The changing regional distribution of grain production in China in the 21st century

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.

Extreme meteorological disaster effects on grain production in Jilin Province, China

Extreme meteorological disaster effects on grain production is mainly determined by the interaction between danger degree of hazard-induced factors and vulnerability degree of hazard-affected bodies. This paper treats physical exposure, sensitivity of the response to the impact, and capabilities of disaster prevention and mitigation as a complex system for vulnerability degree of hazard-affected bodies, which included the external shocks and internal stability mechanism. Hazard-induced factors generate external shocks on grain production systems though exposure and sensitivity of hazard-affected body, and the result can be represented as affected area of grain. By quantile regression model, this paper depicts the quantitative relationship between hazard-induced factors of extreme meteorological disaster and the affected area in the tail of the distri- bution. Moreover, the model of production function have also been utilized to expound and prove the quantitative relationship between the affected area and final grain output under the internal stability mechanism of the agricultural natural resources endowment, the input factors of agricultural production, and the capacity of defending disaster. The empirical study of this paper finds that impact effects of drought disaster to grain production system presents the basic law of ＂diminishing marginal loss＂, namely, with the constant improvement of the grade of drought, marginal affected area produced by hazard-induced factors will be diminishing. Scenario simulation of extreme drought impact shows that by every 1% reduction in summer average rainfall, grain production of Jilin Province will fell 0.2549% and cut production of grain 14.69% eventually. In re- sponse to ensure China＇s grain security, the construction of the long-term mechanism of agricultural disaster prevention and mitigation, and the innovation of agricultural risk management tools should be also included in the agricultural policy agenda.

Distribution, residence time, autotrophic production, and heterotrophic removal of DOP in the Mirs Bay, northern South China Sea

The importance of dissolved organic phosphorus(DOP) as a potential nutrient source for primary producers in marine systems has been recognized for up to eight decades, but currently, the understanding of the biogeochemistry of DOP is in its infancy. In the present study, monthly data between 2000 and 2014 were used to analyze the temporal and spatial distributions of DOP in the Mir Bay, the northern South China Sea. The DOP residence time(TDOP) was also investigated using a simple regression analysis in combination with chlorophyll a(Chl a) measurements while excess DOP(ΔDOP), produced by the biogeochemical processes of autotrophic production and heterotrophic removal, was determined using a two-component mixing mass-balance model in combination with salinity measurements. The results showed that the DOP concentration was(0.017±0.010) mg/L higher in the surface-water compared with the bottom-water and higher in the inner Tolo Harbour and waters adjacent to Shatoujiao compared with the main zone of the bay. Although seasonal changes and annual variability in the DOP were small, the surface DOP concentration was higher in the wet season(April–September)than in the dry season(October–March) due to the impacts of seaward discharges and atmospheric deposition into the bay. Measurement and regression results showed that the DOP release rate from phytoplankton production was about 1.83(gP)/(gChl a) and the TDOP was about 7 d, which implied that the DOP cycle in the bay was rapid. The ΔDOP was calculated from the model to be about 0.000 mg/L in the main zone of the bay and about 0.002 mg/L in the inner Tolo Harbour and waters adjacent to Shaotoujiao, suggesting that the autotrophic production of DOP was almost balanced by the heterotrophic removal in the main zone of the bay and dominated in the inner Tolo Harbour and waters adjacent to Shaotoujiao. In conclusion, the Mirs Bay is very productive and fairly heterotrophic.

Decoupling of grain production from land resources in China:Land use reduced but fertilizer and water use intensified

The issue of grain security in China is attracting global attention. In this research, we analyze the relationship between grain production and cropland resources. The results indicate that decoupling of these two variables is realized at the national level, and fertilizer and irrigation play increasingly important roles in grain production. Of the 18 principal grain producing provinces, seven showed absolute decoupling, three showed relative decoupling, five showed quasi-relative decoupling, and three provinces showed coupling. Also, the relative importance of fertilizer and irrigation in grain production is different among the four different modes of coupling/decoupling.

