Abstract:This article derived wisdom from the long history and explored how to integrate the traditional farming civilization with the notion of ecological low-carbon to achieve sustainable development in agriculture on the journey towards modernization with Chinese characteristics.It was proposed that four principles including balancing the food production and the development of agriculture with ecological low-carbon， pursuing a synergistic approach between common prosperity and the development of agriculture with ecological low-carbon， continuing the legacy of farming civilization and the development of agriculture with ecological low-carbon， and composing a way to respect for nature and protect the development of agriculture with ecological low-carbon should be followed in developing agriculture with ecological low-carbon under the background of modernization with Chinese characteristics.In the future， it is necessary to construct a collaborative mechanism for the development and application of agriculture technology with ecological low-carbon， improve the market integration and value realization pathways of agriculture with ecological low-carbon， establish a system for the integration and passing on of farming techniques and agriculture with ecological low-carbon， and form a framework for the coordinated development of natural resources and agriculture with ecological low-carbon.

Abstract:Agricultural carbon trading is an essential tool that facilitates the transition from traditional to low-carbon agriculture， offering significant potential to enhance farmers’ income. At present， notable progress has been achieved in China’s pilot agricultural carbon trading initiatives. However， how to achieve widespread participation among farmers and effectively enhance their income remains a key issue that needs to be urgently addressed. To synergistically propel the attainment of the “Dual-carbon” objectives and the realization of common prosperity， by examining the typical scenarios of agricultural carbon trading pilots and delineating the process of agricultural carbon trading， this study elucidated the mechanisms through which agricultural carbon trading promotes farmers’ income. Additionally， we categorized agricultural carbon trading projects based on farmers’ participation demands and income potential， delving into the real-world challenges faced by different types of projects and offering corresponding countermeasures and recommendations. The study revealed that the benefits of farmers’ income enhancement stem from transfer payments from regulatory agencies， input contributions from farmers， organization and guidance from intermediary institutions， and product purchases from consumers. Therefore， it is imperative to improve the policy support system for agricultural carbon trading， strengthen capacity building for agricultural carbon trading， stimulate social service vitality in agricultural carbon trading， and optimize the mechanism for sharing benefits of farmers’ income enhancement.

Abstract:In promoting the realization of the “Dual carbon” goals， the agricultural sector holds tremendous potential. However， the actual progress in unlocking this potential has been relatively slow. Currently， China’s agriculture is at a crucial juncture in its low-carbon transformation and urgently needs to define devolping mechanisms to steadily advance low-carbon agriculture in the new era. Based on this foundation， this paper aimed to conduct an in-depth analysis of the complex issues that hinder the sustainable development of low-carbon agriculture in our country， and to clarify the theoretical underpinnings of these issues. Through this analysis， the research seeked to explore a pathway for the development of low-carbon agriculture that aligns with our national conditions. This paper examineed a vast amount of literature to uncover the specific challenges facing China’s agriculture in its low-carbon transition， theoretically analyzed the key bottlenecks during this transformation， and identified opportunities for the stable development of low-carbon agriculture in China. The research indicated that significant pressures in the agricultural sector during the transition towards a low-carbon model. These pressures were primarily characterized by the absence of mechanisms to convert low-carbon concepts into new avenues for value creation. At the same time， agricultural operators and top-level designers still maintained the inertia of the high-carbon era development models. It is essential to reevaluate the roles of the market and the government in China’s transition to low-carbon agriculture， to seize the real opportunities under the “dual carbon” objectives， and to leverage the “Market-Government” co-construction mechanism. This approach aims to achieve low-carbon agricultural development targets that balance economic efficiency， social benefits， and ecological gains.

Abstract:This article analyzed the logic of reducing application of fertilizer under the constraint of plot scale based on the theory of induced technological change. The data about maize farmers in seven provinces of China obtained from 2020 China Rural Revitalization Survey （CRRS） and the 2SLS model were used to analyze the impact of plot size on fertilizer input. The results of empirical studies showed that expanding the plot scale reduced the input intensity of fertilizer and improved the input efficiency of fertilizer. The results of heterogeneity analyses showed that the expansion of plot scale by large-scale farmers had a greater impact on reducing application of fertilizer compared with small-scale farmers. The impact of expanding plot scale on fertilizer input was even more pronounced in term of farmers with higher input intensity and lower input efficiency of fertilizer. The results of analyzing mechanism showed that replacing agricultural labor with mechanical operations was a mechanism for reducing the expansion of plot scale and promoting the reduced application of fertilizer.

Abstract:Synchronizing the food security strategy with the goal of “carbon peaking and carbon neutrality” is the key to accelerate the pace of agricultural and rural modernization and the construction of a strong agricultural country. To promote the synchronization of the food security strategy with the “Dual-carbon” objective， this study， based on the perspective of food security， explained the scientific connotation of eco-low-carbon agriculture， clarified the dialectical relationship between food security and eco-low-carbon agriculture， analyzed the problems and challenges faced by eco-low-carbon agriculture under the food security strategy， and put forward the development strategies and the promotion paths. The study revealed that， under the guidance of “all-encompassing approach to food”， “large-scale industrial view” and “view of big agriculture”， ecological low-carbon agriculture involves the ecological low-carbon of the entire food category， industrial process， and life link. Food security is the bottome-line requirement for the development of ecological low-carbon agriculture， and ecological low-carbon agriculture represents the true meaning of sustainable food security. At present， the development of ecological low-carbon agriculture is facing various practical difficulties， including natural resource constraints， scientific and technological bottlenecks， small-scale agricultural production patterns， the limitations of the residents’ concepts and others， It is urgent to explore the effective paths for expanding water and land resources， applying technological innovations， and improving the quality of residents， so as to promote ecological low-carbon agriculture and achieve the goal of “storing grain in the land”， “storing food in technology” and “storing food in the people”.

