Weed Technology (2003) 17, 42-50

Steven A. Fennimore and Louise E. Jackson (2003)
Organic amendment and tillage effects on vegetable field weed emergence and seedbanks
Weed Technology 17 (1), 42-50
Abstract: Evaluations of the effects of minimum tillage vs. conventional tillage and the effects of organic amendments (cover crops and compost) vs. no organic amendments were conducted in a California vegetable field. Weed densities were monitored, and soil samples were taken to measure the effects of the treatments on weed seedbanks and microbial biomass over a 24-mo period. Reduced tillage increased the density of shepherd's-purse in the upper soil layer (0 to 15 cm) of the soil seedbank compared with conventional tillage. Evidence is presented that suggests relationships between organic amendments, weed population reductions, and increases in soil microbial biomass: (1) shepherd's-purse emergence and seedbank densities were lower in the organic amendment plots, (2) microbial biomass was nearly always higher in the organic amendment plots, and (3) significant negative correlations between microbial biomass and burning nettle and shepherd's-purse emergence densities were found. These results suggest that organic matter addition may lead to reduced weed emergence.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Steven A. Fennimore

Research topic(s) for pests/diseases/weeds:
environment - cropping system/rotation
population dynamics/ epidemiology

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Urtica urens (weed)		U.S.A. (SW)
	Capsella bursa-pastoris (weed)		U.S.A. (SW)