Marginalization of Arable Land and its Correlation with Rural Labor Migration——A Case of Tongcheng County,Hubei Province,China

Based on the introduction of the connotation of marginalization,the index of diagnosing the marginalization degree is put forward.According to the 685 copies of questionnaires on peasant households in Tongcheng County of Hubei Province and the statistical data of local government,marginalization of arable land and its correlation with rural labor migration in Tongcheng County are studied by using aggregative indicator method,clustering analysis method and correlation analysis method.Result shows that marginalization of arable land has happened two times in Tongcheng County since 1985.Dry land has severer marginalization degree than paddy field.There is significant correlation between marginalization degree of arable land and rural labor migration;and the correlation between marginalization degree and rural labor migration in paddy field is greater than that in dry land.Marginalization of arable land will advance the rural labor migration,while in response to the poor current circulation of lands;the rural labor migration will further deepen the marginalization degree.Marginalization of arable land is one of the important factors affecting the labor migration in rural areas.

Comparative Analysis on Eco-Efficiency of Arable Land Ecological Footprint in Hubei

This paper uses the ecological footprint model to make comparison of the eco-efficiency of arable land ecological footprint in different years in Hubei Province, and makes comparison of that in Hubei and some countries. The results indicate that, since 1965, the eco-efficiency of arable land ecological footprint in Hubei has been improved year by year. However, the efficiency of arable land ecological footprint, compared with some other areas in the world, is much lower. In 1965, average eco-efficiency of world arable land ecological footprint is 3 421 US dollar/hm^2 while that of Hubei Province is 134 US dollar/hm^2, about 1/26 of the world＇s average level. The eco-efficiency of arable land ecological footprint for 2003 in Hubei Province, however, has become about 1/9 of the world＇s average level for the same year. Finally the author puts forward the ways to raise the eco-efficiency of arable land ecological footprint.

On arable land changes in Shandong Province and their driving forces

The decrease of total cultivated area and the lower per capita available arable land resource are now serious problems in Shandong Province, a major agricultural province in China. These problems will become more serious along with the further development of economy. In this paper, based on the statistical information at provincial and county levels, the changes of arable land in Shandong Province and their driving forces during the last 50 years are analyzed. The general changing trends of arable land and per capita available arable land are reducing, and the trends of decrease will continue when the economy is developing. The result of GIS spatial analysis shows that the change of the arable land use in Shandong Province has a regional difference. Eight variables having influences on cultivated land change are analyzed by principal component analysis. The results show that the dynamic development of economy, pressure of social system and progress of scientific techniques in agriculture are the main causes for cultivated land reduction. The principal factors which can be considered as driving forces for arable land change include per capita net living space, total population and per ha grain yield. By using regressive equation, along with analysis on population growth and economic development, cultivated areas in Shandong Province in 2005 and 2010 are predicted respectively. The predicted cultivated areas in Shandong will be 6435.47 thousand hain 2005 and 6336.23 thousand ha in 2010 respectively.

Process and mechanism of arable land change in Hebei Province during the past 50 years

Hebei Province is one of the regions with most densely population, fastest economic growth and most intensive land use in China. The contradiction of land shortage sharpened by high-speed economic development with population growth has become a serious problem, which has restricted regional sustainable development.This paper revealed the basic process, regional differences of change and the gravity center of arable land area according to the long-series statistical data of arable land during the past 50 years. On the basis of the above mentioned, the major driving forces that influence the changes of the arable land are discussed. The research results indicate that there is a trend of obvious fluctuating decrease in arable land area during the last 50 years. The changes of arable land area undergo the process from increase to sharp decrease to gently decrease. The regional disparity of change in arable land area is very notable and the gravity center of arable land area moves to the northeast 49.22 km. Regarding the decrease in arable land, the direct driving forces include adjustments of agricultural structure and reclamation, and indirect driving forces include advance in technology, economic interest and population growth etc.

Arable land increase in northern China: facts and findings

Based on investigations between 1986 and 1996 in the four provinces of northern China, major problems on land reclamation were discovered. The increase of arable land was mainly low quality fields from barren land and was susceptible to disertification and water-induced soil erosion. In the meantime, large area of grassland and forestland was lost or degraded, and original fertile arable land was occupied for residential and industrial use. As a result the environment deteriorated. This change was mainly caused by economic development, population growth, inferior natural conditions, and irrational management strategies. Finally some positive measures were suggested to stop this negative cycle.

