Evaluation And Control Countermeasures Of Cultivated Land Fragmentation In Typical Counties Of Black Soil Area

Cultivated land is the essence of land,and is the basis of grain production.Cultivated land fragmentation is a land use pattern contrary to scale management,and it is one of the main problems in many agricultural underdeveloped countries.Even in the northeast region with high per capita cultivated land area,there is a certain degree of cultivated land fragmentation,which affects the large-scale operation of agriculture.The third round of rural land contracting will be launched in 2023,and the ownership of cultivated land needs to be adjusted appropriately at that time.Baiquan County,Heilongjiang Province is located in the fertile black soil area,but the proportion of low mountain and shallow hill landform area is high.In the second round of rural land contracting,the county has a large number of cultivated plots per household,the scale of a single plot is small,and there is the phenomenon of cultivated land fragmentation,which does not meet the needs of modern agricultural development.Comprehensively evaluating the degree of cultivated land fragmentation,revealing its spatial pattern and discussing the influencing factors can provide reference for three rounds of rural land contracting and comprehensive land improvement.Cultivated land fragmentation includes landscape fragmentation and ownership fragmentation.In this paper,the scale of landscape fragmentation is cultivated land patch;The fragmentation of ownership is based on the scale of farming unit plot,and the evaluation is based on the plot contracting status in the second round of rural land contracting.Based on the three survey data and the rural land contract management right confirmation database,the evaluation index system is constructed from the perspective of landscape fragmentation and ownership fragmentation,and the characteristics of cultivated land fragmentation are revealed with the help of Arc GIS spatial analysis.This paper attempts to focus on the cultivated land boundary,identify the influencing factors of cultivated land fragmentation in Baiquan,and put forward the control countermeasures of cultivated land fragmentation in typical counties in black soil area.The main research contents and conclusions are as follows:(1)There are significant differences in the degree of cultivated land fragmentation among administrative villages in Baiquan County,showing a spatial distribution pattern gradually decreasing from southeast to west.In the second round of contracting,the average number of contracted land by farmers reached 3.55 pieces/household,and the average cultivated land scale per household was 2.097 hm~2/household.The highest comprehensive evaluation index of cultivated land fragmentation is 0.636,which is located in Xing’an village,Xinsheng town;The lowest value is 0.204,which is located in satellite village of Longquan town.The comprehensive evaluation index is divided into four grades:mild,moderate,severe and extremely severe fragmentation.The administrative villages with cultivated land fragmentation above severe are mostly concentrated at the junction of Xinsheng town,Sandao town and Xingguo town.In addition,the fragmentation of cultivated land ownership is more serious than that of landscape,with the highest values of 0.346 and 0.295 respectively;The two show the trend of high in the southeast and low in the northwest,and gradually increasing in the southwest north east.It is mainly located in Xinsheng town and Xihua town with high value,and the landscape is mainly concentrated in Xinsheng town and Xihua town.(2)Analysis of influencing factors of cultivated land fragmentation.Cultivated land fragmentation in Baiquan County is the result of the joint action of three cutting forces,mainly reflected in ownership,facilities and natural cutting forces.The correlation coefficients between the three and cultivated land fragmentation are-0.775,0.617 and 0.661 respectively.The cultivated land in Baiquan County has become the most dominant factor of cultivated land fragmentation;Secondly,as an external physical force,natural cutting can be regarded as a measure of severe fragmentation in the plain area,although the direct impact range is small,with a total of 84administrative villages.The cutting force of facilities mainly plays an auxiliary role.While optimizing the mechanized farming environment and supporting the sustainable development of agriculture,it is easy to cause spatial separation of cultivated land.The average cutting densities of the three were 4.70 strips/hm~2,6.60 strips/hm~2and 0.56 strips/hm~2respectively.(3)Countermeasures for the treatment of cultivated land fragmentation.Based on the action density of three cutting forces and adopting the three-dimensional magic cube graphic method,Baiquan County is divided into four governance zones,which are key ecological remediation areas,ownership scale optimization areas,cultivated land facility improvement areas and cultivated land intensive utilization areas.The following countermeasures are put forward:land leveling according to local conditions.Actively respond to the three rounds of rural land contracting,advocate one household and one field,and encourage various forms of moderate scale operation.Reasonably arrange cultivated land facilities and build high standard cultivated land.Each administrative village should guide differentiated governance according to its own situation and with reference to zoning.