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- Abstract：In order to improve the stability of seed germination test result, two maize varieties(‘Zhengdan 958' and ‘Nongda 87')and two wheat varieties(‘Jimai 22' and ‘Shannong 21')were taken as experimental materials in this study. A spraying germination box including 3×2 spraying heads, plastic hoses, water pumps and timers was designed. None sterile seeds were put in the germination box, water pump sprayed at a fixed time and each time sprayed a total of 1. 9 L water by 6 sprinkler heads. Firstly, the appropriate spraying intervals for maize and wheat seeds were selected. The stability of seed germination test results were then analyzed under different conditions, such as different varieties, different seeds vigor, different testing time points and different operating personnel. The results showed that maize and wheat seeds should be sprayed every three and four hours, respectively. Compared with a rolling paper germination method, the germinative force, germination percentage or simply vigor index(SVI)of spraying germination method displayed no significant differences, but had much lower bacteria carrying rate(P<0. 05). In conclusion, the spraying germination method avoided the sterilization process and kept the stability of water potential during germination period. The germination testing results of different testing time points, different operators showed that the spraying germination method could supply more stable and consistent results. The difference between any two tests was within the error range of the national seed testing regulations.Keywords：seed germination test;spraying germination box;maize;wheat;bacteria carrying rate26|11|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To investigate the effects of different concentrations of phosphorus stress on soybean seedling growth and the genomic DNA methylation level, methylation sensitive amplification polymorphism(MSAP)and real-time fluorescence quantitative PCR(qRT-PCR)were used to analyze the DNA methylation level and related gene expression in the root of soybean material ‘CP016' seedlings under different concentrations of phosphorus stress. The results showed that: 1)With the increase of phosphorus concentration, the plant height, fresh weight, root length and root surface area of soybean seedlings increased first and then decreased. Both the phosphorus-free and high phosphorus(1 000 μmol/L)stresses significantly inhibited soybean growth, while the low phosphorus stress(100 μmol/L)promoted the growth of above ground and the extremely low phosphorus stress(10 μmol/L)promoted root growth. 2)With the gradual increase of phosphorus concentration, the POD and CAT activities decreased first and then increased in the root of soybean seedlings, while the SOD activities, starch and sucrose contents increased first and then decreased. 3)The results of MSAP analysis showed that the DNA methylation rate and full methylation rate of soybean seedlings increased gradually with the increase of phosphorus concentration. Specifically, the DNA methylated rates of soybean seedling roots treated with phosphorus-free, normal phosphorus and high phosphorus supply were 43. 04%, 48. 52% and 51. 05%, respectively. 4)The results of qRT-PCR analysis showed that the expression levels of genes that regulate the activity of POD and synthesis of starch, and the methylase gene DRM2 up-regulated significantly, while regulated SOD activity and sucrose synthesis, and ROS1 down-regulated significantly under phosphorus-free stress. In conclusion, this study showed that the phosphorus-free and high phosphorus stress significantly inhibited soybean growth, disturbed its antioxidant enzyme system, and reduced the content of starch and sucrose. However, a certain degree of low phosphorus stress could promote the growth of soybean seedlings. The levels of DNA methylation in the root of soybean seedlings were decreased and increased under phosphorus-free and high phosphorus stress, respectively.Keywords：soybean;phosphorus stress;DNA methylation;antioxidant enzymes;methylation sensitive amplification polymorphism(MSAP)32|11|8<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to clarify the function of SPL in Amaranth, 17 members of SPL family were screened based on the database of ‘all-red' Amaranth transcriptome and bioinformatics analysis was used for prediction. The results showed that: The 17 AmSPL proteins were composed of 186-777 amino acids with relative molecular weight from 20. 53 to 88. 