Abstract:To promote the protection of cultivated land and green and low-carbon development in the Yangtze River Economic Belt， this study employed methods such as the equivalent factor method and the environmental cost method to quantify the ecological service value and negative externalities of cultivated land. By cakulating the ecological footprint and ecological carrying capacity of cultivated land resources， the 11 provinces in the Yangtze River Economic Belt were categorized into surplus areas， balanced areas， and deficit areas. The ecological spillover value of cultivated land was assessed， and its spatiotemporal variation characteristics were explored. The results showed that： Firstly， from 2011 to 2021， the total ecological value of cultivated land in the Yangtze River Economic Belt showed an increasing trend， rising from 367.037 billion yuan to 466.155 billion yuan. The ecological spillover value of cultivated land also gradually increased， from 135.382 billion yuan to 197.077 billion yuan. Secondly， cultivated land resources in the Yangtze River Economic Belt were in a surplus state overall. The ecological value of cultivated land exhibited an “east-low and west-high” pattern. Sichuan had the highest ecological value and surplus quantity of cultivated land， while Shanghai had the lowest ecological value. Thirdly， from 2011 to 2021， the cultivated land ecological values of Zhejiang and Shanghai were deficit， Sichuan was in the ecological high-surplus area， Chongqing and Guizhou were in a balanced state， and Jiangxi， Anhui， and Jiangsu showed no significant changes in the ecological surplus or deficit of cultivated land. Yunnan and Hubei provinces saw an increase in the ecological surplus of cultivated land， while Hunan province experienced a decrease. Based on this， each province in the Yangtze River Economic Belt should make full use of its own resources and advantages， formulate and implement adaptive cultivated land protection strategies， so as to promote the sustainable use of cultivated land resources， and contribute to realize the goal of “ecological priority， green and low-carbon development” in the Yangtze River Economic Belt.

Abstract:Developing eco-friendly and low-carbon agriculture is an effective pathway toward building a strong agricultural nation with Chinese characteristics and is also an important feature of modernizing agriculture in China. To promote the comprehensive green transformation of agricultural development and accelerate the construction of a strong agricultural country with Chinese characteristics，this article，based on clarifying the characteristics of ecological low-carbon agriculture，put forward the vision for developing ecological low-carbon agriculture. It analyzed the current realistic foundation and challenges of developing ecological low-carbon agriculture in China，and proposed strategic ideas accordingly. The study found that China has laid a certain foundation for the development of eco-friendly agriculture，but still faces challenges such as conflicting multiple goals，limited space for emission reduction and carbon sequestration，insufficient technological reserves，and difficulties in realizing the value of ecological products. In the new stage and new journey，the specific approach to develop eco-friendly and low-carbon agriculture involves fully utilizing farming experience and modern science and technology，simultaneously promoting green technological innovation and dissemination，and integrating proactive government policies with effective market mechanisms. The key tasks include improving the green-oriented agricultural subsidy system，establishing a technical system to support the development of eco-friendly and low-carbon agriculture，and establishing a sound mechanism to realize the value of ecological products.

Abstract:Reducing agricultural carbon emissions and improving the capacity of agricultural carbon sinks are important measures for China to realize the goal of “Dual-carbon”， which is also where the potential lies. Therefore， it is undoubtedly of great significance to clarify the current status of research on agricultural carbon issues and its characteristics. In order to contribute to the early realization of China’s “Dual-carbon” goal， this paper comprehensively comprehends the existing studies based on the three dimensions of agricultural carbon emissions， agricultural carbon sinks， and driving factors of agricultural low-carbon development. Specifically， firstly， the basic concepts of agricultural carbon emissions are clarified and common measurement methods are introduced， and the current research status is reviewed， taking into consideration temporal evolution， spatial distribution， efficiency characteristics， and emission reduction pathways. Secondly， the basic concepts of agricultural carbon sinks are defined， and the forest carbon sink， soil carbon sink and ocean carbon sink are derived， followed by the introduction of their respective measurement method. Then， the focus is on the net agricultural carbon sink and the marketization of carbon sink. Finally， the main factors that affect the development of low-carbon agriculture are discussed from both macro and micro levels. At the macro level， policy， economic and social factors are considered， while at the micro level， the internal factors of the head of the household and the external environment faced by the farmers are examined. With regards to the direction of future research on agricultural carbon issues， this paper believes that it should focus on the following four aspects， namely， the scientific prediction of agricultural carbon peaks and the design of differentiated emission reduction paths， the scientific assessment of the potential for agricultural carbon reduction and carbon sequestration and the discussion of paths to achieve these goals， the construction of an agricultural carbon market， and exploration of the idea of realizing the value of carbon sinks， as well as the exploration of the matching of the supply and demand of low-carbon production techniques by farmers and the optimization of their systems.

Abstract:Ecological space is an important vehicle for maintaining regional carbon balance and securing carbon storage， and the redline area of ecological protection is an important part of ecological space. This article aimed at studying the spatial and temporal response of the carbon storage of the ecological space under the constraints of the ecological bottom line. The ArcGIS platform was used to integrate the PLUS model and the InVEST-Carbon model to predict and simulate the changes in carbon storage of ecological space and its spatial characteristics in Xiangyang City， Hubei Province， China， from 2000 to 2030. The results showed that the area of ecological space in Xiangyang City decreased between 2000 and 2020. It is predicted that the degradation rate of ecological space will decrease by 2030 under the constraints of the ecological bottom line. By 2030， the carbon storage in Xiangyang City will undergo a corresponding transformation due to changes in ecological space. The maximum carbon storage per grid unit is about 18.47 kg， mainly distributed in the forest land in the west， northeast， and southeast. The hotspot analysis presents a pattern of “concentrated hotspot and scattered cold spots”. The constraint of ecological bottom line helps to optimize the pattern of carbon hotspot in the ecological space of Xiangyang City. It will provide scientific guidance for implementing “carbon peaking and carbon neutrality” strategies and promoting low-carbon planning in similar regions.

