Dynamic changes in weed abundance and biodiversity following different green manure establishment

Weeds have a negative impact on agricultural production by competing with cultivated crops for resources and fostering conditions conducive to disease and insect pest dissemination. Hence, optimal weed management is of paramount importance for sustainable agricultural. In this study, the ability of four distinct green manure species to suppress weeds was determined in a field experiment conducted in Chongqing, Southwest China. After cultivating the green manure species, the weed density and diversity were monitored over the following year. The findings highlight a notable trend in the suppressive ability of green manures, with increased suppression observed from November to March, an optimal level observed from March to May, and a gradual decline observed thereafter. Poaceae (Lolium perenne L.) demonstrated the highest efficacy in suppressing weeds. The meta-analysis underscore the exceptional suppressive effects of poaceous green manures on weed as well and prove sustained planting for three or more consecutive years yielded superior weed suppression outcomes. Green manure had the most prominent inhibitory effect on poaceae weeds, followed by Polygonaceae and Caryophyllaceae. The field experiment also investigated the effect of green manures on weed community composition, they increased in the proportion of perennial weeds within these communities. This study offers valuable insights that can guide policymakers, agricultural experts, and farmers in devising effective weed management strategies. By highlighting the potential benefits of green manures and unraveling their nuanced impact, this study contributes to the arsenal of sustainable agricultural practices.