Spatial distribution of cultivated land quality at different scales in Chongyi County

While the quality of cultivated lands is the primary basis for judging the productivity of land, the characteristics of the spatial distribution of land quality are critical for farmland research. Multi-scale study of cultivated land quality and spatial structural characteristics are inevitable in strengthening rational allocation of land resources for the protection of cultivated lands. The enrichment of scientific connotation of cultivated land quality should objectively reflect spatial distribution differences in natural quality, utilization quality and economic quality at different scales. Based on the First Law of Geography and specific characteristics of Chongyi County, typical hilly and mountain areas were selected and evaluated for cultivated land quality in a spatial autocorrelation model supported by platforms such as Geoda and GS+. The work discussed the spatial interactions and distributions of natural quality, utilization quality and economic quality of cultivated lands at county, township and village scales. The results show that:1) the natural quality of cultivated lands in Chongyi County was during grade 9-12 and the utilization quality during grade 6-9. There was a gradually increasing "northwest to southeast" trend with an economic quality of grade 7-10. There was a degree of spatial aggregation effect which was strongest when spatial distance was 4 500 m. The Moran's I value of cultivated land quality showed that natural quality (0.445) > economic quality (0.406) > utilization quality (0.281). The natural quality of cultivated land had the strongest positive spatial correlation with weakest degree of variation, while the utilization quality was weakest in spatial correlation and strongest in spatial variability. 2) The quality of cultivated lands showed different scale effects for different quality indexes. For the difference in spatial aggregation between township and county scales, the natural quality was largest, followed by economic quality and then utilization quality. Larger spatial scales weakened spatial aggregation, and spatial aggregation effect was most significant at village scale. 3) The spatial agglomeration type HH of cultivated land quality was mainly distributed in the southwest of county, LL distributed in Jinkeng Village and Zhukeng Village. The HH type of utilization quality was mainly distributed in the flat Longgous and Qianchang Townships, and LL type in deep mountain area where the elevation was higher and the cultivated land most dispersed. The HH type of economic concentrated in Guantian Town, Longqi Township and Shangbao Township where the terrain was relatively flat and the road access degree high. The LL type was distributed in a strip shape in relatively occluded area. The research results revealed that cultivated land quality had different spatial differentiation characteristics at different spatial scales and large spatial scale weakened the aggregation difference of cultivated land quality. The research had practical significance for monitoring and protection of cultivated lands at different spatial scales and more accurate management of arable land quality.