Current situation and trend of arable land change in China

How to protect arable land in the process of economic development and urbanization is a critical issue in China. In this paper, an attempt is made to analyze the situation of arable land change in China and it's relationship with population growth, economic development and urbanization. In depth analysis is also made in different regions. Forecasting is conducted to show the trend of arable land change in China based on the results of correlation analysis. Some suggestions are put forward for the policy making of reasonable utilization and protection of arable land in the future.

Dynamic Change of Arable Land Ecological Security: A Case Study of Panyu District, Guangzhou City

Ecological security of arable land is closely related to grain security and social stability. This paper took 12 typical indexes from the aspects of ecological pressure, state and response of arable land considering natural, social and economic conditions to construct the ecological index system of arable land in Panyu District, Guangzhou City, and adopted objective weighting method and comprehensive analysis method to analyze the dynamic change of ecological security and security level of arable land in the study area. The results showed that ecological security pressure value and response value of arable land in Panyu District from 2008 to 2013 increased and the overall ecological security level was low, manifesting the level of "sensitive–risky–sensitive". Specifi cally, ecological security of arable land in 2008 was sensitive, risky from 2009 to 2011, and the security level rose to the sensitive level again in 2012 and 2013. Ecological restoration and rebuilding of arable land should be enhanced, and ecological security early warning system should be established by protecting quantity and quality of arable land, so as to protect arable land resources effectively, and promote sustainable development of arable land.

Detecting the linkage between arable land use and poverty using machine learning methods at global perspective

Eradicating extreme poverty is one of the UN’s primary sustainable development goals(SDG).Arable land is related to eradicating poverty(SDG1)and hunger(SDG2).However,the linkage between arable land use and poverty reduction is ambiguous and has seldom been investigated globally.Six indicators of agricultural inputs,crop intensification and extensification were used to explore the relationship between arable land use and poverty.Non-parametric machine learning methods were used to analyze the linkage between agriculture and poverty at the global scale,including the classification and regression tree(CART)and random forest models.We found that the yield gap,fertilizer consumption and potential cropland ratio in protected areas correlated with poverty.Developing countries usually had a ratio of actual to potential yield less than 0.33 and fertilizer consumption less than 7.31 kg/ha.Overall,crop extensification,intensification and agricultural inputs were related to poverty at the global level.

An Analysis on Driving Forces of Arable Land Resource Change in Jieshou City

By the qualitative and quantitative analysis method,we analyze the driving forces of arable land resource change in Jieshou City and find that the arable land resource change in Jieshou City arises mainly from social and economic driving forces. Based on the social and economic indicator data about arable land resource in Jieshou City,we use principal component analysis to establish evaluation index system,and analyze the driving forces of dynamic arable land resource change in Jieshou City during 2006-2015. It is concluded that Jieshou's arable land change is mainly affected by economic and social factors.

Integrated Quantity, Quality and Ecology of County-Level Arable Land Improvement Potential Comprehensive Zoning: The Example of Tongxu County, China

The scientific evaluation of arable land remediation potential can be used to formulate remediation policies based on local conditions. This study took arable land resources in Tongxu County, China as the research object and administrative villages as the evaluation unit, constructed an evaluation index system by integrating three aspects—quantity, quality and ecology. Based on the evaluation of arable land remediation potential, the K-means++ spatial clustering algorithm combined with elbow method is used to divide the remediation partition and give the remediation strategy. The results showed that: 1) the evaluation index system of arable land improvement potential, which integrated “quantity-quality-ecology”, was more systematic in analyzing the potential of arable land improvement than the previous single target evaluation index, and explored its internal linkage. 2) There are some spatial differences in the quantitative, qualitative and ecological potentials in Tongxu County, with the quantitative potential being higher in Changzhi Township, the intersection of Lizhuang Township and the southern part of Yuhuangmiao Township, the qualitative potential being more evenly distributed, and the ecological potential being higher around Chengguan Township. 3) Through K-means++ clustering algorithm combined with elbow method, Tongxu County was divided into five subzones: quality improvement zone, intensive improvement zone, quantity improvement zone, comprehensive improvement zone and health improvement zone, among which the highest percentage of quality improvement zone and the lowest percentage of comprehensive improvement zone were 49.2% and 1.5% respectively, and differentiated remediation strategies were provided by research for each sub-district to promote high quality of arable land.

