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- Abstract：In order to investigate the variation characteristics of the traits of internodes below ear with internode position(IP)and growth process of different maize varieties, ‘Jingnongke 728'(mechanical grain harvest variety), ‘Zhengdan 958'(common variety)and ‘Xianyu 335'(common variety)were used to measure internode morphologies, dry matter content, moisture content and proportion of white pith area from silking to 4 weeks after physiological maturity. The results showed that: With the increase of IP, the internode length increased first and then decreased, the 6th or 7th internode was the longest. The cross-sectional area decreased gradually following IP increasing. The dry weight per volume decreased first and then increased slightly following IP increasing, and the 5th to the 7th internode was the smallest. The moisture content of the 2nd or 3rd internode was the largest, and the moisture content of upper internodes decreased gradually. The proportion of white pith area increased gradually following IP increasing. From silking to 4 weeks after physiological maturity, the variation of dry weight per volume of internodes in the progress of growth were greatly influenced by environments and varietys. The dry weight per volume of internodes of the three varieties in 2018 increased dramatically in the late stage of grain filling. In 2019, only the data of ‘Jingnongke 728' and ‘Zhengdan 958' increased in the middle and late stages of grain filling, the data of other varieties and stages changed little. The moisture content of internodes changed little in the early stage of grain filling, then decreased from middle stage to 4 weeks after physiological maturity: The moisture content of ‘Jingnongke 728' decreased mainly in the middle and late stages of grain filling, that of ‘Zhengdan 958' was mainly in the late stage of grain filling, and that of ‘Xianyu 335' was mainly in the late stage of grain filling and the 2-4 weeks after physiological maturity. The proportion of white pith area increased gradually with growth progress, but it varied greatly in different years: It changed little in 2018 but increased significantly in 2019, especially during the 2-4 weeks after physiological maturity; the pith of all internodes of ‘Zhengdan 985' and ‘Xianyu 335' became completely white on the 4th week after physiological maturity. In conclusion, with the increase of IP the internode became longer and thinner, the dry weight per volume became smaller, the moisture content became smaller and the proportion of white pith area became larger upward. With the progress of growth, the variation of dry weight per volume of internodes were affected by environments and varietys, the moisture content decreased rapidly from the middle stage of grain filling, the proportion of white pith area was affected by environment, it increased rapidly from the 2nd to the 4th week after physiological maturity.Keywords：maize;internodes below ear;morphology;dry matter content;moisture content;proportion of white pith area9|13|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to understand the research status of the response mechanism of plants to low temperature stress, the literature published from 2000 to 2022 were searched in Web of Science Core Collection, SpringerLink and China National Knowledge Infrastructure(CNKI)with “low temperature stress”, “CBF” and “cold resistance” as keywords. The literature related to the research on the response mechanism of plant to low temperature stress were reviewed and analyzed. The results showed that: 1)The study on the response mechanism of plants to low temperature stress is helpful to provide a basis for improving plant low temperature resistance, which is of great significance for coping with complex global climate changes; 2)When plants suffer from low temperature stress, their biofilm system will be damaged, the content of cell osmotic adjustment substances will also change to maintain normal osmotic pressure, and the activity of antioxidant enzymes will generally increase first and then decrease; 3)Plants have a complex and precise signaling pathway to resist low temperature stress. CBF-dependent pathway can regulate the low temperature resistance of plants through post-translational modification of some key proteins, and play an important role in plants resisting low temperature stress; 4)The research on CBF-independent pathways, low temperature signal receptors and low temperature signal molecules still needs to be further studied.Keywords：low temperature stress;CBF;cold resistance;transcription factors6|11|15<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore the starch accumulation pattern of the potato variety ‘Longshu 8' with super high starch and its key regulatory genes, the contents of starch and sucrose, and transcriptome sequencing of ‘Longshu 8' tuber from full flowering(T1)to 15 d(T2), 30 d(T3), 45 d(T4)and 60 d(T5)after full flowering were determined. The results showed that: During the whole sampling period, the sucrose content decreased significantly from T1 to T3 stage, and then increased afterwards. The total starch content increased with the development of the growth process, and the starch content increased rapidly during T2 to T3 period and slowly during T3 to T5 period. The transcriptional expression data of 14 634 genes in tuber of potato at different developmental stages were obtained, and the total number of differentially expressed genes in 4 adjacent period comparison groups T1 vs T2, T2 vs T3, T3 vs T4 and T4 vs T5 were 1 279, 427, 184 and 300, respectively. The results of functional annotation and metabolic pathway analysis found that 24 genes related to starch and sucrose metabolic pathways differentially expressed in different periods, among which only sucrose synthase