Study On The Change Of Rice Cropping System In Jiangxi Province And Its Typical Grain Producing Areas

The government has been highly concerned about agricultural production.In recent years,the National Development and Reform Commission put forward the structural reform of agricultural,which purpose is to achieve the adjustment and optimization of agricultural economic structure.Therefore,the timely grasp of the regional of grain cultivation of the system,planting scale and production methods,the food safety issues can be controlled and got an effective response."13th Five-Year Plan" period of Jiangxi Province is the critical period for the coordinated development of industrialization,urbanization and agricultural modernization.Rice is the main crop in Jiangxi province,and it is one of the ways to improve the grain yield by promoting the expansion of the cultivation areas of the multi-cropping rice.The rice cropping systems remote sensing dynamic monitoring,analysis of rice planting space changes,is conducive to the rational distribution of agricultural production.This paper takes the typical grain producing areas of Jiangxi Province as the research area,from different regional areas discussed the situation of rice cultivation and its changes,including the following aspects:(1)Collect a number of periods of remote sensing images of the Landsat satellite,then based on the ArcGIS software and the Google Earth platform,the distribution range of paddy field was analyzed by visual interpretation of remote sensing image in Jiangxi Province.(2)According to the characteristics of different growth phenology of rice,the normalized vegetation index(NDVI)of the characteristic time window was selected to judge the remote sensing extraction of the spatial distribution of single / double cropping rice in Jiangxi Province in 2015.(3)For the Poyang Lake Plain area is the famous hometown of fish and rice,to carry out the Poyang Lake Plain years for many years of rice cultivation system of temporal and spatial changes in remote sensing analysis,combined with farmersurveys to explore the changes in natural and social factors.(4)According to the land use and its change of Poyang Lake returning farmland to lake region,analyzed the phenomenon and reasons of the cultivated land in retreat.Research indicates:(1)The paddy field area in Jiangxi Province was 274.85×104hm2,which was contiguous clustering distributed in the Poyang Lake Plain and Jitai Basin,but in the hilly areas of the mountain show scattered distribution;(2)In 2015,double cropping rice in Jiangxi Province accounted for 51.82% of the paddy field area and 48.17% of single season rice.The double-cropping rice is distributed in Poyang Lake Plain,Ganfu Plain,Jitai Plain and Jiangxi West High Yield Area.On the other hand,in the urban surrounding areas,mountains,hills and other areas,farmers tend to plant single-cropping rice.Using the data of large grain growers and field survey as verification sample,the extract results of rice in Jiangxi Province in 2015 were verified,and the precision of the sample was over 70%.(3)In 1990,the area of double cropping rice in Poyang Lake Plain was 308,500hm2.In 2003,the cropping area of double cropping rice was reduced to 232,900 hm2.In recent years,due to agricultural tax exemption,grain subsidies and other benefits of agricultural policy impact,the planting area of double cropping rice incresed to28.04 million hm2.From 1990 to 2003,the cropping area of single cropping rice increased continuously,while the area of single cropping rice decreased in the period from 2003 to 2015.From 1990 to 2015,the spatial change of rice cropping systems in Poyang Lake area was obvious.The rice planting system in Poyang Lake area is affected by many factors.(4)From 1990 to 2015,the area of single / double cropping rice abandoned lake polder area showed a tendency to inversely proportional relationship.In recent years,the abandoned lake polder area of paddy field decreased.The cultivation of rice is affected by the combination of natural and human factors.As a result of the government's guidance and advocacy,the pattern of planting multi-cropping rice has become more common,the impact of efforts began to increase.