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Study on the water deficit trend of summer maize in recent 35 years in Wuqiao County, Hebei Province
Abstract：To improve the WUE and grain yield of summer maize and make the best of rainfall in limited irrigation conditions in Heilonggang, based on summer maize yield and observed daily meteorological from 1981 to 2015, the crop water requirement, coupling degree between rainfall and water requirement, crop water deficit index (CWDI) and influence of CWDI on summer maize yield in the growth periods of summer maize were analyzed by SIMETAW model. The results showed that:1) In recent 35 years, CWDI in the summer maize season was not significantly decreased with time, while coupling degree between rainfall and water requirement not significantly increased, and the water requirement of summer maize increased significantly. The extension of growth period was the dominant factor for the increase of summer maize water requirement, and the growth period extended more than 20 days in recent 30 years. 2) The main drought types in summer maize growth period, no drought and light drought probability, were respectively 51.43% and 45.71%. From seeding to emergence period and from tasseling to maturity period, CWDI were the highest. 3) In general years, when the coupling degree between rainfall and water requirement were high, rainfall could offer summer maize basically enough water. However, in serious water deficit years, maize should be irrigated between tasseling and maturity period.Keywords：summer maize;water requirement;drought;crop water deficit index;Heilonggang area2|7|5<HTML><L-PDF> <Meta-XML>Updated：2024-02-27- Abstract：Oat variety Baiyan 2 was used as study object to investigate the effects of humic acid (HA) on the sugar components and endogenous hormones of oats under severe drought stress by HPGC-MS. Using potted plants, four treatments with different amounts of water and spraying humic acid (Normal water condition; Normal water condition spraying humic acid; Severe drought stress; Severe drought stress spraying humic acid) were set up. The results showed that:1) Ribose and sucrose were the main sugars of humic acid to relieve severe drought stress. Compared with CK, the ribose content of SS increased by 5.78%, sucrose increased by 83.08%,and the difference was significant (P<0.05 the same below). After spraying humic acid severe drought stress, sucrose and ribose decreased significantly. 2) Compared with the control, the contents of ABA, JA and SA were significantly increased and the content of IAA significantly reduced under severe drought stress. Under severe drought stress after spraying humic acid, the contents of ABA, JA and SA were significantly decreased. 3) The content of JA was positively correlated with xylose such as xylose, fucose and ribose. The correlation between SA and sugar was similar to that of ABA and sugar, and the content of SA was negatively correlated with fructose and glucose content. In conclusion, the humic acid could relieve severe drought stress by regulating soluble sugar components and endogenous hormones.Keywords：oat;humic acid;sugar;endogenous hormone;drought stress2|8|9<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore the elite germplasm resources of Sophora flavescen, EST-SSR markers were developed using the existing EST resources, the genetic diversity of the herb from various geographic locations was analyzed, and their DNA fingerprints were constructed. SSR information was obtained from NCBI by bioinformatics methods, and EST-SSR primers were designed by the software Primer 5.0 Plus. The DNA samples of Sophora flavescens were used as templates in PCR amplification with polymorphic primers. Their genetic diversity was analyzed based on UPGMA clustering. DNA fingerprints were constructed. A total of 92 Unigenes were obtained from Sophora flavescentis EST data bank, among which 126 simple sequence repeats were distributed in 61 Unigenes accounting for 66.30% of the total number of Unigenes. The frequency of SSRs was 0.512 kb. Penta-nucleotide and hexa-nucleotide repeats were the dominant types among the obtained Unigenes accounting for 68.05% and 25.40%, respectively. No trinucleotide appeared. AAAAT/ATTTT and AAGTGG/CCACTT were respectively the most abundant motifs for penta-nucleotide and hexa-nucleotide motifs. The 65 pair primers were designed by Primer 5.0 and 26 pairs of which were randomly synthesized. Among them, 18 pairs produced clear and stable bands. The genetic diversity of 48 samples from 12 geographical populations was investigated. A total 77 loci with an average of 4.3 loci for each pair of primers were detected, and the polymorphic primer ratio was 69.2%. The materials were divided into 5 groups according to the genetic relationship in Clustering. Materials with the same or close origins were clustered into one group, indicating their geographical distribution characteristics. Two pairs of core primers DYH011 and DYH018 were selected, and the DNA fingerprints of Sophora flavescens were constructed, which could be used as a basis for the rapid and accurate identification and traceability of different geographical sources.Keywords：Sophora flavescens;EST-SSR;marker development;genetic diversity;fingerprinting0|8|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