Grain Production and Cultivated Land in China

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Forecast of Grain Production of China during the Twelfth Five-Year Plan Period

According to the latest revised agricultural economic statistical data in China Statistical Yearbook-2010,by selecting and establishing the square root-treated grey model,the empirical analysis and forecast research on the grain output of China from 2011 to 2015 are conducted.The results show that the grain output of China in 2011 will reach 557.739 million tons,and it will break through 600 million tons at 605.617 million tons in 2015.The persistent and stable grain output will ensure that the national economy develops in normal during the twelfth five-year plan period and remit the world grain crisis efficiently;meanwhile,the problem of exorbitant grain prices should be remitted in some level.

Spatio-temporal distribution of net primary productivity along the northeast China transect and its response to climatic change

An improved Carnegie Ames Stanford Approach model （CASA model） was used to estimate the net primary productivity （NPP） of the Northeast China Transect （NECT） every month from 1982 to 2000. The spatial-temporal distribution of NPP along NECT and its response to climatic change were also analyzed. Results showed that the change tendency of NPP spatial distribution in NECT is quite similar to that of precipitation and their spatial correlation coefficient is up to 0.84 （P 〈 0.01）. The inter-annual variation of NPP in NECT is mainly affected by the change of the aestival NPP every year, which accounts for 67.6% of the inter-annual increase in NPP and their spatial correlation coefficient is 0.95 （P 〈 0.01）. The NPP in NECT is mainly cumulated between May and September, which accounts for 89.8% of the annual NPP. The NPP in summer （June to August） accounts for 65.9% of the annual NPP and is the lowest in winter. Recent climate changes have enhanced plant growth in NECT. The mean NPP increased 14.3% from 1980s to 1990s. The inter-annual linear trend of NPP is 4.6 gC·m^-2·a^-1, and the relative trend is 1.17%, which owns mainly to the increasing temperature.

Sediment distribution characteristics and environment evolution within 100 years in western Laizhou Bay,Bohai Sea,China

This study is about the reconstruction of fluvial origins based on the grain size distribution of sediment deposits in the western Laizhou Bay,Bohai Sea,China.Thirteen sediment cores were selected to research sediment characteristics using the Sahu discriminant formula,C-M diagram,and Folk method.The results showed:(1)Bounded by the Guangli River estuary,the north sediment was affected by the water and sand flowing from the Yellow River during different periods.The south sediment came from multi-source rivers under the influence of the Xiaoqing River,Mihe River,and other coastal rivers;(2)the deposited sediments were dated by a clear historical record of the branched channel oscillation combined with the characteristics of the diversion channel,erosion,and regression.The subaqueous delta overlapped during several Yellow River channel runs(1897–1904,1929–1934,1938–1947,1947–1953,1976–1996)and the deposited sediment facies changed(the north tidal flat-abandoned subaqueous delta-lateral delta-delta front);(3)the deposited sediment characteristics can be revealed by studying the branched diversions of the Yellow River and coastal multi-rivers of the past one hundred years.

Characteristics and Advantages of Regional Grain Production in Guangxi Zhuang Autonomous Region of China

According to the latest Land Use Planning of Guangxi Zhuang Autonomous Region, Guangxi is divided into five regions, which are eastern Guangxi, western Guangxi, southern Guangxi, northern Guangxi, and central Guangxi. Regional variation characteristics of grain production are introduced from two aspects of the decline of grain sowing area and the increase of grain output. According to the data in Guangxi Statistical Yearbook, comparative advantages of regional grain production in Guangxi Zhuang Autonomous Region are analyzed by the method of Comprehensive Comparative Dominance Index. Result shows that eastern Guangxi and northern Guangxi have the maximum comprehensive dominance indices with the minimum increasing amount of dominance indices. Their advantages in grain production are gradually diminished; and the grain production center is moving to central Guangxi and southern Guangxi. In order to solve the problems in grain production, Guangxi should make full use of the comparative advantage in agricultural production, carry out structural adjustment of agricultural production, and try to realize the rational distribution and specialization of agricultural production.

