Weeds are often harmful to crop growth due to the competition for space and resources. A field experiment containing four treatments with three replications in a complete randomized design was conducted at Yucheng Comprehensive Experiment Station, Chinese Academy of Sciences since 2008 to assess the impact of shifting from conventional tillage to no-till with crop residue management on weeds and wheat production at the North China Plain. We found that both aboveground weed density and species richness were higher under continuous no-till (NT) than conventional tillage (CT) in the regrowth and stem elongation stage of wheat growth. On the other hand, aboveground weed density in the stage of flowering and filling decreased with crop residue mulching. The density of the soil seed bank in crop residue removal treatments was significantly higher than that of crop residue retention. Besides, either crop residue mulching or incorporating into the soil significantly increased the wheat yield compared with crop residue removal regardless of tillage management. In conclusion, crop residue retention could decrease the weed density and species richness both aboveground and in the soil seed bank and inhibit the growth of broadleaf weeds by the residue layer. Moreover, crop residue retention could improve the wheat yield.

Crop residues management has great effects on weeds in croplands. To understand the weed responses to crop residues management and weeds impact on crop yield, a field trial with three crop residues management strategies has been conducted in the North China Plain since 2008. Weed community composition and structure across the species, morphological types, life forms, and community levels were investigated during 2019–2020. The results show that the field with crop residues retention significantly decreased weed density than that in the field with no crop residues retention. Furthermore, total crop residues retention significantly decreased weed density than half crop residues retention. Compared with no crop residues retention, the weed aboveground dry matter in the field with total and half crop residues retention significantly decreased. Meanwhile, the maize grain yield significantly increased, resulting from weeds decreased with crop residues retention on the field. Negative correlations were found between maize grain yield and the density and aboveground dry matter of monocotyledonous weeds. These findings indicate that long term crop residues retention under conventional tillage might be an effective agronomic practice to retard weed growth. However, the mechanism of crop residues retention on weed control is still needed to research.