27 ku. A phylogenetic tree AmSPL and 16 AtSPL members of Arabidopsis was constructed, and the AmSPL members were divided into 6 groups according to the classification criteria of AtSPLs gene family. Real-time fluorescence quantitative PCR analysis displayed that the expression of AmSPLs in dark was higher than that in blue light. It was speculated that the expression of AmSPLs might be negatively regulated by blue light in some way. The 8 AmSPLs might be the target genes of miR156.Keywords：Amaranthus tricolor;L.;transcriptome sequencing;AmSPL gene family;bioinformatic analysis;expression34|10|3<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to study the effect of exogenous nitric oxide(NO)on the growth of peanut seedlings under salt stress, ‘Shanhua 11' was taken as the test material. A liquid culture test was used to determine the exogenous NO donor sodium nitroprusside(SNP)250 μmol/L on the growth and physiological indexes of peanut seedlings treated with normal growth(0 mmol/L NaCl, CK)and salt stress(100 mmol/L NaCl, T1 and 150 mmol/L NaCl, T2). The results showed that: Under normal growth conditions, the increase of endogenous NO concentration in peanuts displayed a slight toxic effect on seedling growth; The addition of SNPs under salt stress could effectively improve the salt tolerance of peanut seedlings, and the alleviating effect of exogenous NO on peanut salt stress is affected by the external salt concentration. When peanut was subjected to higher salt concentration stress, the NO relieved membrane lipid peroxidation more quickly and had better salt tolerance. Within the concentration range of this experiment, the exogenous NO had better mitigating effect on peanut seedlings under 150 mmol/L NaCl stress. Compared with T2 treatment, the content of endogenous NO in leaves and roots of peanut treated with T5 increased by 41. 83% and 35. 45%, respectively. NO significantly increased the antioxidant enzyme activity and osmotic substance content in peanuts. The SOD, POD, CAT and APX activities of leaves were increased by 9. 84%, 64. 82%, 91. 84% and 26. 09%, respectively. Proline content was increased by 60. 73%. The accumulations of malondialdehyde(MDA)and reactive oxygen species(ROS)in the body were reduced, the electrolyte extravasation rate of leaves was decreased by 17. 61%, and the membrane lipid peroxidation damage was effectively reduced; the peanut seedling plant height, fresh and dry weight and total chlorophyll content were increased; The root vigor of peanut was increased. It could effectively relieve the inhibitory effect of salt stress on the growth of peanut seedlings. In conclusion, the addition of SNP under normal conditions was not conducive to peanut growth. However, the addition of SNP under salt stress significantly improved the salt tolerance of peanut seedlings, and the effect of exogenous NO on alleviating the effects of higher concentrations of salt stress on peanut growth was better.Keywords：peanut;nitric oxide;salt stress;physiological characteristics;mechanism28|12|8<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The objective of this study was to investigate the effect of fermented total mixed ration(FTMR)on the nutrients digestion and growth performance of mutton sheep. The fermentation and feeding tests were conducted in order to determine the nutrient quality of FTMR, as well as the changes of apparent digestibility, rumen fluid characteries and daily weight gain of mutton sheep. The results indicated that after total mixed ration(TMR)was fermented, the pH and neutral detergent fiber(NDF)content was decreased significantly(P<0. 05), and the content of lactic acid and acetic acid was increased significantly(P<0. 05). The pH of rumen fluid was significantly reduced(P<0. 05)and the ammonia nitrogen content of that was decreased more than 50% in comparison with that of the control group(P<0. 05). The utilization rate of crude protein, ether extract, neutral detergent fiber, acid detergent fiber and acid detergent lignin(ADL)in tested group was significantly higher than that in the control group(P<0. 05). In particular, the ADL utilization rate of tested group was about 29. 92% higher than that of control group(P<0. 05). In addition, the average daily weight gain of tested group was 50% higher than that of the control group. In summary, the rumen environment, digestion-absorption function and growth performance of mutton sheep, as well as the straw feed efficiency can be improved by fermentation TMR.Keywords：mutton sheep;mixed microbial inoculants;fermented total mixed ration;digestibility;growth performance26|12|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to investigate the effects of different body conditions on the vaginal flora of cows in early pregnancy, the vaginal secretions of 18 Simmental cows(6 cows in each group, fat cattle group、middle cattle group and thin cattle group)in the early pregnancy under the same grazing conditions were collected. The diversity of vaginal flora was analyzed by 16S rRNA sequencing. The results showed that: A total of 70 567 sequences were measured in average for each of the 18 samples, an average of 68 309 sequences were obtained, and the effective rate of quality control was 96. 84% after quality control; And 2 677 operational taxonomic units(OTU)were obtained through clustering, and among which 37. 