Abstract: This study synthetically evaluated the effects of three kinds of soil conditioner (sodium carboxymethyl cellulose,phosphogypsum and biochar) on the physiochemical properties of Aeolian sandy soil and cotton plant growth. A pot experiment was carried out under different ratios of soil conditioner additions,and 12 indexes were determined. The methods of principal component analysis (PCA)and mathematical calculation of weighted summation were used to establish the comprehensive evaluation equation for the improvement effect by calculating the comprehensive score so as to select the best ratio of soil conditioner. The results showed that all three kinds of soil conditioner could be used to decrease the soil bulk density and pH value,increase thesoil porosity and contents of organic matter,total nitrogen,total phosphorus,available phosphorus and available potassium,and slightly change the total potassium content. Moreover,the plant height,basal stem and biomass of cotton were increased substantially. Based on the comprehensive evaluation equation,the comprehensive score under high irrigation was significantly higher than that under low irrigation,and the comprehensive score was in an order of CG3>CG2>CG1>BG3>BG2>AG3>BG1>AG2>AG1. The improvement effect of applying biochar for 45 g·kg^-1 under high irrigation was the best,and its score was the highest (4.69).

Key words: aeolian sandy soil, soil conditioner, principal component analysis, pot experiment, cotton