Primary screening of high phosphorus use efficiency of rice varieties under NH-N and NO-N conditions
Abstract：The aim of this study was to provide theoretical basis for screening rice varieties with high phosphorus efficiency by investigating the aboveground biomass, phosphorus content and phosphorus accumulation of different rice varieties under same concentration of NH4+-N and NO3--N. A of 102 rice varieties at seedling stage were taking as study material. The subordinate function of interval[0, 1] was adopted to standardize the evaluation indices of rice standardized using. The 102 rice varieties were classified based on the integrated value of phosphorus efficiency and hierarchical cluster analysis. There were significant differences in leaf, root and whole plant stem, as well as P accumulation in roots, stems and leaves of the different rice varieties under same NH4+-N and NO3--N incubation conditions, and the coefficients of variation were ranged from 52.83% to 69.54% and from 52.82% to 73.82%, respectively. Different rice varieties had same principal components under both NH4+-N and NO3--N conditions. The first principal component, which reflected the biomass indices and P accumulation, was mainly determined by the whole plant, stem, leaf and root biomass, as well as accumulated P in the whole plant, stem and leaf and root. The second principal component was determined by P content in different parts of rice plants. By integrating variation characteristics and statistic analysis of P uptake and accumulation in rice, the whole plant biomass, stem and leaf biomass, root biomass, whole plant P accumulation, stem and leaf P accumulation and root P accumulation were considered as indices to evaluate high P use efficiency potentials of rice varieties at seedling stage. The rice varieties of ‘2845’, ‘ZS2503’, ‘HRD’, ‘LJ 7’, ‘DX 4103’, ‘YY 9’, ‘ⅡY 602’, ‘LY 766’, ‘YJ 11’, ‘FLY 80’ and ‘SLY 1813’ were identified as the high P use efficiency varieties under both NH4+-N and NO3--N conditions.2|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27- Abstract：To optimize the regeneration system of grape, the regeneration system of Vitis vinifera×V.labrusca ‘Hei Xiangjiao’ leaf, petiole and shoot apical meristem were optimized, and the regeneration effects of different organs were compared. The results showed that:The optimum media for the regeneration of adventitious buds from leaf is MS +2.0 mg/L 6-BA + 0.1 mg/L IBA, but the regeneration rate is only 4.88%; The suitable medium for petiole is NN69 + 1.33 mg/L 6-BA+ 0.02 mg/L NAA, the regeneration rate was increased to 16.92%; The regeneration rate of petiole was higher than that of leaf, but neither exceeded 20%; The effects of NAA enhanced the regeneration of adventitious buds from petioles better than that of IBA; The NN69 medium was better than MS, and the regenerated rate at 40 days was maximum; The stem was cultured on initiation media (MS+6-BA 1.40mg/L+NAA 0.09 mg/L) and then subcultured on induction medium(MS + 6-BA 2mg/L + NAA 0.09 mg/L) and wounding treatments was supplied to produced meristematic bulk tissue. The adventitious bud induction rate is 87.63%. The results indicated that the regeneration system of meristematic bulk was more suitable for grape genetic transformation.Keywords：grape;organogenesis;media;explant;meristematic bulk0|8|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Alginate-derived oligosaccharides of different molecular weight (ADO) were applied to the leave of cucumber seedlings to explore the effects of ADO on the growth and physiological characters of cucumber seedlings. The results showed that:ADO promoted the growth of cucumber seedling in stem diameter, the height and width of seedling; The fresh weight of plant were significantly increased compared with that of control; Moreover, the activities of antioxidant enzymes such as SOD and POD were significantly enhanced in samples treated by ADO. ADO also promoted the synthesis of chlorophyll in cucumber leaves; Meanwhile, photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), intercellular CO2 concentration (Ci) and chlorophyll fluorescence parameters Fv/Fm were also increased. In conclusion, ADO of different molecular weights of displayed different effects on the growth of cucumber seedling and the treatment of ADO with molecular weight of 8 000 was the best.Keywords：cucumber;alginate-derived