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- Abstract：Local crop residue management policy plays an important role on promoting its comprehensive utilization,reducing the abandoning and burning of residue and protecting environment.In this paper,According to the related literatures searched in this study,a total of 122 provincial policy documents on crop residue management released from 2003 to 2015.The number of published policy documents is correlated with the production of crop residue,but not positive correlation relationship.On one hand,although crop residue policy documents exhibited large variation between provincial governments,all local governments have paid more attention to the residue management.The policy documents accounted for 41% of all the residue files on prohibiting residue burning in field are enacted strict financial penalties to the responsible person.On the other hand,in order to reduce the burning of residue,and promote resource recycling utilization,the local government of Tianjin,Hebei,Heilongjiang,Shanghai,Jiangxi,Shandong,Guangdong,Jiangsu etc.released the residue utilization planning and related solution separately.A variety of policies to encourage comprehensive utilization of residue such as returning to field,making power and biogas,and producing animal feed were implemented.The high subsidies are offered to promote residue utilization technologies in Tianjin,Hebei,Jilin,Shanghai,Anhui,Henan,Chongqing,and Sichuan province.In this way,crop residue is not only used by farmers consciously,but also promotes industrialization development of residue.The key point in eliminating residue burning is not in "banning" but in "finding the new way of utilization".The local governments need to summary the present problems,and then establish the rational and effective management policy for comprehensive utilization of residue according to the local conditions,in order to promote appropriate residue utilization technology.Keywords：residue;biomass;bioenergy;biogas;feed;policy2|11|7<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Taking the CMS line UG93A and maintainer line UG93B of kenaf as materials,gDNA(genomic DNA) were extracted from seedling leaves,tetrad stage anthers and binucleate stage anthers respectively.MSAP (methylation sensitive amplified polymorphism) technology was used to analyze and compare their methylation of gDNA.The expression patterns of methylated genes were studied by qRT-PCR.The results showed that:1) During the growth and development of kenaf,DNA methylation showed spatio-temporal variation pattern.The gDNA methylation rate (MSAP%) of UG93A and UG93B at seedling stage were 56.79% (full methylated rate was 44.25%,similar as follows) and 58.89% (43.24%);MSAP% at tetrad stage was 48.08% (36.24%) and 44.25% (33.22%);MSAP% at binucleate stage was 45.30% (34.15%) and 48.78%(37.98%), respectively.2) The ratio of UG93A was the highest at seedling stage,tetrad stage before anther abortion came the second,then binucleate stage after abortion.It displayed a trend of high to low during growth and development.The rate of UG93B was highest at seedling stage,followed by binucleate stage and tetrad stage showing a trend of high to low,and then gradually rising.Although,the rate of UG93B was higher than that of UG93A,but the UG93A was significantly higher than UG93B in the tetrad stage before anther abortion.3) Gene methylation or demethylation happened in many genes including atp8、SCL13、SRF6、phytosulfokine receptor 2.These genes in UG93A and UG93B were differentially methylated.The results from qRT-PCR analysis reviewed that the differentially expression levels of methylated fragments between the cytoplasmic male sterile line and maintainer line showed significant differences,indicating gene methylation played an important role of in kenaf CMS.Keywords：kenaf;DNA methylation;CMS;MSAP;qRT-PCR1|8|5<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The objective of this study was to clarify the dynamic patterns of the chemical composition of Cistanche tubulosa during the whole life cycle.The variation on dry weight and the contents of soluble sugar,starch,echinacoside,verbascoside as well as mannitol in C.tubulosa were fully characterized.The results indicated that:1) The contents of soluble sugar consistently decreased from 146.89 mg/g to 54.28 mg/g during the whole growth period of C.tubusola. The content of starch increased during pre-elongation stage while decreased rapidly after germination of C.tubulosa. The highest content of starch was 44.87 mg/g."S" type increment was observed for the plant weight during the entire growth period,and maximum value occurred after elongation stage.2) The contents of pharmacological ingredients in C.tubulosa corresponding to the same weight were not