Effects of Applying Accumulator Straw in Soil on Nutrient Uptake and Soil Enzyme Activity of Capsella bursa-pastoris under Cadmium Stress

摘要

The effects of applying four accumulator species (Conyza canadensis, Eclipta prostrate, Nasturtium officinale and Cardamine hirsute) 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 plant species (C. canadensis, E. prostrata, N. officinale and C. hirsuta). When applying the four accumulator 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: N. officinale straw > C. hirsuta straw > C. canadensis straw > E. prostrata straw > control. The soil available P and K contents were also increased by the four accumulator species straws, which were ranked as: N. officinale straw > C. hirsuta straw > C. canadensis straw > E. prostrata straw > control. The four accumulator species straws enhanced soil sucrase and soil urease activities, but reduced soil catalase activity. Therefore, applying accumulator straw could used to increase nutrient content and enhance soil enzyme activity of C. bursa-pastoris for the phytoremediation of Cd, and the straw of N. officinale was the best.