| As the carrier of agricultural production,cropland plays a very important role in food security.In recent decades,Arable land has become one of the most important trends in land use and cover change,which has aroused widespread concern.However,due to global climate change and the impact of population growth and socio-economic development level,the composite index fluctuates significantly.Poyang Lake plain is located in the middle and lower reaches of the Yangtze River.It is an important food production base in China.However,there are few studies on the replanting of cultivated land in Poyang Lake plain,and the research on driving mechanism is relatively weak and needs to be strengthened.So this article is based on remote sensing quantitative performance Poyang Lake plain multi-cropping index,supplemented by the ground survey data and statistics,reveals the Poyang Lake plain from 2001 to 2015 multi-cropping space-time dynamic characteristics,and combined with statistics and peasant household survey data to investigate the Poyang Lake plain multi-cropping change driving mechanism.Based on the statistical data of grain production and remote sensing data of remote sensing yield estimation model,calculation of multiple cropping changes in grain yield change of time and space distribution characteristics,and combining the population spatial data,discusses the Poyang Lake plain general characteristics of grain supply and demand.The results are as follows:(1)The farmland of Poyang Lake plain was mainly composed of replanted cultivation mode,which accounted for 60.80% of the total area of cultivated land,triple-cropping rotation systems was founded in some regions.In addition,single cropping system was mainly found in Xingzi,Ani,Xinjian,Poyang and Xinyu,accounting for 39.20% of the total area of cultivated land in Poyang lake plain during 2001~2015.(2)The overall cultivated land resumption index of Poyang Lake plain showed an upward trend,but there were three distinct periods of fluctuation,which showed the characteristics of decreasing,increasing and decreasing.And there are significant spatial differences.Except Ruichang,Jiujiang,Zhangshu,Fengcheng,Jinxian,Fuzhou,Dongxiang,Yujiang and Yingtan,the other counties are on the rise,in Poyang Lake plain during 2001~2015.(3)Areas where the multiple cropping index increased then decreased,the trend occupied 49.83% of the total cultivated land,decreased then increased and continual decreasing trend second,continual increasing accounted for the smallest proportion,in Poyang Lake plain during 2001~2015;(4)Regional scale analysis show that the film usage,total power of agricultural machinery,pesticides,the yield of grain,fertilizer,evaluation,per capita GDP,per capita arable land area,labor were the major factors which influenced the multiple cropping index in the Poyang Lake Plain;(5)Farmer scale analysis show that multi-cropping behaviors driven by the irrigation conditions,the types of landforms,cultivated land quality,family size,drought,farmers subsidies for agriculture,non-agricultural income among them,the most affected by irrigation conditions,then the micro landform types,cultivated land quality third,in Poyang Lake plain;(6)The grain production on unit area showed a trend of increase,mainly distributed in Anyi,Gaoan,Xinyu,Xingan,Fengcheng,Nanchang,Jinxian,Fuzhou,Yugan,Yu Jiang,Yingtan,Dongxiang,Poyang,Duchang,Hukou and Leping,in Poyang Lake plain during 2001~2015;(7)The total grain yield showed an upward trend,accounting for 70.33% of the total area of cultivated land,and the area of the decline trend accounted for 29.67% of the total area of cultivated land,with the cultivated land restoration index,the positive correlation increase,in Poyang Lake plain during 2001~2015;(8)The Grain surplus rate showed an upward trend,accounting for 57.07% of the total area of cultivated land,it can relieve regional food security pressure to some extent. |
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