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- Abstract：Aim of this study was to explore the effects of postponing N-fertilizer application by drip fertigation on photosynthesis improvement,kernel capacity regulation and yield-increasing effect in summer maize.Hybrids with different kernel sink capacity,Denghai 605 and Zhengdan 958,were taken as study object.Four nitrogen (N) fertilization treatments including N-fertilizer applied 100% at sowing (CK),40% at sowing and 60% at 12-leaf stage (V12),40% at sowing and 60% at silking stage,40% at sowing,20% at V12 and 40% at silking stage were implemented by drip fertigation.The effects of postponing N-fertilizer application on the characteristics of source-sink and yield formation were investigated.Compared to CK,dressing N at the late stages could increase photosynthetic rate of ear leaf by 14.4%-33.3% in Denghai 605 and 6.1%-16.9% in Zhengdan 958.Zeatin riboside content,water content and volume during the late lag period were increased by 9.4%-53.0%,5.2%-13.5%,5.1%-13.5% in Denghai 605 and 9.7%-45.9%,12.5%-36.4%,5.6%-30.6% in Zhengdan 958,respectively.The improvement in the characteristics of source-sink enhanced grain filling rate,and grain filling rate during the fast filling period increased 0.66-2.24 mg/(kernel·d) in Denghai 605 and 0.65-1.64 mg/(kernel·d) in Zhengdan 958.In the end,the kernel weight of the two hybrids and the ear kernel number of Denghai 605 were stimulated,and grain yield were improved by 5.8%-13.6% in Denghai 605 and 5.1%-12.4% in Zhengdan 958.In conclusion,postponing N-fertilizer application ensured the N requirement during whole period for summer maize,improved the characteristics of source-sink,and promoted grain yield.The treatment of 40% N-fertilizer applied at sowing,20% at V12 and 40% at silking stage showed the most obvious effect.Keywords：summer maize;drip irrigation;postponing N-fertilizer application;sink capacity;yield0|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Pot experiment was adopted to explore the possibility of soybean drought tolerance of Fendou 65 and Zhongzuo 3088 under drought stress conditions and well-watered treatment at seed filling stage.Tolerance to drought stress with the established method of 7 soybean cultivars was evaluated.The results showed that:Soybean seed filling rate decreased or even stopped when soybean suffered drought stress for several days at seed filling stage;Pod thickness appeared a sharp compensation increase after re-watering,but the late seed filling rate of drought-stressed soybeans was lower than that of under well-watered treatment;Zhongzuo 3088 displayed higher tolerance to drought stress than Fendou 65;Under the same conditions of drought stress,drought-tolerant soybean was characterized as delayed canopy wilting,higher seed filling rate in the period of drought stress,and better compensation ability for seed filling after re-watering.Based on the comparison of average drought resistance coefficient and subordinate function value at seed filling stage,Lu 96150,Handou 5 and Qindou 11 were ranked as higher tolerance cultivar,Zhonghuang 35 and Qindou 8 as normal tolerance cultivar,and Fendou 65 and Zhonghuang 30 as less tolerance cultivar.In conclusion,soybean seed filling rate estimated by pod thickness was well responded to drought stress indicating its potential to evaluate soybean drought tolerance at seed filling stage.Keywords：soybean;drought stress;pod thickness;seed filling rate;seed filling period;pot experiment0|6|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to accurately estimate the evapotranspiration of spring maize at different growth stages,the applicability of six daily evapotranspiration models (Combined method,FAO 56-Penman-Monteith;Temperature-based methods,Hargreaves-Samani and Blaney-Criddle;Radiation-based methods,Makkink,Jensen-Haise and Priestley-Taylor) were evaluated in spring maize farmland ecosystem.This study was conducted based on latent flux data from eddy covariance during 2007—2008 at Jinzhou Agricultural Ecosystem Research Station and by using the linear weighted sum method and three statistical indicators:correlation coefficient,mean bias error and root mean square error.The results showed that:1)The average daily variation of evapotranspiration at different growth stages was expressed as a single peak curve and the maximum of daily evapotranspiration appeared at initial stage of flowering;2)Different canopy density differences of spring maize at different growth stages displayed effect on evapotranspiration.The general evaluation results indicated that the radiation-based models performed better than combined and temperature-based methods excluding Priestley-Taylor model;3)The calibrated Blaney-Criddle model in seedling stage,the original Jensen-Haise model in heading stage and the calibrated Makkink model in flowering stage accurately evaluated the evapotranspiration of spring maize.In conclusion,the results provide references for estimating daily spring maize evapotranspiration at different growth stages in Northeast,China.Keywords：spring maize;evapotranspiration;models simulation;growth stage;applicability1|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The