58% OTU were annotated to phylum level and 24. 36% OTU were annotated to genus level; The Shannon index, Chao1 index and ACE index of Alpha diversity index of vaginal flora in MC group were significantly lower than those in the FC group and the TC group(P<0. 05). The Good's coverage index of vaginal flora in each group was more than 99. 4%, indicating that the sequencing quality of the samples was high. At the phylum level, the top 10 dominant phylum in the vagina of cows in the TC group, MC group and FC group in early pregnancy were Firmicutes, Bacteroidetes, Proteobacteria, Tenericutes, Actinobacteria, Fusobacteria, Verrucomicrobia, unidentified_Bacteria, Spirochaetes and Melainabacteria, respectively; At the genus level, the top 10 dominant genus in TC group, MC group and FC group were Bacteroides, Alistipes, Aerococcus, Faecalibacterium, Streptobacillus, Streptococcus, Corynebacterium, Histophilus, Ureaplasma and Mycoplasma, respectively. Among them, the Histophilus in the MC group was significantly higher than that in the other two groups(P<0. 05).Keywords：pregnant cow;different body condition;vaginal flora;diversity25|11|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The study was conducted to investigate the effect of the rumen microbiota environment formed by Baatar-7 powder early intervention on immunity in calves infected with pathogenic Escherichia coli O1. A total of 30 Holstein calves were randomly divided into the normal control group(NC), untreated group(UC), cipfloxacin group(CIP), Baatar-7 powder low(1. 25 g/kg, BSP. L), medium(2. 50 g/kg, BSP. M)and high(5. 0 g/kg, BSP. H)groups(n=5). At 7 days after administration, blood samples were collected. The rumen contents were detected by 16S rRNA sequencing technology, and the levels of interleukin 6(IL-6), tumor necrosis factor(TNF-α), interleukin 4(IL-4), interleukin 2(IL-2)and Interferon γ(IFN-γ)in serum were detected by ELISA. The results showed that: 1)Compared with the NC group, ACE index in the UC group was significantly decreased(P<0. 05); Compared with the UC group, the Chao1 index, Shannon index, and ACE index in the BSP. M group were significantly increased(P<0. 05). 2)Compared with the NC group, the level of abundance of Fusobacteria, Proteobacteria, Actinobacteria and E. coli in the UC group were significantly increased(P<0. 05); Compared with the UC group, the levels of Fusobacterium, Proteobacteria, and Escherichia coli in the BSP. L, BSP. M, and BSP. H groups were significantly reduced(P<0. 05), but in the BSP. L group, the level of Faecalibacterium was significantly increased(P<0. 05). 3)The body weight and average daily gain of calves in BSP. M group were significantly increased(P<0. 05), and the diarrhea rate was also decreased. 4)Compared with the UC group, the serum levels of IL-4, IL-2, and IFN-γ in BSP. M group were significantly higher those in UC group, and the levels of IL-6 and TNF-α were significantly lower(P<0. 05). In summary, the rumen microbiota environment formed by the early intervention of medium dose of Baatar seven powder increased the number, richness and diversity of ruminal microflora infected with the pathogenic E. coli, increased the proportion of beneficial microflora, reduced the proportion of opportunistic pathogens, enhanced anti-inflammatory and immune capabilities, and reduced the risk of diarrhea.28|9|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to clarify the bacterial pathogens causing frequent pneumonia in Tibetan yak, 145 nasal mucus of Tibetan yak were collected. Bacteriological determination was carried out through pathogen isolation and culture, colony morphology observation, biochemical test, and PCR detection. The growth curve of the isolate strain was determined by the change of optical density OD630 and pH, and K-B disk method was used for antimicrobial susceptibility test. The results showed that ten strains of Mycoplasma bovis in total were isolated from 145 yak nasal mucus; The results of colony morphology and biochemical test were consistent with the biological characters of Mycoplasma bovis. One 238 bp target fragment corresponding to the uvrC specific gene and one 1 500 bp target fragment corresponding to the 16S rRNA gene were amplified by PCR. The nucleotide sequences of uvrC specific gene and 16S rRNA gene among the 10 isolates were highly homologous, and the homology between uvrC specific gene and the international standard strain PG45 was 98. 4%-100% and the homology between 16S rRNA gene and PG45 was 99. 1%-99. 