a b s t r a c tLaboratory biological simulation experiment was conducted to investigate growth disturbance of high, moderate, low concentration of aqueous extracts (i.e. the original extracts with a solid-liquid ratio of 1:40 g mL −1 and its 5 times diluents and 25 times diluents) from several crops straw (residue) on Ageratina adenophora, a worldwide notorious invasive weed. The results showed: (a) aqueous extracts from several crops straw (residue) brought about different impacts on the single index for germination and growth of A. adenophora, e.g., high concentration of aqueous extracts from Brassica oleracea waste leaves showed a strong inhibition against the germination rate (GR) and germination index (GI) of A. adenophora, while high concentration of aqueous extracts from Vicia cracca straw showed a strong inhibition against radicle length (RL) and hypocotyl length (HL) of A. adenophora; (b) high concentration of aqueous extracts from B. oleracea waste leaves and high, moderate and low concentration of aqueous extracts from Oryza sativa straw and Triticum aestivum straw showed rather strong synthetic effects (inhibition) on GR and GI of A. adenophora, which could be chosen for the control over the seeds germination of A. adenophora; (c) high and moderate concentrations of aqueous extracts from V. cracca straw, high concentration of aqueous extracts from B. campestris waste leaves, and moderate and low concentrations of aqueous extracts from O. sativa straw and T. aestivum straw showed rather strong synthetic effects (inhibition) on RL and HL of A. adenophora, which could be selected as ideal materials for the control over the seedlings growth of A. adenophora; and (d) high concentrations of aqueous extracts from V. cracca straw, B. oleracea waste leaves and B. campestris waste leaves, and high, moderate and low concentrations of aqueous extracts from O. sativa straw and T. aestivum straw showed rather strong synthetic effects (inhibition) on GR, GI, RL and HL of A. adenophora, which could be selected as ideal materials for the control over the seeds germination and seedlings growth of A. adenophora. Thus, this study would provide a theoretic guidance and technical support for the resources utilization of crops straw (residue) and the prevention and control over invasive weeds as well.

In order to study characteristics of anaerobic co-digestion of corn straw and cabbage, the experiment was performed with corn straw to cabbage (S:C) of 4:1, 6:1 and 10:1 based on total solids (TS) at 35±1°C at initial TS of 8%. The effects of co-digestion on pH, volatile fatty acid (VFA), and biogas yield were examined. Results showed that the S:C of 4:1 was optimal with accumulative biogas yield of 334.53mL/gTS compared with S:C of 6:1 and 10:1 with accumulative biogas yield of 289.31mL/gTS and 311.37 mL/gTS, respectively. This should be attributed to the high VFA concentration achieved by S:C of 4:1.