genes Soltu. DM. 09G031820 and Soltu. DM. 07G013370, ADP-Glucose pyrophosphorylase gene Soltu. DM. 01G049590, starch synthase gene Soltu. DM. 02G027020 and glycogen phosphorylase gene Soltu. DM. 03G007710 were expressed at high levels throughout the sampling period, and their expression levels at stage T2 and T5 were higher than those of the low-starch variety ‘Longshu 13'. Combining the dynamic changes of sucrose and starch content, with gene expression pattern, it is speculated that Soltu. DM. 09G031820, Soltu. DM. 07G013370, Soltu. DM. 01G049590 and Soltu. DM. 02G027020 genes may play important regulatory roles in the synthesis and accumulation of starch in ‘Longshu 8' tuber.Keywords：potato;developmental stages;starch-sucrose metabolism;transcriptome analysis14|13|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to screen strawberry cultivars at molecular level, 18 SSR primer pairs with high polymorphism were identified from 59 primer pairs, and 84 octoploid cultivated strawberry samples were screened. By using capillary electrophoresis method, the size of different alleles were detected, and the molecular fingerprinting and genetic analysis for all samples were established. Different alleles of every prime were digitally labelled on 84 strawberry variety according to certain principles. For simplicity, the primers P1 to P18 were labelled as A to R, then the code for one strawberry variety on specific primer was got through combining the primer label and the corresponding allele label. Combination of these codes of 18 primers according to the primer sequence to form one DNA fingerprint for one particular variety. The results showed that: A total of 150 polymorphic bands were amplified, and the number of polymorphic bands amplified by different primers ranged from 4 to 17. Finally, 377 band combinations were obtained in this study. The value of polymorphism information content ranged from 0. 494 to 0. 908, and the average value was 0. 738. DNA fingerprint of all 84 strawberry variety was constructed following the above method. The result of clustering analysis showed that all varieties were completely differed from each other by using these 18 primer pairs based on the threshold of genetic similarity coefficient at 0. 99. Some cultivars from same origin were clustered together obviously. In conclusion, the DNA fingerprint of all 84 strawberry variety was constructed, and the relationship among them was close.Keywords：strawberry;SSR;DNA fingerprinting;genetic analysis8|13|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The aims of this study were to further study the growth and development characteristics of sugar beet in different ecological regions of Xinjiang, clarify the ecological adaptability of sugar beet and screen high quality sugar beet varieties in this study. By analyzing changes of photosynthetic and agronomic characters of 20 sugar beet varieties in three different ecological regions, the stability of different sugar beet varieties was investigated by well-posed parameter method and coefficient of variation method, and their comprehensive scores were scored by principal component analysis. The results showed that: There were significant differences in photosynthetic characters, photosynthetic rate, stomatal conductance, intercellular CO2 concentration, intercellular CO2 concentration and transpiration rate among among 20 varieties of sugar beet in three regions. There were no significant differences in agronomic characters among varieties, but were significant differences among regions, indicating that different meteorological factors had great influence on agronomic characters of sugar beet. The results of correlation analysis showed that each agronomic trait and sugar beet yield and sugar content were significantly correlated. The performance of different varieties in different ecological regions was comprehensively evaluated by principal component analysis. About 4, 3 and 3 principal components were extracted from Changji, Shihezi and Yili ecological regions, respectively. Their cumulative contribution rate reached 63. 50%, 68. 70% and 63. 65% respectively. According to the comprehensive score obtained, it was found that the sugar beet varieties‘BeTa379', ‘KWS9968', ‘KWS5599'and ‘KWS6637' were in a higher position in the comprehensive ranking of the three pilot sites. Their average yields were 102 000. 45, 88 613. 85, 96 501. 90 and 95 214. 90 kg/hm2, respectively and their average sugar contents were 15. 19%, 15. 08%, 14. 29% and 14. 14%, respectively. In conclusion, the three varieties have good ecological adaptability and potential advantages.Keywords：sugar beet;ecological regions;photosynthetic characters;agronomic characters;ecological adaptability5|11|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to select and validate the real-time PCR reference genes stably expressed in Lilium leichtlinii, tepals in different stages, root, stem, leaf and scale were taken as study objects. This study measured and compared the total carotenoids contents, analyzed the specificity and the expression levels of AP4, Actin, β-TUB, CYP, eIF, GAPDH, RH2, UBC and 18S in L. leichtlinii by RT-PCR and qRT-PCR. GeNorm, NormFinder, Bestkeeper, ΔCT and RefFinder were used to evaluate expression stability of these candidate reference genes. PSY gene was used to verify the stability of reference genes. The results showed that: In tepals during development of L. leichtlinii, AP4 and Actin were the most stable genes and UBC was the least stable gene among 9 candidate reference genes. In different tissues, eIF and AP4 were the most stable, 18S was the most unstable. In addition, the expression levels of PSY calculated using the most stable reference genes were consistent with the trend of total carotenoids contents during tepal development process and at different