oligosaccharide;seedling growth;physiological characters;photosynthetic characters1|7|6<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The microspores of 3 leaf mustard genotypes (MR-1, MR-2 and MR-3) were cultured to research embryos induction, plant regeneration, ploidy analysis, haploid doubling, optimize the isolated microspore culture technical system of leaf mustard and create excellent DH lines of leaf mustard for production practice. Buds selection was crucial to microspore culture. The morphological index of buds were:Petal length:anther length was 3:4; its color was yellow green. Embryos were obtained for the 3 cultivars. There were differences of the number of embryos generating between varieties and MR-1, MR-2 and MR-3 were 45, 198 and 4 per dish, respectively. The natural doubling rate of leaf mustard chromosomes was 82% by flow cytometry and the haploid doubling rate was 75% with 0.1% colchicine soaking stem tip 1 hour in tissue culture seedling. Cotyledon-stage embryos were cultivated on regeneration culture and 128 plants were obtained and the rate of plant formation reached 98%. A total of 105 double haploids were identified by flow cytometer and 4 excellent DH lines were screened from them. A double haploid line was supplied to the spring market for postponed bolting date, thick petioles and high yield and it was suitable for fresh food processing.Keywords：mustard;microspore culture;technical system;double haploid line0|7|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to investigate the factors influencing milk yield and the calving interval of Holstein cow in Ningxia, milk performance records and reproductive records from 6 236 Holstein cows were taken as experimental material from an Ningxia dairy company. By taking 305-day milk yield and calving interval as research object, the effects of SAS8.1 GLM on 305-day milk yield and calving interval were analyzed. The results showed that:Farm, parity, calving years, calving season and calving interval had highly significant effects on the milk yield (P<0.01). The age at first calving also showed significant effect on the milk yield (P<0.05). The farm, parity, calving season, and milk yield showed highly significant effects on calving interval (P<0.01). In conclusion, the parity, age at first calving and calving season were the important factors influencing the 305-day milk yield. The parity, calving season and milk yield were the important factors affecting the calving interval.Keywords：Holstein;305 d milk yield;calving interval;non-genetic factors0|7|6<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The rumen of bovine is rich in various microorganisms. The relationship between microorganisms and rumen is a mutually beneficial relationship, which plays an important role in the growth and development of cattle. In this study, the microbial flora and the variation characteristics of bovine rumen are reviewed, and the factors which influence the microbial flora changes in bovine rumen are analyzed to provide scientific and effective guidance for the development of bovine growth, disease prevention and control as well as quality safety.Keywords：cattle;rumen;microbial flora;diversity change;influential factor1|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In this study, the abundance of total bacteria, ammonia oxidizers and denitrifying bacteria in the soils under six different N and P fertilization regimes were investigated by using real-time PCR. The results showed that:1) The N and P fertilization significantly increased the abundance of bacterial 16S rRNA gene, archaeal and bacterial amoA genes, and nirK and nosZ genes compared with CK. 2) The abundance of bacterial 16S rRNA gene and archaeal amoA gene in low rate (T1) to high rate (T5) treatments, bacterial amoA genes in moderate low rate (T2) to high rate (T5) treatments, and nirK and nosZ genes in moderate rate (T3) to high rate (T5) treatments were significantly higher than those in CK, respectively. 3) The abundance of archaeal amoA gene was significantly higher than that of bacterial, the abundance of nosZ gene was significantly higher than that of nirK and nirS genes, and the abundance of nirS gene was significantly higher than that of nirK gene in all the treatments. 