Agricultural Production Structure Optimization: A Case Study of Major Grain Producing Areas, China

A large number of mathematical models were developed for supporting agricultural production structure optimization decisions; however, few of them can address various uncertainties existing in many factors （e.g., eco-social benefit maximization, food security, employment stability and ecosystem balance）. In this study, an interval-probabilistic agricultural production structure optimization model （IPAPSOM） is formulated for tackling uncertainty presented as discrete intervals and/or probability distribution. The developed model improves upon the existing probabilistic programming and inexact optimization approaches. The IPAPSOM considers not only food security policy constraints, but also involves rural households’income increase and eco-environmental conversation, which can effectively reflect various interrelations among different aspects in an agricultural production structure optimization system. Moreover, it can also help examine the reliability of satisfying （or risk of violating） system constraints under uncertainty. The model is applied to a real case of long-term agricultural production structure optimization in Dancheng County, which is located in Henan Province of Central China as one of the major grain producing areas. Interval solutions associated with different risk levels of constraint violation are obtained. The results are useful for generating a range of decision alternatives under various system benefit conditions, and thus helping decision makers to identify the desired agricultural production structure optimization strategy under uncertainty.

Fruit Production Distribution and Adjustment Strategies under the Constraint of Grain Security

Grain security is the foundation of national security,and guaranteeing the grain security by every possible means is a development priority for the whole country.Rapid development of the fruit industry satisfies increasing demands of people for fruits,but also presents certain competition for grain production.From the perspective of limited resources and comparative income,this paper analyzed potential threats of fruit production distribution to grain production in farmland and labor resources,and came up with pertinent adjustment strategies.

Changes in Grain Production and the Optimal Spatial Allocation of Water Resources in China

Changes in grain production are decomposed and compared among nine major Chinese river basins for the sake of optimal water allocation. The results show that water-deficient northern China, especially the Songliao River Basin and Huai River Basin, contributed the greatest share of the total grain increment from 1995 to 2010. The Songliao River Basin achieved increased grain output largely by expanding multiple cropping, while the Huai River Basin achieved it mainly by improving the yield per unit area. With increased reliance on expanding irrigation and multi-cropping, most northern basins have high levels of agricultural water consumption, despite the rising share of corn, a lower water intensive crop. In contrast, over the same period the warm and humid south, traditionally a major rice-growing area, mostly experienced a sharp decline in rice cropping area and the Southeast Rivers Basin even reduced multiple cropping indexes, contributing to decreased agricultural water consumption. Implications of our findings and the need for tackling the imbalance of agricultural water use in grain production are discussed.

Spatial and Temporal Characteristics of Rice Potential Productivity and Potential Yield Increment in Main Production Regions of China

The vast area and marked variation of China make it difficult to predict the impact of climate changes on rice productivity in different regions.Therefore,analyzing the spatial and temporal characteristics of rice potential productivity and predicting the possible yield increment in main rice production regions of China is important for guiding rice production and ensuring food security.Using meteorological data of main rice production regions from 1961 to 1970（the 1960s） and from 1996 to 2005（the 2000s） provided by 333 stations,the potential photosynthetic,photo-thermal and climatic productivities in rice crop of the 1960s and 2000s in main rice production regions of China were predicted,and differences in the spatial and temporal distribution characteristics between two decades were analyzed.Additionally,the potential yield increment based on the high yield target and actual yield of rice in the 2000s were predicted.Compared with the 1960s,the potential photosynthetic productivity of the 2000s was seen to have decreased by 5.40%,with rates in northeastern and southwestern China found to be lower than those in central and southern China.The potential photo-thermal productivity was generally seen to decrease（2.56%） throughout main rice production regions,decreasing most in central and southern China.However,an increase was seen in northeastern and southwestern China.The potential climatic productivity was observed to be lower（7.44%） in the 2000s compared to the 1960s,but increased in parts of central and southern China.The potential yield increment from the actual yield to high yield target in the 2000s were no more than 6×103 kg ha-1 and ranged from 6×103 to 12×103 kg ha-1 in most of the single-and double-cropping rice growing regions,respectively.The yield increasing potential from the high yield target to the potential photo-thermal productivity in 2000s were less than 10×103 kg ha-1 and ranged from 10×103 to 30×103 kg ha-1 in most of the single-and double-cropping rice growing regions,respectively.The potential yield increment contributed by irrigation was between 5×103 and 20×103 kg ha-1,and between 20×103 and 40×103 kg ha-1 in most of the single-and double-cropping rice growing regions,respectively.These findings suggested that the high yield could be optimized by making full use of climatic resources and through a reasonable management plan in rice crop.

