Research Of The Method For Arable Land Quality Gradation Based On The New Era Background

In the context of the new period,China’s economic development has entered a new normal,new-type industrialization continues to advance,and the protection of cultivated land resources faces new demands in terms of quantity,quality,and ecological environment.The No.4 document issued by the Central Committee of the Chinese Communist Party and the State Council in 2017 clearly stated that in order to strengthen farmland protection and improve balance management,it is necessary to vigorously implement land remediation,and also to improve the evaluation index system and evaluation method of farmland quality.In recent years,the implementation of the land rectification project has played an important role in the effective and sustainable use of farmland as a supplemental and balanced farmland resource.At present,the implementation effect of the land remediation project is generally expressed in terms of "classification" However,"classification" does not fully reflect the transformation of the land remediation project to the environmental conditions of farmland production.The grading of cultivated land quality reflects the comprehensive differences in the quality of cultivated land determined by natural factors and social and economic conditions,and can reflect the evaluation of specific measures for land improvement projects.However,the factor method and revised method in the “Regulations for Classification on Agricultural Land”(GB/T28405-2012)also have certain limitations.It shows that the sensitivity of the response to land remediation is not sensitive and the timeliness is not high.Therefore,a new method for determining the quality of cultivated land should be studied and improved.The accuracy and timeliness of grade work is of great significance for strengthening management of farmland balance and promoting the implementation of the “trinity” integrated management and control of cultivated land resources.Based on the methods in the “Regulations for Classification on Agricultural Land”,this study draws on domestic and foreign arable land quality assessment results to build a new grading method for farmland quality—“Gradually revised method”.Taking Pingshan County in Hebei Province as the study area,the county’s quality assessment level for theentire county was determined using the new method and the "Factor method" and "Revised method" in the "Regulations",and through the comparison to prove the new method is reasonable.In addition,the new method and “Factor method” were used to evaluate the land quality level of 13 land remediation projects in Pingshan County in 2014 to compare the sensitivity of the two methods.The findings are as follows:(1)This study analyzed the differences in the factors that formed the quality of cultivated land at different scales,and concluded that the quality of cultivated land was mainly affected by the three major elements of “climate,earth and human” from the macro to the middle to the micro scale,combine the specific role of the land remediation project for each element,and based on this,the quality of cultivated land was determined.Indicator system.Among them,the “climate” has a macro-control effect on the quality of cultivated land and is characterized by the “light and temperature potential productivity”.“Earth” has an impact on the quality of arable land in terms of basic land resources,reflecting the differences in arable land itself,and using eight indicators such as field slope and surface soil texture.The influence of “human” is reflected in the production efficiency,which reflects the degree of human activity transformation of cultivated land quality,and the selection of 10 indicators such as irrigation guarantee rate and drainage conditions.(2)This study is based on the "Marxist differential rent theory" and combines the "soil fertility theory",the "location theory" and the "restriction factor theory" to reveal the logical relationship between the factors of farmland quality formation.Learn from “Agricultural Ecology Zone”(AEZ)and “Land Production Simulation Model”(PS123)by the idea of progressive correction,this study suggests that step-by-step revisions can also be used to express the relationship between climate,basic fertility,and production efficiency.Therefore,this study constructs the “Gradually revised method”,using the “light and temperature potential productivity” as a basis,and use the “basic productivity coefficient” and“production efficiency coefficient” as amendments.(3)This study uses the gradually revised method to divide the quality of cultivated land in the county into 10 levels.Judging from the composition of the grades,Pingshan County’s arable land is mainly middle-level and high-level,and the low-level is less.The spatial distribution of cultivated land quality is such that the level of the eastern plain is the highest,that of the central hilly region is low,and that of the western mountainous region is the lowest.According to the analysis,the results obtained by the gradually revised method are in line with the actual situation in Pingshan County.Through the linear regression analysis of the grading index and the standard grain yield obtained from the survey,it is further verified that this method is correct and feasible.(4)According to the “Regulations for Classification on Agricultural Land”(GB/T28405-2012),the quality grade of cultivated land in Pingshan County was evaluated by the factor method and the revised method respectively,and then compared with the results obtained by the progressive correction method.Compared with the factor method,the difference in the quality level of cultivated land obtained by the gradually revised method is more pronounced.According to the analysis,this is because the continuous multiplication operation is more advantageous than the comprehensive weighted operation.This advantage is that the individual indicators have a more significant impact on the overall level.Compared with the traditional revised method,the distribution of the cultivated land levels obtained by the two methods is relatively obvious.However,the gradually revised method can better reflect the impact of production efficiency,and it does not depend on updating the results,and is more time-efficient.(5)In this study,Pingshan county’s 13 land remediation project areas in 2014 were graded before and after remediation.The results show that the quality of cultivated land in each project area has been upgraded to different degrees through land remediation.The results obtained by the gradually revised method show that after the implementation of the land rectification project,the quality of cultivated land in the 13 project areas has increased by an average of 1.93 grades,and that obtained by the factor method has averaged 0.87 grades.The former has achieved a result of 1.03 grades higher than the latter.Therefore,the gradually revised method can better reflect the effect of land remediation and serve the farmland to make up for the balance.