4) Almost all soil properties, except soil pH, were significantly positively correlated with the abundance of bacterial 16S rRNA gene, archaeal and bacterial amoA genes, and nirK and nosZ genes. In conclusion, these results demonstrated that long-term N and P fertilization significantly increased the abundance of bacteria, ammonia-oxidizing archaea and bacteria, and denitrifying bacteria harboring nirK and nosZ genes, and the N and P fertilization rates had differential impacts on the abundance of different types of microorganisms.Keywords：nitrogen fertilizer;phosphate fertilizer;bacteria;ammonia oxidation;denitrification2|10|7<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To study the stoichiometric characteristics of cotton at different continuous cropping years. the Alar Oasis in the upper reaches of the Tarim River was selected as the target area, and the cotton fields of 5, 8, 15, 20, and 30 years of continuous cropping were selected as the study plots, and the ecological and chemical characteristics of cotton and yield were analyzed. The results showed that:1) The contents of C and N were the highest in leaves ((422.3±20.6) g/kg, 11.4±4.6), and the contents of N and P were the highest in cottonseed ((38.1±11.8), (14.4±5.0) g/kg). The C, N and P were the highest in the fiber (193.0±44.2, 1 008.4±305.4). The C, N and P of cotton were increased first and then decreased Trend, C:N, C:P, N:P no uniform law of change. 2) The variability of C, N, P and metering ratio of each organ in cotton was N:P > P > C:P > C:N > N > C; the variance of the whole variance showed that C, N, P, C:N, C:P and N:P were greater than those of continuous cropping. 3) Cotton production with the extension of the number of years for the first increase after the reduction, the highest in 20 years, the lowest in 5 years. The C, N, C:N, C:P and cotton C of cotton soil had significant or significant positive correlation with cotton yield.Keywords：cotton;ecological stoichiometric;nutrient elements;continuous cropping years;yield2|9|3<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Study on the characteristics and spatial distribution of soil selenium in cultivated land can provide references for the development of selenium-enriched agriculture. Tailai County, a major grain-producing county in Heilongjiang Province, was selected as the study area in this study. Based on the multi-target regional geochemical survey results, the multivariate statistics, geostatistics and ordinary Kriging interpolation are used to study the selenium content and the spatial distribution characteristics of soil in Tailai County. The results show that:1) The average selenium content of topsoil and deep soil of cultivated land in Tailai County are respectively 0.155 and 0.056 mg/kg, which are lower than those of Heilongjiang Province.The average content of selenium in paddy field is higher than that in dry land in both surface and deep soil. 2) In addition to the influence of soil parent material, soil selenium content is related to soil organic carbon, total nitrogen, Fe2O3, Al2O3, pH and so on. 3) The areas with high selenium content in surface soil are mainly distributed in the middle part. According to the distribution of soil selenium content, the area of selenium-enriched area accounts for 6.2% of the total area of cultivated land. The selenium content of cultivated land in 631 Factory, Harvest Village, 63 Sanqiangye Market, Hebei Village, 632 Branch, Xinjian Village, Shuangshan Village, Jiefang Village and Yongfa Village in the middle part of the study area is relatively high, and the accumulative index shows that the heavy metal elements are basically free of pollution in the study area. Therefore, the selenium-enriched agricultural products can be developed in these areas to promote local economic development.Keywords：soil;selenium;content;spatial distribution1|8|6<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To clarify the current status of water pollution on Xiangjiang River Basin in Changzhutan, export coefficient modeling and equal standard pollution method are used to calculate the water pollution loads composing of industry waste water, city lives and agricultural pollution in Changzhutan's 23 counties from 2002 to 2015. The spatial-temporal distribution and causes of water pollution loads are fully analyzed. The results show that the water pollution loads especially industrial wastewater decreased in general, and the pollutions from industrial wastewater emission are mainly concentrated in Zhuzhou and Xiangtan City. The ascending order of contribution-rate of urban domestic sewage is Changsha, Zhuzhou and Xiangtan. The agricultural non-point source pollution is mainly contributed by the counties where are large scale of grain cultivations and livestock. The main pollutants includes total nitrogen, total phosphorus, ammonia nitrogen, chemical oxygen demand, petroleum and heavy metals. The primary pollution sources are agricultural non-point source pollution and urban waste water. The important reasons of water pollution in Xiangjiang River are irrational structure, inadequate sewage treatment and extensive operation of planting and pig-breeding. Three countermeasures are put forwarded at last:Rapid and high-quality tertiary industry should be developed in Xiangtan and Zhuzhou. Their industrial structures and region layouts should be optimized; The sewage treatment facilities in these three cities should be continuingly