[Objective] The study aimed to confirm difference of nitrogen uptake and used efficiency with different nitrogen use efficiency for grain output (NUEg) types of indica rice.[Method] 88 and 122 conventional indica rice...[Objective] The study aimed to confirm difference of nitrogen uptake and used efficiency with different nitrogen use efficiency for grain output (NUEg) types of indica rice.[Method] 88 and 122 conventional indica rice cultivars were solution-cultured in 2001 and 2002, respectively. Dry matter weight (including root system, culm and sheath, leaves, panicle), nitrogen content of different organs, yield and its components were measured. The tested rice cultivars were classified into 6 types (i.e. A, B, C, D, E and F, A was the lowest, and F was the highest) based on their NUEg level by the MinSSw method.[Result](1)Difference of NUEg of the cultivars used in this study were very large; (2) No significant difference of N content at heading stage was observed among different NUEg types of indica rice. In the cultivars with higher NUEg, however, N content in leaf, stem-sheath and entire rice plant were lower at mature stage. (3)Cultivars with higher NUEg were characterized with lower N uptake before heading and at mature stage; (4) Cultivars with higher NUEg were characterized with higher N use efficiency in biomass production and harvest index. [Conclusion] The cultivars with higher NUEg showed lower N uptake and N content, while nitrogen use efficiency was higher.展开更多
This paper estimates a stochastic frontier function using a panel data set that includes 4 961 farmer households for the period of 2005-2009 to decompose the growth of grain production and the total factor productivi...This paper estimates a stochastic frontier function using a panel data set that includes 4 961 farmer households for the period of 2005-2009 to decompose the growth of grain production and the total factor productivity （TFP） growth at the farmer level. The empirical results show that the major contributor to the grain output growth for farmers is input growth and that its average contribution accounts for 60.92% of farmer’s grain production growth in the period of 2006-2009, whereas the average contributions sourced from TFP growth and residuals are only 17.30 and 21.78%, respectively. The growth of intermediate inputs is a top contributor with an average contribution of 44.46%, followed by the planted area （18.16%）, investment in fixed assets （1.05%）, and labor input （-2.75%）, indicating that the contribution from the farmer’s input growth is mainly due to the growth of intermediate inputs and that the decline in labor inputs has become an obstacle for farmers in seeking grain output growth. Among the elements consisting of TFP growth, the contribution of technical progress is the largest （32.04%）, followed by grain subsidies （8.55%）, the average monthly temperature （4.26%）, the average monthly precipitation （-0.88%）, the adjusted scale effect （-5.66%）, and growth in technical efficiency （-21.01%）. In general, the contribution of climate factors and agricultural policy factor are positive and significant.展开更多
Although there has been rapid rural-urban migration in rural China since the 1980s, the total grain production of China saw a continuous increase. As of today, the relationship between labor migration and grain output...Although there has been rapid rural-urban migration in rural China since the 1980s, the total grain production of China saw a continuous increase. As of today, the relationship between labor migration and grain output growth remains partial and contradictory. The main aim of this empirical study is to examine some specific measures adopted by peasants to deal with labor shortage and maintain grain output growth. Using tracking survey, participatory rural appraisal methods, and land plot investigation, we investigate 274 households and 1405 arable land plots in four villages in two stages in Jinchuan county, southwestern China. The results show that continuous emigration of labor from the four villages caused the abandon- ment of a small amount of land, decreased labor intensity, and reduced multiple cropping index, shifting from ＂corn-wheat＂ multiple cropping pattern to the ＂corn＂ cropping pattern, which means labor shortage in some households. At the same time, owing to surplus labor in the villages, the peasants utilize a series of means to offset the negative impacts of labor migration on grain output, such as cropland transfer, labor exchange in the busy seasons, and the substitution of capital and technology for labor. The econometric analysis also shows that labor migration boosts grain production. This study provides a reasonable explanation of grain output growth under rural-urban migration.展开更多
