. Among them, the volumetric water content of the soil layer in the control area of 0-10 cm accounts for 47. 61% and 38. 08% of the volumetric water content of the soil layer below the front eaves of the photovoltaic panel and below the gap between the photovoltaic panels, respectively. The accumulated evaporation of the soil under the two bolts under the photovoltaic panel and under the back eaves of the photovoltaic panel were only 3. 52, 2. 76 and 2. 91 mm, which were less than the soil evaporation in the area where the panel was not installed; 3)The regression coefficients R2 of the water storage and precipitation in the 0-10 cm and 10-20 cm soil layers under the photovoltaic panels were 0. 716 6 and 0. 829 2, respectively. The water storage in the 0-20 cm soil layer was significantly affected by precipitation. The fitted R2 of soil cumulative evaporation and precipitation under photovoltaic panels was 0. 771 6. In conclusion, there was a strong correlation between daily soil evaporation and initial soil volumetric water content, and this correlation has enhanced over time.Keywords：photovoltaic power plant;precipitation;soil moisture content;soil evapotranspiration;law of differentiation7|8|9<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
Study on the spatiotemporal changes of Xinjiang urban expansion based on DMSP/OLS and NPP/VIIRS data
Abstract：Based on DMSP/OLS and NPP/VIIRS night-time lighting data, with the help of ArcGIS and Matlab software, the spatial and temporal evolution of Xinjiang's urban expansion from 1993 to 2018 was studied. Four kinds of urban expansion metrics, hotspot analysis and standard deviation ellipse method were used to analyze the dynamic changes and evolution characteristics of Xinjiang's urban expansion during this period. The results show: The area of Xinjiang's urban built-up area increased from 9 665 km2 from 1993 to 2018. Among them, Xinjiang's cities developed rapidly under the background of the “Belt and Road” initiative in 2013. Xinjiang's urban growth during 2013-2018 was 6 111 km2, which expanded The velocity reached 1 222. 2 km2/a, which was 9. 7 times higher than that in 1993-1998, and the dynamic change was most obvious. 2)From 1993 to 2018, the area of the standard deviation ellipse and the center of gravity movement of Xinjiang's city scales changed significantly. In each period, the long axis of the standard deviation ellipse moved from northeast to southwest; 3)The urban spatial form of Xinjiang is in an unstable and complex state, with extensive extension. The irregularity of the urban spatial shape is strong, the degree of fragmentation is high, and it is increasingly complex. In conclusion, the use of night-time lighting data reflected the scientific and feasibility of optimizing the spatial development and expansion pattern of regional cities. The study of urban expansion in Xinjiang has scientific significance in the practice of the “Belt and Road” initiative.Keywords：DMSP/OLS;NPP/VIIRS;standard deviation ellipse;morphological change indicator3|9|7<HTML><L-PDF> <Meta-XML>Updated：2024-02-27- Abstract：Aiming the problem of the regional imbalance of the technical efficiency of winter rapeseed production in China, 11 provinces or cities including Sichuan and Hubei were taken as study examples. The regional statistics and survey data of households in 2018 were adopted. Nonparametric analysis was used based on data envelopment and linear regression respectively. The regional differences of technical efficiency and the relevant impact factors in China's winter rapeseed production were investigated in this study. The results showed that: There were regional differences of technical efficiency in China's winter rapeseed production, among which Sichuan and Jiangsu provinces were higher, Yunnan, Jiangxi and Shanghai were lower. The regional differences of technical efficiency in China's winter rapeseed production mainly came from scale efficiency. Among the impact factors of regional differences of technical efficiency in China's winter rapeseed production, the impact level descending order was financial expenditure to agriculture, the density of science & technology members, the age of householders, members engaged in rapeseed and the income level of a household. At the same time, the impact factors of financial expenditure to agriculture, density of science & technology members and members engaged in rapeseed were positively correlated with regional differences of technical efficiency in China's winter rapeseed production, while the impact factors of age of householders and income level of a household were negatively correlated. Therefore, for the regions of winter rapeseed production in China, policy formulation should lie in focusing on promoting scale efficiency in winter rapeseed production, ensuring the level of financial expenditure to agriculture, density of science & technology members and members engaged in rapeseed. At the same time, attention should be paid to the influences of age of householders and income level of a household on technical efficiency in winter rapeseed production.Keywords：technical efficiency;regional differences;winter rapeseed production;pure technical efficiency;scale efficiency0|9|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
Spatial-temporal patterns variation of grain production and security evaluation in Shandong Province
Abstract：Based on the gravity center model, exploratory spatial data analysis and fluctuation coefficient method, the temporal and spatial patterns of grain production and the evaluation of grain security in Shandong Province from 1995 to 2015 were examined. The results showed that: 1)From 1995 to 2015, the total grain output experienced two stages from fluctuating decline to steady rise, while the grain yield per unit area showed an upward trend. Among the main grain crops, the wheat production and sown area accounted for the highest, followed by corn, while the area of sweet potato and soybean continued to decline. 