Study On Identification Of Key Elements Of Multi-Scale-Dimensional Cultivated Land Quality

As the most valuable resource,cultivated land resources and the quality of cultivated land determine the food security situation in China to a large extent.Since the reform and opening up,the intensity of land use has been continuously refreshed,and the situation in which cultivated land is occupied and polluted is not uncommon,and the contradiction between people and land has become increasingly prominent.How to adapt to local conditions,it is very important to improve the overall level of cultivated land quality in terms of the distribution of key elements of cultivated land quality and the detailed conservation and differential protection of cultivated land in the vicinity.This paper selects the cultivated land in the Changsha-Liuyang-Pingjiang hilly area as the research object,conducts field surveys and interviews with farmers through questionnaires,summarizes and analyzes the farmland quality concept based on farmers’ cognition;divides the study area into three-level scale areas,and then selects cultivated land.The arable land components of quantity,quality and ecology of quality are used as evaluation indicators to construct multi-scale cultivated land quality evaluation index system.Finally,based on Arc GIS and Open Geo Da software,spatial autocorrelation analysis method is used to calculate the space of each element in Changsha-Liuyang-Pingjiang hilly area.The correlation coefficient is tested to determine the key elements of cultivated land quality and to reveal the spatial correlation degree and regularity of cultivated land at different scales.The specific research results are as follows:(1)Propose the concept of key elements of cultivated land quality,which is specifically defined as the quality components of cultivated land that have a decisive effect on the overall quality of cultivated land,crop growth status and grain yield.(2)The quality view of cultivated land based on farmers’ cognition is mainly formed by the education level of farmers,farmland farming techniques,crop growth status and grain yield,and farmers generally have weak farmland ecological awareness and ageing.(3)According to the characteristic scale of 60 km,the cultivated land in Changsha-Liuyang-Pingjiang hilly area is divided into three scale ranges.Based on the quantity,quality and ecological three-dimensional view of cultivated land quality,the multi-scale cultivated land quality evaluation index system in Changsha-Liuyang-Pingjiang hilly area is constructed.(4)Through the spatial autocorrelation calculation and analysis,all the selected cultivated land quality evaluation indicators show spatial positive correlation.Among them,the three factors of irrigation guarantee rate,organic matter and plough layer texture are the key elements of cultivated land quality.The degree of contiguous arable land and the degree of arable land fragmentation are shown as key elements of arable land quality on the second and third scales.(5)The quality dimension of cultivated land contributes the most to the overall quality of cultivated land,followed by the quantity and ecological dimension.With the increase of observation scale,the Moran’s I index of each element of the quantity and quality dimension of cultivated land increases,while the ecological dimension element The Moran’s I index decreases as the scale becomes larger.