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.

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.

Spatial and Temporal Changes of Arable Land Driven by Urbanization and Ecological Restoration in China

Since the industrial revolution, human activities have both expanded and intensified across the globe resulting in accelerated land use change. Land use change driven by China’s development has put pressure on the limited arable land resources, which has affected grain production. Competing land use interests are a potential threat to food security in China. Therefore, studying arable land use changes is critical for ensuring future food security and maintaining the sustainable development of arable land. Based on data from several major sources, we analyzed the spatio-temporal differences of arable land among different agricultural regions in China from 2000 to 2010 and identified the drivers of arable land expansion and loss. The results revealed that arable land decreased by 5.92 million ha or 3.31%. Arable land increased in the north and decreased in the south of China. Urbanization and ecological restoration programs were the main drivers of arable land loss, while the reclamation of other land cover types(e.g., forest, grassland, and wetland) was the primary source of the increased arable land. The majority of arable land expansion occurred in the Northwest, but the centroid for grain production moved to northeast, which indicated that new arable land was of poor quality and did not significantly contribute to the grain production capacity. When combined with the current ‘Red Line of Arable Land Policy’(RAL) and ‘Ecological Redline Policy’(EPR), this study can provide effective information for arable land policymaking and help guide the sustainable development of arable land.

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.

Physico-Chemical Properties and Enzyme Activities of the Arable Soils in Lhasa,Tibet,China

An understanding of the physical,chemical,and biological properties of a soil provides a basis for soil use and management.This paper reports the major physico-chemical properties and enzyme activities of the soils of Lhasa's main arable lands and the factors that influence these soil properties.Composite and core samples were taken from the three main arable soil types(alluvial soil,subalpine arable steppe soil,and subalpine arable meadow soil) and were analysed using standard methods.The bulk density and the ventilation porosity ratio of the soils were close to the recommended values for arable lands,and the dominant soil texture was sandy.The soil moisture release rates were arable steppe soil > alluvial soil > arable meadow soil.Soil organic matter content,Cation-Exchange Capacity(CEC),total and available nitrogen content,and catalase activity of the arable meadow soil were higher than those of the alluvial and the arable steppe soils,while soil pH in the arable meadow was lower.Most of the measured properties did not show a significant variance among these three soils.However,the measured indices(apart from the total potassium) indicate that there are notable differences among the three types of soil.The results implied that the utilisation patterns of the arable soil or human activities,such as tillage practices and fertiliser applications,have a substantialeffect on the soil properties in this region.Our results suggest that the cultivation practices in the region have apparently positive impact on the soil organic matter,nutrient contents and bulk density probably due to the sound fertiliser management such as the applications of farmyard manure and chemical fertilisers.However,intense cultivation practices lowered the activity of most soil enzymes.The results demonstrate that the choice of soil management strategy had a significant impact on the soil physicochemical and biological properties in the region studied.

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.

Soil CO_2 flux in relation to dissolved organic carbon,soil temperature and moisture in a subtropical arable soil of China

Soil CO 2 emission from an arable soil was measured by closed chamber method to quantify year round soil flux and to develop an equation to predict flux using soil temperature, dissolved organic carbon(DOC) and soil moisture content. Soil CO 2 flux, soil temperature, DOC and soil moisture content were determined on selected days during the experiment from August 1999 to July 2000, at the Ecological Station of Red Soil, the Chinese Academy of Sciences, in a subtropical region of China. Soil CO 2 fluxes were generally higher in summer and autumn than in winter and spring, and had a seasonal pattern more similar to soil temperature and DOC than soil moisture. The estimation was 2 23 kgCO 2/(m 2·a) for average annual soil CO 2 flux. Regressed separately, the reasons for soil flux variability were 86 6% from soil temperature, 58 8% from DOC, and 26 3% from soil moisture, respectively. Regressed jointly, a multiple equation was developed by the above three variables that explained approximately 85 2% of the flux variance, however by stepwise regression, soil temperature was the dominant affecting soil flux. Based on the exponential equation developed from soil temperature, the predicted annual flux was 2 49 kgCO 2/(m 2·a), and essentially equal to the measured one. It is suggested the exponential relationship between soil flux and soil temperature could be used for accurately predicting soil CO 2 flux from arable soil in subtropical regions of China.

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.

Survey and Evaluation of Reserve Arable Land Resources in Xinjiang's Makit County

Using " limiting factor" evaluation method,we make survey and evaluation of reserve arable land resources in Makit County.The results show that 9876.1 ha of land resources can be reclaimed in the county;there is no mining land to be reclaimed;9447.58 ha of grassland can be reclaimed,and it is mainly distributed in Gazikule Township and Kizilawat Township.We make the following recommendations:broadening investment channels and increasing capital investment for arable land consolidation;combining unused land development and environmental protection;making suitability evaluation of reserve arable land resources and determining reasonable direction and path of development and reclamation.

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.

Comprehensive Evaluation of Unsafe State of Arable Land Resources:A Case Study of Chengdu City

We establish the unsafe state indicator system reflecting the unsafe state of arable land within the scope of the city. Using analytic hierarchy process and entropy method,we determine the weight of indicator; using linear weighted method,we conduct comprehensive evaluation of unsafe operation of arable land resource system in Chengdu City during the period 1999-2010. Through the unsafe state analysis,we draw the following conclusion: the share of arable land area in total land area,effective irrigation area,the area of low-yielding field,application rate of chemical fertilizer per unit area of arable land,and application rate of pesticide per unit area of arable land,are the key factors for easing the unsafe state in the short term. Finally we put forth the following recommendations: strengthening profound understanding of the seriousness of unsafe state of arable land; strengthening the basic arable land protection; continuing to tap the quality enhancement potential of arable land; consistently implementing the guideline and policy of " Combination of Use and Maintenance" .

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.

Adoption of Herbicides by Arable Crop Farmers in Edo State, Nigeria

This study examined the adoption of herbicides by arable farmers in Edo State. It assessed the proportion of arable farmers using herbicides, level of use and factors affecting adoption of herbicides. Simple random sampling was used to compose a sample size of 556 respondents. Various descriptive and inferential statistics were employed in data analyses. The results showed that onehalf of the respondents used herbicides(27.9% regularly using herbicides), and most of the adopters used non-selective herbicide. Avalanche of factors, including education attainment, farm size and farming experience also affected the adoption of herbicides.