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

Talks . ................................................................................................................... xxii
Posters . ................................................................................................................ xxiii
A GENERAL INTRODUCTION ......................................................................................... 1
A.I THE CHALLENGES OF SUSTAINABLE AGRICULTURE
A.II THE ‘WEEDS TRADE-OFF’
A.II.1
............................................... 1
........................................................................................ 3
Weeds & crop production ............................................................................... 3
A.II.2 Weed control & environment .......................................................................... 4
A.II.3 Weeds & biodiversity ...................................................................................... 6
A.II.4 Summary ......................................................................................................... 9
A.III APPROACHES TO ALLEVIATE THE ‘WEED TRADE-OFFS’
A.III.1
....................................... 10
Overview of the approaches .......................................................................... 10
A.III.2 Integrated Weed Management ...................................................................... 11
A.III.3 Combining high weed diversity with low weed abundance? ........................ 12
A.III.4 ‘Good’ vs. ‘bad’ weeds? ................................................................................ 12
A.III.5 Favouring weed seed predation ..................................................................... 14
A.III.6 Integration or spatial separation of farming and biodiversity? ...................... 15
A.III.7 Temporal separation of farming and biodiversity? ....................................... 16
A.III.8 Crop rotation ................................................................................................. 18
A.III.9 Perennial forage crops (PFCs) ....................................................................... 21
A.IV EXPECTED IMPACTS OF PERENNIAL CROPS ON WEEDS
......................................... 22
A.IV.1 Literature review ........................................................................................... 22
A.IV.1.1 Farmers interview ....................................................................................... 22
A.IV.1.2 Regional weed survey ................................................................................. 23
A.IV.1.3 Field experiments ........................................................................................ 23
A.IV.1.4 Discussion and limits of the reviewed studies ............................................ 26
A.IV.2 Hypothetical mechanisms causing the impacts ............................................. 27
A.V DIVERSIFIED CROPPING SYSTEM CONCEPT
A.V.1
........................................................... 30
Expected impacts on weeds ........................................................................... 31
A.V.2 Expected impacts on biodiversity ................................................................. 33
A.V.3 Expected impacts on the environment ........................................................... 33
A.V.4 Expected impacts on crop production ........................................................... 34
....................................................................................... 35
A.VI.1 Objectives and questions ............................................................................... 35
A.VI.2 Structure of the thesis .................................................................................... 36
A.VI THE RESEARCH PROJECT
B OVERWIEW OF THE MATERIALS & METHODS ................................................. 38
B.I ANALYZING THE IMPACTS OF TEMPORARY GRASSLANDS ON WEED
COMMUNITIES: LARGE-SCALE FIELD SURVEYS
B.I.1
..................................................... 38
Rationale ........................................................................................................ 38
B.I.2 Methods in analyzing weed composition and crop rotation histories ........... 38
B.I.3 Statistical analysis ......................................................................................... 40
B.II FIELD EXPERIMENTS ANALYZING THE IMPACTS OF TEMPORARY GRASSLANDS
ON WEED POPULATIONS (EPOISSES)
...................................................................... 41
B.II.1 Rationale ........................................................................................................ 41
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