Fig. 1

Diagram of intercropping and monocropping sampling sites in the field and pot experiments. a The peanut and cassava intercropping system (i), and the peanut monocropping system (ii) in the field. The intercropping combination included a 2.0-m peanut strip (five rows of peanut, with a 0.4 m interrow distance) and a 0.4-m cassava strip (one row of cassava). The interplant distance within the same column was 0.2 m. In the monocropping system, the interrow distance was 0.4 m, and the interplant distance within the same column was 0.2 m. CRi, BSi and PRi represent soils from the cassava rhizosphere, the bulk soil and the peanut rhizosphere in the intercropping system; PRm and BSm represent soils from the peanut rhizosphere and the corresponding bulk soil in the monocropping system. b Schematic of the intercropping and monocropping pot experiments. Pairs of plants were grown together in a pot separated into compartments with a wire mesh screen filter (red dotted line). Treatment I, cassava monocropping; treatment II, peanut and cassava intercropping, treatment III, peanut monocropping; treatment IV, peanuts were cultured with the addition of cyanide dilution; and control, peanuts were cultured with the addition of water. The rhizosphere and bulk soil collected from the corresponding coloured sites are indicated by the site name plus lowercase “s”; the peanut plants collected from the sites are indicated by the site name plus lowercase “p”