tissues. The expression level of PSY calculated using unstable reference genes was different and even opposite to the trend of total carotenoids contents. In conclusion, reference genes should not be used randomly in test, and they need to be evaluated and verified before use. This study provided the stable reference genes for the analysis of gene expression during tepal development and different tissues in L. leichtlinii.Keywords：Lilium leichtlinii;reverse transcription real-time polymerase chain reaction;reference gene;carotenoid3|11|6<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to deeply explore the research progress and hotspots related to interplanting grass in orchard(IGIO), the visualization software VOSviewer and CiteSpace methods were adopted, statistics and analysis on CNKI and WOS database related to IGIO research literature from 1990 to 2022 were conducted. It is found that there has been an overall trend of fluctuating growth in the number of publications on the related research of “IGIO”, and the subject research fields mainly focus on horticulture, environmental science and ecology. The most representative journals are Journal of Ecology, Plos One, Science of the Total Environment and Journal of Northwest A & F University(Natural Science Edition), with more publications and the greater academic influence of the journal. In terms of international cooperation, China has close exchanges with state-owned countries such as the United States and Australia, and has the closest cooperation with scholars from relevant institutions in the United States. IGIO research institutions are relatively scattered, Chinese Academy of Sciences and Northwest A & F University have carried out a large number of orchard grass research, which has made positive contributions to the development of IGIO techniques in China. IGIO mostly adopts control simulation test as the research method, based on grass mulching practice. The research theme is gradually changed from orchard forage cultivation in the early stage to orchard weed, disease and insect pest control, and then more attentions are paid to the comprehensive benefits of the orchard. To sum up, the research directions of IGIO in China mainly focus on the selection of orchard grass species, pest control, soil physical and chemical properties, fruit tree quality improvement and orchard ecological effect, while foreign orchard grass research gradually tends to focus on self-own grass and fruit quality.Keywords：interplanting grass in orchard;bibliometrics;co-occurrence analysis;selection of orchard grass species;soil physical and chemical properties;orchard ecological effect7|12|7<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to screen microRNA(miRNA)related to the morphogenesis and development of secondary hair follicles in cashmere goats and verify their target genes, in this study, based on the previous high-throughput sequencing technology of the research group, the miRNA expression profiles of cashmere goat fetal period(45, 55, 65, 75, 95, 115 and 135 d)skin tissue were obtained. The differentially expressed miRNAs were screened according to the hair follicle morphogenesis rules, and the miRNAs related to the development of secondary hair follicles were identified. RNAhybrid, miRanda and TargetScan software were used to predict the screened miRNA target genes and intersected with the genes related to the development of secondary hair follicles. The intersected genes were enriched and analyzed by go and KEGG to screen the key genes in the important pathway of hair follicle development, construct the miRNA mRNA regulation network, and further verify the targeting relationship of key miRNA mRNA by using the double Luciferase Report. The results showed that: 1)A total of 53 miRNAs related to secondary hair follicle development were screened, and 32 978 target genes were predicted; 2)After the intersection, 1 352 targeted genes related to secondary hair follicle development were obtained, which were significantly enriched in 29 KEGG pathways, including TGF-β, an important pathway of hair follicle development; 3)Similarly, 232 pairs of miRNA mRNA pairs that may be related to the occurrence and development of secondary hair follicles, such as chi-miR-26b-5p-SMAD1 and chi-miR-495-3p-SMAD1, were constructed. The dual-luciferase reporter system further verified the key targeting relationship. In conclusion, this study laid a preliminary foundation for analyzing the molecular mechanism of miRNA in the development of secondary hair follicles of cashmere goats.Keywords：cashmere goats;secondary hair follicle;miRNA;target gene1|9|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The aim of this study was to investigate the effects of adding different levels of tannalbin to wheat soybean peanut meal basal diet on growth performance, plasma biochemical indices, immune function, antioxidant capacity and lipid metabolism of yellow-feathered chickens during 1 to 48 days of age. A total of 540 one-day-old male rapid ephedra chickens with an initial body weight of(40. 33±0. 05)g in good health were randomly assigned to 3 groups according to the principle of consistent body weight, each group with 6 replicates and 30 chickens in each replicate. Control group(basal diet), tannalbin 1 groups(basal diet supplementation with 300 mg/kg tannalbin), tannalbin 2 groups(basal diet supplementation with 500 mg/kg tannalbin). The experiment lasted for 48 days. The results showed as follows: 1)Dietary different levels of tannalbin had no significant effects on growth performance of chickens(P>0. 05). 2)Compared to the control group, alanine aminotransferase(ALT)activity and uric acid(UA)content in plasma of tannalbin 1 and 2 groups were significantly increased(P<0. 05), glucose(GLU)content in plasma of tannalbin 2 group was significantly decreased(P<0. 