China's food supply and demand have significant implications for both China's own national food security and that of the world. This study reviews China's food security prospects and their implications, focusing on...China's food supply and demand have significant implications for both China's own national food security and that of the world. This study reviews China's food security prospects and their implications, focusing on international trade in the coming decade. The results show that China's policies for ensuring food security will be enhanced and China will move to sustainable agriculture. Most studies anticipate that China will increase its food and feed imports in the coming decade. China's overall food self-sufficiency is likely to fall from 94.5% in 2015 to around 91% by 2025. The greatest increases in imports are likely to be soybean, maize, sugar, and dairy products. However, within the production capacity of the major exporting countries and of many food-importing developing countries, China's additional imports of 3 to 5% of its total food consumption in the coming decade are unlikely to threaten global food security. Indeed, the projected imports of feed and several foods could provide opportunities for many exporting countries to expand their production and save global resources.展开更多
Developing and developed countries alike are increasingly facing the dififcult question of how to feed more people amidst a host of emerging demographic, environmental, and health challenges. At the same time, in addi...Developing and developed countries alike are increasingly facing the dififcult question of how to feed more people amidst a host of emerging demographic, environmental, and health challenges. At the same time, in addition to food quantity, increased attention is being given to food quality attributes, in particular nutrition and safety. This is especially evident in China, where concerns are on the rise regarding the ability of China’s food production systems to deliver nutritious and safe food to a growing, urbanizing and more aflfuent population. These food and nutrition concerns come at a time when China is an increasingly inlfuential actor within the global food security network through activities such as production, consumption and trade. We argue that China has the opportunity to increase food and nutrition security both nationally and globally through a comprehensive policy agenda that focuses on institutional reforms, investments for and in agriculture, productive social safety nets, mutually beneifcial trade, and the exchange of know-how and technologies among developing countries and donors. This agenda will help China adapt its food production systems to the changing face of agriculture and to play a vital role in addressing the emerging challenges facing food and nutrition security within and beyond China in the coming decades.展开更多
With the rapid economic expansion, environmental degradation has become increasingly sever during the past three decades. Soil pollutions associated with toxic organic compounds and heavy metals have been identified i...With the rapid economic expansion, environmental degradation has become increasingly sever during the past three decades. Soil pollutions associated with toxic organic compounds and heavy metals have been identified in China. The accumulation of heavy metals in soils and its impact on food safety is of increasing concern. It has been reported that more than 20 million ha of land have been contaminated with heavy metals that can result in the potential health risks to human beings and soil ecosystems. This can potentially jeopardize the food security in China. Accumulation of heavy metals in suburb and rural soils is closely related to many anthropogenic activities, such as application of fertilizers and pesticides, irrigation of wastewater, discharge of mining, improper disposal of metal containing wastes, land application of animal manures, sewage sludge and coal combustion residues. Arable crops and vegetables in suburb and rural can take up heavy metals from contaminated soils, which is one of the main pathways of introducing heavy metals to human food chain. Events related to soil and vegetable contamination, food safety and human health risks, e.g., rice and vegetables with elevated concentrations of cadmium, are often reported in the media in recent years. The Chinese government has recently developed a number of new policies for prevention of soils from further soil contamination, and remediation of contaminated soils. This presentation will provide a comprehensive review on heavy metal pollution in soils and its impacts on food security in China, and also summarize some new technologies for remediation of soils contaminated with heavy metals.展开更多