varied with seasons in the nutrition growth stage;however,the increment were found for the contents of those effective compounds with the dry weight growing of C.tubulosa;The highest contents of echinacoside and verbascoside occurred at pre-elongation stage,which was successively followed by elongation stage,squaring stage,flowering stage,and pod formation stage.The content of mannitol increased before July in the nutrition growth stage,and subsequently decreased until the end life cycle.The accumulations of echinacoside,verbascoside and mannitol were continuously observed over the nutrition growth stage.However,their contents were decreased in the reproductive stage.3) The content of soluble sugar exhibited significant correlation with the contents of echinacoside along with verbascoside,and the correlation coefficients were 0.87 and 0.89,respectively.Keywords：Cistanche tubulosa;echinacoside;verbascoside;mannitol2|8|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：From aspects of nature,ecological environment and social economy and in order to explore saline-alkali land sustainable utilization for saving water,decreasing soil salinity and improving cotton field production,datasets including field experiments in Manas County of Xinjiang,farmers' land use investigation data and literature review were systemically analyzed in this study.The results showed that:1) For short term condition of drip irrigation under mulch,brackish water and fresh water had similar effects that make soil root layer (0-30 cm) in desalination status,which ensured the environment for cotton's growth;and The order of four treatments by their effects to decrease soli salinity salt down in descending was as:large amount of fresh water (N5000),small amount of fresh water (N4500),large amount of brackish water (X5000),and small amount of brackish water (X4500).2) The effects of fresh water treatment was higher than that of brackish water treatment on the plant height,dry matter weight and leaf number of cotton in the flocculent period;The cotton production from high to low was N5000,X5000,N4500,X4500;Therefore,although brackish water affected the growth of cotton (plant height,dry matter weight and leaf number),the effect of large amount of brackish irrigation water on cotton yield was not obvious whose production was just 92 kg/hm2 lower than that of large amount of fresh water treatment,which decreased by 1.45%.3) Ecological and environmental problems caused by drip-irrigated cotton field under mulch in Xinjiang mainly included affecting the residual soil moisture permeability,soil water content,soil porosity and physical and chemical properties (i.e.bulk density), resulting in the inhibition of cotton growth and decrease in yield.Solutions to solve the problems included strengthening the research and application of recycling machine of residual plastic film,improving the quality and thickness of plastic film,uncovering mulch in time,straw returning and developing biodegradable film.4) Social and economic sustainability included:building long-term and stable land circulation mechanism,promoting innovation of farmers' and farms' management approach;carrying out autonomous land consolidation to make arable land concentrated,expanding the farm size;actively promoting the development of the rural financial microfinance and ensuring land investment.To promote planting model of "one film three belts six lines" planting patterns (2.05 m mulch) and "short,dense,early" cultivation techniques;promoting straw returning,plow early in autumn sowing early in spring farming technology;and improving the labor market and cultivating new type of professional farmers.Keywords：system theory;drip irrigation under mulch;cotton fields;saline-alkali arable land;sustainable land utilization;Xinjiang3|11|7<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Twelve elite maize inbred lines were hydroponically cultured in this study to investigate the genotypic differences of Fe-efficiency at their seedling stage.After supplying different amount of HEDTA-Fe (2 and 100 μmol/L) in nutrient solutions,plant phenotypes were observed and traced,and plant height,leaf number,dry matter,the ratio of root to shoot,SPAD value and micronutrients were measured.Under low iron supply condition,the plant height,SPAD value,shoot weight,root weight and total dry weight decreased significantly,especially on the genotypes of D340,B77 and CI7.The total weight of B77 was significantly lower than that of others.The total weight of DE3 decreased the least.Zinc,manganese and copper concentrations in shoots and roots enhanced significantly.There was significant differences among these 12 maize inbred lines on their iron efficiency,which varied from 5% to 40%.DE3 displayed the highest iron efficiency,and