Diversifying crop rotations with temporary grasslands - Université de ...
Diversifying crop rotations with temporary grasslands - Université de ...
Diversifying crop rotations with temporary grasslands - Université de ...
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perennial <strong>crop</strong>s <strong>with</strong> different management options (<strong>crop</strong> species, sowing date and cutting<br />
frequency), and three treatments represented a succession of annual <strong>crop</strong>s varying only by the<br />
inter<strong>crop</strong> management (see Table 6 in Manuscript 3 for <strong>de</strong>tails). The natural soil seed bank of<br />
the experimental field was supplemented by homogeneously adding seeds of 17 common<br />
annual weed species (see Table 7 for species names) on all experimental plots. One sixth of<br />
each plot stayed unsown for control (see methods in Manuscript 3 for <strong>de</strong>tails).<br />
B.II.3 Data collection<br />
The <strong>de</strong>velopment of weed populations and community dynamics was investigated by<br />
<strong>de</strong>termining and counting the number of plants of all species every 4-7 weeks in spring,<br />
summer and autumn on permanently installed quadrats in the sown and unsown zones.<br />
Additionally, the aboveground biomass of <strong>crop</strong>s and all weed species was measured 5-6 times<br />
per year to assess the competitive relations between the species.<br />
B.II.4 Statistical analysis<br />
The temporal <strong>de</strong>velopment of weed species composition in the nine <strong>crop</strong> treatments was<br />
compared using Multiple Response Permutation Procedure (MRPP, McCune and Grace, 2002)<br />
<strong>with</strong> pairwise tests at each measurement date. Indicator Species Analysis (ISA, Dufrene and<br />
Legendre, 1997) was used to calculate and test ‘Indicator Values’ (IV) for the emerged weed<br />
plants at the end of the experiment.<br />
B.III GREENHOUSE EXPERIMENTS ANALYZING THE REGROWTH<br />
CAPACITY OF WEED PLANTS AFTER CUTTING<br />
B.III.1 Rationale<br />
PFCs are harvested several times per year which is one of the most important differences to<br />
most annual <strong>crop</strong>s. Forage mowing creates frequent disturbances of the aboveground<br />
vegetation, <strong>de</strong>stroying the upper parts of the shoots of both the forage and the weed plants. In<br />
PFCs, weed population and community dynamics may thus strongly <strong>de</strong>pend on the plant’s<br />
capacity to survive, grow and reproduce after such cutting operations. There are several other<br />
situations, where weeds may be submitted to repeated physical disturbances of the<br />
aboveground plant organs, including mowing in set-asi<strong>de</strong> fields (Dalbies-Dulout and Dore,<br />
42