Ensuring global food security requires a sound understanding of climate and environmental controls on crop productivity.The majority of existing assessments have focused on physical climate vari-ables(i.e.,mean temper...Ensuring global food security requires a sound understanding of climate and environmental controls on crop productivity.The majority of existing assessments have focused on physical climate vari-ables(i.e.,mean temperature and precipitation),but less on the increasing climate extremes(e.g.,drought)and their interactions with increasing levels of tropospheric ozone(O3).Here we quantify the combined impacts of drought and O3 on China’s crop yield using a comprehensive,process-based agricultural eco-system model in conjunction with observational data.Our results indicate that climate change/variability and O3 together led to an annual mean reduction of crop yield by 10.0%or 55 million tons per year at the national level during 1981-2010.Crop yield shows a growing threat from severe episodic droughts and in-creasing O3 concentrations since 2000,with the largest crop yield losses occurring in northern China,causing serious concerns in food supply security in China.Our results imply that reducing tropospheric O3 levels is critical for securing crop production in coping with increasing frequency and severity of extreme climate events such as droughts.Improving air quality should be a core component of climate adaptation strategies.展开更多
The population growth and demand for high living standard not only increase food demand but also cause more loss of the limited cultivated land resources.Cultivated land loss caused by disasters and the implementation...The population growth and demand for high living standard not only increase food demand but also cause more loss of the limited cultivated land resources.Cultivated land loss caused by disasters and the implementation of the “Conversion of Cropland to Forest or Grassland” project make this situation even worse in China.Thus,there is a problem to be solved imminently that to what extent the cultivated land can guarantee food security of China.Based on time-series data on food production and cultivated land area from 1989 to 2003 and other research results,this paper constructs quality index of cultivated land according to different land quality.Regression models are adopted to predicate changes of main factors from 2004 to 2030,which have great effect on cultivated land area or grain productivity,and verify accuracy with coefficient of determination(R2).Nine results were got according to three scenarios of decreasing rate of population growth rate and three cases of urban and rural built-up area per capita.There results show that China’s food supply can only be maintained at a low to middle level of 370-410kg per capita,that is,China has enough land productivity to meet primary demand of food independently.However,it cannot reach the safe target of 500kg per capita if there is no breakthrough in breeding or no remarkable improvement of irrigation works,when the grain self-sufficiency maintains no less than 80%.To breed productive crops and to improve land productivity by meliorating low quality cultivated land are appropriate measures to shrink the gap between food demand and supply.The results may offer helpful information for the formulation of policies on population growth,land use,protection of cultivated land.展开更多
China’s food security has always been the top priority in China. As the huge increase of animal food consumption, the current agriculture system in China namely “grain farming”, whose major animal feed are grains, ...China’s food security has always been the top priority in China. As the huge increase of animal food consumption, the current agriculture system in China namely “grain farming”, whose major animal feed are grains, seems to meet a great challenge to ensure China’s food security in the future. Not only the current situation, but also the production capacity as developing grassland agriculture is analyzed in this paper. The results show that half of provinces don’t have enough grain to meet their various needs for grain, and the whole country’s potential of grain yield is reaching a limited position. On the other hand, implementing cereal-forage rotation on 20% of the total arable land and developing high productivity sown pastures on 3% of the total rangeland areas could create approximately 1.2 times Arable Land Equivalent Unit (ALEU) than ever. So changing the traditional agriculture system into Grassland Agro-Ecosystems is an effective way to insure China’s food security. It includes utilization of rangeland rationally, establishment of more sown pasture and implementation of cereal-pasture rotation system, increase livestock production, and use of arable land more efficiently.展开更多
The quantity and quality of farmland is the key factor determining grain production capacity, so protecting farmland has become the key to guaranteeing food security. I take Anshan City in Liaoning Province as the stu...The quantity and quality of farmland is the key factor determining grain production capacity, so protecting farmland has become the key to guaranteeing food security. I take Anshan City in Liaoning Province as the study area which has its own particularity in terms of protecting farmland. Based on the prediction of population, coupled with the relevant data concerning farmland area, the per unit area yield of grain, the prediction and analysis of the balance of supply and demand of farmland in Anshan City are conducted. The results show that in the year 2010, the maximum supply amount of farmland that the city can offer is 239 000 hm2, and in the year 2020 the maximum supply amount of farmland that the city can offer will be 238 000 hm2; in the year 2010, the maximum demand amount of farmland is 204 186.02 hm2, and in the year 2020 the maximum supply amount of farmland will be 226 409.61 hm2. So the supply amount of farmland that the city can offer can meet the need of grain production objective. Some problems concerning farmland protection are pointed out in order to provide beneficial exploration of the farmland protection based on the model of food security.展开更多