05), and total bilirubin(TBIL)content in plasma of tannalbin 1 group was significantly decreased(P<0. 05). 3)Compared to the control group, interleukin 6(IL-6)content in jejunal mucosa of tannalbin 1 group was significantly decreased(P<0. 05). 4)Compared to the control group, malondialdehyde(MDA)content in plasma of tannalbin 2 group was significantly decreased(P<0. 05), while total antioxidant capacity(T-AOC)and reduced glutathione(GSH)content in liver of tannalbin 2 group were significantly increased(P<0. 05). 5)Compared to the control group, contents of estradiol(E2), triglyceride(TG), total cholesterol(TC)and low density lipoprotein cholesterol(LDL-C), and activity of fatty acid synthetase(FAS)in liver of tannalbin 1 and 2 groups were significantly decreased(P<0. 05). In summary, application of 300 or 500 mg/kg tannalbin to wheat soybean peanut meal diet can regulate lipid metabolism of chickens respectively, and 300 mg/kg tannalbin can improve immune function, 500 mg/kg tannalbin can improve antioxidant capacity. Considering the above indicators and growth performance, the recommended supplemental level of tannalbin is 300 mg/kg.Keywords：tannalbin;yellow-feathered chickens;growth performance;immune function;antioxidant capacity;lipid metabolism0|10|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore the population characteristics of plasma prolactin(PRL)concentration in dairy cows and its variation under different environmental conditions and physiological stages, estimate the genetic parameters, and estimate the association between polymorphism of gene PRL, PRLR, TRH and plasma PRL concentration, a total of 1 169 records of plasma PRL concentration from 472 lactating Holstein cows were tested in a large-scale dairy farm in Beijing in 2014 and 2017. Firstly, the effects of sampling season, parity, milking status and lactation stage on plasma PRL concentration were analyzed by employing a fixed model. Then, the genetic parameters of plasma PRL concentration were estimated using a repeatability animal model. In addition, polymorphic loci of gene PRL, PRLR and TRH were screened in Holstein cattle; and the SNP- and haplotype-based association analyses were performed with plasma PRL concentration. The results showed that: 1)The average plasma PRL concentration of Holstein cattle was 224. 29 mIU/L. Parity, sampling season and lactation stage had significant or highly significant impacts on plasma PRL concentration. Plasma PRL concentration gradually increased with the increase of parity and lactation stage, and plasma PRL concentration in spring and summer were extremely significantly higher than that in autumn and winter(P<0. 01); 2)The heritability of plasma PRL concentration was 0. 02, indicating a lowly inheritable nature; 3)Association analyses showed that no SNP within gene PRL and PRLR had significant effect on plasma PRL concentration; rs137596325, rs109144892, rs108991567, rs109468305 and rs109330999 within gene TRH had significant or highly significant effects on plasma PRL concentration. Based on linkage disequilibrium analysis of SNPs in three genes, haplotype block in PRLR gene tended to associate with plasma PRL concentration(P<0. 1), and two haplotype blocks in TRH gene were significantly associated with plasma PRL concentration. In conclusion, this study obtained the population characteristics, genetic parameters and associated genetic markers for plasma PRL concentration in Holstein cows, which was beneficial for further understanding the genetic mechanism of plasma PRL concentration.Keywords：dairy cattle;plasma prolactin;genetic analysis;PRL;PRLR;TRH2|10|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：When lambs are born, the rumen is not well developed physiologically and metabolically and the lambs mainly rely on breast milk to meet their maintenance and growth needs. With the growth of lambs' age and the intake of solid feed, the physiological function of rumen gradually becomes mature. Recent studies have found that feeding lambs with only concentrate feeds can easily cause symptoms such as decreased rnumen pH, agglutination of rumen nipples and incomplete keratinization, while adding hay on the basis of concentrate can increase rumen pH, increase rumen volume, reduce agglutination of rumen nipples and maintain normal morphology of rumen nipples. Although there have been studies on the effects of hay on the rumen development of lambs and its mechanism, the understanding is not comprehensive. Herein, the latest research progress on the rumen development of lambs and the effect of hay on rumen development and its mechanism are reviewed. The results show that: 1)Supplementation of hay before weaning of lambs helps to colonize cellulolytic bacteria in the rumen; 2)Supplementation of hay before weaning of lambs can promote rumen epithelium development and volatile fatty acid metabolism; 3)The mechanism of hay promoting rumen development of pre-weaning lambs is related to hay regulating the intracellular calcium signaling pathway and metabolic network of amino acids and fatty acids, decreasing gene expression levels of insulin-like growth factor binding protein 2(IGFBP2)and IGFBP4, inhibiting nuclear factor kappa-light-chain-enhancer of activated B cells(NF-KB)signaling pathway, increasing gene expression levels of 3-Hydroxymethyl-3-methylglutaryl-CoA lyase(HMGCL), 3-hydroaxy-3-methylglutaryl-CoAsynthase Ⅱ(HMGCS2), 3-hydroxybutyrate dehydrogenase 1(BDH1)and monocarboxylate transporter 1(MCT1), and activating gene pathway of estrogen-related receptor α(ESRRA)involved in energy production. This review provides a comprehensive and in-depth understanding of hay promoting rumen development and its mechanism in lambs.Keywords：lambs;hay;rumen development;mechanism7|11|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to promote the popularization and application of laser land leveling technology and improve autumn irrigation quality, compared with ordinary farmland, the effects of laser land leveling on soil bulk density, soil porosity, soil moisture infiltration rate and autumn irrigation quality in laser land leveling farmland in Hetao irrigation area of Inner Mongolia were measured. The results showed that: Laser land leveling mainly affected soil bulk density, soil total porosity and capillary porosity in 0-10 cm soil layer, and significantly decreased air-filled porosity porosity in 0-30 cm soil layer, but had no significant effects on soil bulk density, soil total porosity and capillary porosity in 10-30 cm soil layer. Laser land leveling significantly reduced the stable infiltration rate of soil moisture and reduced irrigation amount of autumn irrigation by 25. 