Abstract:It is of great theoretical significance to study the changing characteristics of net carbon emissions and the capacity of regional carbon neutrality for accelerating the transformation of social and economic development and realizing the goal of carbon neutrality. In this article， the carbon emissions， carbon sinks and net carbon emissions in Hubei Province were evaluated with the methods given in IPCC Guidelines for National Greenhouse Gas Inventories and Guidelines for the Preparation of Provincial Greenhouse Gas Inventories， carbon density method and other methods. The changing trend of net carbon emissions was studied to evaluate the capacity of regional carbon neutrality in Hubei Province. The results showed that the total amount of regional carbon sinks in Hubei Province from 2000 to 2020 was 264.178 million tons， showing a significant upward trend over the years， with an increase rate of about 135.21% and an average annual increase rate of about 6.76%. The total carbon emissions in Hubei Province from 2000 to 2020 was 910.331 million tons. The changing trend of total carbon emissions over the years was divided into two stages including the total carbon emissions in Hubei Province from 2000 to 2010 and from 2011 to 2020 showing a trend of significant increase and a trend of fluctuating downward， respectively. The net carbon emissions in Hubei Province from 2000 to 2010 had an upward trend， and the Z_M-K statistic passed the significance test with statistical significance. The net carbon emissions in Hubei Province from 2011 to 2020 had a downward trend， but the Z_M-K statistic failed the significance test， indicating that the net carbon emissions in Hubei Province had a downward trend in the second stage， but this trend was not statistically significant. It is indicated that there is still a huge gap between the carbon sink and carbon emissions of the ecosystem in Hubei Province， and there is still some uncertainty in the changes of net carbon emissions. Carbon reduction should be continued. The carbon sink function of the ecosystem should be optimized， and carbon capture technology and related industries vigorously developed.

Abstract:Banghu Lake， Changhu Lake， and Sizhoutou wetland on the Poyang Lake National Nature Reserve in Jiangxi Province were used to study the spatial distribution characteristics of the content of organic carbon in surface soil in seasonal flooded wetlands of Poyang Lake and the applicability of remote sensing methods for estimating the content of organic carbon in surface soil. Remote sensing image processing and GIS technology were used to extract feature factors of remote sensing from the images based on the data about the content of organic carbon in soil measured in the field and Landsat8 OLT remote sensing images from the same period. The regression models of univariate linear， univariate curve， and multiple stepwise linear for parameters of remote sensing and the content of organic carbon in soil were constructed. The optimal estimation models of remote sensing were selected by comparing and analyzing to predict the content of organic carbon in the surface layer （0-20 cm） of seasonal flooded wetlands in Poyang Lake. The results showed that 33 feature factors of remote sensing including reflectance values （b₁-b₇） in 7 bands， 4 vegetation indices（NDVI，SR，SAVI，EVI）， first principal component feature （PCA1）， the mean （MEAN） ， entropy （ENT）， and correlation （COR） of single band texture features were extracted from the images. Texture features were important factors of remote sensing for predicting the content of organic carbon in the areas studied， and their fitting effect with the multiple stepwise linear regression model Y=42.708－2.817X_b3MEAN－4.887X_b5COR＋0.667X_b7MEAN （b_3MEAN，b_5COR and b_7MEAN representing the mean value， correlation and mean value of texture features in bands 3，5 and 7， respectively） constructed for the content of organic carbon in soil was the best. The determination coefficient of model， R² was 0.772， with an average relative error （MRE） of 45.53% and a root mean square error （RMSE） of 2.417. The results of remote sensing inversion showed that the predicted content of organic carbon in surface soil in the areas studied was mainly concentrated at 0-20 g/kg， with an average content of organic carbon in soil about 10.75 g/kg. It is indicated that it is feasible to use remote sensing to predict the content of organic carbon in soil of wetlands.

Abstract:The taste quality of steaming and cooking is an important evaluation criterion for consumers when choosing rice.Starch，protein，and lipids，as the three main components of rice，are closely related to the taste quality of steaming and cooking in rice.This article reviewed the progress on the composition and distribution，anabolic characteristics of the three main components in rice and their relationship with the taste quality of steaming and cooking to further study the formation mechanism of the taste quality of steaming and cooking in rice and the techniques for cultivating the rice with high quality.The effects of irrigation with alternating wet and dry （AWD） on the three main components of rice and the taste quality of steaming and cooking in rice were summarized.Problems including the unclear relationship between the interaction of the three main components of rice and the taste quality of steaming and cooking in rice and the unknown mechanisms underlying the effects of AWD on the taste quality of steaming and cooking in rice were pointed out.It is recommended to conduct in-depth studies on the formation mechanism of the taste quality of steaming and cooking in rice and the regulatory mechanism of AWD on the taste quality of steaming and cooking in rice based on the relationship between the accumulation of starch，protein，and lipids and the anabolism of starch，protein，and lipids in the future.

Abstract:Field experiments were conducted on the cultivation of ratoon rice using the widely used Yongyou indica-japonica hybrid rice varieties Yongyou 1540 and Yongyou 4949 as experimental materials and the indica-hybrid rice variety Longliangyou 534 as control materials to study the ratoon characteristics and yield formation of Yongyou indica-japonica hybrid rice planted as ratoon rice. The results showed that there are significant differences in the ratoon characteristics between indica-japonica hybrid rice and indica- hybrid rice. The dominant regenerated nodes of the indica-japonica hybrid rice Yongyou 1540 and Yongyou 4949 were the 4th and 5th nodes from top at the lower nodes， which produced a sum of 81.9% and 68.9% of effective panicles with 89.6% and 72.5% of the yield contribution in YongYou 1540 and YongYou 4949， respectively. The panicle length and the number of grains per panicle of these two nodes were significantly higher than that of the 2nd and 3rd nodes from top， showing a decreasing trend from the bottom to the top. The 2nd and 3rd nodes from top at the higher nodes of the Longliangyou 534 were dominant， producing 71.5% of effective panicles with 72.5% of the yield contribution. The spike rate， ratios of effective panicle and yield contribution of were 89.4%， 74.6% and 79.2% for regenerated seedlings of YongYou 4949 within 1-7 d after the first harvesting， significantly higher than those of regenerated seedlings within 8-12 d and 12 d above after the first harvesting. The panicle length and the number of grains per panicle in regenerated seedlings of Yongyou 1540 and Yongyou 4949 were significantly higher than those of Longliangyou 534， with yield increase of 21.6% and 17.3%， respectively. It is indicated that the strong regeneration ability of the low nodes， long panicles， and large number of grains per panicle in regenerated seedlings of Yongyou indica-japonica hybrid rice are the key factors that make it easy to achieve high yield when planted as ratoon rice.