2)There were obvious spatial differences in grain production in Shandong Province. Most of the counties(cities, districts)in the west of Shandong Province developed into the main high-yield areas in the province. The barycentre of grain production shifted to westward. It is found that the spatial agglomeration range of grain production presented a strengthen trend. The grain production in the west of Shandong Province formed a large-scale stable hot spot, while the grain production in the north, central and east of Shandong Province formed a stable cold spot. 3)From the perspective of changes in grain security, the grain production capacity is gradually improving; the grain security situation is generally turning for the better. However, the stability of grain supply is poor, so the grain security situation remains grim.Keywords：grain production;spatial-temporal patterns variation;grain security;Shandong Province5|10|6<HTML><L-PDF> <Meta-XML>Updated：2024-02-27- Abstract：A total of 13 cities in Jiangsu Province were selected as study case for this approach. The information entropy, window analysis based on SBM with undesirable outputs, factor analysis methods were employed to measure the order degree of urban land use structure, land use efficiency and urbanization degree. On this basis, the coupling coordination degree model was used to evaluate the spatial-temporal characteristics of urban land use structure, land use efficiency and urbanization level. The results showed as follows: 1)The coupling degree between land use structure, land use efficiency and urbanization was in low antagonistic stage and the coordination degree was mainly in barely coordination. Both have a volatile growth trend and great potential for improvement. 2)The distribution of land use structure, land use efficiency and urbanization was characterized by large spatial differences. The high coupling and coordination degree were mainly located in southern Jiangsu; The coupling and coordination degree were increasing year by year during the period 2006-2017. The results provided references for the government to formulate urban sustainable development plan and urban industrial policy.Keywords：land use structures;urban land use efficiency;urbanization;coupling and coordination degree;Jiangsu Province4|8|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To explore whether new agricultural management entities ability is able to drive the development of smallholder farmers, this study adopts three-stage DEA Tobit model, based on the survey data of 342 samples from 47 villages in 13 cities of Heilongjiang Province. From the perspective of the comparison of technical efficiency between new agricultural management entities and smallholder farmers, the technical efficiency of corn production between them are compared and the factors leading to the difference of technical efficiency are analyzed. The results show that: The technical efficiency of corn production of new agricultural management entities is generally higher than that of small farmers, and is able to drive the development of small farmers. Among them, the strongest driving force is farmers' professional cooperatives, followed by family farms and large professional planting households. The environmental factor has a significant impact on the technical efficiency of corn production. After excluding the environmental factor and the random factor, producer management is the main factor leading to the differences in technical efficiency. Therefore, reshaping the cultivation policy of the main body, consolidating the basis of cooperative operation and creating a good production environment help to give full play to the leading role of new agricultural management for smallholder farmers.Keywords：new agricultural management entity;smallholder farmer;comparison of technical efficiency of corn production;three-stage DEA Tobit model2|8|7<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To explore how different capital deficient farmers respond when facing different livelihood risk, 414 peasant household survey data in Qinba mountains are taken as study case. Based on the judgment of farmer's livelihood capital type and measuring their livelihood risk, using effectiveness evaluation and Logistic regression analysis method, the influence factors on peasants' coping strategies are studied. The results show that different kinds of peasant household take different combination strategies to respond to the risks. Moreover, the effectiveness evaluation of the strategies of “Social insurance and social relief” and “Improving production technology” is good, with the comprehensive evaluation values of 2. 41 and 2. 39, respectively. The interaction term of livelihood risk and livelihood capital types has significant influence on farmers' risk coping strategies, and the interaction effects of different types of livelihood capital and capabilities of resist risks are different. Therefore, in order to realize stable poverty alleviation and consolidate the achievements of poverty alleviation, it is necessary to combine the types of livelihood capital of farmers and external livelihood risks first, and then to formulate differentiated poverty alleviation measures to achieve a stable poverty alleviation strategy, which is risk prevention and strengthens livelihood.Keywords：livelihood capital;livelihood risk;risk coping strategies;validity ranking;interaction effect0|8|3<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To explore the impact of agricultural machinery on farmers' main grain acreage, 1 667 farmer field survey data are taking as study case, and the endogenous variable merging model(IVTobit)and unconditional quantile regression(UQR)are used. The results are as follows: 1)Agricultural mechanization has a significant positive impact on the area of staple food planted by farmers, but it has a different impact on the area of staple food planted by different types. The impacts in descending order are potato, rice, corn and wheat. 2)The impact of agricultural mechanization on the planting area of different types of staple grains has a tendency to increase in scale, and the impact of agricultural mechanization on the planting area of different types of staple grains increased with the increase of the quantile. 3)It is recommended to further cultivate agricultural machinery and equipment manufacturing enterprises with international competitiveness, and promote the “Appropriate mechanization” of the field further to effectively reduce the cost of agricultural machinery operations and increase the yield of staple food and increase the enthusiasm of farmers to grow staple food and ensure national food security.Keywords：agricultural mechanization;farmers;grain planting area;IV Tobit;unconditional quantile regression5|10|3<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