The northeastern China is an important commodity grain region in China,as well as a notable corn belt and major soybean producing area.It thus plays a significant role in the national food security system.However,larg...The northeastern China is an important commodity grain region in China,as well as a notable corn belt and major soybean producing area.It thus plays a significant role in the national food security system.However,large-scale land reclamation and non-optimum farming practices give rise to soil degradation in the region.This study analyzed the food security issues coupled with global climate change in the northeastern China during 1980–2000,which is the period of modern agriculture.The results of statistical data show that the arable land area shrank markedly in 1992,and then increased slowly,while food production generally continually increased.The stable grain yield was due to the increase of applied fertilizer and irrigated areas.Soil degradation in the northeastern China includes severe soil erosion,reduced soil nutrients,a thinner black soil layer,and deterioration of soil physical properties.The sustainable development of the northeastern China is influenced by natural-artificial binary disturbance factors which consist of meteorological conditions,climate changes,and terrain factors as well as soil physical and chemical properties.Interactions between the increasing temperature and decreasing precipitation in the region led to reduced accumulation of soil organic matter,which results in poor soil fertility.Human-induced factors,such as large-scale land reclamation and non-optimum farming practices,unsuitable cultivation systems,dredging,road building,illegal land occupation,and extensive use of fertilizers and pesticides,have led to increasingly severe soil erosion and destruction.Solutions to several problems of soil degradation in this region requiring urgent settlement are proposed.A need for clear and systematic recognition and recording of land use changes,land degradation,food production and climate change conditions is suggested,which would provide a reference for food security studies in the northeastern China.展开更多
After the publication of Mr. L. Brown's article and book Who Will Feed China [1,2] , a series of discussions have been evoked at home and abroad. The present paper will give an in depth analysis of his mai...After the publication of Mr. L. Brown's article and book Who Will Feed China [1,2] , a series of discussions have been evoked at home and abroad. The present paper will give an in depth analysis of his main point of view, including the positive and negative ones. Food security of China will also be dealt with as well.展开更多
Since ancient times, the Chinese government has always attached a great deal of importance to food security . However, the problems have been different at different times, with a variety of different solutions. For a ...Since ancient times, the Chinese government has always attached a great deal of importance to food security . However, the problems have been different at different times, with a variety of different solutions. For a considerably long period of time, production efficiency was low due to the planned economy. Food supply was in a constant state of shortage due to limited investment,展开更多
THROU GHOUT hroughout the ages, food security has been a top priority for ensuring the stability and prosperity of nations. Not surprisingly, therefore, the supply of food to more than a billion people is of paramount...THROU GHOUT hroughout the ages, food security has been a top priority for ensuring the stability and prosperity of nations. Not surprisingly, therefore, the supply of food to more than a billion people is of paramount importance on China’s national agenda. Great value has been attached to food self-sufficiency by the country.展开更多
Various land use and land cover(LULC)products have been produced over the past decade with the development of remote sensing technology.Despite the differences in LULC classification schemes,there is a lack of researc...Various land use and land cover(LULC)products have been produced over the past decade with the development of remote sensing technology.Despite the differences in LULC classification schemes,there is a lack of research on assessing the accuracy of their application to croplands in a unified framework.Thus,this study evaluated the spatial and area accuracies of cropland classification for four commonly used global LULC products(i.e.,MCD12Q1V6,GlobCover2009,FROM-GLC and GlobeLand30)based on the harmonised FAO criterion,and quantified the relationships between four factors(i.e.,slope,elevation,field size and crop system)and cropland classification agreement.The validation results indicated that MCD12Q1 and GlobeLand30 performed well in cropland classification regarding spatial consistency,with overall accuracies of 94.90 and 93.52%,respectively.The FROMGLC showed the worst performance,with an overall accuracy of 83.17%.Overlaying the cropland generated by the four global LULC products,we found the proportions of complete agreement and disagreement were 15.51 and 44.72% for the cropland classification,respectively.High consistency was mainly observed in the Northeast China Plain,the Huang-Huai-Hai Plain and the northern part of the Middle-lower Yangtze Plain,China.In contrast,low consistency was detected