Spatio-temporal Evaluation of Multi-scale Cultivated Land System Resilience in Black Soil Region from 2000 to 2019:A Case Study of Liaoning Province,Northeast China

It is of great significance to systematically analyze the cultivated land system resilience(CLSR) for the black soil protection and national food security.The CLSR is impacted by planting structure adjustment and cultivated land quality decline,posing major hidden dangers to food security.It is urgent to evaluate the CLSR at multiple spatio-temporal scales.This study took Liaoning Province in the black soil region of Northeast China as an example.Based on the resilience theory,this study constructed the CLSR evaluation system from the input-feedback perspective at the provincial-scale and the city-scale,and used the rank-sum ratio comprehensive evaluation method(RSR) to analyze the key influencing factors of CLSR in Liaoning Province and its 14 cities from 2000 to 2019.The results showed that:1) the time series changes of CLSR at the provincial-scale and the city-scale in Liaoning Province were similar,both showing an increasing trend.2) The CLSR in Liaoning Province presented a spatial pattern of ‘high in the west and low in the east’ at the city-scale.3) There were seven and six main influencing factors of CLSR at the provincial-scale and the city-scale,respectively.In addition to the net income per capita of rural households,other influencing factors of CLSR were different at the provincial-scale and the city-scale.The feedback factors were dominant at the provincial-scale,and the input factors and feedback factors were dominant at the city-scale.The results could provide a reference for the utilization of black soil and draw on the experience of regional agricultural planning and adjustment.

Spatiotemporal characteristics of cultivated land use eco-efficiency and its influencing factors in China from 2000 to 2020

Improving cultivated land use eco-efficiency(CLUE)can effectively promote agricultural sustainability,particularly in developing countries where CLUE is generally low.This study used provincial-level data from China to evaluate the spatiotemporal evolution of CLUE from 2000 to 2020 and identified the influencing factors of CLUE by using a panel Tobit model.In addition,given the undesirable outputs of agricultural production,we incorporated carbon emissions and nonpoint source pollution into the global benchmark-undesirable output-super efficiency-slacks-based measure(GB-US-SBM)model,which combines global benchmark technology,undesirable output,super efficiency,and slacks-based measure.The results indicated that there was an upward trend in CLUE in China from 2000 to 2020,with an increase rate of 2.62%.The temporal evolution of CLUE in China could be classified into three distinct stages:a period of fluctuating decrease(2000-2007),a phase of gradual increase(2008-2014),and a period of rapid growth(2015-2020).The major grain-producing areas(MPAs)had a lower CLUE than their counterparts,namely,non-major grain-production areas(non-MPAs).The spatial agglomeration effect followed a northeast-southwest strip distribution;and the movement path of barycentre revealed a"P"shape,with Luoyang City,Henan Province,as the centre.In terms of influencing factors of CLUE,investment in science and technology played the most vital role in improving CLUE,while irrigation index had the most negative effect.It should be noted that these two influencing factors had different impacts on MPAs and non-MPAs.Therefore,relevant departments should formulate policies to enhance the level of science and technology,improve irrigation condition,and promote sustainable utilization of cultivated land.

Change of cultivated land area and effect on ecosystem service in black soil region in Northeast China: a case study of Lishu County, Jilin Province

It is of great significance to study the influence of spatial pattern change of cultivated land on eco-system service,including the sustainable utilization and ecological protection in black soil region in Northeast China.Taking Lishu County of Jilin Province as the study area,we quantitatively evaluated soil conservation,habitat quality,carbon storage and grain production service,and analyzed the change of cultivated land and ecosystem service pattern in Lishu County from 1990 to 2020 by using Pearson correlation analysis on the correlation between cultivated land change and ecosystem service.The results show that:(1)The cultivated land area of Lishu County was reduced by 19.67 km2,the characteristics of cultivated land change are signifi-cant;(2)the overall change rate of carbon storage,habitat quality,soil conservation and grain production ser-vice in the study area was 10.82%,-0.09%,4.07%and 1.80%,respectively.They all had significant spatial differentiation features;(3)the change of habitat quality,grain production service showed a significant pos-itive correlation with the change of cultivated land area.The change in soil conservation and carbon storage were negatively related to cultivated land area.In order to promote the rational development and utilization of cultivated land in the research area,it is suggested to scientifically carry out the comprehensive utilization of cultivated land reserve resources such as saline-alkali land,strengthen the management and protection of newly added cultivated land at the same time.The results can provide scientific reference for formulating comprehensive land use planning under ecological security conditions.

