Effects of Intercropping with Bidens Species on Nutrient Absorption of Grape Seedlings under Cadmium Stress

To study the effects of intercropping on nutrient absorption of plants under cadmium (Cd) stress, a pot experiment was conducted to study the effects of intercropping with four Bidens species (Bidens bipinnata, Bidens pilosa, Bidens parviflora and Bidens biternata) on the nitrogen (N), phosphorus (P) and potassium (K) uptake of grape seedlings under Cd stress. When grape seedlings intercropped with four Bidens species, the total N and total K contents in grape seedlings decreased compared with the monoculture. Intercropping decreased the total P content in roots of grape seedlings except intercropping with B. pilosa and increased the total P content in shoots of grape seedlings except intercropping with B. parviflora. Compared with the monoculture, the soil available P and available K concentrations of intercropping decreased, but the soil alkali soluble N concentration of intercropping significantly increased. On the whole, intercropping with B. pilosa could most effectively improve the P absorption of grape seedlings and inhibit the N and K absorption of that. Therefore, intercropping with B. pilosa could benefit the nutrient absorption of grape seedlings under Cd stress.