Effects of Hyperaccumulator Straw on Soil Nutrient Availability and Soil Enzyme Activity of Cyphomandra betacea under Cadmium Stress

Keywords: Hyperaccumulator straw; Cyphomandra betacea; Soil nutrient; Soil enzyme Abstract: A pot experiment was conducted to study the effects of hyperaccumulator straw on soil nutrient availability and soil enzyme activities of Cyphomandra beracea under Cadmium (Cd) stress. Four Cd-hyperaccumulator species (Solanum photeinocarpum, Tagetes erecta, Galinsoga parviflora, Bidens pilosa) straws were applied as mulches on the Cd-contaminated soil surface which planted C. beracea. The results showed that mulching hyperaccumulator straw on soil surface increased soil organic matter content, a nd soil available contents of N, P and K. The contents of organic matter content and available N were r anked as: T. erecta > S. photeinocarpum > G. parviflora > B. pilosa > control, and the available P and K contents were ranked as: S. photeinocarpum > T. erecta > G. parviflora > B. pilosa > control. The straws of S. photeinocarpum and T. erecta increased the soil catalase, polyphenol oxidase, urease and sucrase activities, but the straws of G. parviflora and B. pilosa reduced them. Therefore, mulching with the straws of S. photeinocarpum and T. erecta could promote growth of C. betacea under Cd stress.