primarily on the eastern edge of the northern and semiarid region,the Yunnan-Guizhou Plateau and southern China.Field size was the most important factor for mapping cropland.For area accuracy,compared with China Statistical Yearbook data at the provincial scale,the accuracies of different products in descending order were:GlobeLand30,FROM-GLC,MCD12Q1,and GlobCover2009.The cropland classification schemes mainly caused large area deviations among the four products,and they also resulted in the different ranks of spatial accuracy and area accuracy among the four products.Our results can provide valuable suggestions for selecting cropland products at the national or provincial scale and help cropland mapping and reconstruction,which is essential for food security and crop management,so they can also contribute to achieving the Sustainable Development Goals issued by the United Nations.展开更多
Discussions about the U. S-Iraq war would last for years, but the war will surely produce long-term influences on international strategic structure and China’s security environment. The feature and influence of the w...Discussions about the U. S-Iraq war would last for years, but the war will surely produce long-term influences on international strategic structure and China’s security environment. The feature and influence of the war are determined by the America’ purposes in launching the war, which, in the common.展开更多
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...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.展开更多
With the rapid and continual growth of national economy, the gap between oil demand and supply keeps widening in China, therefore China will increasingly depend on imported oil. However, the world's oil and gas resou...With the rapid and continual growth of national economy, the gap between oil demand and supply keeps widening in China, therefore China will increasingly depend on imported oil. However, the world's oil and gas resources are unevenly distributed; global world's oil prices remain high; and over 70 percent of China's imported oil has to be shipped through the Malacca Strait. There are various ways to ensure China's oil security today, and the practical and feasible strategic option is to increase the discovery and production of domestic oil, raise energy efficiency and develop petroleum substitutes. Scientific and technological innovation is crucial both in new oil reserves discovery and production, energy conservation, and in the development of petroleum substitutes, establishment of a strategic oil reserve system and for environment protection. This indicates that China should take effective measures in investment strategy, fiscal policies, financing instruments, intellectual property protection, fostering talents and professionals, so as to establish its own scientific and technological innovation system in the petroleum industry and be better able to ensure oil security.展开更多
Against the background of economic globalization, the economy of many countries has been inevitably affected by the globle financial crisis. But the impact varies. China, as one of the leading countries in globalizati...Against the background of economic globalization, the economy of many countries has been inevitably affected by the globle financial crisis. But the impact varies. China, as one of the leading countries in globalization, the direct or indirect impact it suffered can be imagined. The Chinese government adopted a series of measures to deal with the financial crisis.展开更多
There is a Chinese saying that goes like this, when stormy weather comes, a giant dragon will rise. It is the feature of the present era. When China begins to rise, it will advance at an enormous inertial force. It ha...There is a Chinese saying that goes like this, when stormy weather comes, a giant dragon will rise. It is the feature of the present era. When China begins to rise, it will advance at an enormous inertial force. It has become the important factor that influences world future trend. In the meanwhile, changes in international situation also exerted increasing influence on China. Therefore it is of special significance to discuss and assess the international environment that China faces.展开更多
The US Asia-Pacific strategy is witnessing and will continue to witness new developments along with the evolution of its domestic politics as well as of the regional situation in Asia Pacific,particularly with Republi...The US Asia-Pacific strategy is witnessing and will continue to witness new developments along with the evolution of its domestic politics as well as of the regional situation in Asia Pacific,particularly with Republican candidate Donald展开更多
