| As an important natural resource,the quality of cultivated land is closely related to crop yie ld,and it directly affects food security and the healthy development of agriculture.The black soil area in the northeast of our country has the advantages of high fertility and strong fertilization capacity,which plays a key role in the national food security strategy.However,in recent years,due to the influence of natural factors and unreasonable use of man-made,the quality of black soil and cultivated land has become worse and worse.Therefore,it is particularly important to realize the dynamic monitoring and evaluation of cultivated land quality and grasp the changes of cultivated land quality.However,the distribution of cultivated land is wide and large,and as time changes,information such as the quantity and quality of cultivated land will chang e significantly.Traditionally,the evaluation of the cultivated quality relied more on field sampling and subjective analysis,which caused many problems,such as high cost of survey and monitoring,and poor timeliness of data.Therefore,in the current rapid development of remote sensing technology,how to effectively combine GIS and remote sensing technology has very important practical significance.Because it can give full play to the advantages of these two means to achieve a comprehensive and efficient evaluation of the cultivated land.The study takes Friendship Farm as the research area and makes full use of GIS and multi-source remote sensing data.Then,based on the comprehensive analysis of multiple factors,construct an evaluation index system of cultivated land quality that meets the actual conditions of the study area from five aspects: site conditions,physical and chemical properties,nutrient properties,land management,production capacity.Introduce the standard deviation of NDVI to characterize crop growth for many years,revealing the difference in quality response of cultivated land in the same pixel.Then use the analytic hierarchy process to determine the weight and the membership function to determine the degree of membership.At the same time,through the analysis of the evaluation indicators and the distribution characteristics of the cultivated land quality,the restrictive factors that affect the quality and the filed of cultivated land are clarified.Finally,based on this,reasonable suggestions are made for protection and quality improvement of cultivated land.The main contents and results of the research are as follows:(1)The NDVI time series data can reflect crop growth and characterize the response of cultivated land quality.The larger the standard deviation of the curve,the worse the crop growth and the quality of cultivated land.On the contrary,the better t he quality of cultivated land.(2)The farm’s comprehensive scores of cultivated land quality are divided into five gra des.On the whole,the quality of cultivated land inside the farm is good,of which the top three levels of cultivated land account for 82.58%.(3)Cultivated land of different grades is distributed in each management area of the farm.Due to the influence of slope,soil nutrient content,agricultural infrastructure,crop conditions,etc.,the quality of cultivated land within the management area varies significantly,and filed is restricted to a certain extent.(4)Using spatial Gini coefficient to measure the degree of spatial agglomeration of cultivated land.The slope of the woodland in the southwest is relatively large,which makes it diff icult to construct facilities of drainage and irrigation,and the overall quality of cultivated land is poor,and the degree of spatial agglomeration is high.In the remaining areas,the overall quality level is relatively uniform,and the distribution of cultivated land at various levels is relatively scattered.(4)According to the evaluation results of cultivated land q uality of Friendship Farm,this article is based on the transformation of middle and low fields and the protection of cultivated land,and put forward reasonable suggestions and opinions from the following aspects.Such as: the promotion of innovative straw returning technology,the prevention and control of soil erosion,deepening the construction of farmland water conservancy,increasing t he application of organic fertilizers,insisting on the use of cultivated land that combines the use of crops and crop s,and the combination of the strict basic agricultural system and economic encouragement. |