9%. The growth curve assay showed that the isolates cultured in PPLO medium were in lag phase for 24 h, entered stable period in 42 hours, and entered decline phase 78 hours later. In addition, the pH of the three isolates decreased with the prolongation of the culture time. The pH decreased the most rapidly during the period of 24-42 h, then decreased slowly and almost stayed unchanged after 78 h. The antimicrobial susceptibility analysis showed that the isolates were resistant to macrolides, aminoglycosides and lincomycin at various degrees, but they were sensitive or moderately sensitive to doxycycline and kanamycin.Keywords：Tibetan yak;Mycoplasma bovis;isolation and identification;growth curve;antimicrobial susceptibility27|9|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to analyze the differences of liver metabolite profiles in Muscovy duck during pre-laying and laying stages from the perspective of nontargeted metabolomics, twelve Muscovy ducks were selected at the age of 22 weeks of pre-laying(TT group)and 40 weeks of laying(FT group), respectively. Twenty-four metabolite profiles were obtained by ultra-high performance liquid chromatography-electrospray mass spectrometry(UPLC-MS)nontargeted metabolomics. Differential metabolites were screened out based on variable importance in projection(VIP)and independent-sample T-test and analyzed for pathway enrichment. The results showed that: Compared with TT group, 156 of the 324 differential metabolites in FT group were significantly up-regulated(P<0. 05), and 168 metabolites were significantly down-regulated(P<0. 05). The number of lipids and lipid-like molecules and organic acids and derivatives accounted for 19. 87% and 21. 79% in the up-regulated differential metabolites, and 41. 07% and 13. 1% in the down-regulated differential metabolites, respectively. Seventeen metabolic pathways were obtained by pathway enrichment and showed significant difference(P<0. 05), including amino acid metabolism, glycerophospholipid metabolism, nucleotide metabolism, and vitamin metabolism, among which 9 pathways were amino acid metabolism. In addition to one carbon pool by folate, cysteine and methionine metabolism, purine metabolism, lysine degradation and glutathione metabolism, the other 12 pathways were significantly up-regulated(P<0. 05). The glutathione and cysteine abundance were significantly down-regulated(P<0. 05)and the choline abundance was significantly up-regulated(P<0. 05). In conclusion, the nontargeted metabolomics analysis revealed that lipids and lipid molecules, organic acids and derivatives were highly enriched in the liver during egg-laying period, and the increased metabolism of amino acids, pyrimidine, amino sugar and nucleotide sugar provided essential materials for the synthesis of yolk precursor.Keywords：Muscovy duck;nontargeted metabolomics;liver;yolk precursor42|11|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore the impact of different disinfection methods on the soil environment, the strawberry field in Beijing Changping, which has been continuesly cropped for many years was taken as research object. Field experiments were established to investigate the impact of different soil disinfection methods on soil temperature, nutrients, and enzyme activity, and its effect of reducing soil-borne pathogenic fungi. The results showed that: High-dose activated carbon + solarizing film could quickly increase the surface temperature of the soil to above 50 ℃. And the reduction effects on soil borne pathogenic fungi Fusarium spp. and Phytophthora spp. were better, and the reduction rates in the 0~10 cm soil layer were more than 90% and 85%, respectively. At the same time, soil nutrients increased significantly and soil enzyme activity was activated with the addition of activated carbon. Although the chemical fumigants dazomet and chloropicrin fumigation had a good control effect on Fusarium spp. and Phytophthora spp. , the content of soil nutrients and inhibited the activity of soil enzymes were also decreased. Therefore, the non-chemical soil disinfection method, active carbon+solar radiation film mulching, has great potential in improving soil and controlling soil borne pathogens during continuous cropping, which provides a new way for green control of soil borne diseases in continuous cropping fields.24|12|9<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To further describe the latest research progress on strigolactone biosynthesis, by taking “trigolactone” as the keyword, the literatures published in the NCBI database from 2000 to 2020 are retrieved and summarized. The progress in the biosynthesis pathway and the functions of related genes of strigolactone in the past two decades are reviewed. The functions of strigolactone in abiotic stress and its interaction with other hormones are also summarized. The results show that: 1)The pathway of strigolactone biosynthesis is preserved and may interact with other pathways; 2)The functions of strigolactone are diverse and play a role in multiple stages of plant growth and development; 3)Genes related to the biosynthesis of strigolactone are not only the key genes of biosynthesis, but also interact with other hormones participating in the regulation. Therefore, on the basis of important breakthroughs in the studies on the biosynthesis and regulatory effects