Sustainable Intensification and Large-scale Operation of Cultivated Land Use at the Farmers’ Scale:A Case Study of Shandong Province,China

Sustainable intensification of cultivated land use(SICLU) and large-scale operations(LSO) are widely acknowledged strategies for enhancing agricultural performance.However,the existing literature has faced challenges in precisely defining SICLU and constructing comprehensive indicators,which has hindered the exploration of factors influencing LSO within the SICLU framework.To address this gap,we integrated self-efficacy theory into the design of an index framework for evaluating SICLU.We subsequently employed econometric models to analyze the significant factors that impact LSO.Our findings reveal that SICLU can be divided into four key dimensions:intensive management,efficient output,resource conservation,and ecological environment optimization.Furthermore,it is crucial to incorporate belief-based cognitive factors into the index system,as farmers’ understanding of fertilizer and pesticide application significantly influences their willingness to engage in LSO.Moreover,we identify grain market turnover as the most influential factor in promoting LSO,with single-factor contribution rates reaching 70.9% for cultivated land transfer willingness and 62.5% for the total planting areas.Interestingly,unlike irrigation and agricultural machinery inputs,increased labor inputs correspond to larger planting areas for farmers.This trend may be attributed to reduced labor availability because of rural labor migration,whereas the reduction in irrigation and agricultural input is contingent on innovations in production practices and the transfer of cultivated land management rights.Importantly,SICLU dynamically influences LSO,with each index related to SICLU having an optimal range that fosters LSO.These insights offer valuable guidance for policymakers,emphasizing farmers as their central focus,with the adjustment of input and output factors as a means to achieve LSO as the ultimate goal.In conclusion,we propose research avenues for further enriching the SICLU framework to ensure that it aligns with the specific characteristics of regional agricultural development.

Plasma nitrogen fixation system with dual-loop enhancement for improved energy efficiency and its efficacy for lettuce cultivation

Plasma nitrogen fixation(PNF)has been emerging as a promising technology for greenhouse gasfree and renewable energy-based agriculture.Yet,most PNF studies seldom address practical application-specific issues.In this work,we present the development of a compact and automatic PNF system for on-site agricultural applications.The system utilized a gliding-arc discharge as the plasma source and employed a dual-loop design to generate NO_(x)from air and water under atmospheric conditions.Experimental results showed that the system with a dualloop design performs well in terms of energy costs and production rates.Optimal operational parameters for the system were determined through experimentation,resulting in an energy cost of 13.9 MJ mol^(-1)and an energy efficiency of 16 g kWh^(-1)for NO_(3)^(-)production,respectively.Moreover,the concentration of exhausted NO_(x)was below the emission standards.Soilless lettuce cultivation experiments demonstrated that NO_(x)^(-)produced by the PNF system could serve as liquid nitrate nitrogen fertilizer.Overall,our work demonstrates the potential of the developed PNF system for on-site application in the production of green-leaf vegetables.

Spatiotemporal patterns and drivers of cultivated land conversion in Inner Mongolia Autonomous Region,northern China

