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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intratns, production of perennial forage or biomass <strong>crop</strong>s, and the provision of favourable<br />
habitats and food resources for wildlife) will be continuously provi<strong>de</strong>d. The proposed<br />
‘temporal separation’ strategy might also be combined <strong>with</strong> the ‘spatial separation’ and the<br />
‘complete integration’ strategies (illustrated in Fig. 5 in the General Introduction). In this way,<br />
the different strategies may be complementary. This shows that beneficial intermediate<br />
solutions may exist between the two extreme alternatives, ‘complete integration’ or ‘complete<br />
spatial separation’, formulated by Green et al. (2005).<br />
Besi<strong>de</strong>s the advantages for biodiversity, facilitating the access of wild animals to different<br />
food resources in PFCs (and overwinter stubble fields) may also have a regulating impact on<br />
weed populations (‘biological weed control’). This would correspond to a positive feedback<br />
useful for alleviating the ‘weeds tra<strong>de</strong>-off’.<br />
Of course the work done during this PhD program does not cover all the interesting questions<br />
in the area of the agro-ecological management of weeds and other components of biodiversity<br />
involving perennial forage <strong>crop</strong>s. The investigations presented in this thesis directly motivate<br />
various further research:<br />
• Finalising a mo<strong>de</strong>l of <strong>crop</strong>–weed competition <strong>de</strong>dicated to PFCs, accounting for the<br />
specific process of post-cutting regrowth and potentially of seed predation. Such a mo<strong>de</strong>l<br />
would make it possible to conduct in silico experiments, testing alternative scenarios for<br />
agro-ecological management of arable fields.<br />
• Conducting socio-economic evaluations of the <strong>crop</strong>ping system concept <strong>with</strong> various agro-<br />
ecological functions fulfilled at different phases of the <strong>crop</strong> rotation. In regions where farm<br />
animals are currently rare, perennial forage <strong>crop</strong>s may be replaced by other perennial <strong>crop</strong>s<br />
grown for energy or for biomass (see chapter A.V.4). Future studies should verify whether<br />
they may have similar benefits as PFCs.<br />
• Conducting additional investigations in the area of agro-ecology <strong>de</strong>aling <strong>with</strong> the<br />
complexity of the consequences of <strong>crop</strong> rotation. For example, there is a clear need for<br />
<strong>de</strong>fining what is actually a diversified <strong>crop</strong> rotation. Such a research program could aim at<br />
<strong>de</strong>fining an indicator of <strong>crop</strong> rotation diversity, which would probably be a new useful tool<br />
for explaining weed communities and characterising the agro-ecological value of <strong>crop</strong>ping<br />
systems in a given region.<br />
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