According to the cultivated area and grain yield during 1996-2008 and adopting the prediction method of farmland demand based on food security,five indexes,including the cultivated area,grain sown area,yearly food yie...According to the cultivated area and grain yield during 1996-2008 and adopting the prediction method of farmland demand based on food security,five indexes,including the cultivated area,grain sown area,yearly food yield per unit area,total population and per capita grain yield,are selected to analyze and predict the farmland demand in Yunnan Province in 2020.As the prediction results of each index show,the total population of Yunnan Province in 2020 will reach 51 464 000,significantly higher than the upper bound(50 million);the per capita food demand of Yunnan Province in 2020 will be 400 kg below the bottom line of the well-off type;food self-sufficient ratio will be respectively given the value of 100%,95% and 90% in three schemes;the prediction will be conducted with the yearly food yield per unit area at an average annual growth rate of 2.5% and 3.0% in two schemes;the rate of grain sowing in 2010 is determined to be 66%.As the prediction results of farmland demand show,there are totally 6 schemes about farmland demand in Yunnan Province obtained through analysis,among them,scheme Ⅰ is difficult to achieve,the prediction results of scheme Ⅳ,Ⅴ and Ⅵ are relatively low,which do not conform to the state policies and regulations to protect farmland and are also not conductive for ensuring the food security;scheme Ⅱ and Ⅲ are close to each other,but scheme Ⅲ obtains better prediction results and determines the farmland demand of Yunnan Province in 2020 based on food security to be 5.9 million so as to ensure the provincial food security and realize the "red line" of basic provincial food self-sufficiency.展开更多
基金financial supports from the National Natural Science Foundation of China (71333013 and 71503243)the Chinese Academy of Sciences (Y02015004 and GJHZ1312)+1 种基金the Tsinghua University, China (CIRS2016-03)the China Postdoctoral Science Foundation (2017M610710)
文摘China's food supply and demand have significant implications for both China's own national food security and that of the world. This study reviews China's food security prospects and their implications, focusing on international trade in the coming decade. The results show that China's policies for ensuring food security will be enhanced and China will move to sustainable agriculture. Most studies anticipate that China will increase its food and feed imports in the coming decade. China's overall food self-sufficiency is likely to fall from 94.5% in 2015 to around 91% by 2025. The greatest increases in imports are likely to be soybean, maize, sugar, and dairy products. However, within the production capacity of the major exporting countries and of many food-importing developing countries, China's additional imports of 3 to 5% of its total food consumption in the coming decade are unlikely to threaten global food security. Indeed, the projected imports of feed and several foods could provide opportunities for many exporting countries to expand their production and save global resources.
文摘Developing and developed countries alike are increasingly facing the dififcult question of how to feed more people amidst a host of emerging demographic, environmental, and health challenges. At the same time, in addition to food quantity, increased attention is being given to food quality attributes, in particular nutrition and safety. This is especially evident in China, where concerns are on the rise regarding the ability of China’s food production systems to deliver nutritious and safe food to a growing, urbanizing and more aflfuent population. These food and nutrition concerns come at a time when China is an increasingly inlfuential actor within the global food security network through activities such as production, consumption and trade. We argue that China has the opportunity to increase food and nutrition security both nationally and globally through a comprehensive policy agenda that focuses on institutional reforms, investments for and in agriculture, productive social safety nets, mutually beneifcial trade, and the exchange of know-how and technologies among developing countries and donors. This agenda will help China adapt its food production systems to the changing face of agriculture and to play a vital role in addressing the emerging challenges facing food and nutrition security within and beyond China in the coming decades.
文摘With the rapid economic expansion, environmental degradation has become increasingly sever during the past three decades. Soil pollutions associated with toxic organic compounds and heavy metals have been identified in China. The accumulation of heavy metals in soils and its impact on food safety is of increasing concern. It has been reported that more than 20 million ha of land have been contaminated with heavy metals that can result in the potential health risks to human beings and soil ecosystems. This can potentially jeopardize the food security in China. Accumulation of heavy metals in suburb and rural soils is closely related to many anthropogenic activities, such as application of fertilizers and pesticides, irrigation of wastewater, discharge of mining, improper disposal of metal containing wastes, land application of animal manures, sewage sludge and coal combustion residues. Arable crops and vegetables in suburb and rural can take up heavy metals from contaminated soils, which is one of the main pathways of introducing heavy metals to human food chain. Events related to soil and vegetable contamination, food safety and human health risks, e.g., rice and vegetables with elevated concentrations of cadmium, are often reported in the media in recent years. The Chinese government has recently developed a number of new policies for prevention of soils from further soil contamination, and remediation of contaminated soils. This presentation will provide a comprehensive review on heavy metal pollution in soils and its impacts on food security in China, and also summarize some new technologies for remediation of soils contaminated with heavy metals.