Protection and optimization of cultivated land resources are of great significance to national food security.Cultivated land conversion in northern China has increased in recent years due to the industrialization and urbanization of society.However,the assessment of cultivated land conversion in this area is insufficient,posing a potential risk to cultivated land resources.This study evaluated the evolution and spatiotemporal patterns of cultivated land conversion in Inner Mongolia Autonomous Region,China,and the driving factors to improve rational utilization and to protect cultivated land resources.The spatiotemporal patterns of cultivated land conversion in Inner Mongolia were analyzed using the cultivated land conversion index,kernel density analysis,a standard deviation ellipse model,and a geographic detector.Results showed that from 2000 to 2020,the trends in cultivated land conversion area and rate in Inner Mongolia exhibited fluctuating growth,with the total area of cultivated land conversion reaching 7307.59 km^(2) at a rate of 6.69%.Spatial distribution of cultivated land conversion was primarily concentrated in the Hetao Plain,Nengjiang Plain,Liaohe Plain,and the Hohhot-Baotou-Ordos urban agglomeration.Moreover,the standard deviational ellipse of cultivated land conversion in Inner Mongolia exhibited a directional southwest-northeast-southwest-northeast distribution,with the northeast-southwest direction identified as the main driving force of spatial change in cultivated land conversion.Meanwhile,cultivated land conversion exhibited an increase-decrease-increase change process,indicating that spatial distribution of cultivated land conversion in Inner Mongolia became gradually apparent within the study period.The geographic detector results further revealed that the main driving factors of cultivated land conversion in Inner Mongolia were the share of secondary and tertiary industries and per-unit area yield of grain,with explanatory rates of 57.00%,55.00%,and 51.00%,respectively.Additionally,improved agricultural production efficiency and the coordinated development of population urbanization and industry resulted in cultivated land conversion.Collectively,the findings of this study indicated that,from 2000 to 2020,the cultivated land conversion in Inner Mongolia was significant and fluctuated in time,and had strong spatial heterogeneity.The primary drivers of these events included the effects of agriculture,population,and social economy.

Regulatory potential of soil available carbon,nitrogen,and functional genes on N_(2)O emissions in two upland plantation systems

Dynamic nitrification and denitrification processes are affected by changes in soil redox conditions,and they play a vital role in regulating soil N_(2)O emissions in rice-based cultivation.It is imperative to understand the influences of different upland crop planting systems on soil N_(2)O emissions.In this study,we focused on two representative rotation systems in Central China:rapeseed–rice(RR)and wheat–rice(WR).We examined the biotic and abiotic processes underlying the impacts of these upland plantings on soil N_(2)O emissions.The results revealed that during the rapeseed-cultivated seasons in the RR rotation system,the average N_(2)O emissions were 1.24±0.20 and 0.81±0.11 kg N ha^(–1)for the first and second seasons,respectively.These values were comparable to the N_(2)O emissions observed during the first and second wheat-cultivated seasons in the WR rotation system(0.98±0.25 and 0.70±0.04 kg N ha^(–1),respectively).This suggests that upland cultivation has minimal impacts on soil N_(2)O emissions in the two rotation systems.Strong positive correlations were found between N_(2)O fluxes and soil ammonium(NH_(4)^(+)),nitrate(NO_(3)^(–)),microbial biomass nitrogen(MBN),and the ratio of soil dissolved organic carbon(DOC)to NO_(3)^(–)in both RR and WR rotation systems.Moreover,the presence of the AOA-amoA and nirK genes were positively associated with soil N_(2)O fluxes in the RR and WR systems,respectively.This implies that these genes may have different potential roles in facilitating microbial N_(2)O production in various upland plantation models.By using a structural equation model,we found that soil moisture,mineral N,MBN,and the AOA-amoA gene accounted for over 50%of the effects on N_(2)O emissions in the RR rotation system.In the WR rotation system,soil moisture,mineral N,MBN,and the AOA-amoA and nirK genes had a combined impact of over 70%on N_(2)O emissions.These findings demonstrate the interactive effects of functional genes and soil factors,including soil physical characteristics,available carbon and nitrogen,and their ratio,on soil N_(2)O emissions during upland cultivation seasons under rice-upland rotations.

Comparative Study of Genetic Structure and Genetic Diversity betweenWild and Cultivated Populations of Taxus cuspidata,Northeast China