Abstract:The ZmEREB46 （Zm00001d015759） gene as a member of the ERF family in maize was cloned to identify and mine the resistance genes to waterlogging stress in maize.The resequencing，functional mutation site and expression pattern of the ZmEREB46 gene were analyzed.The role of the ZmEREB46 gene in waterlogging tolerance in Arabidopsis thaliana was preliminarily studied.The results showed that ZmEREB46 encoded one AP2/EREBP transcription factor.There was a G/A conversion and a 911 bp fragment insertion in the coding and promoter regions of the ZmEREB46 gene in the waterlogging susceptible inbred line A3239，compared to the waterlogging tolerant inbred line A3237.The insertion of a 911 bp fragment in the waterlogging susceptible inbred line A3239 significantly inhibited the expression of ZmEREB46.The results of subcellular localization showed that ZmEREB46 was localized in the nucleus.The results of quantitative PCR （qRT-PCR） analysis showed that ZmEREB46 was up-regulated by waterlogging stress，and the expression level of ZmEREB46 in A3237 was two-fold higher than that in A3239 after 8 h of waterlogging treatment.The overexpression of ZmEREB46 in A. thaliana improved the waterlogging tolerance of A. thaliana at the stage of seedling.

Abstract:SSR markers were used to analyze the genetic diversity and construct a DNA molecular ID database of 60 buckwheat germplasms in order to accurately identify the buckwheat germplasm resources in Guizhou province. The results showed that 16 pairs of stable and polymorphic primers were screened from 100 pairs of SSR primers. A total of 174 polymorphic bands were amplified from 60 germplasm studied. The mean value of Shannon’s information index， Nei’s diversity index， and polymorphic information index was 0.337， 0.206， and 0.693， respectively. It is indicated that the polymorphism of primers is good， which can effectively identify the genetic diversity of 60 buckwheat germplasms. When the Dice genetic similarity coefficient was 0.374， all materials tested were clustered into three groups including A， B， and C. When the Dice genetic similarity coefficient was 0.484， the Tartary buckwheat group （Group A） was further divided into two subgroups including A1 and A2. The results of clustering SSR amplification products validated by capillary electrophoresis and 8 polyacrylamide gel （PAGE） electrophoresis were consistent. It is indicated that the efficient SSR molecular markers developed can effectively identify the genetic diversity and can be used to construct DNA molecular ID cards of important buckwheat germplasm in Guizhou province.

Abstract:A highly glyphosate resistant strain of Halomonas sp. was screened from marine bacteria to breed crops with high glyphosate resistance to cope with the evolution of glyphosate weeds. The gene encoding EPSPS in this strain was identified through sequencing genome and bioinformatics analysis. The fHoEPSPS， mfHoEPSPS （G384A site mutant）， and mHoEPSPS （a mutant with N-end PDT deletion of mfHoEPSPS） were recombinantly expressed and purified in E. coli （DE3）. A gene pyramiding strategy mediated by the self-cleaving peptide LP4/2A was used to locate the glufosinate-resistant enzyme （Repat） at the N-end of mHoEPSPS. A dual resistance to glyphosate/ammonium phosphatase （RLH） was constructed. Tobacco transformed with the RLH gene exhibited simultaneous resistance to glyphosate/glufosinate compound herbicides. The results showed that the EPSPS gene （fHoEPSPS） of this strain encoded an N-end fused with a bifunctional enzyme of prephenate dehydratase （PDT）. The results of analyzing glyphosate resistance showed that the resistance of mfHoEPSPS was 19 times higher than that of fHoEPSPS. Introducing the coding gene of mHoEPSPS into tobacco endowed tobacco with three times the recommended dose of glyphosate tolerance. Tobacco plants transformed with the RLH gene had simultaneous tolerance 3-5 times the recommended dosage of glyphosate/ammonium phosphine compound herbicides. It is indicated that the glyphosate-resistant EPSPS derived from Halomonas sp. is a new type of glyphosate-tolerant enzyme. The enzyme activity is further improved through the G384A site mutation. The transgenic tobacco with RLH gene obtained through gene pyramiding strategy mediated by the self-cleaving peptides shows high glyphosate/glufosinate compound resistance. It will provide ideas for dealing with the evolution of glyphosate weeds.

Abstract:“Yunxue 1” variety and the multivariate statistical analysis was used to study the climate resource allocation basis of tobacco leaves for cigar wrapper and its impact on the agronomic traits of tobacco plants and the chemical composition of fermented tobacco leaves by changing the climate indicators during the growth period of tobacco plants through adjusting the period of transplanting to study the basis of climate resource allocation for the production of tobacco leaves for cigar wrapper.The results of correlation analysis showed that the accumulated temperature， effective accumulated temperature ≥10 ℃， total precipitation， and total temperature difference during the field stage of tobacco plants had a significant impact on every indicator of agronomic traits， with correlation coefficient ranging from 0.478 to 0.939.The accumulated temperature， effective accumulated temperature ≥10 ℃， and average temperature had a significant impact on the content of total sugar， nicotine， total nitrogen， and protein in tobacco leaves， with correlation coefficient ranging from -0.955 to -1.000.Two principal factors including climate accumulation factor and humidity factor were extracted from eight climate indicators with factor analysis.The results of grey correlation analysis showed that the two factors mentioned above were the main factors affecting the agronomic traits of tobacco plants and the conventional chemical components of tobacco leaves.It is indicated that the main climatic factors for determining the transplanting period of tobacco plants for cigar wrapper are based on the comprehensive configuration of temperature， precipitation， and relative humidity during the period of field growth.

Abstract:Cadmium pollution in soil brings a serious threat to food security and human health， and the problem of cadmium pollution in paddy fields is a priority for heavy metal pollution and prevention in soil.Pot experiments were conducted to screen suitable cadmium passivators for soil remediation in farmland.10 passivators including T1 （anomaterials， etc.）， T2 （lime）， T3 （oyster shells， etc.）， T4 （CaO）， T5 （silica-calcium fertilizers）， T6 （organic fertilizers of goat dung）， T7 （Bacillus cereus， etc.）， T8 （organic fertilizers of pig manure）， T9 （oyster shells）， and T10 （microorganisms， etc.） were used to compare the remediation effect of 10 passivators on cadmium contaminated rice paddy and the growth of rice.The results showed that passivators increased the pH of soil in rice paddy and altered the form of cadmium stored in the soil.The content of exchangeable cadmium in the soil treated with each passivator decreased by 4.6% to 44.8% compared to the control， with significant decrease in T8 （44.8%）， T6 （36%）， T1 （31.15%）， and T10 （28.4%）.The content of carbonate bound states increased.The changes in the content of Fe-Mn oxide-bound state and organic matter bound state were not significant.The proportion of residual cadmium showed an overall upward trend， with T6 having the largest increase， increasing by 53.85% compared to that of the control.The biomass of rice seeds treated with various passivators increased by 5.75% to 25.30%.The content of cadmium in the seeds， husks， and straw of rice was in the decreasing order of straw > grain > husk.The content of cadmium in the rice seeds ranged from 0.068 to 0.254 mg/kg， with T2 （0.152 mg/kg）， T5 （0.143 mg/kg）， T6 （0.088 mg/kg）， T7 （0.126 mg/kg）， T8 （0.072 mg/kg）， T9 （0.068 mg/kg）， and T10 （0.071 mg/kg） being lower than the national limit standard （0.2 mg/kg）.The content of cadmium in rice seeds of T6，T8，T9， and T10 significantly decreased by 61.90%， 68.83%， 70.56%， and 69.26%， respectively， compared to that of the control.T2， T6， and T8 had better effects of passivation based on analyzing the transformation of cadmium form in soil， rice biomass， and the content of cadmium in rice seeds.