This article selects 8 main factors(the number of rural employees,total power of agricultural machinery,effective irrigation area of crops,growing area of grain crops,fertilizer consumption,electricity consumption in ...This article selects 8 main factors(the number of rural employees,total power of agricultural machinery,effective irrigation area of crops,growing area of grain crops,fertilizer consumption,electricity consumption in rural areas,area affected and area covered) as the factors influencing grain output,and offers the method of determining weight of factors influencing grain output using entropy weight method.According to the relevant data in the period 1985-2005,we analyze the weight of factors influencing grain output in China by example.The results show that the electricity consumption in rural areas has the greatest impact on grain output,followed by total power of agricultural machinery,fertilizer consumption and area covered.To increase grain output,we must enhance the degree of mechanization,free people from the former process of direct cultivation,strengthen water conservancy construction,and do a good job in disaster prevention and mitigation.展开更多
Under the support of National Natural Science Foundation of China including international cooperative research project, key project and other project, professor Chen Xikang from Academy of Mathematics and Systems Scie...Under the support of National Natural Science Foundation of China including international cooperative research project, key project and other project, professor Chen Xikang from Academy of Mathematics and Systems Science under the Chinese Academy of Sciences, together with his colleagues, put forward in-put-occupancy-output technique and then used it in national grain output prediction approach. The main achievements are as follows:展开更多
China is a large agricultural and the most populous country, so it is a crucial importance for the food security. The basic situation of food in our country is self-sufficiency, a certain amount of imports and reserve...China is a large agricultural and the most populous country, so it is a crucial importance for the food security. The basic situation of food in our country is self-sufficiency, a certain amount of imports and reserves. The output of grain in our country has increased annually, however, as a result of policy adjustments and other factors like environmental pollution, together with a large population base and the trend of excessively popu- lous growth, the growth of grain output is relatively slow, which will be harmful for our grain security as well as the healthy development of the na- tional economy. In this case, several solutions could be tried, such as improving the level of science and technology, adjusting industrial policies and controlling environmental pollution. Besides, we ought to strongly advocate thrifty behavior to increase income and reduce expenditure.展开更多
This paper examines the changing regional distribution of grain production in China. Based on the analysis of data from county statistics for the period 2000-2003, major differences in the main grain-output regions in...This paper examines the changing regional distribution of grain production in China. Based on the analysis of data from county statistics for the period 2000-2003, major differences in the main grain-output regions in China can be observed. The main grain-producing areas have shifted from the south to the north of China. New grain production regions have been also added to westem China since the late 1990s. The per capita grain consumption in one third of China＇s main grain-producing counties has fallen below 400 kg; most of these areas are located in southern China. In the new millennium, Northeast China, the central-south North China, and the add and semi-arid regions of Northwest China produced three quarters of the surplus grains. Most of these areas are located in regions susceptible to environmental change. The amount of grain production in these regions shows high fluctuations. It is argued here that fi.trther studies of recent environmental changes as well as a risk assessment of China＇s food security in main grain-output regions are needed.展开更多
This far stern difficulhes and challenges fatal by the dev ofadn P in etna. to the bac national snon of China and the of and min the world market, China must meet the and Inainly by her own production. Using the input...This far stern difficulhes and challenges fatal by the dev ofadn P in etna. to the bac national snon of China and the of and min the world market, China must meet the and Inainly by her own production. Using the input output and system edence metal, this makesa foast abbot China’s glain output, grain and allsupport rate in the year 2030.展开更多
In this paper, we first look back at China’s grain production since reform and opening up and review the main factors of grain production at different stages. Secondly we find that the improvement of the per unit yie...In this paper, we first look back at China’s grain production since reform and opening up and review the main factors of grain production at different stages. Secondly we find that the improvement of the per unit yield has become a major factor in the increase of grain production, and that corn has become a major grain production support variety; compared with the other varieties, paddy rice is most vulnerable in production; grain production has increasingly become dependant on scientific and technological progress and the role of infrastructure. Thirdly, the transformation of low-yielding fields in the future, the development of reserve land resources and acceleration of scientific and technological progress – these