Fig. 2.

Relative abundance of key weed species in different depths (0–15 and 15–30 cm) under various tillage and crop establishment methods. Vertical bars represent the standard error of the mean; bars followed by different lower-case letters are significantly different at P < 0.05. [RPTR: Puddled random transplanted rice; BCW: Broadcast wheat; LPTR: Puddled line transplanted rice; CTW: Conventional-till wheat; CTMTR: CT machine transplanted rice; ZTW: Zero-till wheat; ZTMTR: Zero-till MTR; SRI: System of rice intensification; SWI: System of wheat intensification; DSR: Direct-seeded rice].