Spatio-temporal Evolution Of Non-grain Cropland And Its Driving Factors In Poyang Lake Region

The grain production of China not only affects the food and clothing of 1.4 billion Chinese people,but also affects international grain supply,demand and price.With the acceleration of urbanization,the cropland in China has been reduced to some extent.Meanwhile,driven by economic interests,non-grain phenomena such as conversion of cropland to other types of agricultural land and wasteland are also appearing constantly,which poses a serious threat to national food security.Here,we analyzed the spatial-temporal evolution of non-grain production within cropland during 2005,2010,2015 and 2020 and its driving mechanism of 38 counties in Poyang Lake region,where a major grain producing area in China.Meanwhile,methods such as spatial statistics,random forest regression model,temporal global principal component analysis,K-mean cluster analysis and other methods by statistical data from the scale of region were used to analysis above study content.Based on the survey data of farming households and using binary Logistic regression model,the characteristics and driving factors of two typical non-grain phenomena in Poyang Lake region,namely "cropland abandonment"(cropland idled for more than one year)and "double cropping to single cropping"(rice planting from double cropping to single cropping),were expounded from the scale of farming households.The main conclusions were as follows:(1)Temporal and spatial evolution characteristics of non-grain production within cropland in Poyang Lake region from 2005 to 2020:(1)Temporal evolution characteristics.The level of non-grain production within cropland in Poyang Lake region was relatively high(40%-50%),but showed a decreasing trend,with a total decrease of 10.16% from 2005 to 2020.From 2005 to 2020,oil,vegetables and cotton were the main non-grain crops,among which oil crops accounted for a relatively stable and dominant position,the proportion of cotton crops plummeted by 9.98%,and the proportion of vegetables crops fluctuated up 15.06%.(2)Evolution characteristics of spatial pattern of the non-grain rate of cropland.From 2005 to 2020,the non-grain rate of cropland was higher in the northwest(most counties in Jiujiang)and most counties of Nanchang.Until 2020,the non-grain rate of cropland had decreased in most counties and districts,and all counties and districts in Jingdezhen except Changjiang District were in a trend of continuous growth.The situation of the non-grain within cropland should be vigilant.(3)Evolution characteristics of spatial pattern of the non-grain area of cropland.From 2005 to 2020,the non-grain area of cropland had decreased to a certain extent in most counties.Except Changjiang District and Wannian County,all the other counties in Jingdezhen and Shangrao were in the trend of continuous growth.In nearly 90% of counties,the change of the non-grain area within cropland was in the same direction as the change of non-grain rate.(4)Spatial pattern evolution of non-grain types.From 2005 to 2020,the situation of “oil crops were cultivated in most counties,while cotton,vegetables and other non-dominant non-grain crops were cultivated in some counties” in Poyang Lake region changed to “oil crops were still the dominant type of non-grain crops in most counties,and vegetables increased the most in most counties,and the number of counties with vegetables as the main non-grain crops increased significantly.Cotton had dropped out of the dominant category of non-grain crops”.(2)Driving factors and driving types of non-grain within cropland in Poyang Lake region from 2005 to 2020:(1)Driving factors.The factors that had the greatest influence on the degree of non-grain within cropland were the grain sown area,the urbanization rate and the number of farming labors.The urbanization rate had a positive impact,while the grain sown area and the number of farming labors had a negative impact.(2)Driving types.Agriculture was the dominant type of the northwest and southeast in Poyang Lake region.The belt(northeast,central and southwest)was resource-dependent.(3)Characteristics and driving factors of cropland abandonment of different types of farming households in three topographic regions:(1)Characteristics of cropland abandonment.In Poyang Lake region,the overall abandonment characteristic was nonfarm households> part-time households> pure households.In the mountainous region,non-farm households> pure households> part-time households;In hilly and plain regions,pure households> part-time households> non-farm households.(2)Driving factors of cropland abandonment by pure households.Low agricultural economic benefits and uneconomical investment of time and energy were the decisive factors of abandonment by pure households.Cropland was abandoned by pure households in the mountainous region mainly because of low economic benefits.The pure households in the hilly region were greatly affected by the input time to cropland.The input of time and money to cropland had more influence on pure households in the plain region.(3)Driving factors of cropland abandonment by part-time households.Lack of labor force,time and energy consuming,and unfavorable to cultivating were the main reasons for households to abandon cropland.The abandonment factors of part-time households in different topographic regions were different.(4)The driving factors of cropland abandonment by non-farm households were complicated.(4)Characteristics and driving factors of "double cropping to single cropping" of different types of households in three topographic regions:(1)The feature of "double cropping to single cropping".In Poyang Lake region,the overall characteristic of "double cropping to single cropping" was non-farm households> part-time households>pure households.In mountainous and hilly regions,non-farm households> part-time households> pure households;In the plain region,part-time households> non-farm households> pure households.(2)Driving factors of pure households’ "double cropping to single cropping".The distance to home was the main factor for the "double cropping to single cropping" of pure households in the plain region,and the underlying reason was the heavy labor,time and burden.(3)"Double cropping to single cropping" driving factors of part-time households.The shortage of labor force,low yield of grain planting and the restriction of double-cropping rice and large risk were the main reasons of parttime households.The reasons for the "double cropping to single cropping" of households in mountainous and hilly regions were basically the same,and the main reasons were the lack of labor force,poor economic benefits,and more constraints and risks of double cropping rice.Part-time households in the plain region planted singleseason rice because of low demand for grain yield and poor grain economic benefits.(4)The driving factors of non-farm households’ "double cropping to single cropping" were complex and diverse.