vine water uptake in bordeaux area

SCIENCE DU SOL n° 1986/1 - pp. 77-78 - PLAISIR-FRANCE
VINE WATER UPTAKE IN BORDEAUX AREA
DU RING A DRY PERlOn
(SAINT·EMILION and POMEROL, summer 1980)
J. DUTEAU
(1)
Science du Sol, n° 1982-1)
A study of the relationship between soUs and grape vines of Saint-Emilion and
Pomerol has been carried out. In 1980, regulation mechanisms were demonstrated
to occurin vine water uptake, at least during the dry period. These mechanisms are
very different from those observed in Haut-Medoc vineyards which occur on gravelly
soUs and which are characterised by a very deep root system.
a ln Saint-Emilion, superficial soUs with a loamed-sandy texture occur on the
"calcaire à Asteries ". The water stored in the thinnest pores of the bedrock can
migrate by capillarity through a thick layer of rock (figure 7). This phenomenon allows
the vines to take up water regularly during the ripening of grapes (table III).
Very clavey soils of Pomerol are located in the heart of Ouaternary alluvial
b substrata of the river " Isle". In summer, the roots which have lived through winter
anoxy develop a network of rootlets. The resulting slow decrease in water content
between - 70 and - 100 cm depth (figure 5) suggests that uptake is neither excessive,
nor too difficult (table V), which is an important quality factor for the vintage.
So, each year, these phenomena permit the very good wines of Bordeaux to be
obtained on soils of various substrata; but, the characteristics of these wines are
very different according to the "terroirs".
0.1
0.1
0.3
..
0.4
0.5
Humidité
volumique
cm 3.cm- 3
5L
..
100
.. 03.03.1980
- - - 17.07.1980
'--15.08.1980
.......... 06.10.1980
150
Profondeur
cm
Figure 5 : Evolution of drying during summer in soif B (1980).
(1) Institut d'Œnologie, 351,
cours de la libération, 33405 Talence Cédex.
Association Française pour l'Etude du Sol - www.afes.fr - 2010
77
0.3
0.1
Humidité
..
~ ..
\\
\
\ \
•
/:
'
\ ...
- - - - _/~ . ;:~~ =~_; : ,,1 .
\
.
100
""
..
150
~
'-'25.08.1980
\
.,
.,
\
J :
\....1:
\
\.\"
"~.\\
.~\\
'.. 1
200
.,
1
fi,'
.: .,'
.......... 06.10.1980
..
......... , ...
/! (/ ,/ "..
'\
- - - 11.07.1980
\
• -
.
\
., 03.03.1980
..
/
"
1
:
1
1 ..
,/i"-...
",
..
\
\\
50
volumique
cm 3.cm-3
ft
...
.
..
Profondeur
cm
Figure 7 : Evolution of drying du ring summer in soil A (1980).
Table III : Water uptake of vine in plot A (1980).
17 juillet
au
24 août
SAINT-EMILION
mm
mm
mm
P
ETR
ETP
ETR/ETP X 100
P : pluviosité; ETR
(PENMAN).
25 août
au
7 septembre
8 septembre
au
21 sept.
22 sept.
au
5 octobre
11
23
52
44
19
20
39
51
3
14
29
48
26
105
182
58
évapotranspiration réelle; ETP
évapotranspiration potentielle
Table V : Water uptake of vine in plot B (1980).
17 juillet
au
24 août
POMEROL
mm
mm
mm
P
ETR
ETP
ETR/ETP X 100
P : pluviosité;
(PENMAN).
78
ETR
25 août
au
7 septembre
8 septembre
au
21 sept.
22 sept.
au
5 octobre
11
21
52
40
17
20
39
51
2
16
29
55
25
88
182
48
évapotranspiration réelle;
ETP
évapotranspiration potentielle
Association Française pour l'Etude du Sol - www.afes.fr - 2010