Problems and Strategies for Arable Land Eco-conservation in China

Arable lands are so important to China concerning food security and ec- onomy development. And eco-problems are rising and food security risks are widespread. The research reviewed quantity and quality of domestic arable lands, analyzed existing problems and proposed countermeasures for reinforcing domestic arable land conservation.

Annual Monitoring and Evaluation of the Grades of Arable Land Quality——Taking Lingchuan County as an Example

With the increasing requirement for the protection of arable land, monitor- ing the grades of arable land quality is becoming more important, which can accu- rately and fully reflect the current situation and development trends of arable land quality. It is also an important measure for protecting the quality of arable land. in the present study, the distribution and changes of arable lands of different gradient types and grades in Lingchuan County, Guangxi Zhuang Autonomous Region in 2015 were monitored and evaluated, to analyze the trends and reasons for the changes in the quality and productivity of arable lands, and to provide references for dynamic monitoring of the quality of arable land.

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.

Sustainable Utilization of Arable Land Resources in Karst Area:A Case Study of Anshun City of China

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.

Research of Dynamic Monitoring on Arable Land Quality

In China with such a large population and few land, the problem of arable land is particularly prominent. While the amount of arable land per capita is small, the quality of arable land is declining. Compared with the decreasing arable land, the decline in the quality of arable land is invisible and hard to be detected. But the impact is no less than the amount of arable land reduced, and ~;hanges in the quality of arable land pose a serious threat to ecological environment and socio- economic development. Against the background of high-intensity development and the amount of arable land decreasing, the research of monitoring of arable land quality is of great realistic significance.

Comparative Analysis of Influence Factors on Arable Land Use Intensity at Farm Household Level:A Case Study Comparing Suyu District of Suqian City and Taixing City,Jiangsu Province,China

Using data from the farm household survey conducted in 2009,arable land use intensity(ALUI)and its influence factors at farm household level were investigated by the Tobit model.Suyu District of Suqian City and Taixing City of Jiansu Province,China were chosen as the regions for comparison.The results show that:1)On the average, the ALUI,labor intensity,yield-increasing input,and labor-saving input are 15 238.14 yuan(RMB)/ha,192 d/ha, 7233.01 yuan/ha,and 2451.32 yuan/ha in the less economically developed Suyu District,and 13 020.65 yuan/ha,181 d/ha,5871.82 yuan/ha,and 2625.97 yuan/ha in more economically developed Taixing City.The figures indicate that Suyu District has higher ALUI and labor intensity input but lower labor-saving input.2)Comparing all the influence factors,the total arable land area in available and average plot size have bigger effects on arable land intensive use;to a small degree,family′s non-farm income affects labor intensity,yield-increasing input,and labor-saving input;the yield-increasing input decreases significantly when the householder has higher education attainment;the commercialization rates of agricultural products and the planting proportion of cash crops both have unstable influence on ALUI; the share of arable land rented in has few impacts on labor intensity,yield-increasing input,and labor-saving input. 3)There are no differences found in the internal impact mechanism of influence factors on the arable land intensive use behaviors of farm households.However,there are conspicuous disparities in the impact degrees and statistical significance based on varying economic levels.4)Using the results as bases,this study proposes that the government should implement land management and agricultural policies according to local condition.And these policies should decrease land fragmentation to promote scale management of land and arable land use intensification.

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.

Application of Remote Sensing and GIS Technology to the Study of Desertification of Arable Lands in North Shaanxi, China

The policy of the Chinese government concerning the horizontal expansion of the cultivated land through the reclamation of desert soils result in a total increase of 665.985 km 2 during the period 1987\|1999 in North Shaanxi. This increase is less than the loss in arable land by urbanization. The accelerated rate of change in agricultural areas calls for more rapid surveys of urbanization and loss of arable land. Remote sensing has a number of advantages over ground\|based methods for such surveys. The multi\|scale concept of remote sensing data help us study the problem in four towns. Several maps were produced to analyze the situation of urban coverage in different times. The evaluation of the status, rate and risk of urbanization are based on an accepted average of urban increase as 2% of population growth per year.

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.

Distribution of Soil Nutrients in Arable Land of Tropical Hilly and Mountainous Area

[Objective] The aim was to explore spatial distribution characters of soil nutrients in arable lands of Hainan mountainous areas and provide references for soil nutrient management in tropical mountainous areas. [Method] The research took arable lands in Wuzhishan City as an example by field survey, sampling and lab analysis and investigated soil nutrients and distributions based on analysis of soil nutrient contents. [Result] The soils were dominated by acid soils, with pH of 5.1; soil nutrients were distributed in a non-uniform manner; contents of soil organic matter, available phosphorus, available potassium, as well as medium elements kept lower or moderate levels; effective copper and available zinc were rich. Local spe- cial climate, uneven distribution of parent material and non-uniform fertilization con- tributed to acid soils and unbalanced distribution of soil nutrients in Wuzhishan. [Conclusion] It is recommended to facilitate soil nutrient balance by promoting re- turning straws to farmlands and technical specification of balanced fertilization by soil testing as per nutrient distribution of arable lands in Wuzhishan City.

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.

Characteristics and Process of Land Use Changes in the Yangtze River Delta, China

As one of the developing countries China has an arable land per capita far below the world’s average level. With a high-density population and the quick development of economy and urbanization, the Yangtze River Delta shows the typical characteristics of land use in developed regions of China, which are: high land reclamation rate and low arable land per capita; intensive land use and high output value; and rapid increasing of construction land area and fast diminishing of arable lands. The analysis indicates that the process of the arable land changes in the Yangtze River Delta could be divided into four different change stages over the past 50 years.