aim of this study was to explore the correlation between the calf birth weight and the adiponectin in cows' venous blood,placenta,cord blood and calves' venous blood.Based on the calf birth weight,54 healthy Chinese Holstein cows with normal delivery term were divided into 3 groups:Group A (≤40 kg,n=9),Group B (40~45 kg,n=25) and Group C (≥45 kg,n=20).ELISA was used to evaluate the level of adiponectin in cows' venous blood,placenta,cord blood and calves' venous blood.The correlation between adiponectin and calf birth weight were analyzed by correlation analysis method for further study.Adiponectin levels in cows' venous blood ((29.15±4.02)mg/L) were significantly higher than that in cord blood ((13.79±1.14) mg/L) and calves' venous blood ((13.46±0.94)mg/L) (P<0.01);Adiponectin levels in cows' cord blood were higher than that in venous blood of calves,but the differences were not significant (P>0.05).Adiponectin levels in cows' venous blood had no significant correlation with that in placenta,cord blood and calves' venous blood (P>0.05) and adiponectin levels in placenta also had no significant correlation with that in cord blood and calves' venous blood (P>0.05).However,adiponectin levels in cord blood had highly significantly positive correlation with that in venous blood of cows (P<0.01).The calf birth weight had no significant correlation with the adiponectin levels in cows' venous blood (P>0.05),while it had highly significantly positive correlation with adiponectin levels in cord blood and placenta (P<0.01) and had significantly positive correlation with adiponectin levels in calves' venous blood (P<0.05).Adiponectin levels in cows' venous blood,placenta,cord blood and calves' venous blood had no significantly differences between male and female calves (P>0.05).In conclusion,adiponectin levels in cows' cord blood and placenta showed highly significant influence on the calf birth weight,adiponectin levels in calves' venous blood influenced calf birth weight to a certain extend,while adiponectin levels in cows' venous blood had no significant influence on the calf birth weight.Keywords：adiponectin;venous blood;placenta;cows;calf birth weight0|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The aim of this study was to study the antibacterial effects of 16 Chinese herbal medicines on 5 different serotypes of pathogenic Escherichia coli (O1、O2、O8、O78and O86) in vitro.The diameter of inhibition zone was determined by Oxford cup method.Micro dilution and plate method were determined by minimal inhibitory concentration (MIC) and minimum bactericidal concentration (MBC).1)Lonicera japonica and Coptis chinensis had the best inhibitory effects on E.coli O1,and the inhibition zones were 29.35 and 37.71 mm respectively.Schisandra chinensis had the best inhibitory effect on E.coli O8 the inhibition zone was 28.97 mm.2)The MIC of L.japonica and C.chinensis on E.coli O1 were 0.016 and 0.008 g/mL respectively.The MIC of S.chinensis on E.coli O8 was 0.008 g/mL.All herbs displayed better inhibitory effects.3)Polygonum cuspidatum had the worst inhibitory effects,inhibition zone,MIC and MBC were not detected.The inhibition zone of L.japonica,C.chinensis and S.chinensis on 5 different serotypes were above 15 mm and reached significantly sensitive,Radix sanguisorbae,Andrographic,P.cuspidatum,R.bupleuri,golden cypress and Pomegranate husk were not sensitive.L.japonica,C.chinensis,P.multiflorum,R.sanguisorbae,S.chinensis and Cortex fraxini displayed better inhibitory effects on 5 different serotypes.0|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To investigate the influence of different application method of boron (B) on seed yield and quality of alfalfa (Medicago sativa L.) in B deficiency conditions of Chifeng area,field experiment was conducted in 2-year old alfalfa cv Gongnong No.1 treated by furrow and foliar application.For furrow application(B1),5.3 kg Borax/hm2 was applied to the furrows at initial flowering stage.For foliar application,0.70% Borax solution was sprayed once (B2) and twice (B3) during flowering stage.The pollen number and viability,B content,seed yield and quality of alfalfa were compared and investigated to determine the optimal methods for B application in alfalfa seed production.The results showed that all three different application methods of B increased the seed yield of alfalfa,and the foliar application was better than that of B1,but the seed quality of B1 was better than that of foliar application.B1,by increasing pod setting rate and seed setting rate,increased seed yield;B2,by improving the seed number,seed weight and pod setting rate,increased seed yield.However,it reduced the germination percentage and germination potential;B3,by increasing the number of racemes/stem,number of flowers/raceme,number of pods/raceme and pod setting rate,increased seed yield.However,increased the number of dead seeds and decreased the germination rate.B2 obtained the highest alfalfa seed yield,but it adversely affected the quality of the seeds.The results suggested that the optimum B application method of alfalfa for seed production was B3.2|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The