Differential characteristics of cultivated land grade and its effect on cultivated land protection in China

In order to profoundly understand the cultivated land quality, efficiently protect and improve cultivated land quality, the differential characteristic of cultivated land grade between provincial regions were found out by contrast analysis method based on the results of cultivated land gradation in China and the 1:50 000 national agricultural land gradation database. The results showed that the basic differential characteristic of cultivated land in China was summed up as “less area of excellent grade, more area of low grade, and complex differential characteristics between and in provincial regions”. The total cultivated land of 31provinces in China was calculated as 68390.2 khm2 by using the Standard Area defined as Guangdong Province’s average grade(5.4 grade), or 45 750.7 khm2 by using the Standard Area defined as 1 grade. According to the primary farmland protection area of 31 provinces in 2020 in national land use planning, primary farmland protection ratio by law and cultivated land grade in provinces must be plan as a whole. Based on the results, it is suggested that both quality and quantity should be paid attention, and taking grade advance and land capability construction as core role, constituting cultivated land grade and land capability dynamic inspection and report system are all necessary in land rehabilitation programming system, primary farmland regulating, high criterion primary farmland construction and permanence primary farmland protection.