Abstract
This study aimed to determine the effects of different dosages of Chinese herbal compound soil amendment on cassava growth and rhizosphere microbial diversity. In this study, Cassava SC8 growth was determined under four treatments. The growth was promoted by the application of the Chinese herbal compound soil amendment powder and agent. After 240 days of treatment, we measure its height, diameter of the stem, maximum perimeter of cassava, tuber number, weight of single tuber, yield per hectare, the mineral elements in cassava, the ash content in starch and the microbial diversity in the soil. Compared with the control group, the height, diameter of the stem, maximum perimeter of cassava, tuber number, the weight of a single tuber, yield per hectare in the treatment groups all show increase, and the application of 1200 kg of Chinese herbal compound soil amendment per hm2 (T2) had the strongest positive effect on the cassava growth. As for the water content of tubers, that of T2 decreased by 5.96% compared with T4, while no substantial difference among other groups. The Fe content in T2 decreased by 29.46%, and Zn in T3 increased by 39.48%, while the content of other metal ions in four treatments showed no substantial difference. At the same time, the experiment also found that, as bacterial abundance in soil, Streptophyta dominated in T2, and Fimbriimonas is a unique genera of T2. In addition, the abundances of Nocardioides and unclassfied_Spartobacteria in the T2 were greatly considerable than other treatment groups. As fungal abundance in soil, after treated with different concentrations, the composition of soil fungi differed greatly among the groups, and the samples at different concentrations contained more than 20 species of unique bacteria. At the genus level, compared with the control group, the relative abundance of unclassfied_Chaetomiaceae in the treatment group was considerably reduced, and the relative abundance of Psathyrella in the T1 increase substantially. We speculates that these advantages and the existence of bacteria and fungi can affect rhizosphere soil microorganisms, further improve soil effective nutrients and enzyme activities, thereby affecting the growth and physiological indicators of cassava plants.