purpose of this study was to detect biochemical indexes and genes related to cold and heat stress and non-stress in Sanhe cattle.Using real-time fluorescence quantitative PCR and ELISA,the expression quantity of HSP70 family genes (HSPA1A,HSPA1B ,and HSPA8) mRNA in lymphocyte and concentrations of CK,LDH,GLU and BUN in serum were detected respectively after cold stress,heat stress and non-stress time.The results showed that CK and LDH activity in serum of cows were higher than non-stress time during cold and heat stress time,especially remarkably rose during heat stress (P<0.05).The content of GLU was remarkably lower than non-stress time during heat stress time (P<0.05).The content of BUN showed no remarkable changes during heat stress time.The content of GLU and BUN were remarkably higher than non-stress time during cold stress time (P<0.05).Three HSP70 family genes mRNA expression quantities in lymphocyte of Sanhe cattle were increased during cold and heat stress.The results indicated that high and low temperature changed the activities of enzyme,glucose and protein metabolism in serum.Enhanced expressions of HSP70 family genes mRNA during cold and heat stress time improved the function of animal self-protection and enhanced resistance to adverse external stimulate.Keywords：Sanhe cattle;cold and heat stress;enzymatic activity;biochemical parameters of nutrition metabolism;mRNA expression quantity0|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：This study was to discuss the effect of proanthocyanidins on the liver function of iron overload rats according to test the iron content,level of liver alanine aminotransferase (ALT) and aspartate aminotransferase (AST),the liver pathological changes,transferrin receptor-2 (TfR2) and hepcidin gene expression.Forty healthy male SD rats were randomly divided into 4 groups:Control group,proanthocyanidins group,iron overload group and test group.The rat liver were collected.ICP method was then used to measure the content of Fe supplemented with the identification of liver Prussian blue stain to check whether the iron-overloading rat model was set up successfully.The levels of ALT and AST were measured by related kits.HE staining was used to decide the liver pathological changes. TfR2 and hepcidin gene expressions were examined by real-time PCR.Results comparison showed that the content of Fe and the level of ALT and AST in the overload group increased significantly (P<0.05).The liver tissue structure was disorder severely.hepcidin gene expression decreased significantly (P<0.05) and TfR2 gene expression did not change significantly (P>0.05).Compared with the control group,the content of Fe decreased significantly in the proanthocyanidins group (P<0.05) while the activity of ALT and AST did not change significantly.No obvious lesion was observed in the liver tissue.The gene expression of TfR2 and hepcidin both decreased significantly (P<0.05).Compared with the iron overload group,the level of ALT and AST in the test group decreased significantly (P<0.05).The liver tissue disorder was reduced.The content of Fe, TfR2 and hepcidin gene expression all decreased,but there were no significant differences.In conclusion,proanthocyanidins could restrain the intake of iron.In the condition of the body's iron overload,proanthocyanidins can improve liver function to a certain extent through inhibiting iron absorption.Keywords：iron overload;proanthocyanidins;ALT;AST;hepcidin;TfR21|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To identify the effects of biogas residue application on the soil environment,we carried out a pot experiment of four treatments.Which were BR (biogas residue),OR (organic fertilizer),CF (chemical fertilizer) and CK (unfertilized) was conducted.The structure of soil nematode community was analyzed to evaluate the effect of the different fertilizer applications on soil health.Nematodes were classified into four trophic groups:bacterivores,fungivores,plant parasites and omnivore-predators.Nematode ecological indices were used to evaluate soil quality and food webs.These included a maturity index for nematodes with cp2-5 (MI2-5),enrichment index (EI),structure index (SI) and basal index (BI),which were calculated using the online NINJA program.The ratio of fungivores to bacterivores (FB),and the ratio of omnivore-predators to plant parasites (OPPP) were also calculated.The Shannon index (H') and genus dominance (D) were also computed to describe nematode diversity.The results showed biogas residue stimulated populations of enrichment opportunists.The number of nematode found in this treatment was higher than in other treatments.A total of 22 genera were recorded,and bacterivores were dominant in all treatments.However,the composition of bacterivores differed among treatments.Most nematodes observed in BR were cp1 guilds (Rhabditidae),while the proportion of cp1 and cp2 nematodes were approximately equal in OR.In both CF and CK soils,cp2 guilds were the most dominant bacterivores.The relative abundance of omnivore-predators was significantly higher in OR treatments compared with other treatments (P<0.05).Biogas residue application suppressed plant feeders,compared