Plant-mediated weathering of purple soils in Southwest China: a laboratory column experiment
摘要
Weathering is not only the fundamental process of soil formation but also a critical factor in maintaining soil nutrient balance. However, it is still unclear how plant root traits affect the microbial composition and soil chemical weathering intensity in purple soils.
Materials and methodsHere, a column experiment in laboratory was carried out in purple soils with four treatments of no plants (CK), Acacia, Dodonaea, and Sporobolus. The clay composition, plant root traits, and soil chemical index of alteration (CIA) were measured to understand the main factors for the enhanced purple soil weathering intensity.
ResultsRoot traits of Sporobolus, Dodonaea, and Acacia were greater than those of CK. Compared with CK, the CIA values of Sporobolus, Dodonaea, and Acacia increased by 3.9%, 1.2%, and 3.7%, respectively. In purple soil, the Quartz and Illite were observed the main composition, and the relative contents were measured 82.8 ~ 86.4%. The Chlorite relative contents in Sporobolus, Dodonaea, and Acacia treatments were increased by 28.4%, 22.4%, and 31.7% compared to CK, respectively. Notably, the variability in the relative content of Chlorite in Acacia treatment was more pronounced. The Mantel tests showed that the root diameter showed a significant positive correlation with Quartz and Chlorite, while exhibiting significant negative correlations with Potassium feldspar and Illite.
ConclusionThe variation in clay minerals composition in purple soil were primarily regulated by soil fertility characteristics mediated by plant root parameters.