Applying Hyperaccumulator Straw in Cd-Contaminated Soil Enhances Nutrient Uptake and Soil Enzyme Activity of Capsella bursa-pastoris

The effects of applying four hyperaccumulator species (Solanum photeinocarpum, Bidens pilosa, Siegesbeckia orientalis and Youngia erythrocarpa) straws in cadmium (Cd) contaminated soil on phosphorus (P) and potassium (K) uptake and soil enzyme activity of Capsella bursa-pastoris were studied through a pot experiment. Five treatments were used in the experiment: control (no straw applied), and straw applied for each of the four hyperaccumulator species (S. photeinocarpum, B. pilosa, S. orientalis and Y. erythrocarpa). When applying the four hyperaccumulator species straws, the total P and K contents in roots, stems and leaves of C. bursa-pastoris increased compared with control. The total P and K contents in roots, stems and leaves of C. bursa- pastoris were ranked as: S. photeinocarpum straw > Y. erythrocarpa straw > B. pilosa straw > S. orientalis straw > control. The soil available P and K contents were also increased by the four hyperaccumulator species straws. The four hyperaccumulator species straws enhanced soil sucrase, soil catalase and soil urease activities. Therefore, applying hyperaccumulator straw could used to increase nutrient content and enhance soil enzyme activity of C. bursa- pastoris in Cd-contaminated soil, and the straw of S. photeinocarpum was the best.