Diversifying crop rotations with temporary grasslands - Université de ...

C.II.2.1.1 Weed seed addition
At the beginning of the experiment (4 Sept. 2006), the natural soil seed bank was
supplemented by sowing 17 common annual weed species representing 13 families (see Table
7 for species names). Species were selected among the most common arable weeds in France
but excluding wind dispersed species to reduce dispersion and contamination of neighbouring
plots. Weed seeds were provided by ‘Herbiseed’, Twyford, Berkshire, UK
(http://www.herbiseed.com). Weed seeds were sown prior to crop sowing using a specialized
sowing machine and slightly incorporated in the soil (0-5cm deep). Sowing density varied
between 8 and 45 seeds per m² (mean=30) depending on the species (see Table 7) giving a
total of about 500 weed seeds added per m². One out of the six micro plots of each plot was
left unsown for control (‘unsown zone f’ on Fig. 10).
Table 7: Weed species sown on the experimental plots.
Scientific Name Code English name Family D G V R
-2
m % ±SD %
Alopecurus myosuroides Huds. ALOMY blackgrass Poaceae 30.4 52±15 67±12 27.6
Amaranthus retroflexus L. AMARE common amaranth Amaranthaceae 45.4 93±5 98±4 1.8
Anagallis arvensis L. ANGAR scarlet pimpernel Primulaceae 42.0 43±48 95±8 1.9
Bromus sterilis L. BROST barren brome Poaceae 25.0 95±8 95±8 10.4
Capsella bursa-pastoris Medi CAPBP shepherd's-purse Brassicaceae 33.6 20±13 NA 11.5
Chenopodium album L. CHEAL fat hen Chenopodiaceae 29.2 82±13 92±8 1.6
Fallopia convolvulus (L.) Å. Löve POLCO black bindweed Polygonaceae 32.8 0±0 58±15 10.3
Galium aparine L. GALAP cleavers Rubiaceae 7.5 10±15 42±12 42.1
Geranium dissectum L. GERDI cut-leaved crane's-bill Geraniaceae 14.0 58±32 93±10 29.3
Lamium purpureum L. LAMPU red dead-nettle Lamiaceae 30.0 00±0 60±18 0.9
Lolium multiflorum L. LOLMG italian rye-grass Poaceae 23.3 95±5 95±5 21.6
Papaver rhoeas L. PAPRH field poppy Papaveraceae 37.3 10±13 NA 0.9
Poa annua L. POAAN annual meadow grass Poaceae 32.3 95±8 95±8 1.1
Sinapis arvensis L. SINAR charlock Brassicaceae 29.2 50±17 90±11 4.3
Stellaria media (L.) Vill. STEME com. chickweed Caryophyllaceae 36.0 38±42 83±10 27.9
Veronica persica L. VERPE com. field-speedwell Scrophulariaceae 25.2 95±5 95±5 31.6
Viola arvensis Murray VIOAR field pansy Violaceae 30.0 07±10 85±15 2.5
D, density of seeds per m² added on the experimental plots; G, mean percentage of seeds germinated in growth
chambers; V, mean percentage of seeds with viable embryos; R, mean field emergence rate [calculated as the
mean of the maximum densities of emerged seedlings during the first 8 month of the field experiment (September
2006-April 2007) *100 divided by the density of viable seeds sown].
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