of strigolactone, future studies may focus on the yield formation mechanism, morphological formation and regulatory mechanism of hormones.Keywords：strigolactones;biosynthesis;abiotic stress;interaction mechanism27|12|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Currently, there were only a few studies on the extraction and determination of folic acid in foxtail millet, especially the there was lack of in-depth research suitable for large-scale extraction and determination. The single factor test and response surface optimization were carried out for tri-enzymatic extraction method. High performance liquid chromatography(HPLC)analysis was performed to determine the folic acid content. The results showed that the optimum conditions for folic acid extraction were as follows: For 1 mL of extracting solution, 20 μL of α-amylase, 150 μL of protease, 25 μL of rat serum; For the determination of folic acid, The mobile phase of HPLC was at flow rate 1 mL/min, pH=7, and the detection wavelength was 280 nm, the column maintained at 30 ℃. The relative standard deviation(RSD)of repeatability was 0. 5%. In summary, compared with HPLC, the tri-enzymatic extraction method can be used for large-scaleand high-efficient extraction and for accurate quantification of folic acid in foxtail millet.Keywords：folic acid;foxtail millet;trienzyme;HPLC;response surface tests27|11|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to improve to the seeding performance of centralized and precision hill direct-seeding for hybrid rice, a pneumatic cylinder-type centralized seed-metering device was designeded based on the principle of positive pressure airflow for assisting seed filling, carrying and feeding. The bowl-shape model-hole distributed with airflow holes was introduced, and the main structural parameters were determined. The mechanical models of seed filling and seed feeding process were established. The effects of airflow hole's diameter, number of airflow holes and rotational speed on seeding performance were investigated and the adaptability of pneumatic cylinder-type centralized seed-metering device for hybrid rice varieties was analyzed. The results showed that: The orders of affecting factors were the number of airflow holes, and the airflow hole diameter and rotational speed. When the rotational speed of 20 r/min, the number of the air holes of 7 and airflow hole's diameter of 1. 7 mm, and the qualified rate, miss-seeding rate, reseeding rate and cavity rate were 93. 33%, 2. 50%, 4. 17%, and 0. 58%, respectively. The apiece row consistency variation coefficient of seeding quantity was 2. 08%. Furthermore, the qualified rate was 90%, and the missing rate and multiple rate were no more than 6. 00% and 5. 00%, respectively. The seed breakage rates were less than 0. 20%, and the apiece row consistency variation coefficient of seeding quantity was less than 3. 00% for three hybrid rice varieties including Tianyouhuazhan, Fanyou 609, which indicated that the seed metering device had good seeding adaptability to different hybrid rice varieties. The field experiment of the pneumatic cylinder-type centralized seed-metering device was conducted. It was found the average seeds per hill were 3. 56, the qualified seeding rate and the average distance were respectively 89. 33% and 190. 3 mm, which met the requirements of precision hill seeding. This research provided the basis for the structural design of centralized and precision hill direct-seeding for rice.Keywords：rice;centralized metering device;precision seeding;seeding performance24|10|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to verify the spray effect of the single-rotor oil-powered UAV in the hilly mountain orchard, the spray performance comparison tests of the single-rotor oil-powered UAV and the round orchard wind-driven sprayer on the low-root densely planted apple orchard were conducted. The results showed that: For single-rotor, the coverage of fog droplet deposition on the upper and lower layers of fruit trees for oil-driven UAV spray operations were 0. 66%-21. 98%, 1. 20%-16. 17% and 0. 38%-3. 96%, respectively. The average order of the average diameter of the droplet size was the upper layer>Middle layer>Lower layer; The coverages of the droplet deposition on the upper and lower layers of the fruit trees in the round orchard wind sprayer were respectively 5. 68%-24. 94%, 2. 64%-34. 61% and 3. 15%-21. 