Abstract:The purplish soil from the landfill in Yunxi Town， Yanting County， Sichuan Province was used to study the changes in the content of available heavy metals including Cd，Cu，Pb，Zn before and after passivation culture. Different mass ratios of silicon fertilizer （Si1：0.5%， Si2：1.0%） and phosphate ore powder （P1：0.2%， P2：0.4%， P3：1.0%） were mixed as compound and added to the soil. The passivation was cultured for 90 days. The effectiveness of soil remediation was evaluated with risk assessment code （RAC）. The results showed that the effectiveness of heavy metals under the treatment with high silicon （Si2：1.0%） was significantly reduced compared with that under the treatment with low silicon （Si1：0.5%）. Among them， Si2P3 treatment had the highest passivation rate for Cd， Cu， Pb， and Zn， which was 30.79%， 27.27%， 27.13%， and 36.88%， respectively. There was no significant difference between Si2P1 treatment and Si2P2 treatment. Si2P1 treatment significantly reduced the toxicity of heavy metal leaching and the RAC risk assessment code of heavy metals. It is indicated that the passivator for compound mainly enhanced the complex-precipitation of functional groups （O-Si-O，Si-O-Si，H₂PO₄^-，PO₄^3-， etc.） by increasing the pH and EC value in soil， promoting the transformation of heavy metals from highly active weak acid extraction and reducible states to low actively oxidizable and residual states. Overall， the application amount of Si2P1 passivator is lower， making it more suitable for the remediation of heavy metal contaminated soil in landfills.

Abstract:Field experiments were conducted in 11 major winter rapeseed producing counties （cities， districts） in Guizhou Province for two consecutive years from 2018 to 2019 and 2019 to 2020 to optimize the models of fertilizer and pesticide for winter rapeseed with direct seeding in Karst mountainous areas of Guizhou Province. The effects of different models of fertilizer and pesticide including the traditional model of fertilizer and pesticide （T1）， the optimized model of fertilizer and pesticide （T2）， no fertilizer application under the optimized model of fertilizer and pesticide （T3）， and no pesticide spraying under the optimized model of fertilizer and pesticide （T4） on the yield and economic benefits of winter rapeseed with direct seeding were studied. The techniques with high-yield and efficient fertilizer and pesticide suitable for winter rapeseed with direct seeding in Karst mountainous areas of Guizhou Province were explored. The results showed that the total nutrient input of T2 decreased by 19.9% and the pesticide input decreased by 69.5% compared with that of T1. The plant height， stem diameter， effective number of branches per shoot， pod length， pod density of winter rapeseed with direct seeding under T2 was lower than that under T1， with a decrease of 9.8%， 26.4%，10.9%， 10.2%， 24.2% from 2018 to 2019， and 9.5%， 28.3%， 12.8%， 10.9% and 23.9%， from 2019 to 2020. T2 had an advantage of population with a significant increase in harvest density of 199.0% and 194.2%in two consecutive years compared to T1. In two consecutive years， the yield of winter rapeseed under T2 was 2 224.4 kg/hm² and 2 103.3 kg/hm²， increasing by 204.0 kg/hm² and 74.3 kg/hm² compared to that under T1. The utilization efficiency of fertilizer and control efficiency of pesticide under T2 was 2.20 kg/kg， 2.14 kg/kg and 141.82 kg/kg， 106.23 kg/kg， significantly higher than that under T1. The total output value and net benefit of winter rapeseed in two consecutive years under T2 was 11 121.8 yuan/hm²， 10 516.4 yuan/hm² and 5 286.8 yuan/hm²， 4 681.4 yuan/hm²， an increase of 1 020.0 yuan/hm²， 371.6 yuan/hm²， 26 285.0 yuan/hm² and 1 976.6 yuan/hm compared to that under T1， achieving cost savings and income increase. It is indicated that the optimized model of fertilizer and pesticide （T2） can meet the requirements for the growth of winter rapeseed with direct seeding in Karst mountainous areas of Guizhou Province， effectively improving the yield， the utilization efficiency of fertilizer and pesticide， and the economic benefits of winter rapeseed. This optimized model of fertilizer and pesticide （T2） can be promoted and applied as the main promotion model for the production of winter rapeseed with direct seeding in Karst mountainous areas of Guizhou Province.