93%. In laser land leveling farmland, the irrigation water rate of autumn irrigation was faster and more consistent, the field water storage depth was shallow and uniform, and the water recession rate was lower and more consistent. In conclusion, laser leveling should be actively developed in Hetao irrigation area to save irrigation amount and improve autumn irrigation quality.Keywords：laser land leveling technology;soil bulk density;soil porosity;soil moisture infiltration rate;irrigation quality3|10|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To reveal the situatoin of control non-point sources pollution from farmland(NSPF)on regional scale, the main crops and their fertilizer application rates were taken as research objects. The risk grade of NSPF(includes safety, micro-risk, low-risk, mid-risk and high-risk)and conception of grain crop equivalent were put forward in the study. The NSPF risk of main crop and crop type and development process in recent twenty years were disclosed, and the assessment model of NSPF risk at regional scale was set up. Taking 2018 as an example, the assessment of NSPF risk at national, regional and provincial scales in China was carried out. The results are as fellows: 1)There are major differences in NSPF risk about different crops and crop types. Grain crops belong to low-risk of nitrogen non-point source pollution of farmland(N-NSPF)and micro-risk of phosphorus non-point source pollution of farmland(P-NSPF). Oil crops are in the micro-risk of N-NSPF and PNPF, while cotton is in high-risk of N-NSPF and low-risk of P-NSPF. Fiber crops are in high-risk of N-NSPF and micro-risk of P-NSPF and sugar crops are in high-risk of N-NSPF and P-NSPF. Tobacco is safe for N-NSPF and in mid-risk of P-NSPF, vegetables are in mid-risk of N-NSPF and high-risk of P-NSPF, tea plantation is in high-risk of N-NSPF and mid-risk of P-NSPF, and orchards are in high-risk of N-NSPF and P-NSPF. 2)The risk coefficient of nitrogen non-point source pollution from farmland(RCN)and risk coefficient of phosphorus non-point source pollution from farmland(RCP)are 1. 14 and 1. 45 at national scale, which are in low-risk of N-NSPF and P-NSPF. RCN is 1. 02 to 1. 37 at regional scale, other regions all are low-risk except South China. RCP is 1. 08 to 2. 20 at regional scale, Northeast, North, Central and East China are of low-risk, Southeast and Northwest China are of mid-risk, while South China is of high-risk. 3)At provincial scale, RCN ranges 0. 95 to 1. 41, other provinces all belong to low-risk, Guangdong and 7 other provinces belong to mid-risk. RCP ranges from 1. 16 to 2. 99, other 17 provinces all belong to low-risk, except Guizhou and 8 other provinces belong to high-risk, Yunnan and 4 other provinces mid-risk, Heilongjiang and Jilin micro-risk. Crop types and their planting area have important influence on risk of NSPF at regional scale. The more the planting area of grain crops, the less risk of NSPF, such as in Northeast, North, East and Central China. The more the planting area of orchard, vegetable or tea, the more risk of NSPF, especially the risk of phosphorus NSPF, such as Southeast, Northwest and South China.Keywords：fertilizer application rate;regional scale;non-point source pollution from farmland;risk3|10|9<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The aims of this study are to promote the sustainable development of the farmland ecosystem, and deeply investigate the changes of farmland ecosystem services in Heilongjiang Province in the context of the conversion of dry land to paddy fields. Based on the remote sensing image interpretation of 1995, 2005, 2015 and 2020, this study analyzes the changes of farmland distribution and farmland ecosystem services in Heilongjiang Province, evaluates the trade-offs and synergistic relationships, identifies hotspot areas and delineates ecological function management zones. The results show that: 1)The trend of dry land to paddy field conversion in Heilongjiang Province is obvious, and the paddy field areas in the province increased by 162. 45%, which are mainly located in the Sanjiang Plain; 2)The grain yield, carbon sequestration, and soil conservation in the study area show an increasing trend, and the water deficit also increases; 3)Food supply and carbon sequestration display spatial synergistic relationships, while there are significant trade-off relationships with hydrological regulation and soil conservation. It is found that farmland ecosystem services have consistent trade-off synergistic relationships from 1995 to 2020, but there are differences in the degree of correlation. In conclusion, to maximize regional ecosystem services, the whole province area can be divided into three types of ecological function zones, namely, the agricultural products supply zone, soil conservation zone and ecological protection zone.Keywords：farmland;ecosystem services;trade-off;synergy;Heilongjiang Province8|117|9<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to