Allelopathy Journal

Effects of lignin from allelopathic and non-allelopathic rice straws were investigated on Echinochloa crus-galli and soil microorganisms. E. crus-galli growing in the lignin amended soils was significantly inhibited. The inhibitory degree varied with concentrations and time intervals of incubation, but there was no difference between the allelopathic PI312777 and non-allelopathic Liaojing-9 rice straws. Furthermore, inhibition was higher in soil incubated with lignin at low concentration (10 μg/g⁻¹ soil) than at high concentration of (300 μg/g⁻¹ soil). In soil microbial population, bacteria and actinomycetes were less sensitive to applied lignin than fungi. The lignin of rice straws at test concentrations stimulated the soil fungi but inhibited the soil bacteria and actinomycetes during the late incubation periods. The results suggested that both allelopathic and non-allelopathic rice straws left in the field could produce lignin into paddy soils, to interact with plant and soil microbes.