Abstract:Two treatments including co-cropping Zizania latifolia with crayfish （ZC） and Zizania latifolia monoculture （Z） were set up to study the effects of co-cropping Zizania latifolia with crayfish on the content of nitrogen and phosphorus in soil， the accumulation of dry matter and the uptake and distribution of nitrogen， phosphorus， and potassium in Zizania latifolia to explore fertilization strategies for the planting and farming mode of Zizania latifolia. The results of two years showed that ZC increased the content of total nitrogen， total phosphorus， and available phosphorus in the soil during the harvesting period by 10.85% to 38.89%， 5.45% to 13.79%， and 6.19% to 61.79%， respectively， compared to Z. ZC increased the net Zizania latifolia yield by 5.10% to 19.54%. ZC increased the accumulation of dry matter in the stem， leaf， and net Zizania latifolia during the harvesting period by 14.41% to 16.58%， 10.28% to 15.15%， and 10.57% to 21.45%， respectively. In 2021， ZC significantly increased the content of nitrogen in leaves by 25.74% compared to Z during the harvesting period of Zizania latifolia， but significantly reduced the content of phosphorus in stems by 16.76% during the pregnancy period of Zizania latifolia. In 2022， ZC significantly reduced the content of nitrogen in stem by 23.75% during the pregnancy period of Zizania latifolia and the content of phosphorus in leaves by 12.08% during the tillering period of Zizania latifolia compared to Z under the reduction of nitrogen fertilizer and reduced feeding. There was no significant difference in the content of potassium in the same organ during the entire two-year growth period between the two treatments. For nutrient accumulation， the accumulation of nitrogen， phosphorus， and potassium in the leaves of Zizania latifolia under ZC in 2021 significantly decreased by 26.04%， 27.27%， and 30.11% compared to Z during the tillering period. However， the accumulation of nitrogen and potassium in the stems and leaves during the harvesting period under ZC significantly increased by 18.80%， 38.41%， 44.77%， and 35.71%， respectively， compared to Z. In 2022， the accumulation of phosphorus in the leaves and accumulation of potassium in the stems of ZC significantly increased by 30.0% and 30.77% compared to Z during the harvesting period under the reduction of nitrogen fertilizer and reduced feeding. For nutrient distribution， the distribution of nitrogen in the two treatments of Zizania latifolia during the pregnancy and harvesting period was mainly in the stem and leaves， while the distribution of phosphorus and potassium elements was mainly in the stem， with distribution ratio of 42% to 66% in stem. For nutrient transport， the roots， stems， and leaves of the two treatments of Zizania latifolia mostly exhibited “sink”organs in nitrogen and phosphorus transport in 2021， while they mostly exhibited “source” organs in potassium transport. In 2022， the roots， stems， and leaves of Zizania latifolia in the two treatments mostly represented “source” organs in nitrogen， phosphorus， and potassium transport under the reduction of nitrogen fertilizer and reduced feeding. It is indicated that reducing the input of fertilizer and feed appropriately in the co-cropping Zizania latifolia with crayfish can promote the formation of a reasonable source and sink relationship， which is conducive to the formation of yield.

Abstract:The nylon net cages self-made were used to study the characteristics of straw decomposition， nutrient release characteristics， and surface microstructure changes of rice under the disturbance from crayfish simulated in a trenche for aquaculture with rice-crayfish model and with no crayfish as a control in order to investigate the process and characteristics of straw decomposition of rice participated by crayfish under continuous soaking conditions， improve the technology for returning rice straw to the field in the rice-crayfish model， and realize the efficient utilization of straw resources and sustainable development of farmland. The results showed that the average decomposition rate of rice straw in each stage showed a characteristic of fast-slow-fast-slow-fast regardless of whether crayfish participated or not. There was no significant difference in the amount of decomposition， cumulative decomposition rate， and average decomposition rate between the treatment with crayfish and the treatment without crayfish before 150 days. All indexes of the treatment with crayfish were significantly higher than those of the treatment without crayfish after 180 days. The cumulative decomposition rate of rice straw in the treatment with crayfish reached 85.67%， which was 12.35 percentage points higher than that in the treatment without crayfish at 210 days. The cumulative release rate of straw nutrients was in the decreasing order of K>P>N. The cumulative release rate of N in the treatment with crayfish was higher than that in the treatment without crayfish after 150 days. The cumulative release rate of P and the cumulative release rate of total nutrient in the treatment with crayfish were higher trend than those in the treatment without crayfish after 180 days. The cumulative release rate of K in the treatment with crayfish was higher than that in the treatment without crayfish at 210 days. The surface structure of straw treated with crayfish was significantly more damaged than that treated without crayfish after 120 days. It is indicated that the disturbance from crayfish can increase the degree of damage to the surface microstructure of rice straw at the middle and late stages， promote the decomposition and nutrient release of rice straw at the late stage in a trenche for aquaculture with rice-crayfish model.

Abstract:As an important part of urban public space， community public sports service space is the primary place for people to keep fit. Public sports space with high quality can effectively improve the life quality of people. At present， the public sports service space in China is still at the stage of "reconstruction， establishment and neglect of management". The lack of consideration on the use of venues and the satisfaction of residents in planning and construction has led to unscientific allocation of public sports service space， low efficiency of utilization and low level of service， which has affected the development of national fitness. In addition， the old public sports service space in the old city has been unable to effectively meet the high-quality fitness needs of people with the increasing number of residents in the old city and the aging of public sports service facilities. Therefore， it is particularly important to optimize the layout of new and reconstructed public sports service facilities. Jinniu District， Chengdu City was used to conduct empirical studies. POI （roint of interest） for data collection was collected. The accessibility of large public sports facilities was analyzed with ArcGIS road network analysis method. Gini coefficient and Lorenz curve were used to analyze the fairness of the spatial layout of public sports service. The results showed that there were some problems including insufficient scale of public sports service space， low accessibility from residential areas to public sports facilities， and mismatch between the distribution of population and the layout of public sports space in Jinniu District. It is proposed to increase the supply of public sports facilities， improve the transportation conditions from public sports facilities to residential areas， and improve the coverage of public sports space in populous streets to solve the difficulties in fitness and bad experience of fitness in old communities， and promote the development of national fitness with high-quality.

Abstract:The headspace solid-phase microextraction combined with gas chromatography-mass spectrometry （HS-SPEM-GC-MS） technology was used to detect volatile substances in 30 common cultivated varieties of pantropical water lilies to detect the volatile components， identify the aroma active substances， and screen the excellent aromatic varieties of water lilies. The results showed that a total of 60 volatile compounds were identified in the 30 varieties of pantropical water lilies， with seven compounds including alkanes， alkenes， terpenoid， benzenoid， esters， alcohols， and aldehydes in descending order of content. Among them， alkanes and alkenes were the categories with higher content， with an average proportion of 42.43% and 28.61%， respectively， but they had no obvious odor characteristics. 19 active substances of odor were further screened by the odor activity value （OAV）. Among them， the characteristic substances of odor that can be perceived by the odor activity value （OAV>1） were all terpenoids including α-ionone， β-ionone， trans-β-ionone and farnesene， among which ionone endowed water lilies with woody and sweet fragrance， while farnesene endowed water lilies with apple and typical floral fragrance. It is indicated that the five varieties of water lilies including ‘Blue Bird’， ‘Kara Sunshine’， ‘Golden Country’， ‘Ruby’， and ‘Pink Diamond’ screened based on the odor activity value are potential elite varieties for landscaping use and processing product.