improve the efficiency of desertification control and water resources, this study considered the role and restriction relationship between water, land and biological in the process of desertification control, and a nonlinear fractional multi-objective water and land resource model in the desertification control area was developed with the goal of maximizing the total value of carbon sequestration and oxygen production and maximizing water efficiency, using to jointly optimize the planting structure and irrigation water during growth season of plant in the desertification control area; the genetic algorithm was used to solve the model to explore the trade-off process between goals. The model was applied to the example of optimal allocation of water and land resources in the desertification control area to obtain the Pareto solution set and analyze the sensitivity to the amount of water available. The results show that the total value of the system for carbon fixation and oxygen production is the largest when the water distribution increases and a large number of Haloxylon ammodendron are planted. The water efficiency of the system is maximized when the water distribution is reduced while a large number of Hedysarum scoparium are planted. Calligonum mongolicum has no advantage in the process of optimal allocation of water and land resources. The Pareto solution set can reflect the trade-off between goals that can effectively eliminate unreasonable solutions; among the three typical schemes, the 55th scheme with two goals in equilibrium is more reasonable in the distribution of water and land resources; water supply has a significant impact on Pareto solution set. When the water supply exceeds 3 500 m3/hm2, water resources will be wasted. When the goals are in equilibrium, the optimal water supply in the desertification control area is 3 000 m3/hm2, which the ideal total value of carbon fixation and oxygen production can be obtained to make full use of water resources. The model comprehensively considers water resources and land resources in the process of desertification control, quantifies the trade-off relationship between goals, the results can provide effective decision support information for desertification control.Keywords：desertification control;water and land resource optimization;nonlinear fractional programming;multi-objective programming;Pareto solution set1|13|5<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to accurately evaluate and predict the impact damage of Gongli, a combined hyperspectral imaging technology and mechanical parameters in the wavelength range of 397. 5-1 014. 0 nm method was proposed in this study to quantitatively detect the impact damage of Gongli. Firstly, the mechanical parameters such as peak force, average contact force, damage area and average pressure were obtained by using the collision device based on single pendulum principle and intelligent data acquisition system, and the mechanical parameters were statistically analyzed. Then, spectral data on damaged Gongli was obtained by a hyperspectral imaging system. The original spectrum was preprocessed by Gap-segment derivative, SG derivative and baseline calibration(Baseline). The partial least squares regression(PLSR)and principal component regression(PCR)models based on spectral data combined with mechanical parameters were established. Finally, the competitive adaptive reweighting sampling(CARS)and uninformative variable elimination(UVE)algorithms were used to select the characteristic wavelength. The selected characteristic wavelength was used as the input variable and the PLSR model based on characteristic wavelength combined with mechanical parameters was established. The results of the statistical analysis and modelling of the mechanical parameters show that: 1)The average value of mechanical parameters increases with the increase of release angle. The average value of peak force increases from 138. 40 N to 335. 86 N, the average value of contact force increases from 77. 13 N to 188. 20 N, the average value of damage area increases from 208. 07 mm2 to 544. 42 mm2, and the average value of pressure increases from 0. 34 MPa to 0. 42 MPa. The change of mechanical parameters can be used to characterize the impact damage degree of Gongli to a certain extent. 2)The baseline-CARS-PLSR model displays the best prediction performance on mechanical parameters. The values of correlation coefficient(RP)and root mean square error(RMSEP)of peak force, average contact force, damage area and average pressure are 0. 892 and 31. 527 N, 0. 883 and 18. 861 N, 0. 895 and 54. 411 mm2, 0. 661 and 0. 045 MPa, respectively. The overall results show the feasibility of quantitative prediction of impact damage of Gongli by hyperspectral imaging combined with mechanical parameters, and provide a theoretical support for quality sorting and packaging of Gongli.Keywords：Gongli;hyperspectral imaging;mechanical parameter;impact failure;partial least squares regression;principal component regression2|11|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To address the problems of tedious and time-consuming process of the traditional dietary survey methods, this study proposed to investigate an automated dietary survey system based on color depth images. DeepLabv3+ semantic segmentation model was adopted to segment the color images of food acquired by RealSense sensors by calculating the volume of each category of food based on the food segmentation results with corresponding depth images and combining the food ingredient list and nutrient composition to estimate nutrient content. Meanwhile, the human depth image sequences were collected to fit the three-dimensional human model with the skinned multi-person linear model, while the body mass index and waist-hip ratio were calculated by using the model point cloud and human weight information. The results show that: 1)The pixel accuracy of this system is 72. 