Holistic identification and assessment of environmental risks of arable land use in two grain producing areas of China

Taking two typical grain producing areas of southern(Dongting Lake Region)and northern China(Shandong Province)as examples,this study used fault tree analysis and parametric estimation to provide a comparative analysis for environmental risks of intensive arable land use.The results show that(1)in the risks of eutrophication,toxicity,soil structure,greenhouse effect and air pollution,the greenhouse effect was the most prominent with the highest discharge;(2)the Dongting Lake Region discharged less pollutants annually than did Shandong Province,while surpassing Shandong in cumulative pollutant discharge in 2007-2018;(3)the spatial distribution of environmental risk in the Dongting Lake Region was mostly concentrated in the northern area,whereas that in Shandong Province displayed a scattered pattern;(4)in the Dongting Lake Region,Yueyang,Changde,and Yiyang were high environmental risk cities in 2007-2018,whereas in Shandong Province,Zaozhuang,Heze,Liaocheng,and Dezhou exhibited higher comprehensive environmental risk indexes in 2007-2008,while Rizhao replaced them in 2018.The results indicated that ago-production material use must be controlled,reasonable zoning for areas posing environmental risks must be employed and cities with high environmental risk must be dynamically monitored to prevent the intensification of environmental risks of arable land use.

Spatio-temporal analysis of land-use conversion in the eastern coastal China during 1996-2005

Based on the acquaintance of the regional background of urban-rural transformational development and investigations on the spot,this paper discusses the holistic situation, dominant factors and mechanism of arable land loss and land for construction occupation in the coastal area of China over the last decade,with the aid of GIS technology.Conclusions of the research are summarized as follows：（1）the arable land had been continuously decreasing from 1996 to 2005,with a loss of 1,708,700 hm^2 and an average decrement of 170,900 hm^2 per year;（2）land for construction increased 1,373,700 hm^2 ,with an average increment of 153,200 hm^2 per year;（3）total area of encroachment on arable land for construction between 1996 and 2005 was 1,053,100 hm^2 ,accounting for 34.03%of the arable land loss in the same period,the percentages of which used for industrial land（INL）,transportation land（TRL）,rural construction land（RUL）and town construction land（TOL）are 45.03%,15.8%,15.47%and 11.5%,respectively;and（4）the fluctuation of the increase of construction land and encroachment on arable land in the area were deeply influenced by the nation＇s macroscopic land-use policies and development level of regional economy.The growth of population and advancement of technology promoted the rapid industrialization, construction of transportation infrastructures,rural urbanization and expansion of rural settlements in the eastern coastal area,and therefore were the primary driving forces of land-use conversion.

Strengthen Farmland Quality Construction and Build a Strong Foundation for Food Security

As a carrier for food production, protection of arable land quantity and quality is the basis of quality and high yield agriculture. In recent years, with the acceleration of industrialization and urbanization, arable land red line is at risk, and the quality of arable land has been declining, which are not conducive to the sustainable development of agriculture, but also threaten ＂the food problem＂ of the country＇s 1.3 billion people. This paper attempts to analyze the current situation of arable farmland quality, reasons for the arable farmland quality decline and its impact on food security in China, and explore effective measures to improve the quality of cultivated land.

Evaluation of Parametric Limitations in Simulating Greenhouse Gas Fluxes from Irish Arable Soils Using Three Process-Based Models

