Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: ECOLOGY, MANAGEMENT AND ENVIRONMENTAL IMPACT OF WEEDY AND INVASIVE PLANT SPECIES IN A CHANGING CLIMATE

Location: Global Change and Photosynthesis Research Unit

Title: An investigation to enhance understanding of the stimulation of weed seedling emergence by soil disturbance

Authors
item Schutte, B -
item Tomasek, B -
item Davis, Adam
item Andersson, L -
item Benoit, D -
item Cirujeda, A -
item Dekker, J -
item Forcella, Frank
item Gonzalez-Andujar, J -
item Graziana, F -

Submitted to: Weed Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 7, 2013
Publication Date: February 1, 2014
Citation: Schutte, B.J., Tomasek, B.J., Davis, A.S., Andersson, L., Benoit, D.L., Cirujeda, A., Dekker, J., Forcella, F., Gonzalez-Andujar, J.L., Graziana, F. et al. 2014. An investigation to enhance understanding of the stimulation of weed seedling emergence by soil disturbance. Weed Research. 54(1):1-12.

Interpretive Summary: Disturbance of agricultural soils through primary tillage can stimulate the germination and emergence of annual weeds. If timed correctly, tillage can affect weed management positively by allowing farmers to eliminate emerged seedlings, creating a "stale seedbed" for planting the crop. Our goal was to improve knowledge of the temporal relationship between primary tillage and weed seedling recruitment. Field experiments were conducted over 16 site-years at 10 research farms across Europe and North America to quantify the impact of superficial soil disturbance (SSD) on common lambsquarters (Chenopodium album) seedling emergence timing. Each site-year contained two seed lots (local and common, with the common lot studied at all burial sites) grown in soil disturbed at six timings (0, 50, 100, 150, 200 day-degrees [base temperature 3 C] after first emergence from undisturbed soil). Regardless of burial site, lot and SSD timing; SSD promoted seedling emergence relative to undisturbed ground by increasing emergence from a given set of flushes rather than increasing the number of flushes. The promotional effects of SSD on emergence were strongest within 500 day-degrees following SSD; however, low levels of SSD-induced emergence were detected as late as 3000 day-degrees following SSD. Accordingly, stale seedbed practices (e.g. weed harrowing) that eliminate weed seedlings should occur within 500 day-degrees of disturbance, and implementation of such techniques will likely incur slight increases in weed population densities over the course of the growing season.

Technical Abstract: Enhanced understanding of soil disturbance effects on weed seedling recruitment will guide improved management approaches. Field experiments were conducted at 16 site-years at 10 research farms across Europe and North America to 1) quantify superficial soil disturbance (SSD) effects on Chenopodium album emergence behaviours, and 2) clarify adaptive emergence behaviours in frequently disturbed environments. Each site-year contained factorial combinations of two seed lots (local and common, with the common lot studied at all burial sites) and six SSD timings (0, 50, 100, 150, 200 day-degrees [base temperature 3 C] after first emergence from undisturbed soil). Regardless of burial site, lot and SSD timing; SSD promoted seedling emergence relative to undisturbed ground by increasing emergence from a given set of flushes rather than increasing the number of flushes. The promotional effects of SSD on emergence were strongest within 500 day-degrees following SSD; however, low levels of SSD-induced emergence were detected as late as 3000 day-degrees following SSD. Accordingly, stale seedbed practices (e.g. weed harrowing) that eliminate weed seedlings should occur within 500 day-degrees of disturbance, and implementation of such techniques will likely incur slight increases in weed population densities over the course of the growing season. Compared to the common lot, local lots exhibited reduced variance in total emergence measured within sites and across SSD treatments, suggesting C. album adaptation to disturbance involves increased consistency in SSD-induced emergence.

Last Modified: 12/22/2014
Footer Content Back to Top of Page