B77 had the lowest iron efficiency.The correlation analysis showed that the total dry matter,SPAD value and the ratio of root to shoot correlated negatively with iron efficiency.Taken together,these results indicated that there is significant iron efficiency differences among different maize inbred lines,which would provide references for the improvement of maize iron efficiency in the future.Keywords：maize;inbred line;HEDTA;iron efficiency;correlation analysis3|11|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To study the effects of phosphate-solubilizing bacteria (PSB) wj1 and wj3 on the improvement of soybean rhizosphere soil or mixed saline alkali soil.Experiments were conducted by applying bacteria wj1 and wj3 to different soil treatments and the main high yield and high oil soybean variety "Ji Yu 406" in Jilin Province was used as material.The effects of soil enzyme activity,soil microbial quantity and soil micro ecology of exogenous PSB on soybean rhizosphere soil were investigated.The results showed that:The activities of phosphatase,urease,invertase and protease by adding mixed bacteria into black soil were significantly increased at the R2 and R6 stages of soybean.Strain wj1 could affect the phosphatase activity of black soil.The effect of the amount of microorganism was significantly affected by the additional PSB into the black soil at the early growth stage of soybean.Strain wj1 promoted the increase of the quantity of PSB and nitrogen fixing bacteria of black soil.Strain wj3 and mixed bacteria displayed great impacts on the number of ammonifying bacteria and nitrifying bacteria during whole growth period.Adding PSB significantly improved soil phosphatase,urease and invertase activities,and the number of microorganisms of mixed saline alkali soil.The change of microbial community diversity was obvious between bacteria treatment and the control.The Shannon index and microbial community richness of black soil and mixed soil were increased by adding the PSB,and the ability of microbial metabolism in mixed saline alkali soil was enhanced from V3 to R6.In conclusion,adding PSB to black soil and the mixed saline alkali soil could improve the microbial quantity and result in reasonable soil nutrition level.Keywords：phosphate-solubilizing bacteria;saline-alkali soil improvement;soil enzyme activities;soil micro-ecology6|18|12<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to numerically predict tillage soil dynamics process,based on the relationship of liquid bridge force and gap width between two particles,a DEM model for wet particle system was set to investigate tillage soil dynamics.Based on Sartorius-microbalances two schemes,for the measurement of static liquid bridge force were proposed:The former was of manual measurement with an x-y-z manual adjustment slide and a digital microscope connected to a laptop,and the later was for automatic measurement with additional parts including a screw slide module driven by a stepping motor.Measurements were carried out for two equal spheres and unequal ones with both schemes,and the results were compared with available analytical equations or fitting ones.The results showed that the experimental set combined with the procedures enabled the evolution of static liquid bridge force with increment of separation and further determined the rupture distance with satisfactory.In conclusion,the approximate equation was suitable for modeling the static liquid bridge force of soil particles.Keywords：soil dynamics;particle;Discrete Element Method;liquid bridge force;measurement4|9|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore an optimal estimation method for soil organic matter content based on map patches data,the surface Kriging and sequential Gaussian conditional simulation methods are used to estimate the content of soil organic matter in southern Daxing District of Beijing,and then evaluate the accuracy based on test pattern data and surface data.The results show that the estimation results of soil organic matters in the study area are consistent by surface Kriging method and sequential Gaussian conditional simulation method.However,the sequential Gaussian conditional simulation method possess weaker smoothing effect and prominent local change characteristics at single stochastic simulation;The correlation coefficient and concordance coefficient of point verification and surface verification show that surface Kriging method and sequential Gaussian conditional simulation method can be used to estimate soil organic matter content of cultivated land.Under the comprehensive action of multiple stochastic simulation and variogram fitting accuracy,the estimation precision sequential of Gaussian conditional simulation is higher.Keywords：cultivated land plot;sequential Gauss