Globally a large number of process-based models have been assessed for quantification of agricultural greenhouse gas (GHG) emissions. Modelling approaches minimize the presence of spatial variability of biogeochemical processes, leading to improved estimates of GHGs as well as identifying mitigation and policy options. The comparative performance of the three dynamic models (e.g., DNDC v9.4, DailyDayCent and ECOSSE v5+) with minimum numbers of common input parameters was evaluated against measured variables. Simulations were performed on conventionally-tilled spring barley crops receiving N fertilizer at 135 - 159 kg·N·ha-1·yr-1 and crop residues at 3 t·ha-1·yr-1. For surface soil nitrate (0 - 10 cm), the ECOSSE and DNDC simulated values showed significant correlations with measured values (R2 = 0.31 - 0.55, p 0.05). Only the ECOSSE-simulated N2O fluxes showed a significant relationship (R2 = 0.33, p 0.05) with values measured from fertilized fields, but not with unfertilized ones. The DNDC and DailyDayCent models significantly underestimated seasonal/annual N2O fluxes compared to ECOSSE, with emission factors (EFs), based on an 8-year average, were 0.09%, 0.31% and 0.52%, respectively. Predictions of ecosystem respiration by both DailyDayCent and DNDC showed reasonable agreement with Eddy Covariance data (R2 = 0.34 - 0.41, p 0.05). Compared to the measured value (3624 kg·C·ha-1·yr-1), the ECOSSE underestimated annual heterotrophic respiration by 7% but this was smaller than the DNDC (50%) and DailyDayCent (24%) estimates. All models simulated CH4 uptake we

喀斯特区域耕地资源可持续利用研究——以贵州省安顺市为例(英文)

Aiming at utilization status of arable land resources in Anshun City,a Karst area,quantitative and qualitative analyses were performed from the viewpoints of quality,quantity and benefits of arable land.And the benefits of arable land were analyzed with multiple linear regression.Finally,the sustainable utilization of arable land resources was discussed,and several protection measures were pointed out.

Allocation of grassland, livestock and arable based on the spatial and temporal analysis for food demand in China

To explore the distribution of food demand and the projected trend in future food demand in China, this paper analyzed the change in current(1998–2012) percapita demand for grain, grain-consuming and herbivorous livestock products, and predicted the food demand in 2020 The results indicated that in 1998–2012, the national percapita consumption of grain ration declined by about36.66%, and the per-capita consumption of grain-consuming and herbivorous livestock products increased by about 48% and 34.09%, respectively. The grain-consuming livestock products have become the primary source of both calories and protein for consumers. The proportion of herbivorous livestock products in consumer diets has increased steadily and there has been huge potential in substituting beef and mutton for pork in this dynamic market. The demand for food in different regions of China is highly variable, which is important for planning grassland agriculture development and ensuring food safety. The demand for grain, and grain-consuming and herbivorous livestock products will increase by about3.3%, 20% and 14% respectively by 2020. Based on the food demand and trend in the development of grassland agriculture, the 31 regions in China are divided into three priority groups for grassland agriculture development.

Distribution and Abundance of <i>Parthenium hysterophorus</i>L. in Metekel Zone, Northwest Ethiopia

Parthenium hysterophorus L. is a harmful invasive weed to plant biodiversity and human health. It is native to American tropics and first introduced to Ethiopia in the 1970s. Today, it is widely distributed across the country and severely affecting the biodiversity, crop, and animal production in the country. In the Metekel Zone, there was no report on its distribution and impacts so far. Therefore, this study was aimed to assess the distribution and abundance of the plant in the zone. The distribution and abundance data of the weed were recorded at five km intervals following all accessible roads of the zone. The result reveals that P. hysterophorus L. was less distributed in the area with a 4.95% frequency. However, it was found abundantly growing at roadsides, wastelands, around habitation, market place, and around Zeghibridge where it can rapidly spread to most economical lands like the arable and grazing lands. Moreover, it has aggressively invaded a nursery site, which enables the weed to enter agricultural fields directly. This suggests that the weed is on a fast move to agricultural lands in the zone. The regular active development activities such as agricultural investment, construction of roads, and factories are presumed to promote its spread. Therefore, a decisive and timely decision is needed to mitigate the weed when it is still sparse and small.

Evaluation method and empirical application of human activity suitability of land resources in Qinghai-Tibet Plateau