constructed and innovated; And the capacity of the sewage treatment in the counties should be improved; Intensive operation of planting and pig-breeding should be developed.Keywords：water pollution load;spatial-temporal distribution;industrial structures;sewagetreatment;intensive operation of planting and pig-breeding0|8|5<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：At present, the research of diversion is focused on the height consistency of the two sides of the diversion. Actually, most of the side canal bottom elevation is higher than the main canal bottom. Aiming to solve this problem, experiments are conducted. The water depth near the diversion is measured, the diversion's water line is obtained, the different split ratio under the changing of water surface, the relation between the diversion and the Frouder number of the main channel's upstream and downstream the weir head are analyzed. The results show that:Under different discharges, the variation of the water line on the diversion is basically the same for backwater curve; Under the same flow, the split ratio increases with the increasing of the relative weir head, and decreases with increasing the of Frouder number of the main canal's upstream and downstream; Under the same flow, the flow angle increases with the split ratio increases, the increasing trend gradually slows down. The biggest flow angle is close to 60 degree.Keywords：direct export channel;dividing opening;flow ratio;flow angle0|7|3<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To investigate novel accurate and effective detection technique for the identification of seed vigor, the wheat seeds of Shannong 27, which were treated by 58℃ hot water aging method (HW) and 50% methanol solution aging method (MS), were analyzed by electronic nose (E-nose). And the data were then processed by principal component analysis (PCA), linear discrimination analysis (LDA) and Loadings. The E-nose sensor data showed that the wheat seeds with different vigor after aging treatment had different characteristic maps. The PCA analysis could not distinguish seeds with similar vigor after HW aging. In contrast to the PCA analysis, the LDA analysis could well distinguish seeds with different vigor after the two aging method. The Loadings analysis demonstrated that there were sulfur compounds (W1W), nitrogen oxides (W5S), aromatic compounds (W2W), methane (W1S), alcohols (W2S) and hydrogen (W6S) differences in the odor between the seeds after HW aging. After MS aging, aromatic compounds (W2W), nitrogen oxides (W5S), methane (W1S), alcohols (W2S) and sulfur compounds (W1W) were the main gas compositions in seeds. In conclusion, our research indicated that E-nose technology could be used as a feasible and reliable method for the determination of wheat seed vigor by volatile constituent analysis and LDA analysis, and different gas components can be further confirmed by Loadings analysis.Keywords：electronic nose;wheat seeds;vigor;PCA;LDA;Loadings0|8|6<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：A roller type cotton stalk cutting mechanism with crushing plate and cutting knife was designed this study,which was suitable for cutting cotton stalk bundling. Cotton stalk was chopped by rotary knife after crushing and the fixed knife mounted on the frame of bundling machine. In order to achieve the function of cutting after crushing of cotton stalk and reduce the consumption of cutting tools and power consumption, the rotary knife group was adopted the way of which the crushing plate and cutting knife were arranged interlaced in the circle. According to the characteristics of cotton stalk, the parameters of the key components are identified. And SolidWorks Simulation software was then used to check the static strength finite element analysis of cutting knife and the modal analysis of roller type cutting mechanism, and the stress and strain distribution of cutting knife. The natural frequency and vibration mode of roller type cotton stalk cutting mechanism were investigated. The results of finite element analysis showed that the maximum stress and the maximum deformation of the cutting knife all were occurred on the bolt hole, and the values of which was respectively 234.6×106 N/m2 and 7.521×10-4mm. The materials of the cutting knife was 65Mn steel to meet the performance requirements. The work frequency of the roller type cutting mechanism (6.5 Hz) was far below its first natural frequency (53.675 Hz).The main performance of the model machine was tested, and the experimental results showed that the qualified rate of cotton stalk crushing was 95.3%, when roller type cotton stalk cutting mechanism with crushing plate and cutting knife was at 185 r/min speed of the cutting drum, the power consumption was 30 kW.Keywords：cotton stalk;roller type cutting mechanism;crushing plate;cutting