condition simulation;surface Kriging estimation;accuracy evaluation;consistency index2|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The analysis on the hydrochemical characteristics of shallow groundwater is important for local groundwater management.In this study,the spatial and temporal distribution of hydrochemical components in the shallow groundwater of Tongzhou area were described based on the monitoring data of 19 sampling wells during dry and flood seasons from 2007 to 2013.The results showed that:The concentrations of hydrochemical components changed slightly in the dry and flood seasons.The HCO3- takes the largest proportion in the anion group with average value of 423 mg/L in the dry season and 452 mg/L in the flood season respectively,and the content of SO42- and Cl- fluctuated relatively more significantly.Na+ and Ca2+ had the largest proportion in the cation group and the concentration of K+ changed more dramatically than other cations.The correlation of those hydrochemical components in the dry season was the same as that in the flood season.The piper diagram shows that the types of hydrochemistry of the local groundwater in the study area were HCO3-Ca·Mg,HCO3-Mg·Ca·Na and HCO3·Cl-Ca·Na·Mg,and stable during 2007 and 2013.The spatial distribution results showed that the concentration values in the south part of the study area were higher than those in the north part,which increased with the direction of the regional groundwater flow.Keywords：groundwater;hydrochemical characteristics;Tongzhou;spatial and temporal distribution0|9|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to systematically understand the research status of linseed cake (meal) as animal feed at home and abroad,as well as investigate effective utilization of linseed cake (meal) and other by-products of linseed as animal feed in the future,research progress of linseed cake (meal) as animal feed is reviewed based on classification and origin of Chinese linseed, ingredients and nutritional value of linseed cake (meal),toxic and harmful substances,and linseed cake research progress of ruminant animals,pigs,poultry at home and abroad.Linseed cake (meal) is rich in protein.Its crude protein and lysine content are relatively less than soybean meal,peanut meal and cottonseed meal.It is better feed when it is mixed with other high lysine protein feed.Because of its hydrocyanic acid toxicity,its proportion in feed is limited.Therefore,the maximal proportion in pig and ruminant diet are 8%-10% and 20%,respectively.Its optimal proportion in poultry feed is remained to be investigated.Decreasing hydrocyanic acid toxicity in linseed cake (meal) and collocation ratio of cake are research emphasis in the future.Linseed cake (meal),which is rich in linolenic acid,can be applied to improve the value of animal product.Keywords：linseed cake(meal);livestock and poultry;protein feed;linolenic acid1|9|5<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To screen and identify quinolones antibiotic resistance genes of Escherichia coli genome,drug sensitivity tests were performed on clinically separated 13 E.coli strains for relatively wide resistance strains.Mariner transposons were used to construct transposon mutant library of E.coli,and quinolones antibiotics were used to screen the antibiotics sensitive mutants from the library.The transposon insertion sites were then determined by nested-PCR,nucleotide sequencing and sequence alignment.The results showed that:Twenty-two strains,which were sensitive to norfloxacin,ciprofloxacin,levofloxacin and nalidixic acid,were selected from the library;Transposon insertion sites analysis results showed that the damaged genes were ecs4206(Phosphoribulo kinase),ecs3959 (Cryptic beta-D-galactosidase subunit beta),ecs3946 (Hypothetical protein),and ecs1857(DNA-binding transcriptional regulator).These antibiotic resistance genes identified in this study were potential targets for antimicrobial agents.Keywords：Escherichia coli;transposon mutagenesis;antibiotic resistance;screening0|7|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to study the influence of curcumin and nisin on matrix metalloproteinase-9 (MMP-9),matrix metalloproteinase (TIMP-1) and cyclooxygenase-2 (COX-2),tumor necrosis factor α (TNF-α ) function in the endometritis of rats serum,the endometriosis model of rats was established.A total of 160 SD rats were randomly divided into bacteriocin group,curcumin group,positive control group,and normal saline group.Samples were taken at 0 h before the establishment of the model and 24,28,and 72 h after the test,and ELISA kit was used to detect MMP-9 in each experimental group,(TIMP-1),cyclooxygenase-2 (COX-2) and TNF-α changes was used to monitor the effects of treatment.The results showed that:1) Before