The gradation update of cultivated land quality is an important way to implement strict arable land protection policy. According to GB / T 28407- 2012 standard,using the factor method to calculate the natural quality class,land use factor and land economy factor of each classification unit in Guiyang County. Using classification of spacing,the nature gradation,use gradation and economy gradation were obtained. With the comparison of last round of cultivated land quality updating,problems in cultivated land protection in Guiyan...