knife1|8|3<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Through the long-term positioning experiment of "Agro-pastoral integration(API)" on Yanjun Farm. Comparative field experiments were conducted to analyze the impact of agro-pastoral integration production methods on weed biodiversity and corn production efficiency. The weed species, density, coverage, aboveground biomass, and corn yield in the field pre-grazing and post-grazing were investigated. The results showed that:The total weed density API treatment was 1.41 times of that of control (CK) pre-grazing, and the weed dominant species were unitary and its relative abundance was not evenly distributed; The weeds aboveground-biomass of API was 18.12 kg/hm2 higher than that of CK; The Shannon-Wiener diversity index (H'), Pielou evenness index (E), Simpson dominance index (D) and Margalef richness index(DMG) of API weed communities were 1.09, 0.92, 1.05 and 1.08 times of CK, respectively; The total densities of API post-grazing and CK were reduced by 77.00% and 23.10%, respectively. The aboveground-biomass of weed community decreased by 94.18% and 78.17%. Therefore, geese transformed the 16.01% weeds in the field into resources and improve weed productivity. The corn yield in API field was 0.92 times of CK, and the economic loss caused by the reduction of production amounted was up to 2 443.51 yuan/hm2; Goose product output converted to 25 922.80 yuan/hm2, it contributed to the total economic income as high as 48.74%; API investment ratio (2.87) is 1.15 times of that of CK (2.49). In conclusion, API system by raising geese in corn fields to control weeds in API system, converted weeds into resources, improved the productivity and biodiversity, and achieved high economic efficiency.Keywords：agro-pastoral integration;raising geese in corn fields;biodiversity;production benefit0|8|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to realize the agronomic requirements of "one hole two grains" in the southern cotton field, a two-row mechanical precision cotton seed metering device was designed. The seed metering device adopted the principle of seeding with a spoon hole in JPS-12 automatic seeding performance test bench to test the new seeding device's performance In order to evaluate the seeding performance index of the seeding device, the cotton varieties (Xiangzamian No.3, Xiangzamian No.8 and Ciqizha No.3) in the south were evaluated by passing rate, leakage rate and replay rate. The effects of seeding speed, spoon hole diameter and the curvature radius of seed room surface were studied. The results showed that when the speed of seed metering device was 100 rad/s, the diameter of the spoon hole was 9 mm and the radius of curvature of the chamber surface was 25 mm, the pass rate reached 93.62%, the replay rate reached 3.87% and the sowing rate reached 2.51%. The cotton precision bunch sowing device meets the national seeding standard requirements.Keywords：cotton;precision bunch;pass rate;replay rate;leak sowing rate1|8|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Due to the problems of large workload, low accuracy and strong stress reaction existed in traditional sheep body size parameters measurements, on the basis of the principle of binocular vision detection, a non-contact measurement study for sheep body size parameters was implemented by the multi-scale Retinex algorithm, Graph cut algorithm and sheep body size measurement points extraction. The results showed that:1) The multi-scale Retinex algorithm with color restoration enhanced the image of sheep with uneven illumination, which displayed strong processing ability for the details and color restoration of sheep images. 2) The Graph Cut algorithm based on multi-scale watershed accurately segmented the sheep body region and obtained smooth sheep body contour line. 3) The sheep contour line was divided and envelopment analysis method was applied to identify the body size measurement points. The body size parameters were detected. Compared with the real values, the average relative errors for 11 sheep and 9 sheep without cashmere goats were 2.32% and 1.95%, respectively. The measurement accuracy proved that the multi-scale Retinex algorithm with color restoration could enhance the luminance and chrominance of sheep image and the envelopment analysis algorithm could accurately identify the measurement points of body size. The algorithms were stable, which could realize sheep body size detection contactless in sheep farm.Keywords：sheep;non-contact measurement;body size parameter;multi-scale Retinex;binocular stereo vision0|9|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To study the rapid classification of abalone (sub) species, near-infrared spectroscopy combined with machine learning method was used. The spectra of three (sub) species abalone samples were obtained by portable near-infrared