1% in food image segmentation, the mean pixel accuracy is 97. 13%, and the mean intersection over union is 82. 03%; 2)The mean absolute errors are all less than 40 cm3 in food volume calculation; 3)The waist-hip ratio calculated for all human samples deviates from the true value by less than 4%. This system provides references for the nutritional interventions by increasing the preliminary determination of human body weight status and the degree of central obesity based on the realization of automatic monitoring of the intake of each nutrient in food, as well as improving the convenience and automation of dietary surveys.Keywords：dietary survey;RGB-D images;deep learning;food segmentation;food volume estimation5|11|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The aim of this study was to study the natural grassland disturbance failure process under the action of subsoiler tillage tools. Field tests were conducted under different operating depths by using a tillage test bench carrying different types of subsoilers with different wing inclination angles. The failure process of the grassland soil layer, disturbance, soil overturning rate, soil disturbance coefficient, soil bulkiness, working resistance of tillage tools, and specific draft forces were compared and analyzed. The results showed that: The subsoiler tillage tools could break the composite soil structure of grassland and cause disturbance to the grassland soil layer, but their operations were affected by the working depth, structural parameters, and the special composite soil layer structure. After the subsoiling, the surface soil overturning rate was 5. 67%-12. 25%, the disturbance coefficient was 63%-74%, and the bulkiness was 38%-49%. Based on all the disturbance failure characteristic parameters, among the tillage tools tested, the subsoiling shovel with a double-wing inclination angle of 150° has little effect on the disturbance and soil overturn of grassland surface and high disturbance coefficient on soil, and therefor achieved the best working effect.Keywords：subsoiler;natural grassland;wing inclination angle;soil-roots composite structure;coupling failure;applicability evaluation8|16|3<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In view of the complex ventilation design and poor uniformity/stability of the indoor thermal environment of multi-floor pig buildings, the work aimed to study the application effect of targeted ventilation in multi-floor pig buildings. Experiments were conducted to continuously monitor some indicators(the winter and summer indoor wind speed, ventilation, temperature, humidity, and stress)of the farrowing sows, in the multi-floor pig building with a targeted ventilation system. The results show that: 1)The targeted ventilation system can effectively improve the distribution and utilization of indoor air flow. For the wind speed of the stall air outlet and living area, the uniformity in the width direction(P>0. 05)is better than that in the length direction(P<0. 05). The winter and summer average wind speed in the living area are(0. 16±0. 05)m/s and(0. 90±0. 17)m/s, respectively. 2)The targeted ventilation system can regulate the temperature to a suitable range, keeping an average temperature to(19. 5±0. 21)℃ in winter, and(27. 0±1. 77)℃ in summer, it can also maintain good temperature and humidity uniformity in both the horizontal and vertical orientation. 3)The targeted ventilation system can effectively improve the comfort level of sows, with no cold stress in winter, and the percentage of no heat stress is up to 85. 9% in summer. There is no high level heat stress, the percentage of alert level is 13. 3% and the percentage of danger level is merely 0. 8%. In conclusion, the application of targeted ventilation system in multi-floor pig buildings can improve the indoor thermal environment as well as reducing levels of heat stress in summer, and greatly reduce ventilation finally.Keywords：multi-floor pig building;farrowing sow;ventilation;thermal environment;temperature humidity index9|10|5<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Based on the micro survey data of 596 households in 27 experimental stations of the national rape industry technology system, this study systematically analyzes the influence and mechanism of agricultural land scale and planting mode on rape production technology efficiency by using random frontier production function model, limited Tobit model and propensity score matching method. The results showed that: The scale of agricultural land had a significant positive impact on the technical efficiency of rape production; However, the expansion of agricultural land scale promoted the adoption of direct seeding, and direct seeding reduced the technical efficiency of rape production, with a masking effect of 31. 51%; Compared with transplanting, When other factors remain unchanged, the output of rape with direct seeding was about 900 yuan/hm2 lower. In conclusion, this study recommends that when encouraging large-scale management and planting, the masking effect brought by increasing the adoption of direct broadcasting can not be ignored. Relevant institutions should enhance the guidance service of direct seeding and supporting technology, strengthen the improvement of excellent rape varieties, and strengthen the research and development of rape precision cultivation technology.Keywords：scale management;direct seeding;production technical efficiency;masking effect2|13|10<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore the development rules and growth sources of Chinese agricultural TFP since the implementation of agricultural machinery purchase subsidy and farmland transfer, this research calculates and analyzes