modeling,establishment of the model,the concentrations of MMP-9 in bacteriocin group and curcumin group were significantly higher than that of saline group and positive control group (P<0.05);The concentration of MMP-9 in saline group was significantly lower than other groups (P<0.05);Under the influence of the curcumin and nisin groups,MMP-9 concentration was often associated with the increasing concentration of TIMP-1.2) The concentration of TNF-α in serum was reduced in curcumin and nisin groups.And the concentration of saline group between 0 h and 72 h increased,and serum TNF-α concentration decreased with increasing COX-2 concentration.The results showed that nisin and curcumin significantly increased TIMP-1 in the serum of rats with endometriosis and the expression of COX-2,inhibited the activity of MMP-9 and TNF-α and regulatory pathways and environmental balance inside the uterus.In conclusion,nisin and curcumin displayed positive effect on the concentrations of MMP-9,TIMP-1,COX-2,and negative effect on that of TNF-α.Keywords：rat;nisin;curcumin;endometritis;matrix metalloproteinases;tissue inhibitor metalloproteinases0|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The aim of this study was to investigate the effects of β-carotene treatment model and prevention model on cell viability,ROS,inflammatory factors and NF-κ B p65 protein in LPS-induced RAW264.7 cells.To determine the most suitable concentration and time of β-carotene,the cell viability in two models was measured by MTT.The percentage of ROS was detected by flow cytometry analysis,and the mRNA relative expressions of IL-1 β, IL-6 and TNF-α were measured by fluorescence quantitative PCR.The protein relative expressions of NF-κ B p65 were measured by Western Blot to research the effect of β-carotene on NF-κ B signaling pathway.The results showed that: In LPS-induced RAW264.7 cells,the cell viabilities of treatment model and prevention model were higher and the difference was very significant in treatment model (P<0.01);The percentage of ROS,expression of inflammatory factors and protein NF-κ B p65 were lower than LPS-induced group.In summary, β-carotene promoted the cell viability of LPS-induced RAW264.7 cells and inhibited the percentage of ROS and expression of inflammatory factors,indicating the correlation of the inhibition effect with NF-κ B pathway.Keywords：β-carotene;RAW264.7 cell;cell viability;ROS;inflammatory factor1|8|6<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To provide references for the rational exploitation and utilization of climatic resources,the trend of climate change,especially the abrupt change characteristics of climatic factors in Shaanxi were investigated.Based on the observed meteorological data from 78 meteorological stations,the trend and abrupt change of climate resources,e.g.sunshine time,thermal resources and water,in Shaanxi Province from 1961 to 2014 were analyzed using linear trend analysis,Mann-Kendall abrupt test,nonparametric test and moving-t test methods.The results indicated that:By taking Shaanxi Province as whole,the average temperature,accumulated temperature displayed significant increasing trends.The precipitation and potential evapotranspiration had no significant decreasing trends,sunshine time and wind speed had significant decreasing trends,and aridity index had no significant increasing trend.The abrupt change of temperature occurred significantly in the mid-1990s in Shaanxi as a whole,moreover,it occurred earlier in north Shaanxi than in central and south Shaanxi.The abrupt change of accumulated temperature occurred significantly in the late 1990s,and accumulated temperature occurred significantly in the 2004.There had no tested significantly abrupt change of precipitation in Shaanxi as a whole.However,the abrupt change of precipitation occurred only in the south Shaanxi in the mid-1980s.The abrupt change of sunshine time occurred in the mid-1970s,it occurred earlier in north Shaanxi and south Shaanxi than in central Shaanxi.The abrupt change of wind speed occurred in the early 1990s,it occurred earlier in north Shaanxi than in central Shaanxi and in south Shaanxi.Their abrupt change of potential evapotranspiration occurred in mid 1970s,and there is no abrupt change of aridity index.Although the change trends of temperature,light and wind resource during the period were obvious,their impact on agricultural production and ecological environment had advantages and disadvantages:Significant increase of temperature was beneficial to the growth of overwintering crops,but the risk of crop diseases and insect pests and high temperature stress is also increased.Therefore,decisions about rational exploitation and utilization of climatic resources should be made to develop advantages and avoid disadvantages.Keywords：climate resources;Shaanxi Province;abrupt change;aridity index0|8|7<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