Taxus cuspidata is a rare plant with important medicinal and ornamental value.Aiming at the obvious differences between wild and cultivated populations of T.cuspidata from Northeast China,a total of 61 samples,that is,33 wild yews and 28 cultivated yews were used to analyze the differences and correlations of the kinship,genetic diversity,and genetic structure between them by specific length amplified fragment sequencing(SLAF-seq).Finally,470725 polymorphic SLAF tags and 58622 valid SNP markers were obtained.Phylogenetic analysis showed that 61 samples were classified into 2 clusters:wild populations and cultivated populations,and some wild yews were categorized into the cultivated populations;the genetic diversity analysis showed that the Nei diversity index of wild populations(0.4068)was smaller than that of cultivated populations(0.4414),and the polymorphic information content(PIC)of wild populations(0.2861)was smaller than that of cultivated populations(0.3309).The genetic differentiation analysis showed that the total populations of gene diversity(H_(t))of cultivated and wild populations were respectively 0.8159 and 0.5685,the coefficient of gene differentiation(G_(st))of cultivated and wild populations was respectively 0.3021 and 0.1068,and the gene flow(N_(m))(2.4967)of wild populations was larger than cultivated populations(0.8199).The molecular variance(AMOVA)revealed that inter-population variation accounted for 29.57%of the total genetic variation,while intra-population variation accounted for 70.42% of the total genetic variation(p<0.001),this suggested that the genetic variation in the T.cuspidata is mainly attributed to within-population factors.In conclusion,the genetic distance between geographical ecological groups of wild populations was generally smaller than that of cultivated populations,and the degree of genetic diversity and genetic differentiation was smaller than that of cultivated populations.As evident,the utilization of SLAF-seq technology enables efficient and accurate development of SNP markers suitable for genetic analysis of T.cuspidata species.These developed SNP markers can provide a molecular foundation for T.cuspidata breeding,construction of genetic maps,variety identification,and association analysis of agronomic traits.

Ways to Cultivate and Develop Human Resources in the New Situation

In the trend of globalization,digitization,and economic integration,human resources are the core competitiveness of enterprises,and cultivating and developing them is crucial for enhancing competitive advantages.This article delves into how human resource development drives enterprise innovation,promotes team collaboration,and optimizes performance management.Currently,although many enterprises are beginning to attach importance to human resource development,they still face problems such as insufficient investment,weak targeted training,and insufficient exploration of employee potential.Therefore,it is proposed that in the new situation,enterprises need to strengthen diversified training strategies,use digital tools to improve training efficiency,build a fair performance evaluation system,stimulate employee potential,and promote internal talent mobility.The implementation of these strategies will effectively enhance the efficiency of enterprise human resource management and consolidate market position.

Adoption of Solar Pumping Systems by Vegetable Farmers in Niayes Agro-Ecological Zone of Senegal: Adoption as a Sequential Process

This article examines the determinants of the adoption of solar pumping systems (PV) by vegetable farmers in the Niayes area of Senegal. To measure the determinants, we used a sequential logit model to translate the adoption process from becoming aware of solar pumping systems to testing them, i.e. using them at least once, and then continuing to use them over time. The results show that the main variables affecting awareness of the use of solar pumping systems (PV) are age, marital status, experience, access to credit, the farmer’s knowledge of climate change, the farmer’s origin in the Thiès region and length of time in the Niayes area. The first use of PVs is influenced by factors such as the size of the plot, the distance of the plot from the main road or from the market. Finally, the decision to adopt or continue use is influenced by gender, experience, household size and access to credit. Surprisingly, access to credit does not affect the first use of solar pumping systems, but plays a key role in their continued use.

Construction of the Classification and Grading Index System of Cultivated Land Based on the Viewpoint of Sustainable Development

In order to objectively and reasonably evaluate the actual and potential value of cultivated land, both social and ecological values are introduced into the classification and grading index system of cultivated land based on the viewpoint of sustainable development, after considering the natural and economic values of cultivated land. Index system construction of the sustainable utilization of cultivated land should follow the principles of economic viability, social acceptability, and ecological protection. Classification of cultivated land should take into account the soil fertility of cultivated land. Then, grading of cultivated land is carried out from the practical productivity (or potential productivity) of cultivated land. According to the existing classification index system of cultivated land, the soil, natural and environmental factors in plains, mountains and hills are mainly modified in the classification index system of cultivated land. And index systems for the cultivated land classification in plains, mountains and hills are set up. The grading index system of cultivated land is established based on the economic viability (economic value), social acceptability (social value) and protection of cultivated land (ecological value). Quantitative expression of cultivated land grading index is also carried out.

