Study On The Dynamic Change Of Cultivated Land Quantity And Quality In Three Typical Black Soil Areas Of Northeast China

The total amount of cultivated land resources in China is large,but the per capita share is small,and the overall quality of cultivated land is low.However,with the development of industrialization and urbanization,a large number of high-quality cultivated land resources are used in economic construction,resulting in the gradual reduction of the number and quality of cultivated land resources,while the northeast black land resources,known as "ballast stone and pressurizer",also have the same problems.Therefore,based on the administrative scope of Heitu County in Heitu District of three northeastern provinces provided by the agricultural department,112 Heitu counties in the three northeastern provinces are identified as typical black soil research areas,and 6 typical sample counties are selected as the survey objects.At the same time,the land survey data of the land and resources department were collected,and the change characteristics of cultivated land quantity and quality in the typical black soil area of Northeast China were studied by SPSS and origin data statistical analysis software.The existing problems of cultivated land quantity and quality in the typical black soil area of Northeast China were summarized,and the Countermeasures of sustainable utilization and protection construction of cultivated land in the typical black soil area of Northeast China were put forward.The results show that:(1)the quantity and quality caliber of cultivated land in typical black soil area are different,and the protection base is unknown.The main performance is that there are big differences between the agricultural sector and the land sector.In terms of farmland quality identification,the land department implements the farmland grading system,which has formed comparable farmland grading results in China;the agricultural department implements the farmland productivity evaluation,but most areas have not formed comparable urban and provincial achievements,let alone national farmland productivity evaluation results.(2)The number of cultivated land decreased obviously,and construction occupation was the biggest threat.From 2013 to 2017,112 counties(cities and districts)in the typical black soil areas of the three northeastern provinces had a net decrease of 67100 hectares,with an average annual decrease rate of 0.06%,and the decrease rate in the typical black soil areas was significantly higher than that in the three northeastern provinces by 0.04%.Taking Liaoning Province as an example,the main reason for the decrease of cultivated land is the occupation of cultivated land by all kinds of construction.The area of cultivated land reduction is mainly located in the plain and hilly area with flat terrain and concentrated cultivated land distribution.However,most of the supplementary cultivated land is outside the black soil area,resulting in a net decrease in the number of cultivated land in the black soil area,while the supplementary cultivated land is mainly located in the mountainous areas with relatively poor natural conditions in each county.Therefore,no matter in the past or in the future,construction occupation and compensation outside the occupied area are always the biggest threat to the quantity protection of black soil cultivated land.(3)The degradation of cultivated land quality is serious,and the main performance is poor soil.From 2013 to 2017,the typical black soil areas in Northeast China(6-8,etc.)showed a trend of continuous decrease.The middle land(9-12,etc.)experienced the process of first increasing and then decreasing,while the low land(13-14,etc.)experienced the process of decreasing,increasing and basically stable.Among them,higher land decreased the most,which was 23.45%;middle land followed,which was 3.99%;lower land area increased,which was 5.55%.Taking Liaoning Province as an example,higher land(6-8,etc.)increased by 34.86%,middle land(9-12,etc.)decreased by 2.49%,and lower land(13-14,etc.)decreased by 4.23%,indicating that the quality of cultivated land in Liaoning Province has improved.However,through the investigation of sample counties,the actual situation of cultivated land quality degradation is far beyond the macro data.(4)The quantity protection,quality construction and ecological conservation of cultivated land compete with each other,and the conflict is obvious.Due to the different direction of cultivated land protection in different departments,the phenomenon of quantity protection,quality construction and ecological conservation land competing with each other sometimes occurs,even conflicts.(5)Black soil cultivated land protection shows "hot up and cold down",and the public awareness of cultivated land protection is weak.At the national level,the government has made active efforts in the management,policies,funds and other aspects of black soil farmland protection.While the local government and the central government constantly play games on the construction index and the cultivated land protection index,the farmers’ enthusiasm for cultivated land protection is not high because of the low economic benefits of cultivated land management.