78%. The average diameter of the average volume of the droplets in descending order was lower layer>middle layer>upper layer; The droplets sprayed by the single-rotor oil-powered UAV displayed a significant deposition effect on the upper and middle layers of fruit trees, and the round orchard wind-driven sprayer was the middle and lower layer. In conclusion, eliminating the influence of uncertain factors such as machine malfunctions, the working efficiency and water-saving and medicine-saving performance of the UAV is better than that of the sprayer; and the UAV shows good practical performance in the orchard production and farming and emergency treatment of diseases and insect pests.Keywords：single-rotor oil-powered UAV;air-driven orchard sprayer;droplet deposition density;droplet deposition coverage28|8|7<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Aiming at the problem of seasonal increase in rural power grid load caused by the increase in the number of electric heating users in rural areas of northern China, an optimal control model is established for the air source heat pumps. The model was constructed under the scenario of centralized control of electric heating load participated in grid peak shaving, with the goal of minimum daily electricity consumption of users, with combined consideration of the information of each user's temperature demand, outdoor temperature, time-sharing electricity price and compensation electricity price. At the same time, an optimized control strategy is proposed. The typical electric heating users in the “coal to power” area of Beijing are taken as an example to verify the optimal control strategy of the air source heat pumps. The results show that: 1)Optimizing the control of the air source heat pumps could achieve peak clipping and valley filling and at same time reducing user electricity costs and fully satisfying user comfort; 2)Different compensation electricity prices have different effects on the peak shaving effect. The analysis of the setting of the compensation electricity price can provide a reference for the electric heating users to actively participate in the design of the peak-shaving incentive mechanism.24|8|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to study the evolution trend of the regional pattern of potatoes and optimize the regional layout of potato production, the spatial statistical analysis methods and county-level statistical data are used to quantitatively analyze the potato regional pattern and its evolution trend in China from 1990 to 2016. Based on the panel data of 14 provinces from 2011 to 2018, this study empirically studies the influencing factors of the evolution of potato regional pattern. The results show that: 1)Potato cultivation is concentrated in four hotspot areas. The northwestern area with southern Gansu as the core, the southwestern area with Yunnan, Guizhou, Sichuan and Chongqing as the core, the north China area with the central Inner Mongolia as the core, and the northeast area with Heilongjiang as the core. The overall spatial distribution pattern has transferred from “single core+peripheral small center” to “dual core+peripheral small center”; 2)The spatial pattern of potato planting shows obvious agglomeration characteristics. The degree of agglomeration first decreases and then increases, and it is spatially manifested as agglomeration from the northeast and north of China to northwest and southwest regions; 3)The evolution of potato regional pattern is mainly affected by factors such as climate, labor input and technical level. The impact of labor input is greater than other factors. In conclusion, the degree of influence of each influencing factor varies due to time and space differences, but the difference is relatively small.28|11|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To explore the regionalization and implementation approaches for rural integrated territory consolidation in China under the concept of ecological civilization. An indicator system is constructed considering the following four aspects, e. g. efficiency, quality, form, and culture from the focus of rural integrated territory consolidation. The utilisation level of rural land is evaluated. Based on the exploratory spatial data analysis of ArcGIS, the evaluation results are limited and the advantages are identified, which are then superimposed to form the classification of limitations and advantageous factors. The targeted consolidation implementation approaches are proposed in this study according to different regional characteristics. The results show that: 1)There are obvious regional differences in the level of rural land use in China. The overall distribution pattern is high in the east and low in the west. The high-value areas are mainly distributed in the North China Plain and coastal areas, while the low-value areas are mostly distributed in the central and western regions and southwest regions. 2)The spatial distribution of each evaluation subsystem is highly concentrated, and the spatial distribution of high-value and low-value areas presents obvious regularity and significant regional characteristics. 