with OR,CF and CK treatments.The maturity index for nematodes with cp2-5 (MI2-5),basal index and fauna analysis consistently showed that adding biogas residue to soil formed the healthiest soil environment compared with other treatments,with a structured soil food web and enriched soil condition.Chemical fertilizer and unfertilized treatments presented stressed soil conditions.The FB index indicated all treatments were bacteria-based decomposition.The OPPP index suggested a stronger control of predatory nematodes on herbivorous nematodes in BR soils compared with CF and CK soils (P<0.05).No significant correlation was found between two soil properties (available potassium and electrical conductivity) and nematode indices (P>0.05).Soil organic matter,total nitrogen and available phosphorus were significantly correlated with most of the nematode indices (P<0.05 or P<0.01).In general,MI2-5,EI and SI indices were positively correlated with soil nutrient content (P<0.05 or P<0.01),while BI and FB indices were negatively correlated (P<0.05 or P<0.01).In conclusion,the results obtained in this study suggested that application of biogas residue was a better option for soil health,at least in the short-term.It is found that biogas residue had potential ability to suppress plant parasites.However,the mechanisms and regulations of this topic need further study.Keywords：nematode;community;biogas residue;ecology indices;soil health1|11|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Cultivated land resource identification is one of the most important technology to guarantee the safety of food strategy.Based on existing research, from the aspects of precipitation,productivity of cultivated land,potentiality of grain production and quality of cultivated land,a new model based on soil property and terrain features is presented to identify cultivated land resource in Jinxi irrigation area.The model is presented on the platform of ArcGIS.The results show that:Of the total 1 200.59 km2,568.334 km2 is the most suitable for cultivation;5.92 km2 is more suitable to cultivate;The area of cultivated land reaches 564.15 km2 after revision and the rest do not fit cultivate.By taking account of two features,the cultivated land is about 62.19 km2.Compared to traditional methods,the new model is more comprehensive,objective and precise.Keywords：cultivated land identification;soil properties;terrain features;Jinxi Irrigation Area2|9|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：A comprehensive evaluation system and grading system were established in order to provide technological support for screening,cross breeding,development and utilization of Phalaenopsis germplasm resources.Main traits of 213 varieties were observed and counted in 2010—2012.A system was established by means of variation analysis,principal component analysis,analytical hierarchy process,cluster analysis and discriminant analysis.The results showed that:The average coefficient of variation of 18 quality traits was 34.28%,the pedicel lateral branch number was the largest and the coefficient of variation was 128.45%,and the smallest coefficient of variation of type was 9.71%.The 18 evaluation variables could be compressed into ten factors which determined 16 quality evaluation indicators e.g.plant width,leaf length,leaf width,peduncle number,pedicel lateral branch number,pedicel length,pedicel thick,flower length,flower wide,petals thickness,flower number,flower space,flower color,disease index,flower fragrance,type.Probability distribution and analyticalhierarchy process were used to grade the quality indicators.Four quality discriminant functions were established by K-means clustering analysis and discriminant analysis,and 90.1% of original samples had been classified correctly,88.3% of 90.1% original samples were correct classification in cross validation,resulting in high discriminant function of quality has high accuracy;Two hundred and thirteen varieties of Phalaenopsis were clustered into 4 grades by K-means cluster and there were 70 varieties graded excellent(32.86%),19 graded good(8.92%),77graded moderate(36.15%)and 47 graded poor(22.07%).The above methods analyzed and evaluated germplasm resources from different views,and gained the quantitative results,evaluation standard and discriminant function which could comprehensively and objectively evaluate the quality of Phalaenopsis,and reflect the effectiveness of the evaluation system and classification standard.Keywords：Phalaenopsis;quality traits;principal component analysis;analytical hierarchy process;cluster analysis;discriminant analysis;comprehensive evaluation5|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Physical and biological properties of winter jujube in different maturity stages were studied in order to achieve mechanical selective harvesting.The results showed that:The density of winter jujube (902.15,911.68 and 947.06 kg/m3) was increasing from under maturity to crisp maturity stage.The firmness (17.26,16.24 and 13.9 kg/cm2) was decreasing from under maturity to crisp maturity stage.There were significant differences between density as well as hardness of crisp ripe fruits and that of white ripe