A comparative study on three methods of soil quality evaluation of microtopography in the semi-arid Loess Plateau, China

Three soil property test data of microtopography in the semi-arid Loess Plateau were used to compare the following three soil quality evaluation methods: correlation coefficient method, factor analysis method and Nemoro index method. The results of these methods were analyzed and compared to determine the most suitable method for comprehensive evaluation of soil quality. While correlation coefficient method and factor analysis method produced similar results, Nemoro index method showed several differences from the othertwo methods and exhibited higher sensitivity in its assessment results. The soil quality index (SQI) parameters of three methods showed consistent scales and variation trends among the various microtopographies, and there was a highly significant linear positive correlation between the SQI parameters of any two given methods. This result suggested that the three methods were all reliable and could be employed for comprehensive assessment of soil quality of microtopography in the study region. However, the Nemoro index method involves relatively uncomplicated mathematics and is very easy to absorb, and thus should be preferentially employed when three grading standards can be identified. The factor analysis method is the next most preferable, followed by correlation coefficient method.