Prediction model on air temperature in large-span greenhouse with different orientation based on CFD
Abstract：In order to increase land utilization efficiency and decrease the necessary distance between two adjacent greenhouses to prevent shading,a south-north large scale greenhouse was designed to substitute conventional east-west direction greenhouse.To assess the performance of the newly designed greenhouse,a prediction model on temporal and spatial variations of air temperature based on the computational fluid dynamics (CFD) technique was established.Discrete ordinates (DO) radiation model was used to simulate the radiation heat transfer in greenhouses.Solar radiation values were calculated by solar ray tracing method.In order to validate the effectiveness of the prediction model,the spatial and temporal distribution values of air temperature were measured and compared with the simulated data.The results showed that the errors between simulated and measured air temperature at the observation points varied from 0.3 to 2.0℃ and the predicted values matched the measured values.The validated CFD model was then used to further analyze the temperature differences in new type greenhouses with south-north and east-west direction at different time.The simulation results showed that the average indoor air temperature difference in both greenhouses was very small at 10:00 am and 14:00 pm.It was because the sun zenith angle is small during the morning and afternoon,meaning that the solar incident angle is big,and the solar radiation transmissivity is small at 12:00 am.The air temperature in south-north greenhouse was 2.8℃ higher than in the east-west greenhouse at 12:00 am.Relative standard deviation (RSD) was also used to evaluate climate uniformity based on the air temperature distribution.The RSD values of 6 combination scenarios were calculated.The study showed that the south-north greenhouse had lower RSD values compared to the east-west greenhouse meaning more climate uniformity of the south-north greenhouse.Keywords：greenhouse;computational fluid dynamics;prediction model;temperature uniformity1|10|11<HTML><L-PDF> <Meta-XML>Updated：2024-02-27- Abstract：In order to tackle the problem that grape leaf image can not be segmented accurately under different light and weather conditions.An improved graph segmentation algorithm is proposed.Firstly,the seed points are automatically selected by G/R and a* color characteristics,and the probability density of the target and the background is estimated by using the mixed Gaussian model.Then based on the Markov random field,the energy function of pixel feature is established.Finally,the cuts are realized by solving the energy function minimization.The effects on segmentation by many different segmentation features are compared.The results shows that single use of G/R or a* gives better result for leaves image in different time and weather.The segementation accuracy can reach 86.74% and 92.38%,respectively.If they are combined into double characteristic,the result of the segementation will be more accurate and the segmentation accuracy can reach 95.03%.Keywords：grape leaf;color characteristics;energy function;graph cut1|10|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Aiming at the problem that there is no uniform and standard evaluation index and evaluation method for the accuracy of automatic driving operation of agricultural machinery based on satellite navigation,by using a set of high precision RTK-GPS receiver,the measurement method of single point static positioning was adopted.The test object was the ridging operation of the automatic driving of agricultural machinery based on satellite navigation.Test data of 4 pieces of land ridging work were collected and analyzed.The ridge to linearity (RL) and the parallelism between the ridge (PBR) were used as the evaluation index.The evaluation method of the accuracy of the automatic driving operation of agricultural machinery satellite navigation was studied.The results showed that:1) The minimum RL value was 2.70 cm,the maximum RL value is 4.59 cm,the minimum RMS value was 3.36 cm,and the maximum root mean square value was 5.55 cm;2) The minimum PBR value was 5.16 cm,the maximum RL value was 16.88 cm,the minimum RMS value is 6.76 cm,and the maximum root mean square value is 24.72 cm;3) According to RL and PBR,the highest accuracy of the automatic driving operation of the agricultural machinery satellite navigation was the No.1 block,the lowest operating accuracy as No.3 block.In conclusion,the evaluation method could be used to evaluate the accuracy of automatic driving operation of agricultural machinery