the spatial-temporal differences of Chinese agriculture TFP by the Hicks-Moorsteen index, and further uses the Dagum Gini coefficient and its decomposition method to explore the endogenous composition of spatial differences. The results show that: Chinese agricultural TFP is in a sustained growth trend, and the driving factor is technological progress rather than technological efficiency. The growth trend of agricultural TFP in China's seven regions is different, and the growth sources in each region are also different. There are significant differences in agricultural development potential among different regions. The overall differences of agricultural TFP in the seven regions have a gradually expanding evolution trend, and the interregional differences are the main triggers for overall differences.Keywords：Chinese agriculture;total factor productivity;spatio-temporal evolution;Hicks-Moorsteen index;sources of differences5|9|6<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to clarify the impact of the external market environment on farmers' income growth and income distribution, based on the China Land Economic Survey founded by Nanjing Agricultural University in 2020, the study uses quantile regressions, to establish the impact of labor allocation on farm household income and income inequality in the context of the incomplete development of factor markets. The results show that: Incomplete factor market development has a negative impact on farm household income compared to complete factor market development. At the same time, when farmers are divided into different income groups, the incomplete factor market development displays a more significant impact on farmers in the low- and middle-income groups, which exacerbates the inequality of farmers' income to a certain extent. Recommendations such as further strengthening the construction of rural factor markets and optimizing the allocation of labor to farm households are put forward to achieve growth in farmers' income and narrow down the income gap within farm households.Keywords：labor allocation;factor market;farm household income;income inequality2|11|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore the impact of rural transportation facilities improvement and digital countryside development on migrant workers' return to start businesses, this study empirically tested the relationships among the three factors using Logit model and moderating effect test model based on the data of China Labor Dynamics Survey in 2016 and 2018 and the data of China county digital countryside index in 2018. The results show that: Rural transportation facilities improvement has a significant promoting effect on migrant workers returning to start businesses, but there is regional heterogeneity and terrain heterogeneity. Digital countryside development has a moderating effect between the rural transportation facilities improvement and the migrant workers return home to start businesses, strengthening the promotion effect of rural transportation facilities improvement of rural migrant workers returning home to start businesses. Rural transportation facilities improvement will also significantly improve the entrepreneurial performance of migrant workers in their hometowns, and digital countryside development also has a moderating effect on rural transportation facilities improvement and the entrepreneurial performance of migrant workers in their hometowns. Therefore, it is necessary to further optimize rural transportation facilities and strengthen the construction of rural digital infrastructure to further promote the return of migrant workers to their hometowns to start businesses, improve the performance of migrant workers to return to their hometowns to start businesses, promote the high-quality development of agricultural and rural modernization, and help rural revitalization.Keywords：rural transportation facilities improvement;digital countryside development;migrant workers return home to start businesses12|9|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to improve the level of agricultural green technology innovation, based on the panel data of 30 Chinese provinces(The data do not include those of the Tibet Autonomous Region, Hong Kong, Macao and Taiwan regions. The same below), this study analyzed the environmental governance on agricultural green technology innovation mechanism, and used the panel threshold model to explore the environmental governance strength on the threshold of agricultural green technology innovation. The results showed that: Environmental governance significantly promoted the innovation of agricultural green technology; The government R&D inputs, gross agricultural product and agricultural productivity also played significant roles in promoting the agricultural green technology innovation. On this basis, further research found that: The impact of environmental governance on agricultural green technology innovation showed a U-shaped state of declining first and then rising. At the same time, for different types of innovation subjects, the impact of environmental governance on agricultural technology innovation also has non-linear characteristics. However, the U-type inflection point of agriculture-related enterprises appeared earlier. Therefore, the government should adopt appropriate environmental governance strength, increase investment in research and development, and create a good innovation environment, so as to promote the agricultural technology innovation subject research and development of green technology, and improve the level of green technology innovation.Keywords：environmental governance;agricultural green technology innovation;agricultural research institutes;agriculture-related enterprises;threshold regression5|10|3<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