and under ripe fruits.The detachment force between stem and branch is larger than that between fruit and stem,and both of them were decreasing as the fruit ripening.Therefore,the fruit detachment occurred at the location between stem and fruit under vibration harvesting.There was a significant difference in the detachment force of fruit and stalk between the white ripe fruits and the crisp ripe fruits,which indicated a possibility of selective mechanical harvesting.The compression curves of white ripe and crisp ripe fruits changed with a similar trend that both have not the bioyield point.The average maximum rupture force of white ripe fruits (145.77 N) was significantly greater than that of the crisp ripe fruits (128.95 N).The elastic modulus of the white ripe fruits (2.09 MPa) was slightly larger than that of the crisp ripe fruits (1.89 MPa).There was no significantly difference among elastic modulus.Before fruits rupture,linear function can be used to express the relationship between force and deformation.3|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To study the movement of potato on the swing separation sieve of potato digger and the effect of absolute speed of potato on the performance of separation sieve,the characteristics of potato movement relative to separation sieve are analyzed theoretically and the absolute velocity of potato movement formula is deduced.An experiment was conducted to study the movement characteristics of potato relative to separation sieve in the separation process of potato and soil by using high speed video technology.The theoretical analysis results are checked by field experiment to obtain the correction coefficient between the test value and the theoretical value of absolute velocity of potato in sandy soil and clay.The result shows potato goes through continuous forward and reverse slip movement.The results of high speed video test are in good agreement with theoretical analysis.The experimental absolute velocity of potato in sandy soil is greater than the theoretical value,and its correction coefficient is 1.02.The absolute velocity of potato in clay is less than the theoretical value,and the correction coefficient is 0.89.Keywords：potato digger;swing separation sieve;potato;velocity3|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The time of farrowing judgment usually relies on human observation,not only causes work complications,but also leads to problems by keepers own subjective experience.A system to monitor the behavior of sow is designed based on ultrasonic sensors and wireless sensor networks.Nodes of the system collect the distant information of head,back and tail of the sow,and transmit data obtained to gateway node in real time.The distant information is then transmitted to server from the gateway.Server uses K-means clustering algorithm to identify and classify saw's behavior.Testing results confirm that the system could quickly collect sow's physical activity,classify its behavior and detect its nesting,lying and standing behavior.The average correct rate is 90.47%,and the performances of the system are stable during the test.A non-contact method of monitoring the behavior of sows is proposed and provides a basis for predicting the time of farrowing.Keywords：sow;ultrasonic sensor;behavior analysis;K-means clustering algorithm;wireless sensor network1|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to solve the problem of low efficiency of solar greenhouses back wall,a new heating storage type solar greenhouse was built in alpine areas.The experimental greenhouse and an ordinary solar greenhouse were measured in The indoor temperature,soil temperature and different parts temperature of the back wall.The result showed that:Compared with ordinary greenhouse,the experimental greenhouse air temperature was 2.1 ℃ higher on average at night in clear day and 0.9 ℃ higher in overcast day;From the aspect of humidity,it was reduced by 4.7% on average in day and 2.6% at night in clear day.While in overcast day,it was reduced by 2.7% on average in day and 2.2% at night;Soil temperature of the experimental greenhouse was 1.69 ℃ higher on average in clear day and 0.59 ℃ higher in overcast;Heat storage layer was 320-520 mm depth of the wall.During tomato growth period,the advantages in tomatoes height and stem diameter were obvious.The yield of tomato in the heating storage type solar greenhouse was 17.8% higher than the ordinary greenhouses.Keywords：active heating storage;soil temperature;humidity;plant height;stem diameter;yield0|13|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to provide a possible way to implement variable rate fertilization technology in rural areas of Southern Jiangsu,a simple method for obtaining the prescription of farmland fertilization was put forwarded according to Southern Jiangsu's agricultural production experience.A variable rate fertilization electronic prescription map system combined with Baidu map API was constructed and the structure and realization method of the system were introduced.The construction of electronic field map and the method of rapid location identification based on ordinary precision GPS module were also introduced