Evaluation and Driving Force Analysis of Cultivated Land Quality in Black Soil Region of Northeast China

Cultivated land is an important natural resource to ensure food,ecological and economic security.The cultivated land quality evaluation(CQE)is greatly significant for protecting and managing cultivated land.In this study,320 counties in the black soil region of Northeast China(BSRNC)represent the research units used to construct the CQE system measuring the soil properties(SP),cultivated land productivity(CLP),ecological environment(EE)and social economy(SE).The total of 19 factors were selected to calculate the integrated fertility index(IFI)and divided into grades.Simultaneously,we used the coupling coordination degree model to comprehensively analyze the spatial pattern of the cultivated land quality(CLQ)in the BSRNC,and use the structural equation model(SEM)to analyze the driving mechanism.The results show the following:1)The CLQ of 262 counties in the BSRNC is in a state of coupling and coordination,and the coupling and coordination degree presents a spatial distribution pattern of‘high in the southwest and northeast,low in the northwest and southeast’.The coordinated development degree of 271 counties is between 0.4 and 0.6,which is in a transitional state between coordination and disorder.2)The CLQ in the BSRNC is generally good,with an average grade of 3.High-quality cultivated land accounts for 58.45%of all counties,middle-and upper-quality cultivated land accounts for 27.05%,and poor-quality cultivated land accounts for 14.49%.3)The SEM analysis shows that the SP,CLP,EE,and SE all influence the CLQ.Among them,the SP has the largest driving force on the CLQ,while the SE has the smallest driving force on it.The results confirm that the main factors affecting the evaluation results are crop productivity level,normalized difference vegetation index,ratio vegetation index,difference vegetation index,and organic carbon content.When implementing protection measures in counties with a low CLQ,considering a balanced coordination of multiple systems and reasonably controlling the quality degradation are important.This study provides the current situation and driving factors of the CLQ in the BSRNC and will play an important role in black soil governance and utilization.

Application of System Dynamics in Analyzing the Cultivated Land-Water Resources Carrying Capacity in Bijie Prefecture,China

The cultivated land-water resources carrying capacity （CL-WRCC） with the method of system dynamics （SD） were analyzed. Bijie prefecture of Guizhou province served as a case in this study. Bijie prefecture is one of the least-developed areas in China. In Bijie, the physical and chemical characteristics of karst as well as the rapid economic development lead to the scarcities of cultivated land-water resources （CL-WR）. On the basis of analysis on the subsystems of Bijie CL.WRCC system, the fundamental feedback structure of CL-WRCC was presented by causal loop diagram. Considering the three alms （＂ poverty alleviation and development, ecological construction, and population control＂） of Bijie as the major goals, Bijie CL-WRCC SD model was developed. Three scenarios, resource-saving and environment-friendly development-oriented scenario （Scenario 1 ）, fast economic development-oriented scenario （ Scenario 2 ）, and coordinated development-oriented scenario （Scenario 3 ）, were investigated. Simulation results indicate that Scenario 3 which takes social economic development, environment protection, and cultivated land- water resources utilization into account, is the best alternative scenario. It can promote the coordination development of society, economy, cultivated land, water resources, and environment. In this study, the technological support and the decision-making for the rational use of CL-WR are provided not only in Bijie, but also in other similar regions of China.

Non-cropping period accounting for over a half of annual nitric oxide releases from cultivated calcareous-soil alpine ecosystems with marginally low emission factors

Nitric oxide(NO)emissions from alpine ecosystems conventionally being long-term cultivated with feed crops are not well quantified.The authors attempted to address this knowledge gap by performing a year-round experimental campaign in the northeastern Tibetan Plateau.Fertilized(F)and unfertilized(UF)treatments were established within a flat calcareous-soil site for the long-term cultivation of feed oats.NO fluxes and five soil variables were simultaneously measured.A single plow tillage accounted for approximately 54%–73%of the NO releases during the cropping period(CP);and the non-cropping period(NCP)contributed to 51%–58%of the annual emissions.The direct NO emissions factor(EFd)was 0.021%±0.021%.Significantly lower Q10 values(p<0.01)occurred in the F treatment during the CP(approximately 3.6)compared to those during the other period or in the other treatment(approximately 4.9?5.1),indicating a fertilizer-induced reduction in the temperature sensitivity.The selected soil variables jointly accounted for up to 72%(p<0.01)of the variance for all the fluxes across both treatments.This finding suggests that temporally and/or spatially distributed fluxes from alpine calcareous-soil ecosystems for feed crop production may be easily predicted if data on these soil variables are available.Further studies are needed to test the hypothesis that the EFd is larger in alpine feed-oat fields than those in this study if the soil moisture content is higher during the period following the basal application of ammoniumor urea-based fertilizer.