Research on the Forecast of Grain Production in Henan Province from 2010 to 2015

According to the latest amended agricultural economic statistical data from 1996 to 2009 in Henan Statistical Yearbook-2010,by selecting and establishing the optimized grey model of logarithmic new developed coefficient, we conduct the empirical analysis and forecast research on the grain output and the relevant main economic indices in Henan Province from 2010 to 2015. The results show that the grain output of Henan Province in 2010 will reach 54.896 9 million tons, and it will break through 60 million tons at 60.17 million tons in 2015. In years ahead, the grain output of Henan Province will develop to a new stage steadily, which guarantees the national grain supply and socio-economic sustainable development forcibly.

China’s New Rural Income Support Policy:Impacts on Grain Production and Rural Income Inequality

This paper analyses the impact of agricultural tax abolition and direct income payments to grain farmers on grain production and rural inequality in China. To separate the impact of the income support measures from recent price trends for grains and inputs, and to account for differences in household responses, we use a village-level general equilibrium model that we calibrate for two villages with different degrees of market access in Jiangxi province. The results show that the income support policy does not reach its goal of promoting grain production. The increased incomes allow farm households to buy more inputs for livestock production and involve other activities that are more profitable than grain farming. Selling of rice outside the villages declines more than rice production, because households in the villages consume more rice when incomes rise. We further find that the income support measures tend to reduce income within a village, but that tax abolition tends to widen income inequality between villages.

Changes in China’s Grain Production Pattern and the Effects of Urbanization and Dietary Structure

Grain production patterns are the basis of a nation’s food security.Since China’s reform and opening-up began in 1978,China’s urbanization process,driven by rapid social and economic development,has accelerated steadily.During this time,the dietary structure of urban and rural Chinese has also changed significantly.Accordingly,grain production patterns have undergone major changes.First,traditional grain production patterns in the north and the south have changed,and the food production center has shifted toward the north.In 1980,the grain yield of southern provinces accounted for 60%of China’s total,while that of northern provinces accounted for 40%.In 2015,the grain yield of southern provinces accounted for 56%of the total,while that of northern provinces accounted for 44%.Second,grain production by regions of the country is“shrinking in the east but expanding in the central regions,”meaning that grain production in eastern coastal provinces has decreased significantly,while that in the central region has expanded.The proportions of the nation’s total grain production from the eastern,central and western regions were 38%,36%and 26%,respectively,in 1980.These had changed to 27%,46%,and 27%,respectively,in 2015.Third,the spatial centralization of grain production has increased.The total grain yield of 13 major grain-producing provinces and regions in the country accounted for 69.27%of nation’s total in 1980,and it had reached 76.18%in 2015,showing that the impact of major grain-producing areas on national food security has increased.The influence of rapid urbanization on grain production areas shows remarkable regional differences.As the level of urbanization has increased,build-up land occupies a large number of high-quality farmland,especially in east coastal provinces and thus the grain planting area decreased obviously.The effect of dietary structure changes on grain production patterns was evident in two ways.On the one hand,as dietary diversity has increased,total grain consumption has decreased.The reduction in the proportion of planting area for grain crops to total crop planting area dropped from 82%in 1980 to 68%in 2015,making this change in total grain consumption evident.On the other hand,the ratio of grain for human consumption declined as the ratio of grain consumed by animals increased.The reduction in the proportion of rice and wheat grown and an increase in the proportion of feed grain production(mostly maize)from 20%in the 1980s to 36%in 2015 makes this change in grain production and consumption evident.In the future,with the establishment of national functional areas for grain production,the spatial pattern of grain production will return,while the demand for feed grains will continue to increase but with the space for expansion limited.