spectrometer MicroNIRTM1700. The spectra was divided into training set and testing set, which were 180 and 93 spectra, respectively. The CART method was applied to build a decision tree model and its criterion was Gini impurity. Cross validation was used in the model to control the depth of decision tree model. The accuracy rate of the training set was 90.00%. The final accuracy rate of the testing set reached 90.32%. The combination of NIRS and chemometric method was proposed in this study as a fast and new method for the classification of different abalone (sub) species.Keywords：near infrared spectroscopy;abalone;aquatic product;machine learning;classification and regression tree1|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The aim of this research was to study and discuss the current situation and driving factors of rural construction land expansion in China. By using the data of rural population and total floor space of rural residential buildings, the overall timing characteristics, spatial pattern and coupling and cooperation state of the rural population and housing area change in China were analyzed quantitatively. The results showed that:China's rural resident population showed a linear decrease during 2006-2015, with an annual reduction of 1.32×107, and the number of rural registered population entered a period of extremely slow reduction in 2008; The difference between rural registered population and rural resident population was rising yearly, which reached the highest since the reform and opening up to 2×108 at the end of 2015; Meanwhile, rural housing area in China continued growing with an average annual increase of 2.48% and an average annual growth rate of 5.8×108m2. The overall rural housing area per capita under both resident and registered caliber showed an increasing trend. The numbers of resident population in 25 provincial administrative regions showed a steady linear growth trend; While under the registered caliber, the per capita housing areas of all provinces showed an increase. During the study period, the temporal correlation of the overall rural population and housing area in China showed a characteristic of non-cooperative, and the change rates of housing area in those years were higher than the former. The rural resident population and housing area changes of 27 regions showed the same characteristics; The change rates of housing area in all the regions evaluated were higher than the rates of registered population, while rural registered population and housing area in 21 regions showed cooperative changes. To promote the development of urban and rural unified planning management, get rid of the segmentation between urban and rural gradually, reform the household registration system and ease the population flow between urban and rural, the problem of increasing housing area in the process of rural population decline should be solved under ideology guidance.Keywords：rural registered population;rural resident population;total floor space of rural residential buildings;China;cooperation1|9|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To investigate the spatial and temporal differences and driving factors of green development level in rural China, a index system is constructed from the 3 dimensions of production, life and ecology. Based on the measurement of the green development level of rural areas from 2005 to 2014, the Dagum Gini coefficient method is used to analyze the spatial and temporal differences, and a econometric model is established to explore the influencing factors. The results showed that:1) The green development level of China's rural areas is getting better, the east region > the central region > the west region > the northeast region. 2) The overall gap among China's rural green development and the gap between the eastern and western regions are getting larger, and the overall gap is mainly from the regional differences. 3) Economic development, urbanization, agricultural technology and farmers' investment ability have significant impacts on the rural green development. The economic development displays a significant positive impact on the eastern and western regions while the urbanization has a greater role in the central and northeast. However, the urbanization and ecological protection of social investment in the western region play a negative impact.Keywords：rural green development;entropy weight method;spatial-temporal difference;Dagum-Gini index;driving factors0|7|9<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Based on the perspective of family life cycle, this study analyses the impact of social capital on farmers' livelihood strategy by adopting field survey data and using Mlogit regression model. The results showed that the rural families in Hubei Province had a higher degree of part-time incorporation, and the family structure