Characteristics and driving factors of abandoned cultivated land in the hilly regions of southern China:A case study in Longnan,Jiangxi Province

The abandonment of cultivated land in southern China was gradually obvious.This research aims to provide a reference for solving the abandonment of cultivated land in hilly regions and promote rural development in China.We examined Longnan county located in the hilly regions of southern China as an example,where abandoned cultivated land is very common.We analyzed its land use data with a field survey to identify the abandoned cultivated land and geospatial characteristics.From the two aspects of social and natural factors,we analyzed the factors driving cultivated land abandonment with the help of Geodetector.The results showed that in 2019,the total area of the abandoned cultivated land in Longnan county was 4,962.35 hm^(2),covering 39.51% of this region.Among the topographic factors,the abandonment rate is positively correlated with elevation and slope gradient,but not with slope direction.Among the land parcel conditions,the abandonment rate is positively correlated with the access to road network and cultivation distance from settlement.At the county level,the abandonment of cultivated land in study area was affected by multiple factors,among which,the direct factor was the reduction in the labor force,such as the decrease of farming laborers and the increase of female population,which made farming unsustainable.Changes in production factors also promoted transformations in farmers’motivation to engage in production,such as the decrease of grain crops and the increase of cash crops,which was the indirect factor affecting cultivated land abandonment.The development of the rural nonagricultural industry affected farmers’enthusiasm,such as the decrease of farming households,which was the fundamental factor leading to cultivated land abandonment in this area.

Spatiotemporal Pattern of Cultivated Land Pressure and Its Influencing Factors in the Huaihai Economic Zone, China

Cultivated land pressure represents a direct reflection of grain security. Existing relevant studies rarely approached the spatiotemporal pattern of cultivated land pressure or the spatial heterogeneity of its influencing factors from the level of economic zones.Taking the Huaihai Economic Zone(HEZ), China for case analysis, this study investigated the spatiotemporal pattern of cultivated land pressure in diverse periods from 2000 to 2018 based on a modified cultivated land pressure index and spatial correlation models. On this basis, it explored the influencing factors of the spatial differentiation of cultivated land pressure in the late stage of the study using geographical detector as well as multi-scale geographically weighted regression model. The results indicated that: 1) in the study period, the global cultivated land pressure index of the study area decreased gradually, but cultivated land pressure increased locally in a significant way, especially in the central and southern Shandong Province;2) the spatial pattern of cultivated land pressure manifested global clustering features. Hot and secondary-hot spots presented a narrowing and clustering trend, whereas cold and secondary-cold spots manifested a spreading and clustering trend;3) average slope, the proportion of non-grain crops, population urbanization rate, and multiple cropping index have significant effects on the spatial differentiation of cultivated land pressure. The former three factors were positively correlated with cultivated land pressure, and the last factor was negatively correlated with cultivated land pressure;and 4) the amount of cultivated land has increased in the central and southern Shandong Province through land consolidation which, nonetheless, failed to improve the grain production. In regards to major grain producing areas similar to the HEZ in China, the authors suggest that great importance should be given to the balance of the quality and quantity of cultivated land, the optimization of agricultural production factors and the rational control of non-grain crops, thus providing a powerful guarantee for grain security in China.

Spatiotemporal Interaction Between Rural Settlements and Cultivated Land in Karst Mountainous Area,China