satellite navigation.Keywords：agricultural machinery;satellite navigation;operation accuracy;evaluation method;evaluation index0|14|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The feeding rate prediction of combine harvester was greatly influenced by artificial experience and artificial factors.The power of header screw conveyer theoretically was analyzed intensely through torsion analysis to reveal the dynamic law between the feeding rate of combine harvester and the power consumption of header screw conveyer.An on-line monitoring system was developed based on CAN bus technology to collect the real-time dynamic data of screw conveyer.Experiments were conducted to verify developed model based on the real-time data.The result demostrated and verified that:1) The model between the feeding rate and power of header screw conveyer could be described as mathematical relationship.2) The on-line monitoring system was realizable to collect working data of combine harvester in real time.3) Regression analysis of real-time data showed that the power of screw conveyor and the feeding rate was a mathematic expression (R2=0.909 9).In conclusion,it was feasible to predict feeding rate by monitoring screw conveyer power consumption.Keywords：combine harvester;screw conveyer power;feeding rate prediction;embedded system;CAN bus0|10|9<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Aiming at the existing problems such as the hug membrane device bruising on potato tuber epidermis easily,the low recovery rate of residual film and the phenomenon of tearing plastic film,a field test of combined operation machine for potato harvesting and plastic film collecting was conducted and the recovering part of residual film was improved.Based on the 4U-83 potato harvester,its film feeding device and roller type film rolling device were used for recovering part of residual film.The key parameters of all devices were calculated and determined,and the location of the film pressing wheel was determined,as well as the film feeding device and film rolling device.The results showed that:This machine could smoothly dig and transport potato,and effectively separate soil and potato.The plastic film can be rolled up continuously by the roll film tube and reliably unloaded in convenient.The potato distinct rate reached 97.2%,the damage rate was 3.7%,the loss rate was 4.2%,and the recovery rate of the residual film was 90.1%.In conclusion,the improved operation machine reached the relative technical requirements for the potato machinery harvest and the recovery of the plastic film.Keywords：potato;digging;plastic film;combined operation machine2|11|5<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The spatial distribution characteristics and influencing factors of rural settlements could reveal the development status of rural residents,which has great significance to rural settlements under the rural transformation.Taking Qing'an County as study object,the distribution and scale of rural settlements were analyzed by GIS.The results showed that:The total area of rural residents in Qing'an city was 9 771.83 hm2;The fractal dimension value of rural residential land was between 1.186-1.305 in Qing'an,which was lower than the average settlement;The spatial pattern of rural settlements presented 3 kinds of patterns,e.g.uniformity,randomness and cluster;The residential area kernel density was 0.082-1.227 per square hectometer.With the influence of geography,the central terrain of rural residents was bigger than those of south and north,displaying gathering phenomenon.It is strongly influenced by elevation,slope and stream except the designated town.This study provided the basis and reference for the renovation of typical rural residential area especially flat area which had great productivity.Keywords：rural settlements;patter;regulation;green agriculture;Qing'an County0|9|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The changes of meat price have important influence on people's life and livestock production.In recent years,the range of China's meat price is becoming wider.The prices display strong correlation between different products.To analyze the correlation between different meat prices,the monthly price data is selected in this study to establish the dynamic model of time series based on the recognition of time series' feature.The empirical results show that:There is a strong correlation and a stable equilibrium relationship between different products prices in a long period;Pork price is most closely associated with other livestock prices.Advices on relevant policy making are put forwarded in this study:It is necessary to take full consideration of the correlation between meat prices and let the market and fully play the self-adjustment function of