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

Biomass [g dry matter m -2 ]
400
200
0
400
200
0
400
200
0
400
200
0
400
200
0
400
200
0
400
200
0
T2 Med Aut C-
T4 Med Aut C+
T5 Med Spr C+
T6 Dac Spr C+
T7 Dac Aut C+
T8 Dac Aut C-
T9 WB T+
669g 559g
838g
820g 769g
1.9
1.11
1.1
1.3
1.5
1.7
1.9
1.11
1.1
1.3
1.5
1.7
1.9
1.11
Crops
Lucerne
Dactylis
W-Wheat
S-Barley
Weeds
VERPE
STEME
SON
SINAR
POL
LOLMU
GERDI
GALAP
CHEAL
BROST
AMARE
ALOMY
Other grasses
Other dicots
2006 2007 2008
2006 2007 2008
Fig. 18: Temporal development of crop and weed biomass Time
in perennial and annual crop treatments.
Left part: Mean absolute biomasses of crops and weeds (g dry matter above 5 cm from the soil surface per m²,
N=4). Cumulated values higher than the plotted limit (400g/m²) are given as numbers. Biomasses go down to
zero at crop cutting harvesting dates. Successive measurements are linearly interpolated; however, real biomass
dynamics may differ. Right part: Relative biomass of grass (□ quadrats) and broad -leaved (○ circles) weeds
expressed as the ratio of weed biomass on total (crop + weed) biomass. Each point linked by traits represents one
replicate block. Med, Medicago sativa; Dac, Dactylis glomerata; Aut, autumn sown; Spr, spring sown; C+, 5
cuts/year; C-, 3 cuts/year (see Table 6B or Fig. 16 for cutting dates); WB T+, succession of annual crops with soil
93
Ratio weed BM / total BM
Broadleaved
weeds
Grass
weeds
1.0
T2 Med Aut C-
0.8
0.6
0.4
0.2
0
T4 Med Aut C+
0.8
0.6
0.4
0.2
0
T5 Med Spr C+
0.8
0.6
0.4
0.2
0
1.0
0.8
0.6
0.4
0.2
0
0.8
0.6
0.4
0.2
0
0.8
0.6
0.4
0.2
0
1.0
0.8
0.6
0.4
0.2
0
1.11
T6 Dac Spr C+
T7 Dac Aut C+
T8 Dac Aut C-
T9 WB T+
1.1
1.3
1.5
1.7
1.9
1.11
1.1
1.3
1.5
1.7
1.9
1.11