Settlements and cultivated land are important production and living spaces in promoting rural revitalization.However,few studies have explored the relationship between rural settlements and cultivated land from spatiotemporal interaction perspective.This paper analyzed the spatiotemporal conversion and the interactive mechanism between rural settlements and cultivated land in a karst mountainous area(Qixingguan District of Guizhou Province)with fragile ecological environment in China during 2009–2018.The results showed that the expansion of rural settlements and the loss of cultivated land coexisted in Qixingguan District.Only 2.68%of the new cultivated land was reclaimed from rural settlements,whereas 85.45%of the new rural settlements occupied cultivated land.Six spatial expansion modes of rural settlements when occupying cultivated land were identified.Among these six modes,the area of the edge-expansion&along traffic roads(EA)mode accounted for 52.75%.The occupation by rural settlements made the cultivated land landscape more fragmented.The area ratio index of cultivated land to rural settlements(ARICR)of Qixingguan District averaged 18.75in 2009 and 17.21 in 2018,respectively.The ARICR reduced in all township administrative regions.Cultivated land with suitable slope condition for farming or without rocky desertification was more likely to be occupied by rural settlements.The probability of cultivated land occupied by rural settlements increased with the decrease of the distance to traffic roads,towns,and old rural settlements.The better the economic and social development of the township administrative regions,the more the ARICR decreased,while the richer the agricultural resources and the better the rural development of the township administrative regions,the less the ARICR decreased.The optimal reconstruction path of rural settlements,the comprehensive conservation path of cultivated land and the urban-rural integration development path in karst mountainous area were proposed.The findings would contribute to our understanding of the spatiotemporal interaction between rural settlements and cultivated land,and would provide a theoretical basis for promoting the coordinated development of rural man-land relationship and rural revitalization in karst areas.

Cultivation system influenced the critical period for weed control in cotton field

Background The critical period of weed control(CPWC) refers to the period of time during the crop growth cycle when weeds must be controlled to prevent yield losses.Ultra-narrow row(UNR) is a method of planting of cotton in rows that are 25 cm or less apart.Amongst cultural techniques for weed control,the use of narrow row spacing is considered to be a most promising approach that can effectively suppress weed growth and provide greater yields in cotton.This cultivation system can shorten the length of the critical weed-crop interference duration and results in greater yield.The current research aimed to determination of critical time of weed control in cotton(Gossypium hirsutum L.) under conventional and ultra-narrow row spacing conditions.Field experiments were arranged as factorial experiment in a randomized complete block design with three replications.Factors were cultivation system(conventional(50 cm row spacing) and ultra narrow row(25 cm row spacing and weed treatment including 30,45,60,and 75 days weeding after emergence during the growing season(weed free),and 30,45,60,and 75 without weeding(weed infested) in the growing season along with weedy and weed-free from sowing to harvesting.A four-parameter loglogistic model was fit to the two sets of relating relative crop yield to data obtained from increasing durations of weed interference and lengths of weed-free period.Results In both years and cultivation systems,the relative yield of cotton decreased with the increasing duration of weed-interference but increased with the increasing duration of weed-free period.Ultra-narrow row cultivation delayed the beginning of the CPWC in cotton.Under ultra-narrow row condition,the CPWC ranged from 21 to 99 days after germination in 2021 and 23 to 91 days in 2022 based on the 5% acceptable yield loss.Under conventional cultivation CPWC ranged from 17 to 102 days after emergence in 2021 and 18 to 95 days after emergence in 2022.Conclusions Under both conventional and Ultra-narrow row conditions,weed interference reduces seed yield.Under ultra-narrow row condition,weed interference until 21.1–23.5 days after cotton emergence and under conventional condition,weed interference until 16.9–18.5 days after cotton emergence had not significant reduction on cotton yield.

China's 15-year-old Postdoc System Cultivates 13,100 High-level Professionals

Since its founding in 1985, China’s Post-doc system has cultivated a total of 13,100 high-level professionals, a national conference of postdocs revealed recently. The program’s establishment was given the green light by Deng Xiaoping in 1985 in response to a suggestion by Prof. Tsung Dao Lee, a Nobel physics prize laureate. Starting from scratch, so far 798 programs for postdocs have been established, to be distributed in

Coordination of urbanization and cultivated land resources in Guangdong-Hong Kong-Macao Greater Bay Area:A case study of Guangzhou City

Guangzhou,a significant hub city in the Guangdong-Hong Kong-Macao Greater Bay Area,has seen fast social and economic growth as well as steady progress in the degree of urbanization.This research,taking Guangzhou city as an example,aims to provide an understanding of how land resources,urbanization,and spatial planning are coordinated in the study area.It also aims to explore how the coordination degree of land resources,urbanization,and spatial planning changes over time.It seeks to provide effective suggestions for land resource protection,national spatial planning,and urban transformation development to promote the coordinated development of the Guangdong-Hong Kong-Macao Greater Bay Area into a world-class Bay Area.