Abstract:The PhSPL9b gene was cloned to study the role of SPL （SQUAMOSA-promoter binding protein-like） transcription factor in the flowering transformation in petunia. Point mutation of the miR156/157 target site corresponding to the PhSPL9b gene was conducted to obtain rPhSPL9b. The overexpression vectors for 35S∶∶PhSPL9b and 35S∶∶rPhSPL9b were constructed and transformed into petunia and Arabidopsis. Transgenic plants of Arabidopsis overexpressing PhSPL9b or rPhSPL9b and transgenic plants of petunia overexpressing PhSPL9b were obtained. The results showed that overexpression PhSPL9b or rPhSPL9b， especially 35S∶∶rPhSPL9b， significantly reduced the number of rosettes and promoted flowering in Arabidopsis compared with the control （CK）. The phenotype of transgenic Arabidopsis with 35S∶∶rPhSPL9b was more obvious. Overexpression of PhSPL9b significantly promoted flowering in petunia. The results of analyses with RT-PCR and qRT-PCR showed that the expression level of PhSPL9b in transgenic lines with obvious phenotypes was significantly higher than that in the control. The results of transcription activation showed that PhSPL9b was a transcription factor with the function of activating transcription. It is indicated that the PhSPL9b gene in petunia plays an important regulatory role in flowering time， and its function is conserved. At the same time， it may affect plant flowering by transcriptionally activating the expression of downstream genes.

Abstract:To explore the spatial distribution characteristics of soil total nitrogen content in forest farm and its response to environmental factors，random forest model and Cubist model were used to establish a quantitative relationship between soil total nitrogen content and environmental covariates including elevation，normalized difference vegetation index，mean annual precipitation，mean annual temperature，y-coordinate and aspect at soil depths of 0-10，10-30 and 30-50 cm in Wangyedian experimental forest farm. Soil total nitrogen content of the area was predicted and mapped，and the controlling factors affecting the spatial variation of soil total nitrogen were analyzed. The results showed that the average content of soil total nitrogen at soil depth of 0-10，10-30 and 30-50 cm was 3.20，2.02 and 1.47 g/kg，respectively. It decreased with the increase of soil depth. The results of cross-validation showed that the R² of the random forest model for predicting soil total nitrogen at the three soil depths was 0.59，0.42，and 0.39，respectively，better than the R² of Cubist model with 0.56，0.38，and 0.34，respectively. The prediction accuracy of both models decreased with the increase of soil depth. The influence of various environmental factors on the spatial distribution of soil total nitrogen decreased with the increase of soil depth. From the prediction map of soil total nitrogen with the random forest model，the content of soil total nitrogen at different soil depth showed a spatial pattern of low in the western，northern，and central regions，and high in the southwestern，southeastern，and eastern regions. The uncertainty map showed that the random forest model had a low standard deviation in predicting the distribution of the content of soil total nitrogen. The elevation had the greatest impact on the content of soil total nitrogen，followed by the normalized difference vegetation index>mean annual precipitation>mean annual temperature>y-coordinate>aspect. It is indicated that the random forest model can serve as an effective method for predicting the content of soil total nitrogen at different soil depth in the forest farm.

Abstract:To objectively assess the genetic diversity of Procambarus clarkii cultured populations in the vicinity of Nanning， Guangxi， three populations of P. clarkii from Nanning （AJ， LQ and SL）， and one population each from Jingzhou， Hubei （JZ） and Hukou， Jiangxi （HK） were collected. The level of genetic diversity was investigated using morphology and microsatellite markers. Morphological analysis showed that the total discrimination accuracy of female and male populations was 68.59% and 73.60%， respectively. Morphological clustering grouped the three Nanning populations into the same branch as the JZ population， indicating that the three Nanning populations had high morphological similarity. Microsatellite analysis revealed that the AJ population and LQ population had the highest genetic diversity， followed by the SL population and HK population. The genetic differentiation coefficient and genetic distance between the LQ population and SL population were the smallest. The results indicated that the populations of P. clarkii in Nanning， Guangxi had high genetic diversity， and that the introduction of P. clarkii from abroad or hybridization between different geographical populations may be an important way to enhance the genetic diversity of P. clarkii.

Abstract:Two-dimensional composite nanosheet materials （GO-MnO₂ NSs） were prepared by combining graphene oxide （GO） with MnO₂ nanosheets （MnO₂ NSs） through π-π stacking force to develop new broad-spectrum nanomaterials for anti-animal borne virus infections. The morphology， structure， crystallinity and element valences of GO-MnO₂ NSs were characterized by TEM， XRD， XPS. The cytotoxicity of GO-MnO₂ NSs was tested by MTT. The results showed that the cell survival rate of 625 μg/mL GO-MnO₂ NSs exceeded 85%. Porcine epidemic diarrhea virus （PEDV） was used as a model virus for coronavirus to study the effect of GO-MnO₂ NSs on PEDV infection through concentration for 50% of maximal effect （EC₅₀）， indirect immunofluorescence and western blot. The results showed that GO-MnO₂ NSs had significant antiviral activity. It is indicated that GO-MnO₂ NSs can eliminate the overexpression of reactive oxygen species caused by viral infection and inhibit cell apoptosis， while upregulating the expression of antiviral factors including interferon and interferon stimulating genes （ISGs） in cells as well， effectively inhibiting viral infection.