showed a "spindle-shaped" distribution. The accumulation of social capital would encourage farmers to choose partial non-agricultural livelihood strategies. By examining the influence mechanism of social capital, it was found find that there were both regulating and partial mediating effects of social capital in the impact of family life cycle on livelihood strategies. The size of intermediary effect was 35.2%. In order to promote the diversification of farmer households' livelihood, strengthen the anti-risk ability of farmers and prevent families at both ends of the life cycle from livelihood risks, the government should increase human capital of farmers through vocational education or skills training, as well as strengthen support to farmers' funds and loans as well as to expand farmers' social network.Keywords：family life cycle;farmers;social capital;livelihoods strategy1|9|10<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to inspect the effects of agricultural agglomeration on agricultural carbon efficiency, based on the stochastic frontier transcendental logarithmic production function, this study integrated agricultural carbon emissions into the agricultural economic accounting system to calculate provincial agricultural carbon efficiency of China from 1997 to 2014, and then investigated the spatial auto-correlation of agricultural carbon efficiency and its relationship with agricultural agglomeration. The results showed that:Although the carbon efficiency of China's agriculture was increased steadily during the study period, the regional carbon efficiency distribution structure featured by "polar nuclear" area with high value in the eastern part and the western low value was gradually formed due to the long-term influence of "gradient type" development mode, and the imbalance of inter-provincial carbon efficiency became more serious. Meanwhile, agricultural carbon efficiency between provinces in the same region was relatively dependent; Based on the investigation of relationships between agro-industry agglomeration and agricultural carbon efficiency, it was found that there was a characteristic of environmental Kuznets curve between them, which is with the increase of agricultural industry agglomeration, the agricultural carbon efficiency would be improved and then be deteriorated. At the same time, different regions with different relationships between agro-industry agglomeration and agricultural carbon efficiency showed different agglomeration degrees, which meant that the agricultural carbon efficiency of high agricultural agglomeration zone (central and western agricultural advantageous provinces) displayed "rising-decreasing" tendency with the increase of agricultural agglomeration degree. However, in low agricultural agglomeration area (developed coastal areas), the agglomeration of agricultural industry displayed a significant effect on the improvement of agricultural carbon efficiency.Keywords：agricultural industry agglomeration;agricultural carbon efficiency;transcendental logarithmic production function;spatial effects0|9|15<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore the scale dependence of farmers' forest land management and economy of scale, the paper completed two works based on household survey data of three provinces of Zhejiang, Anhui, Guangdong Province. Firstly, taking timber volume per unit area and income per unit area as standards, the quadratic function of fitting was used to calculate the optimal scale of forest land management including bamboo, fruit tree, pine and fir. Secondly, taking capital input per unit area and labor input per unit area as the dependent variables, a multiple linear regression model was used to analyze the scale economy of forest land management. The results showed that:1) The correlation of the operating areas of fruit tree, Chinese fir and pine with output displayed inverted "U" type relationship. The fitting optimal scales of Chinese fir and pine were 6.27 and 7.31 hm2, respectively. The fitting optimal operation scales of the fruit trees were 5.41 and 5.56 hm2, respectively. 2) The operating area of bamboo with output showed "U" type relationship about and the fitting minimum points were 97.71 and 102.15 hm2, respectively. 3) The increase of Chinese fir and pine business area could significantly reduce labor input per unit area. The increasing of bamboo business area could significantly reduce capital investment per unit area. Therefore, not all tree species are dependent on scale. The concentration of forest land might not entirely depend on land circulation. It could also be implemented by cooperation. The socialized service of forestry production was beneficial to increase the income of farmers.Keywords：land scale;forest land management;scale return;economy of scale0|7|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
