Study On Quality Classification And Grade Conversion Of Cultivated Land Resources In Beihai City,Guangxi

Cultivated land quality evaluation is the core content of the current "Trinity" protection of cultivated land in our country.The Third National Land Survey was based on reflecting the natural conditions of cultivated land resources and strengthening the utilization of existing basic data of various departments,and formulated the "Work Plan for Classification of the Quality of Cultivated Land Resources." Based on the above-mentioned background,this study takes Beihai City,Guangxi as an example,to carry out an empirical study on the classification of cultivated land resources and their transformation methods.By interpreting soil survey results and field inspections,updating basic data such as soil layer thickness,soil texture,profile configuration,etc.,using the adjusted evaluation parameter system to update farmland quality and other results;carrying out research on the quality of farmland resources in Beihai City,Statistics obtained category results;according to the two sets of grade conversion methods,the Sum of Points and the Sum of Grade Points,and the Yinhai District of Beihai City was selected to carry out empirical research,the classification results were converted into grade results,which are the same as the updated original grades.The results are compared,and the rationality of conversion methods and their respective advantages and disadvantages are discussed,so as to provide a reference for the practical application of the results of cultivated land resource quality classification.The main conclusions of the study are as follows:(1)It is reasonable to convert the classified results into graded results and apply them in practice.The quality classification results of cultivated land resources are difficult to compare the quality of cultivated land resources,and cannot provide a direct basis for natural resource management such as the balance of cultivated land occupation and compensation.This study proposes two sets of grade conversion methods.The Yinhai District of Beihai City is selected for empirical research.The results show that the span and distribution of grade results after the conversion of the Sum of Points method are roughly the same as the original grade results,and the grade distribution is reasonable.However,national comparability cannot be achieved;the Sum of Grade Points method is conducive to national-wide comparability,but the range of arable land in the region is low,and the difference is not strong.Therefore,the conversion results of the two sets of methods are reasonable in different scopes.It is recommended that when applying the results of regional cultivated land resource quality classification,use the Sum of Points method to convert the classification results into graded results and then apply them on a national scale.Within,you can use the Sum of Grade Points method for grade conversion.(2)The quality classification of cultivated land resources needs to unify the data sources and standards of soil conditions and make data corrections in conjunction with field inspections.There are differences between the quality index values of the cultivated land quality grade survey and evaluation unit data and the updated evaluation data of cultivated land quality grades.The main reasons are inconsistent texture classification standards,insufficient current status of the results of the second national soil census,and errors in the interpolation method and range of sample data.It is recommended to carry out the third national soil survey,update basic data,and unify soil condition data sources and index classification standards.(3)It is necessary to establish a working mechanism for the annual update of the quality classification results of cultivated land resources.In order to ensure that the results of cultivated land resource quality classification can be used for a long time,it is necessary to carry out the update of the classification results,establish an annual change and reporting system,and ensure the current status of the results of cultivated land quality classification.