Abstract:In order to find effective microecological preparations for preventing necrotic enteritis （NE） in chickens in this study， a total of 120 one-day-old 817 chickens were randomly divided into four treatment groups. Control group and NE group （broiler model of NE established by infecting with Clostridium perfringens type G） were fed a basal diet. Probiotic group （Prob1） was fed a basal diet supplemented with 0.2% microbial agent 1， and probiotic group （Prob2） was fed a basal diet supplemented with 0.2% microbial agent 2. On days 14 to 16， broilers in Prob1， Prob2 and NE groups were treated with Clostridium perfringens （CP） by continuous gavage. The preventive effects of the two different Bacillus subtilis compound microbial preparations on NE of broilers were evaluated in the 23-day trial period. The results showed that， on day 17， the body weight of broilers in the NE group was lower than that of the control group. However， broilers in the Prob1 and Prob2 groups had a higher body weight at the 17th and 23rd days of the experiment compared to the NE group. The jejunal epithelial cells of broilers in the NE group were necrotic and exfoliated， with a shorter villus， deeper crypt， and smaller villus length and villus crypt ratio compared to the NE group treated with B. subtilis compound microbial preparation. The activities of T-SOD， T-AOC and AKP in the jejunal mucosa of broilers in the NE group were lower than those in the Control group. However， on day 17， the T-AOC and AKP activities in the jejunal mucosa of broilers in the Prob1 and Prob2 groups were significantly higher than those in the NE group， and the T-SOD activity of jejunal mucosa of broilers in Prob1 group was significantly higher than that in NE group. On day 23， the activities of T-SOD， T-AOC and AKP in jejunal mucosa of broilers in the Prob1 and Prob2 groups were higher than those in the NE group， and there were no significant differences. The content of MDA in jejunal mucosa of broilers in the NE group was higher than that in the control group， and the content of MDA in the Prob1 and Prob2 groups was lower than that in the NE group at the 17th and 23rd days. The gene expressions of intestinal tight junction protein CLDN1 and ZO-2 in the NE group were lower than those in the Control group， and there were significant differences on day 17 of the experiment. On the 17th and 23rd days of the experiment， expressions of the intestinal tight junction protein CLDN1 and ZO-2 genes in the Prob1 and Prob2 groups were higher than those in the NE group， and the expressions of ZO-1 gene in the Prob1 and Prob2 groups were significantly higher than those in the NE group. The results showed that adding B. subtilis compound microbial preparation to the diet could improve the growth and development of chickens with necrotizing enteritis， increase the antioxidant capacity and intestinal tight junction protein gene expression of broilers， and B. subtilis compound microbial preparation 1 had a better preventive effect on chicken necrotic enteritis.

Abstract:Biochar is an efficient adsorption carrier for benzene pollutants， but the adsorption capacity of directly carbonized biochar for benzene pollutants is limited. Low-temperature air oxidation is effective in modifying the structure of biochar and enhancing its adsorption capacity of benzene pollutants. However， the adsorption behavior and mechanism of low-temperature air oxidation biochar for benzene pollutants still needs to be further clarified. Herein， low-temperature air oxidation biochar was prepared by a two-step activation method using bamboo chips as raw material and CaCl₂ as activator. The adsorption processes and behaviors of low-temperature air oxidation biochar for four benzene pollutants including phenol， aniline， hydroquinone， and p-nitrophenol were deeply analyzed with comprehensive adsorption experiments， biochar structure characterization， and density flooding theory（DFT） calculations. The adsorption properties and mechanisms of oxygen-modified biochar for benzene pollutants were studied. The results showed that the adsorption performance of low-temperature air oxidation biochar for benzene pollutants was influenced by the synergistic effect of the pore structure and surface functional groups of biochar. Biochar regulated the adsorption and storage process of benzene pollutants at a spatial geometric scale through the pore filling effect of microporous structure. Oxygen atoms were assigned to the surface of the carbon skeleton of biochar in the form of hydroxyl， aldehyde and carboxyl groups after the oxidation of biochar by low temperature air. The electronic structure of the carbon skeleton was influenced by the electronic scale， modifying the adsorption position and type of interaction between the carbon skeleton and benzene pollutants. The adsorption capacities of biochar for benzene pollutants were significantly enhanced through mechanisms such as electrostatic attraction and hydrogen bonding. Among them， the hydrogen atoms of the hydroxyl and carboxyl groups in the carbon skeleton are easy to become donors of hydrogen bonds， while the oxygen atoms of the aldehyde group are easy to become acceptors of hydrogen bonds.

Abstract:A device and system for measuring storage capacity based on two-dimensional laser radar scanning was designed to improve the automation and intelligence level of measuring storage capacity of raw materials in storage tower and explore the feasibility of measuring storage capacity based on two-dimensional laser radar scanning. The system used RPLIDAR S1 two-dimensional laser radar scanning to obtain the original point cloud data of material with different storage capacity. The original point cloud was preprocessed with methods including coordinate transformation， overlapping point extraction， filtering， segmentation and others. The greedy projection triangulation algorithm was used to reconstruct the preprocessed point cloud in 3D to obtain a 3D model of the raw materials in the storage tower. The storage capacity of raw materials in the storage tower was obtained by combining the three-dimensional model of material and the bulk density of materials， thereby realizing automatic measurement of storage capacity. Maize was used to measure the amount stored in a small storage tower， and scan and measure different amounts stored to verify the accuracy of the model. The results showed that the average absolute error of the measurement results was 8.05 kg， with the average relative error of 1.52%. It is indicated that the method for measuring storage capacity based on two-dimensional laser radar scanning is feasible， with good stability and accuracy of measurement， and can meet the needs of production in practice. It will provide a new method and technical support for automatically measuring the storage capacity of raw materials in large storage tower.

Abstract:A visual positioning scheme for an automatic water-based loading robot was designed to solve the problem of low automation in the water-based loading process for basket-packed eggs during the processing of poultry and egg products in China. This scheme combined YOLOv5s with methods of image processing to locate and recognize basket-packed eggs in complex environments. A relationship model between the optimal segmentation threshold T and the average grayscale value M of the image was established. The dynamic threshold segmentation method was used to segment the entire stack of eggs in the image. The two types of basket-packed egg stacks were distinguished based on the aspect ratio of the minimum bounding rectangle of the stack， with the recognition accuracy of the stack type of 100%. YOLOv5s was used to locate and identify the top egg baskets of the stack， with the recognition accuracy of the model of 98.48% and the time required to detect a single image of 0.005 4 s. The image was cropped based on the results of positioning output by YOLOv5s. The rotation angles of all egg baskets were calculated by using image segmentation to segment the bounding border of the egg baskets and detecting their edge information with the Canny operators， with an average angle error of 0.41°. The pose information of all the egg baskets in the basket-packed egg stack was obtained based on the height of the egg baskets. It is indicated that the method of positioning basket-packed eggs based on YOLOv5s and image processing can accurately identify the pose information of all egg baskets in the stack. This scheme has good robustness and feasibility， and can provide visual system technology support for the automatic loading robot of basket-packed poultry eggs.