factors together promote China's great potential for grain production; but through adjusting variety structure to promote grain production is nearly impossible. Finally, the main constraints of China’s future grain production are as follows: reduction of arable land and water shortages is becoming increasingly constrained; agricultural comparative advantage is low; opportunity cost is high and accelerating at the same time; and the uncertainties of (1) whether the agricultural inputs by government at all levels of can significantly increase the intensity; (2) whether support of the reform of grain production and systems can achieve breakthrough; and (3) whether the risk of the development of grain production can be effectively prevented. On this basis, we draw the relevant conclusions and policy recommendations.展开更多
基金Supported by the National Natural Science Foundation of China(30270777,30471013)~~
文摘[Objective] The study aimed to confirm difference of nitrogen uptake and used efficiency with different nitrogen use efficiency for grain output (NUEg) types of indica rice.[Method] 88 and 122 conventional indica rice cultivars were solution-cultured in 2001 and 2002, respectively. Dry matter weight (including root system, culm and sheath, leaves, panicle), nitrogen content of different organs, yield and its components were measured. The tested rice cultivars were classified into 6 types (i.e. A, B, C, D, E and F, A was the lowest, and F was the highest) based on their NUEg level by the MinSSw method.[Result](1)Difference of NUEg of the cultivars used in this study were very large; (2) No significant difference of N content at heading stage was observed among different NUEg types of indica rice. In the cultivars with higher NUEg, however, N content in leaf, stem-sheath and entire rice plant were lower at mature stage. (3)Cultivars with higher NUEg were characterized with lower N uptake before heading and at mature stage; (4) Cultivars with higher NUEg were characterized with higher N use efficiency in biomass production and harvest index. [Conclusion] The cultivars with higher NUEg showed lower N uptake and N content, while nitrogen use efficiency was higher.
基金supported by Japan International Research Center for Agricultural Sciences
文摘This paper estimates a stochastic frontier function using a panel data set that includes 4 961 farmer households for the period of 2005-2009 to decompose the growth of grain production and the total factor productivity （TFP） growth at the farmer level. The empirical results show that the major contributor to the grain output growth for farmers is input growth and that its average contribution accounts for 60.92% of farmer’s grain production growth in the period of 2006-2009, whereas the average contributions sourced from TFP growth and residuals are only 17.30 and 21.78%, respectively. The growth of intermediate inputs is a top contributor with an average contribution of 44.46%, followed by the planted area （18.16%）, investment in fixed assets （1.05%）, and labor input （-2.75%）, indicating that the contribution from the farmer’s input growth is mainly due to the growth of intermediate inputs and that the decline in labor inputs has become an obstacle for farmers in seeking grain output growth. Among the elements consisting of TFP growth, the contribution of technical progress is the largest （32.04%）, followed by grain subsidies （8.55%）, the average monthly temperature （4.26%）, the average monthly precipitation （-0.88%）, the adjusted scale effect （-5.66%）, and growth in technical efficiency （-21.01%）. In general, the contribution of climate factors and agricultural policy factor are positive and significant.
基金National Natural Science Foundation of China,No.41071066,No.41571093Strategic Priority Research Program of the Chinese Academy of Sciences,No.XDB03030500
文摘Although there has been rapid rural-urban migration in rural China since the 1980s, the total grain production of China saw a continuous increase. As of today, the relationship between labor migration and grain output growth remains partial and contradictory. The main aim of this empirical study is to examine some specific measures adopted by peasants to deal with labor shortage and maintain grain output growth. Using tracking survey, participatory rural appraisal methods, and land plot investigation, we investigate 274 households and 1405 arable land plots in four villages in two stages in Jinchuan county, southwestern China. The results show that continuous emigration of labor from the four villages caused the abandon- ment of a small amount of land, decreased labor intensity, and reduced multiple cropping index, shifting from ＂corn-wheat＂ multiple cropping pattern to the ＂corn＂ cropping pattern, which means labor shortage in some households. At the same time, owing to surplus labor in the villages, the peasants utilize a series of means to offset the negative impacts of labor migration on grain output, such as cropland transfer, labor exchange in the busy seasons, and the substitution of capital and technology for labor. The econometric analysis also shows that labor migration boosts grain production. This study provides a reasonable explanation of grain output growth under rural-urban migration.