Distributed optical fiber acoustic sensor for in situ monitoring of marine natural gas hydrates production for the first time in the Shenhu Area,China

The distributed acoustic sensor(DAS)uses a single optical cable as the sensing unit,which can capture the acoustic and vibration signals along the optical cable in real-time.So it is suitable for monitoring downhole production activities in the process of oil and gas development.The authors applied the DAS system in a gas production well in the South China Sea for in situ monitoring of the whole wellbore for the first time and obtained the distributed acoustic signals along the whole wellbore.These signals can clearly distinguish the vertical section,curve section,and horizontal production section.The collected acoustic signal with the frequency of approximately 50 Hz caused by the electric submersible pump exhibit a signal-to-noise ratio higher than 27 dB.By analyzing the acoustic signals in the production section,it can be located the layers with high gas production rates.Once an accurate physical model is built in the future,the gas production profile will be obtained.In addition,the DAS system can track the trajectory of downhole tools in the wellbore to guide the operation.Through the velocity analysis of the typical signals,the type of fluids in the wellbore can be distinguished.The successful application of the system provides a promising whole wellbore acoustic monitoring tool for the production of marine gas hydrate,with a good application prospect.

Empirical Analysis on the Grain Supply Capacity of Hubei Province,China

According to the investigation results of grain production and demand status of administrative units at county level in Hubei Province in the years 2004-2007,status and trend of grain production and grain demand in Hubei Province are analyzed,so as to discuss the grain supply capacity of Hubei Province.Result shows that affected by the adjustment of agricultural structure and the transfer of rural labor,Hubei Province shows a significant decrease in grain production before the year 2002,and a gradual increase in both grain production scale and grain supply capacity after the year 2004.It is forecasted that in the year 2020,Hubei Province will provide 13 100 thousand tons marketable grain to the state and will become a core province ensuring the grain security of China.

Comparative Study of Impacting Factors of Grain Production of Inner Mongolia Region in Different Periods

On the basis of grey correlation analysis,8 factors impacting grain production prominently as follows are selected to establish indices system:yield per unit(X1),grain planting area(X2),agricultural labor forces(X3),the total power of agricultural machinery(X4),using amount of fertilizer(X5),the damaged area of crops(X6),effective irrigation area(X7),and agricultural fixed assets investment(X8).According to the relevant data of Inner Mongolia Statistical Yearbook from 1988 to 2008,we use the method of grey correlation analysis to analyze the factors impacting grain production in Inner Mongolia,quantify the correlation degree of the total grain output and all factors,and finally conclude the impacting capacity of all factors on grain production in the light of correlation degree value.The results show that yield per unit still is the principal factor impacting the total output of grain in Inner Mongolia;the area of grain planting and the area of affected crops are the two most important factors responsible for the decrease of grain output;effective irrigation area the total power of agricultural machinery are the two primary factors impacting the increase of grain output;the using amount of fertilizer shows dwindling impact on grain production;agricultural fixed assets investment still hovers at the minuscule impact degree on grain production.

Research on Site Selection Model of Distribution Center of Agricultural Products

In the light of the practical situation of logistics distribution of agricultural products,we primarily select transportation factor,economic factor,environment factor,and other factors,to establish evaluation index system of site selection of distribution center of agricultural products.And then we adopt the analytic hierarchy process method to calculate weight of site selection of distribution center of agricultural products.Under the circumstance that the evaluation information is interval number,we use uncertain and multiple attribute decision making method to establish site selection model of distribution center of agricultural products.Finally,taking one city as an example,we discuss the application of this model in site selection of distribution center of agricultural products.The results of empirical analysis show that the model we established fully considers the randomness and uncertainty in the process of evaluation,so as to make the results of evaluation more objective,in line with reality.So the effect of evaluation is better as against the former real number evaluation calibration.