Impacts of cropping system and management practices on the assembly of weed communities

Abstract

Summary Understanding how weed communities assemble as a function of biotic and abiotic filters and transform through time has important implications for the sustainable management of agronomic systems. In a three‐year study, we evaluated weed community responses to lucerne (Medicago sativa, perennial) vs. continuous spring wheat (Triticum aestivum, annual, CSW) and weed management practices where weeds in the CSW system were managed with three contrasting approaches (herbicide, tillage or sheep grazing). Our results indicated no differences in weed diversity between the perennial and annual crops or across the different management practices in CSW. However, there were differences in weed community composition. Lucerne, with the exception of the establishing year, impeded the growth and reproduction of several annual weeds, including Amaranthus retroflexus, Thlaspi arvense, Lamium amplexicaule and Chenopodium album, but favoured perennial broad‐leaved weeds such as Taraxacum officinale and Cirsium arvense. The replacement of herbicide treatments in pre‐plant and post‐harvest in CSW with soil tillage or sheep grazing selected for different weed communities beyond the second year of establishment. The weed species driving the differences in CSW systems were Androsace occidentalis, more common in CSW managed chemically; Asperugo procumbens, more common in CSW managed with tillage; and T. officinale and Lactuca serriola, more common in CSW managed with sheep grazing. Understanding how cropping systems modify weed communities is a necessary step to shift from reactive weed control programmes to predictive management strategies.

Weed seedling emergence in contrasting fodder crop systems following 30 years of cultivation in the lowlands of Northern Italy

“…The study indicates that the cropping systems had a significant impact on the abundance of the major weed species and the composition of the weed assembly, confirming the results of prior studies on a range of cropping and management systems (Menalled et al , 2001; Moonen and Bàrberi, 2004; Barroso et al , 2015; Ruisi et al , 2015; Rotchés‐Ribalta et al , 2017). The total number of emerged seedlings (which was a likely index of the total seedbank) was influenced by the presence of relatively few, very abundant species, while seemingly being not affected by the number of recorded species.…”

Impacts of Dryland Farm Management Systems on Weeds and Ground Beetles (Carabidae) in the Northern Great Plains

“…For example, we observed greater association of grasses such as B. tectorum and H. jubatum in conventional fields than in organic fields. Because tillage is frequently used in organic fields, the weed communities in those systems could shift to exclude perennial grasses and favor annual forbs, as frequent soil disturbance kills perennation structures and moves seeds to more surficial layers of the soil [40,41]. However, we also observed few of the perennial weeds such as C. arvense in our organic fields, possibly suggesting an ineffectiveness of tillage to control this species, but to break its roots and further increase its abundance and spread through vegetative propagation [36].…”

Relationships between soil properties and the occurrence of the most agronomically important weed species in the field margins of eastern Arkansas – implications for weed management in field margins

“…The acquisition of detailed knowledge on the relationships between the occurrence of weed species and abiotic factors where they occur will enhance our understanding of the multifunctional interactions that influence weed distribution and will improve our efforts for effective management (Barroso et al ., ). In addition, Turner and Van Acker () reported a knowledge gap between the occurrence of weed species and their ecology, as in the case of D. sanguinalis .…”