基金This study has been supported by NASA(NNG04GM39C,NNX08AL73G),NSF(1137306)Chinese Academy of Sciences(KFJ-EW STS 002)+3 种基金the National Basic Research Program of China(No.2010CB950900No.2002CB412500)the U.S.Department of Energy(DE-FG02-94ER61937)the U.S.Environmental Protection Agency(XA-83600001-1)。
文摘Ensuring global food security requires a sound understanding of climate and environmental controls on crop productivity.The majority of existing assessments have focused on physical climate vari-ables(i.e.,mean temperature and precipitation),but less on the increasing climate extremes(e.g.,drought)and their interactions with increasing levels of tropospheric ozone(O3).Here we quantify the combined impacts of drought and O3 on China’s crop yield using a comprehensive,process-based agricultural eco-system model in conjunction with observational data.Our results indicate that climate change/variability and O3 together led to an annual mean reduction of crop yield by 10.0%or 55 million tons per year at the national level during 1981-2010.Crop yield shows a growing threat from severe episodic droughts and in-creasing O3 concentrations since 2000,with the largest crop yield losses occurring in northern China,causing serious concerns in food supply security in China.Our results imply that reducing tropospheric O3 levels is critical for securing crop production in coping with increasing frequency and severity of extreme climate events such as droughts.Improving air quality should be a core component of climate adaptation strategies.
基金Under the auspices of the National Natural Science Foundation of China (No. 40671007), Innovation Project of Institute of Geographical Sciences and Natural Resources Research, CAS
文摘The population growth and demand for high living standard not only increase food demand but also cause more loss of the limited cultivated land resources.Cultivated land loss caused by disasters and the implementation of the “Conversion of Cropland to Forest or Grassland” project make this situation even worse in China.Thus,there is a problem to be solved imminently that to what extent the cultivated land can guarantee food security of China.Based on time-series data on food production and cultivated land area from 1989 to 2003 and other research results,this paper constructs quality index of cultivated land according to different land quality.Regression models are adopted to predicate changes of main factors from 2004 to 2030,which have great effect on cultivated land area or grain productivity,and verify accuracy with coefficient of determination(R2).Nine results were got according to three scenarios of decreasing rate of population growth rate and three cases of urban and rural built-up area per capita.There results show that China’s food supply can only be maintained at a low to middle level of 370-410kg per capita,that is,China has enough land productivity to meet primary demand of food independently.However,it cannot reach the safe target of 500kg per capita if there is no breakthrough in breeding or no remarkable improvement of irrigation works,when the grain self-sufficiency maintains no less than 80%.To breed productive crops and to improve land productivity by meliorating low quality cultivated land are appropriate measures to shrink the gap between food demand and supply.The results may offer helpful information for the formulation of policies on population growth,land use,protection of cultivated land.
文摘China’s food security has always been the top priority in China. As the huge increase of animal food consumption, the current agriculture system in China namely “grain farming”, whose major animal feed are grains, seems to meet a great challenge to ensure China’s food security in the future. Not only the current situation, but also the production capacity as developing grassland agriculture is analyzed in this paper. The results show that half of provinces don’t have enough grain to meet their various needs for grain, and the whole country’s potential of grain yield is reaching a limited position. On the other hand, implementing cereal-forage rotation on 20% of the total arable land and developing high productivity sown pastures on 3% of the total rangeland areas could create approximately 1.2 times Arable Land Equivalent Unit (ALEU) than ever. So changing the traditional agriculture system into Grassland Agro-Ecosystems is an effective way to insure China’s food security. It includes utilization of rangeland rationally, establishment of more sown pasture and implementation of cereal-pasture rotation system, increase livestock production, and use of arable land more efficiently.
文摘The quantity and quality of farmland is the key factor determining grain production capacity, so protecting farmland has become the key to guaranteeing food security. I take Anshan City in Liaoning Province as the study area which has its own particularity in terms of protecting farmland. Based on the prediction of population, coupled with the relevant data concerning farmland area, the per unit area yield of grain, the prediction and analysis of the balance of supply and demand of farmland in Anshan City are conducted. The results show that in the year 2010, the maximum supply amount of farmland that the city can offer is 239 000 hm2, and in the year 2020 the maximum supply amount of farmland that the city can offer will be 238 000 hm2; in the year 2010, the maximum demand amount of farmland is 204 186.02 hm2, and in the year 2020 the maximum supply amount of farmland will be 226 409.61 hm2. So the supply amount of farmland that the city can offer can meet the need of grain production objective. Some problems concerning farmland protection are pointed out in order to provide beneficial exploration of the farmland protection based on the model of food security.
