Evaluation of inherent quality and dynamic quality of cultivated land based on comprehensive characteristics of indexes

Abstract: Quality evaluation of cultivated land is the most vital and most fundamental for the utilization and management of cultivated land resource. According to the element characteristics of cultivated land quality, this study aims to construct an index system of quality evaluation for cultivated land, via screening the comprehensive evaluation indicators from five respects: climatic conditions, topographic characteristics, soil properties, farming conditions, and environmental conditions. Two indicators can be proposed, namely the indicator response time (IRT) and degree of human interference (DHI), based on the internal attribute characteristics and external utilization level of indicator comprehensive characteristics. The indicators was divided into inherent indicators and dynamic indicators, and then the quality of cultivated land was also divided into inherent quality and dynamic quality of cultivated land. Therefore, two aspects were classified to measure the quality of cultivated land, including a relatively stable inherent quality and a relatively high dynamic quality. An integrated algorithm was used to calculate the inherent and dynamic quality index of a cultivated land, thereby to obtain the comprehensive quality of cultivated land. Quzhou county of Hebei province was also selected as a case study in the framework of inherent and dynamic quality of a cultivated land. The results showed that: 1) In the indicator of comprehensive characteristics, the quality of cultivated land can be efficiently evaluated from the relatively stable inherent quality and high variable dynamic quality, indicating a better performance to evaluate the impact of changes in the natural environment and human activities on cultivated land quality. 2) The comprehensive quality of cultivated land in Quzhou County was mainly in the high and medium level, accounting for 82.33% of the total cultivated land. The inherent and dynamic quality of cultivated land were dominated by the high-grade land, which was 60.65% and 50.18% of the total cultivated land area, respectively, indicating most distribution in the northern and southern regions of the county. 3) The area with the high inherent and dynamic quality of cultivated land was the largest in Quzhou County, accounting for 29.19% of the total cultivated area, where 48.13% and 58.17% of the areas with the high inherent and high dynamic quality, respectively. The inherent quality of cultivated land in the same soil type was generally higher than that of the dynamic quality, and the degree of spatial variability of cultivated land was lower in the inherent quality. 4) The average grade for the inherent quality of cultivated land in Quzhou County was slightly higher than that of dynamic quality, but the area with equal or slightly different inherent and dynamic quality of the cultivated land accounted for 85.36% of the total cultivated land area. The area of inherent quality equal to dynamic quality accounted for 37.17% of the total cultivated land. The evaluation data can contribute to the establishment of systematic land plans to protect the inherent quality, while improve dynamic quality. Therefore, the finding can provide a basic reference for the comprehensive land management and high-standard farmland construction, further to realize the trinity protection of cultivated land quantity, quality and ecology.