Research On Remote Sensing Zone Of Cultivated Land For Site-Specific Management And Productivity Improvement Strategy

Land remediation is an important means to promote the sustainable development of agricultural land in my country.The construction of high-standard farmland is a key work item proposed by the state.However,the current land remediation work does not pay enough attention to the quality of cultivated land,which is not conducive to the protection of cultivated land resources and food security.In addition,compared with the existing research on farmland quality evaluation,the research on farmland quality remote sensing monitoring and evaluation based on field scale is relatively insufficient,ignoring the impact of land consolidation on farmland quality.This article takes as an example the land remediation of demonstration fields in the ninth management zone of Daxing Farm in Fujin City,Heilongjiang Province(the area underwent the standardization of grid fields in April 2019),based on multi-source remote sensing images,and obtained pixel-based data.Field-scale cultivated land quality information,and on-site measurement and evaluation of the required indicators.The traditional cultivated land quality evaluation indicators are composed of basic indicators and regional indicators.After comprehensively considering the characteristics of local land consolidation,extract the later period of land consolidation(2020)Ratio Vegetation Index(RVI),Difference Vegetation Index(DVI),Normalized Vegetation Index(NDVI)of the rice growing period,rice yield and slope extracted from the UAV high-precision digital surface model DSM(Slope)is used as an evaluation index to construct a cultivated land quality evaluation index system,and the principal component analysis method is used to calculate the weight value of each evaluation index.A farmland quality evaluation model is established,and each index is spatially superimposed in Arc GIS to obtain the farmland quality distribution map of the study area,and the actual measurement of the land size distribution is used as a verification to prove the feasibility of the index.The cultivated land in the study area is divided into five grades,and the quality of cultivated land of different grades is analyzed.Study the law of cultivated land quality changes after land consolidation,and the changes in the proportion of cultivated land of different grades.The research results show that with the development of land improvement projects,the quality of cultivated land has shown a downward trend.Based on the existing cultivated land quality evaluation grades,the quality of cultivated land in the study area is divided into five grades,with the highest quality of cultivated land.,Grade 5 arable land has the lowest quality.The proportions of Grade 1 and Grade 2 have decreased by 3% and 4%,respectively.The proportion of Grade 5 has increased from 1% before land consolidation to 10%.3.From the perspective of changes in rice growth,using the coefficient of variation as an indicator to analyze the changes in the internal growth of the field,the coefficient of variation in 2020 is higher than that in 2018 and 2019,and the decline in the quality of cultivated land is related to the internal growth of the field.The widening of the difference is mainly caused by land improvement.The standardization of grid field leveled the original land,destroying the original effective soil layer thickness,soil particle size and other indicators of the soil,resulting in a decrease in the quality of cultivated land.This paper mainly uses the evaluation indicators extracted from satellite images to monitor and evaluate the quality of cultivated land before and after land consolidation.The spatial distribution map of cultivated land quality in different periods of land consolidation in this area is obtained,and the spatial change trend of cultivated land quality is analyzed.The results show that After land consolidation,the quality of cultivated land has shown a downward trend.In view of this situation,countermeasures and suggestions for rapid improvement of cultivated land quality are put forward.Corresponding control measures need to be taken to improve the quality of cultivated land in different periods.It is the basis for the restoration of the quality of cultivated land after land consolidation,improves the efficiency of cultivated land use,and also achieves the goal of improving the ecological environment and sustainable development.At the same time,it provides a reference for remote sensing monitoring and evaluation methods of cultivated land quality.