in detail.A total of 13.3 hectares of experimental plots in Shuangyulong,Nanjing,Jiangsu Province,was taken as study case.The electronic prescription map system was constructed and embedded into an Android device.Experiments for testing the performance of the system and variable rate fertilization test were carried out in those natural fields.The results showed that the system test data were stable and the accuracy of location identification reached 86.8% after Kalman filtering location information data from the GPS module when the testing points located in a distance less than 2 m from field boundary.The accuracy of location identification reached 100% when the distance was more than 2 m.In the system,the relative error of actual sowing rate was less than 5.9% indicating that the system effectively identified the location of the operation,and showed the ability to guide the field variable fertilization.In conclusion,the system has popularization and application prospects in Southern Jiangsu rural area.Keywords：Baidu map API;electronic prescription map variable rate fertilization;GPS;location identification0|9|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To explore the capability of anaerobic biofilm reactor to treat high concentration organic waste water and the variation of microbial diversity in the reactor,biofilm reactor with carbon fiber carrier was used to handle yeast waste water by gradually raising feeding concentration.Hydraulic retention time (HRT) was controlled to 6 d in this study.The results showed that:The volumetric efficiency of gas production increased from 0.06 to 0.14 and 0.37 L/(L·d);During the process of upgrading,the influent COD concentration was 2 798 mg/L at startup phase and increased to 5 596 and 13 990 mg/L;The average methane contents were 57%,71% and 74% respectively,and the average COD removal rate were 45%,64% and 65% respectively.The reactor displayed strong resistance capability to organic loading shocks.When influent COD concentration continued increasing to 22 980 mg/L and the corresponding COD volume loading was 4.70 g/(L·d),the COD removal rate reduced to 49%,and pH was remained at 7.7,the average methane content was 66% and the volumetric efficiency of gas production further increased to 0.58 L/(L·d).It was found that over feeding volume loading improved the volumetric efficiency of gas production,but also caused the decreasing of gas conversion efficiency.High-throughput sequencing results showed that marsh-microbes in the bio-reactor gradually stabilized with the organic loading increasing and the operation time elapsing.And the main archaea and bacteria of microbial community in the reactor were Methanospirillum,Methanosaeta,Methanobacterium and Acidovorax,Sporosarcina,respectively.The proportion of dominant microorganisms was 58%.The proportions of archaea and bacteria of marsh liquid in start and stable phase were 69.23%,30.77% and 66.86%,33.14%,respectively.The proportion of methanogens in archaea communities was raised from 33.11% (initial stage) to 76.70% (stable stage),and hydrogenotrophic methanogens became the dominant microorganism in archaea community which was increased from 24.67% (initial stage) to 60.13% (stable stage).Keywords：yeast wastewater;biogas fermentation;biofilm reactor;microbial community structure;bio-methane0|11|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to provide theoretical basis to improve Farmland Tax Occupation system and promote the management of agricultural land resources and assets,a series of standard expropriation of orchard,forestland and grassland occupation tax on provincial scale were measured based on the gradation results of arable land tax classifications and national statistics.From the perspectives of production capacity,scarcity,economic development level and local uniqueness,indicators of expropriation standards of orchard,forestland and grassland occupation tax were built.Then,we determined Weight combination was then determined according to results of Analytic Hierarchy Process and Delphi and calculated comprehensive scores of orchard,forestland and grassland occupation tax in different provinces,autonomous regions and municipalities through Multi-objective Linear Weighting Function.Corresponding expropriation classification was determined according to established rules (Orchard and grassland occupation tax had 5 standards respectively,and forestland had 10 standards).Corresponding expropriation standards of expropriation classification were obtained at last through numerical simulation method and correction factor method suggesting that different regions multiplied the tax by a coefficient based on actual situation (Basic expropriation times 1.50,2.50,2.50 or 3.00 to get orchard occupation tax,basic expropriation times 1.50,2.00 or 3.00 to get forestland occupation tax,basic expropriation times 1.25,1.50,1.75,2.00 or 3.00 to get grassland occupation tax).The measurement results of orchard,forestland and grassland occupation tax and current occupation tax were respectively analyzed in this study and confirmed that measurement results were reasonable.Keywords：orchard;forestland and