基金Under the auspices of National Natural Science Foundation of China(No.41171335)Hydroinformatics for Ecohydrology Program of United Nations Educational+2 种基金Scientific and Cultural Organization(UNESCO)China Postdoctoral Science Foundation(No.20110490447)Beijing Postdoctoral Science Foundation(No.2012-49)
文摘The northeastern China is an important commodity grain region in China,as well as a notable corn belt and major soybean producing area.It thus plays a significant role in the national food security system.However,large-scale land reclamation and non-optimum farming practices give rise to soil degradation in the region.This study analyzed the food security issues coupled with global climate change in the northeastern China during 1980–2000,which is the period of modern agriculture.The results of statistical data show that the arable land area shrank markedly in 1992,and then increased slowly,while food production generally continually increased.The stable grain yield was due to the increase of applied fertilizer and irrigated areas.Soil degradation in the northeastern China includes severe soil erosion,reduced soil nutrients,a thinner black soil layer,and deterioration of soil physical properties.The sustainable development of the northeastern China is influenced by natural-artificial binary disturbance factors which consist of meteorological conditions,climate changes,and terrain factors as well as soil physical and chemical properties.Interactions between the increasing temperature and decreasing precipitation in the region led to reduced accumulation of soil organic matter,which results in poor soil fertility.Human-induced factors,such as large-scale land reclamation and non-optimum farming practices,unsuitable cultivation systems,dredging,road building,illegal land occupation,and extensive use of fertilizers and pesticides,have led to increasingly severe soil erosion and destruction.Solutions to several problems of soil degradation in this region requiring urgent settlement are proposed.A need for clear and systematic recognition and recording of land use changes,land degradation,food production and climate change conditions is suggested,which would provide a reference for food security studies in the northeastern China.
文摘After the publication of Mr. L. Brown's article and book Who Will Feed China [1,2] , a series of discussions have been evoked at home and abroad. The present paper will give an in depth analysis of his main point of view, including the positive and negative ones. Food security of China will also be dealt with as well.
文摘Since ancient times, the Chinese government has always attached a great deal of importance to food security . However, the problems have been different at different times, with a variety of different solutions. For a considerably long period of time, production efficiency was low due to the planned economy. Food supply was in a constant state of shortage due to limited investment,
文摘THROU GHOUT hroughout the ages, food security has been a top priority for ensuring the stability and prosperity of nations. Not surprisingly, therefore, the supply of food to more than a billion people is of paramount importance on China’s national agenda. Great value has been attached to food self-sufficiency by the country.
基金supported by the National Key Research and Development Program of China(2022YFB3903503)the National Natural Science Foundation of China(U1901601)the Science and Technology Project of the Department of Education of Jiangxi Province,China(GJJ210541)。
文摘Various land use and land cover(LULC)products have been produced over the past decade with the development of remote sensing technology.Despite the differences in LULC classification schemes,there is a lack of research on assessing the accuracy of their application to croplands in a unified framework.Thus,this study evaluated the spatial and area accuracies of cropland classification for four commonly used global LULC products(i.e.,MCD12Q1V6,GlobCover2009,FROM-GLC and GlobeLand30)based on the harmonised FAO criterion,and quantified the relationships between four factors(i.e.,slope,elevation,field size and crop system)and cropland classification agreement.The validation results indicated that MCD12Q1 and GlobeLand30 performed well in cropland classification regarding spatial consistency,with overall accuracies of 94.90 and 93.52%,respectively.The FROMGLC showed the worst performance,with an overall accuracy of 83.17%.Overlaying the cropland generated by the four global LULC products,we found the proportions of complete agreement and disagreement were 15.51 and 44.72% for the cropland classification,respectively.High consistency was mainly observed in the Northeast China Plain,the Huang-Huai-Hai Plain and the northern part of the Middle-lower Yangtze Plain,China.In contrast,low consistency was detected primarily on the eastern edge of the northern and semiarid region,the Yunnan-Guizhou Plateau and southern China.Field size was the most important factor for mapping cropland.For area accuracy,compared with China Statistical Yearbook data at the provincial scale,the accuracies of different products in descending order were:GlobeLand30,FROM-GLC,MCD12Q1,and GlobCover2009.The cropland classification schemes mainly caused large area deviations among the four products,and they also resulted in the different ranks of spatial accuracy and area accuracy among the four products.Our results can provide valuable suggestions for selecting cropland products at the national or provincial scale and help cropland mapping and reconstruction,which is essential for food security and crop management,so they can also contribute to achieving the Sustainable Development Goals issued by the United Nations.