the market.Keywords：meat price;price correlation;seasonal unit roots;dynamic model of time series data0|7|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In Order to investigate the operating efficiency and influencing factors of some listed agricultural products processing companies in China,Malmquist of C2R,BC2,DEA and Tobit models were used to study 29 major listed agricultural companies from 2011 to 2015.The results showed that the operating efficiency of the listed agricultural products processing companies in China was not stable,the lowest was 0.799,and the operating efficiency gap between the companies was large.In terms of the average of efficiency change,technical efficiency was decreased by 1.2%,and the technical level and total factor productivity was increased by 6.9% and 5.6%,respectively.Technology change was the main cause of the total factor productivity change.Pure technical efficiency and scale efficiency changes were not stable resulted inthe unstable of comprehensive technical efficiency change and affecting the total factor productivity ultimately.And the DEA-Tobit regression results showed that the total asset turnover,company scale,and technical staff were correlated with the company operating efficiency positively,and there was no significant correlation relationship between the decomposition of operating efficiency with the concentration of ownership and the age of companies.Keywords：agricultural products processing companies;operating efficiency;influencing factors;DEA-Tobit model2|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore the moderate scale management of the sugar cane farmers,a total of 295 sample data of sugar cane farmers was used,and the sugar cane moderate scale management in Guangxi was measured.The results showed that the optimal size of 1.61-1.84 hm2 per unit of sugar cane farmers in Guangxi by C-D product function was 1.66 to 1.91 times bigger than the current average size of sugar cane farmers.Empirical analysis of the affecting factors of cane scale management showed that:Whether sugarcane had been grown in slope and employed labor had significant negative impacts on sugar cane farmers moderate scale management;Sugarcane planting space,whether the space could access to planted on path tractor ploughing road and family neat income had significant positive influences on sugar cane farmers moderate scale management.In conclusion,to promote sugarcane moderate scale management,more attention should be paid on the improvement of sugarcane production condition,scientific planting pattern,and the benefit of sugarcane planting.Keywords：sugar cane plant;moderate scale operation;sugar cane farmers;factor of influence;Guangxi0|8|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Based on the survey data of 561 farmers,the statistical description method and the Logistic model were used to analyze farmers' requirements for agricultural machinery and factors influencing their purchasing behavior.The results indicated that there was 39.9% of farmers purchased agricultural machinery and 70.8% of farmers mainly got agricultural services from individual farmers.On the whole,the mechanization degree of agricultural production in descending order was as follows:transport,plowing and leveling,harvesting,planting,irrigation,processing,storage and plant protection.Farmers' demand for different agricultural machinery in descending order was as follows:plowing and leveling,harvesting and processing,fertilizing,planting,irrigation,plant protection and transport.Household income,the proportion of agricultural income,demonstration households,agricultural enterprises,cultivated area,distance from town and purchase subsidies were positively and significantly correlated with the purchasing agricultural machinery,whereas service attitude played significant negative effect.Keywords：agricultural machinery requirements;purchase behavior;farmers;logistic model;factors1|9|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Farmers are ultimate recipients and adopters of agricultural technology and they have a leading role in the promotion of agricultural technology.In order to improve agricultural technology adoption rate,promote agricultural technology extension,guarantee food security of our country,the research contents, methods, perspectives of agricultural technology adoption behaviors of both domestic and foreign farmers were systematically reviewed.This research provided references for further study of agricultural technology adoption behavior of farmers,promoting agricultural technology into practical productive forces, food production capacity and ensure food security of our country.Keywords：farmers;agricultural technology;adoption behavior0|7|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
