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

Mean plant density [plants m -2 ]
Time
Fig. 13: Temporal development of emerged weed densities (plants per m 2
) in six perennial crop treatments (T2-
85
Management
Soil tillage
Cutting
Weed species
T8, upper part) and three successions of annual crops (T9-T11, lower part, plotted with two scales).
Bold vertical lines indicate the dates of soil tillage (all weed plants are destroyed, densities go back to zero);
broken thin vertical lines indicate the cutting dates (weed plant densities do not go back to zero). Med, Medicago
sativa; Dac, Dactylis glomerata; Aut, sown in autumn; Spr, sown in spring; C+, 5 cuts/year; C-, 3 cuts/year; WB,
succession of annual crops (wheat-barley); T+/T-, with/without soil tillage after harvest; M, mustard intercrop;
see
Table 6 for more details on the nine crop treatments. The 21 most important weed species/genera are
separated with a colour code, other minor species are grouped as ‘other Grasses’ and ‘other Dicots’. Mean plant
densities are linearly interpolated between successive measurements and soil tillage dates, real dynamics can
differ due to plant emergences and mortality. Narrow peaks of plant densities (e.g. during 2007 in treatments T4,
T7 and T8) indicate peaks of weed germination followed by high plant mortalities.