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Increasing evidence on environmental and economic benefits has raised farmers' interest in adopting alternative, less intensive soil management practices. To evaluate the influence of weed-competitive ability in response to a different tillage regime, a field study was conducted in maize under humid Central European climatic conditions in Slovenia. This study was established as a split-plot arrangement with three tillage practices (TPs) as the main plot: conventional (CN), conservation (CS), and no tillage (NT); this was combined with glyphosate application and the weed removal timing as the subplot. The weed removal timings were at the V3, V6, V9, V15, and R1 maize stages, with weed-free and weed season-long monitoring. The beginning and the end of the critical period of weed control (CPWC), based on a 5% maize yield loss rate, were determined by fitting the four-parameter log-logistic equations to the relative maize dry grain yield. The weed dry biomass from maize germination until the R1 growth stage in the NT TP was consistently lower than that in the CN and CS TP. Moreover, the NT TP resulted in a shorter CPWC (39 days after emergence (DAE)) compared to the CN (57 DAE) and CS (58 DAE). The results of CTWR (critical timing of weed removal) showed that less intensive tillage operations in the CS resulted in an earlier need for weed control (V2 and 23 DAE) compared to the CN (V3 and 39 DAE) and NT (V3 and 40 DAE). Our study suggests that the intensive tillage operations performed in the CN TP and the pre-sowing use of non-selective burndown herbicide in the NT delay the CTWR by more than 2 weeks, thus reducing the need for early post-emergence herbicide application in maize. [ABSTRACT FROM AUTHOR]

In recent decades, adoption of less intensive soil tillage practices has increased due to numerous environmental and economic benefits. Our investigation was performed during 2020–2022 and examined germinable and persistent weed seed bank response in the early conversion period from conventional (CN) to conservation (CS) and no-tillage (NT) system under the humid, temperate climate of central Europe. The germinable seed bank determined in the spring cropping period was up to four times greater compared to the autumn cropping period. By using NT, consistently lower germinable weed seed banks were seen compared to CN or CS with observed reductions of weed seed density 45–75%. Final abundance of persistent weed seed bank (117,000 seeds m−2) was considerably greater than average size of germinable weed seed bank across years (27,000 seeds m−2). The vertical distribution of germinable weed seed bank in the soil did not differ between the tillage treatments, while using CS and CN more persistent weed seeds were accumulated in the intermediate (5–10 cm) or the bottom (10–20 cm) soil layer. CS and NT facilitated greater weed species diversity and evenness in both germinable and the persistent weed seed bank. Our results showed that introduction of different tillage systems had an almost immediate response in the size of germinable weed seed bank in the soil. Thus, when converting new fields to alternative tillage systems with high weed pressure, weed seed bank studies are advocated to select systems that reduce germinable seed in the seedbank. This method will enable coherent integration of non-chemical weed management strategies and support existing IWM methods in transition to sustainable agroecological based weed management strategies. • Persistent weed seed bank greatly exceeded germinable weed seed bank stock. • No-till resulted in rapid and consistent reduction of germinated weed seeds at all soil depths. • Alternative tillage practices did not alter vertical weed seed distribution pattern in either of both weed seed banks • Weed diversity and evenness were facilitated by spring cropping and less intensive tillage. [ABSTRACT FROM AUTHOR]