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Providing evidence to improve practice

Action: Pest regulation: Use crop rotations Mediterranean Farmland

Key messages

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Pest regulation (0 studies)

Crop damage (0 studies)

Ratio of natural enemies to pests (0 studies)

Pest numbers (1 study): One replicated, randomized, controlled study from Australia found less weed biomass in plots with a canola-wheat sequence, compared to a wheat-wheat sequence.

Natural enemy numbers (0 studies)

Implementation options (1 study): One replicated, randomized, controlled study from the USA found similar amounts of weed biomass in plots with four-year or two-year crop rotations.

Supporting evidence from individual studies

1 

A replicated, randomized, controlled study in 1994–1998 on an irrigated, arable farm near Davis, California, USA, found similar amounts of weed biomass in plots with four-year or two-year crop rotations. Implementation options: Similar amounts of weed biomass were found in plots with four-year or two-year crop rotations (4–273 vs 140–467 kg dry weight/ha). Methods: A four-year rotation (tomato, safflower, corn and wheat, beans) was used on 16 plots (four plots for each phase, each year), and a two-year rotation (tomato, wheat) was used on eight plots (four plots for each phase, each year). Each plot was 68 x 18 m. Fertilizer and pesticide were used on all plots. Weeds were sampled in the tomato plots, at harvest, in 1994–1998.

 

2 

A replicated, randomized, controlled study in 2010–2011 in a rainfed field in Western Australia found less weed biomass in plots with a canola-wheat sequence, compared to a wheat-wheat sequence. Pest numbers: Less weed biomass was found in plots with a canola-wheat sequence, compared to a wheat-wheat sequence (36 vs 43 g/m2). Methods: Wheat or canola was grown on three plots each in 2010, and wheat was grown on all plots in 2011. Each plot was 1.4 x 40 m. Fertilizer (150 kg/ha/year) and herbicide were used on all plots. Weeds were sampled at the end of 2011.

 

Referenced papers

Please cite as:

Shackelford, G. E., Kelsey, R., Robertson, R. J., Williams, D. R. & Dicks, L. V. (2017) Sustainable Agriculture in California and Mediterranean Climates: Evidence for the effects of selected interventions. Synopses of Conservation Evidence Series. University of Cambridge, Cambridge, UK.