文摘This article selects 8 main factors(the number of rural employees,total power of agricultural machinery,effective irrigation area of crops,growing area of grain crops,fertilizer consumption,electricity consumption in rural areas,area affected and area covered) as the factors influencing grain output,and offers the method of determining weight of factors influencing grain output using entropy weight method.According to the relevant data in the period 1985-2005,we analyze the weight of factors influencing grain output in China by example.The results show that the electricity consumption in rural areas has the greatest impact on grain output,followed by total power of agricultural machinery,fertilizer consumption and area covered.To increase grain output,we must enhance the degree of mechanization,free people from the former process of direct cultivation,strengthen water conservancy construction,and do a good job in disaster prevention and mitigation.
文摘Under the support of National Natural Science Foundation of China including international cooperative research project, key project and other project, professor Chen Xikang from Academy of Mathematics and Systems Science under the Chinese Academy of Sciences, together with his colleagues, put forward in-put-occupancy-output technique and then used it in national grain output prediction approach. The main achievements are as follows:
文摘China is a large agricultural and the most populous country, so it is a crucial importance for the food security. The basic situation of food in our country is self-sufficiency, a certain amount of imports and reserves. The output of grain in our country has increased annually, however, as a result of policy adjustments and other factors like environmental pollution, together with a large population base and the trend of excessively popu- lous growth, the growth of grain output is relatively slow, which will be harmful for our grain security as well as the healthy development of the na- tional economy. In this case, several solutions could be tried, such as improving the level of science and technology, adjusting industrial policies and controlling environmental pollution. Besides, we ought to strongly advocate thrifty behavior to increase income and reduce expenditure.
基金National Natural Science Foundation of China, No.40571165 No.40271115
文摘This paper examines the changing regional distribution of grain production in China. Based on the analysis of data from county statistics for the period 2000-2003, major differences in the main grain-output regions in China can be observed. The main grain-producing areas have shifted from the south to the north of China. New grain production regions have been also added to westem China since the late 1990s. The per capita grain consumption in one third of China＇s main grain-producing counties has fallen below 400 kg; most of these areas are located in southern China. In the new millennium, Northeast China, the central-south North China, and the add and semi-arid regions of Northwest China produced three quarters of the surplus grains. Most of these areas are located in regions susceptible to environmental change. The amount of grain production in these regions shows high fluctuations. It is argued here that fi.trther studies of recent environmental changes as well as a risk assessment of China＇s food security in main grain-output regions are needed.
文摘This far stern difficulhes and challenges fatal by the dev ofadn P in etna. to the bac national snon of China and the of and min the world market, China must meet the and Inainly by her own production. Using the input output and system edence metal, this makesa foast abbot China’s glain output, grain and allsupport rate in the year 2030.
文摘In this paper, we first look back at China’s grain production since reform and opening up and review the main factors of grain production at different stages. Secondly we find that the improvement of the per unit yield has become a major factor in the increase of grain production, and that corn has become a major grain production support variety; compared with the other varieties, paddy rice is most vulnerable in production; grain production has increasingly become dependant on scientific and technological progress and the role of infrastructure. Thirdly, the transformation of low-yielding fields in the future, the development of reserve land resources and acceleration of scientific and technological progress – these factors together promote China's great potential for grain production; but through adjusting variety structure to promote grain production is nearly impossible. Finally, the main constraints of China’s future grain production are as follows: reduction of arable land and water shortages is becoming increasingly constrained; agricultural comparative advantage is low; opportunity cost is high and accelerating at the same time; and the uncertainties of (1) whether the agricultural inputs by government at all levels of can significantly increase the intensity; (2) whether support of the reform of grain production and systems can achieve breakthrough; and (3) whether the risk of the development of grain production can be effectively prevented. On this basis, we draw the relevant conclusions and policy recommendations.