grassland;expropriation;classification;standards2|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to analyze the characteristic of fluctuation and transmission of major beef cattle industry chain,prices of major beef cattle industry chain from January 2012 to October 2015 are used,and a Markov Switching Vector Autoregression Model is established.The results show that the prices of the major beef cattle industry chain have significant regime switching effect,which change from abnormal regime to normal regime.And the history of the prices can be divided into two stages,the year of 2012 to the first half year of 2013 and the second half year of 2013 to 2015.Besides,the probability and average duration of the prices in normal regime is bigger than that in abnormal regime.While the transition probability between those two regimes is low indicating the prices fluctuation is smooth.Furthermore,it has obvious transmission effect in the beef cattle industry chain,and the feeder cattle price plays a leading role in this sector.In normal regime,the transmission effect has great difference with the abnormal regime.The transmission effect in the abnormal regime is heavier than that in the normal regime.The duration of the prices transmission lasts generally more than six months.Keywords：beef cattle industry chain;price fluctuation;price transmission;nonlinear;MS-VAR model0|9|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to get an insight into the regularities of price fluctuation of bulk agricultural products in China and foreign countries,complex networks and statistical physics are used to analyze the differences of corn.Wheat,corn and soybeans are taken the study objects of bulk agricultural products in China and the Americas market to investigate the variation regularity,strength distribution and cluster coefficient of bivariate correlation fluctuation modes.Research results show that:The soybean price fluctuation in China and foreign countries is mainly effected by weak positive correlation;The price of wheat displays a weak negative correlation,and the corn price stays more balanced between the positive and negative correlation fluctuations;The correlation fluctuation of three kinds of agricultural products shows different clusters and periodicity.The fluctuation of bivariate correlation is transmitted and evolved by a few modes.Countermeasures and suggestions about price adjustment and control are proposed on the cycle and trend of price fluctuation of agricultural products at domestic and abroad in this study.Keywords：agricultural products price;complex networks;correlation fluctuation;symbolic dynamics3|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Conservation tillage technology has important significance for the smooth implementation of food crop production strategy on farmland management.To reveal the decision-making mechanism of adopting new conservation tillage techniques among new agricultural business operators,large crop-land owners are taken as study object.New agricultural business operators' behavior decision on conservation tillage technology is also analyzed.Using Logit model,the effect of technology demonstration to the behavior decision is verified based on the research data in Liaoning Province.In conclusion,technology demonstration can reduce the famers' expected risk and increase the expected return and enhance probability of the farmers adopting conservation tillage technology.In the process of promoting conservation tillage technology,technology demonstration plays key role.Keywords：conservation tillage technology;technology demonstration;large crop-land owner;subjective risk function0|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore the impact path of labor migration on the health of the elderly in rural areas,China Health and Retirement Longitude Survey (CHARLS) is used and path analysis method is applied to examine the mediating effect of financial and emotional support,labor supply and taking care of grandchildren between labor migration and the health of the elderly in rural areas.The results show that:1)Financial and emotional support,labor supply and taking care of grandchildren play an intermediary role on the effect of labor migration on the health of the rural elderly.Elderly labor supply and grandchildren care display more obvious positive mediating effect to physical health of the elderly and emotional support has more significant negative mediating effect to mental health.2)Interactions exist between some intermediate variables.On one hand,the financial support of the children has weakened the visit frequency of children and reduces the labor supply of the elderly.On the other hand,taking care of the grandchildren by the elderly helps to increase the financial support of their children,but it generally reduces emotional support.3)Among all the mediating effects,the effect of the lack of children's visit on the health of the elderly is greater than that of the rest.Therefore,for the elderly current left behind,emotional support,especially children's visit plays a very important role.Keywords：labor migration;rural area;the elderly;health;path analysis0|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