文摘Discussions about the U. S-Iraq war would last for years, but the war will surely produce long-term influences on international strategic structure and China’s security environment. The feature and influence of the war are determined by the America’ purposes in launching the war, which, in the common.
基金Supported by Humanities and Social Sciences Key Program from Hubei Provincial Department of Education(15D024)Social Science Fund Program from Yangtze University(2014csy006)Open Fund General Program from Hubei Collaborative Innovation Centre for Grain Industry(MS2015004)
文摘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.
文摘With the rapid and continual growth of national economy, the gap between oil demand and supply keeps widening in China, therefore China will increasingly depend on imported oil. However, the world's oil and gas resources are unevenly distributed; global world's oil prices remain high; and over 70 percent of China's imported oil has to be shipped through the Malacca Strait. There are various ways to ensure China's oil security today, and the practical and feasible strategic option is to increase the discovery and production of domestic oil, raise energy efficiency and develop petroleum substitutes. Scientific and technological innovation is crucial both in new oil reserves discovery and production, energy conservation, and in the development of petroleum substitutes, establishment of a strategic oil reserve system and for environment protection. This indicates that China should take effective measures in investment strategy, fiscal policies, financing instruments, intellectual property protection, fostering talents and professionals, so as to establish its own scientific and technological innovation system in the petroleum industry and be better able to ensure oil security.
文摘Against the background of economic globalization, the economy of many countries has been inevitably affected by the globle financial crisis. But the impact varies. China, as one of the leading countries in globalization, the direct or indirect impact it suffered can be imagined. The Chinese government adopted a series of measures to deal with the financial crisis.
文摘There is a Chinese saying that goes like this, when stormy weather comes, a giant dragon will rise. It is the feature of the present era. When China begins to rise, it will advance at an enormous inertial force. It has become the important factor that influences world future trend. In the meanwhile, changes in international situation also exerted increasing influence on China. Therefore it is of special significance to discuss and assess the international environment that China faces.
文摘The US Asia-Pacific strategy is witnessing and will continue to witness new developments along with the evolution of its domestic politics as well as of the regional situation in Asia Pacific,particularly with Republican candidate Donald
基金Supported by National Natural Science Foundation of China(40861014)the Second National Land Survey of Yunnan Province
文摘According to the cultivated area and grain yield during 1996-2008 and adopting the prediction method of farmland demand based on food security,five indexes,including the cultivated area,grain sown area,yearly food yield per unit area,total population and per capita grain yield,are selected to analyze and predict the farmland demand in Yunnan Province in 2020.As the prediction results of each index show,the total population of Yunnan Province in 2020 will reach 51 464 000,significantly higher than the upper bound(50 million);the per capita food demand of Yunnan Province in 2020 will be 400 kg below the bottom line of the well-off type;food self-sufficient ratio will be respectively given the value of 100%,95% and 90% in three schemes;the prediction will be conducted with the yearly food yield per unit area at an average annual growth rate of 2.5% and 3.0% in two schemes;the rate of grain sowing in 2010 is determined to be 66%.As the prediction results of farmland demand show,there are totally 6 schemes about farmland demand in Yunnan Province obtained through analysis,among them,scheme Ⅰ is difficult to achieve,the prediction results of scheme Ⅳ,Ⅴ and Ⅵ are relatively low,which do not conform to the state policies and regulations to protect farmland and are also not conductive for ensuring the food security;scheme Ⅱ and Ⅲ are close to each other,but scheme Ⅲ obtains better prediction results and determines the farmland demand of Yunnan Province in 2020 based on food security to be 5.9 million so as to ensure the provincial food security and realize the "red line" of basic provincial food self-sufficiency.