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Providing evidence to improve practice

Individual study: Forage productivity, species evenness and weed invasion in pasture communities

Published source details

Tracy B.F. & Sanderson M.A. (2004) Forage productivity, species evenness and weed invasion in pasture communities. Agriculture, Ecosystems & Environment, 102, 175-183


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Grow plants that compete with damaging weeds Natural Pest Control

A randomised, replicated, controlled study in 1999 in a greenhouse in Pennsylvania, USA (Tracy & Sanderson 2004) found that the weed curly dock Rumex crispus did not grow in pots where turnip Brassica rapa was used as a pasture species. Curly dock plant weight was 0 g/m² when grown with turnip compared to 80-89 g/m² with other pasture species and 191 g/m² when grown alone. Curly dock also had a reduced germination rate when grown with turnip (19%) compared to other pasture species (31-38%) or when grown alone (60%). The experiment used 30 litre pots which each received 100 turnip or other pasture species seeds and 100 curly dock seeds. The control treatment was not sown with pasture species. Plants were harvested 65 days after planting and weight of above ground plant matter was measured for each species.

 

Use mixed pasture Natural Pest Control

A randomised, replicated trial in 1998-2000 in pasture land in Pennsylvania, USA (Tracy & Sanderson 2004) found that weed density was lower in plots with a higher diversity of pasture species. Total weight of weed plant material was generally lower in plots with six or more species. Pasture species yield was higher in plots with lower weed density. An additional randomised, replicated, controlled greenhouse trial in 1999 found that plant weight of the weed curly dock Rumex crispus was lower when grown with a mix of 10 pasture species (1-10 g/m²) than with one or five species (75-89 g/m²), except when the single species was turnip Brassica rapa which completely suppressed the weed (see "Plant species that compete with damaging weeds"). The field trial used 2.25 m² plots with eight pasture species mix treatments of 1-15 species, replicated 12 times. Each plot received 120 g of seed divided equally between the pasture species. The greenhouse trial used 30 litre pots, each of which received 100 curly dock seeds and 100 pasture species seeds divided equally between species in six species mix treatments with one, five or 10 species. Control pots received no pasture species seeds. Each treatment was replicated six times.