3)There are significant differences between restrictive and advantageous factors in different regions. In the eastern unrestricted area, comprehensive rural integrated consolidation should be carried to create a rural revitalization demonstration area. Attentions should be focused on quality improvement in the northeast area and efficiency promotion in the southwest area.Keywords：rural integrated territory consolidation;land use level;exploratory spatial data analysis;limitation factors;differential paths27|8|3<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To explore the calculation method of compensation criteria for farmers' voluntary withdrawal from homestead(FVWH), the theory of homestead functional value is applied, and a compensation value system for FVWH from the 4 functional dimensions of homestead is established, and a calculation model of compensation criteria for FVWH is built. The empirical questionnaire survey data of 1 242 farmers from 20 villages in 10 provinces are taken as study case to analyze the differences of homestead functional demands among different types of village farmers. The demand rate of homestead function is imported into the calculation model of compensation criteria of FVWH as a correction coefficient, the study empirically measures the compensation criteria for FVWH in Xifeng Village, Houbai Town, Jurong City, Zhenjiang City, Jiangsu Province. The results show that: 1)The economic utility of homestead's housing security value, production and operation value, economic property value, and emotional inheritance value are the significant contents of the compensation value system for FVWH; 2)The housing security value of homestead can be measured by low-rent housing subsidies for low-income urban households, and the production and operation value of homestead can be calculated by decentralized livestock and poultry's farming income. The economic property value of homestead can be measured by usage conversion benefits, and the emotional inheritance value of homestead can be calculated by per capita expenditure on cultural and entertainment in rural areas; 3)The compensation criteria for FVWH based on the theory of functional value is higher than the compensatory criteria for FVWH in practice. It is suggested that formulating compensation guidelines for FVWH should base on the theory of functional value, and developing differentiated plans for FVWH should based on the diversity of the functional requirements of farmers' homestead among various kinds of villages.Keywords：homestead function;homestead withdrawal;compensation criteria;calculation method24|8|13<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to study the spatial spillover effect of agricultural mechanization development level on grain production in different regions and its mechanism, based on theoretical analysis and using the panel data of 13 prefecture-level cities in Jiangsu Province from 2000 to 2016, the spatial Durbin econometric model was used for empirical analysis. The results showed that: The grain yield and the level of agricultural mechanization in Jiangsu Province displayed geographical spatial correlation and aggregation effect. The level of agricultural mechanization in Jiangsu Province had a significant spatial spillover effect on grain yield. Comparing the estimation results of pooled ordinary linear regression, two-way fixed effect and spatial Durbin models, it showed that the systematic estimation errors of direct effect and total effect of agricultural mechanization level on grain yield occurred if the spatial factors were not considered. The spatial spillover effect was heterogeneous among different grain varieties. The spatial spillover effect of corn production mechanization in Jiangsu Province was higher.Keywords：agricultural mechanization;food production;spatial spillover effect;spatial econometrics;Jiangsu Province30|8|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to verify how the land cost affects farmers' cultivated land quality protection behavior, this study conducts an empirical test based on a survey of farmers in Guangxi. The result show that when the land rent is higher, farmers are more likely to adopt two types of cultivated land quality protection behaviors, such as soil testing formula and straw return to the field. The sub-sample regression finds that, campared to smaller scale farm farmers, high land rents can prompt large scale farm farmers to be more actively to adopt the two types of green technologies. Further study discovers that: The reason why farmers are more inclined to apply soil formula fertilizers is that such protective measures can significantly reduce agricultural production costs and effectively increase agricultural income, and the protection of cultivated land quality can significantly increase agricultural business income. In conclusion, the high land rent does not necessarily lead to the consumption of land by farmers, but it will prompt farmers to adopt more green technology-type protective measures for farmland quality protection.Keywords：high land rent;cultivated land quality protection behavior;soil testing formula;returning straw to the field26|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