The current suitability evaluation methods for land resources human activity in China suffer from theoretical deficiencies related to fundamental data accuracy,elevation and slope classification,and suitability class judgment.Empirical application of these methods is also hindered by excessive evaluation indicators,data acquisition difficulties,and limited applicability to high altitude regions.To address these issues,this paper proposes a technical evaluation framework for the Qinghai-Tibet Plateau(QTP) that employs selected key parameters varying with elevation and slope to establish grid-scale evaluation models for construction land suitability(CLS) and arable land suitability(ALS).A generalized algorithm is then proposed for key parameters such as air density,air temperature,slope suitability for construction,and soil erosion resistance of sloping arable land.Empirical research is conducted using Milin County in southeast Tibet as a case study,with interval measurements of 100 m in elevation and 1° in slope.The evaluation model is tested using grid accuracies of 30 m,50 m,100 m,250 m,500 m,and 1000 m.The results reveal that:Firstly,the CLS and ALS can be categorized into five classes:highly suitable,suitable,moderately suitable,marginally suitable,and unsuitable,with varying area ratios under different grid accuracies.Secondly,existing construction lands in Milin County are mainly distributed in suitable,highly suitable,and moderately suitable CLS classes,accounting for over 94% of the total area studied under different grid accuracies.While arable land is mainly distributed in suitable,highly suitable,and moderately suitable ALS classes,accounting for over 96%.Thirdly,the empirical research in Milin County indicates that the evaluation method,quantitative model,and parameters algorithm for evaluating human activity suitability of land resources on the QTP are feasible and applicable,with a recommended grid accuracy within 100 m and a maximum of 250 m.Fourthly,the paper establishes a correspondence between land suitability(including construction land and arable land) and topographic factors(elevation and slope) that can be applied to the QTP.Finally,some professional defects in the evaluation methods of available land resources in Major Function Zoning and “Double Evaluations” of Territorial Spatial Planning in China when applied to the QTP are identified.

Cadmium pollution from phosphate fertilizers in arable soils and crops:an overview

The application of mineral and organic phosphorus fertilizers to arable land has greatly increased crop yield to meet the world food demand.On the other hand,impurities in these fertilizers,such as heavy metals,are being added to agricultural soils,resulting both from the raw materials themselves and the processes used to obtain the final product.Cadmium,a non-essential and toxic heavy metal,has been found in relatively high amounts in common P fertilizers obtained from sediments.This metal poses a high risk for soil fertility,crop cultivation,and plants in general.Furthermore,human health might be compromised by the cadmium concentrations in agricultural and livestock products,due to the bioaccumulation effect in the food web.The accumulation in the different matrixes is the result of the high mobility and flexible availability of this harmful metal.This review summarizes risks to human health,the factors influencing cadmium movement in soils and crop uptake,as well as common plant responses to its toxicity.In addition,it summarizes cadmium balances in soils,trends,long-term experiments,and further studies.Cadmium inputs and outputs in arable soil,together with their calculated concentrations,are compared between two different regions:the European countries(in particular Germany)and China.The comparison appears useful because of the different proportions in the inputs and outputs of cadmium,and the diverse geographical,environmental and social factors.Moreover,these variables and their influences on cadmium contamination improve the understanding of the pollution from phosphate fertilizers and will help to establish future mitigation policies.

Soil carbon stock and emission: estimates from three land-use systems in Ghana

Background:Land-use systems that sequester carbon and reduce CO_(2) emissions are key in the global mitigation strategies of climate change.Greenhouse gas emission from agro-ecosystems in sub-Saharan Africa is little studied.Here,we quantified soil carbon stock(SCS)and CO_(2) emissions from three land-use systems viz.arable land,oil palm plantation and forestland in the semi-deciduous forest zone of Ghana.Results:Soil organic carbon concentration at the 0–15 cm layer in the forestland was 62 and 23%greater than that in the arable land and palm plantation,respectively.The SCS along the 1.0-m profile was 108.2,99.0 and 73.5 Mg ha^(−1) in the forestland,palm plantation and arable land,respectively.Arable land emitted 30–46%more CO_(2) than palm plantation and forestland.In the dry season,CO_(2) emissions were respectively 0.93,0.63 and 0.5 kg ha^(−1) h−1 from the arable land,palm plantation and forestland.Positive relationships were observed between CO_(2) emissions and SCS,soil temperature,and moisture.The SCS greatly influenced CO_(2) emission in the dry season more than in the wet season in the relatively higher carbon-input systems(forestland and palm plantation).Soil temperature accounted for more than 55%of CO_(2) emissions in both seasons,which has implications in the era of rising global temperatures.Conclusions:The study provides relevant information on carbon storage abilities of the three land-use types in tropical climate and calls for drastic climate change actions to reduce degradation of forest cover and soil disturbance in agro-ecosystems in sub-Saharan Africa.