I - --ii

BRIDA
cm Water /Depth Interva',
3 4 5 2 3 4 5
9/12/80 3/3/81
* 2/4 /3/81
30 9/6
30
E 60 60­ 2/y
/
0
120
Recharge
9//
150 (E) 150
90
Discharge
(F)
Figures IE, F
Soil moisture recharge and discharge under winter-sown chickpeI (var. ILC
482) at Brida in northern Syria.
moisture status of the start of the season, and thus the shaded area represents
moisture (6 mm only) stored under the fallow which was available for uptake by
the crop.
At the two driest sites, Tel Hadya and Brida, the recharge front did not extend
beyond 9I and 75 cm, respectively (Figs. IC, D, E, F) and thus the rooting depth
of the crop was greatly restricted compared witli Jindiress. Thus at these sites
there was little difference between treatments in the root distribution of the crop,
even between winter and spring sowing. This is ilustrated in Table 5a which
presents the "extractable" moisture within discrete depth intervals under all
treatments. "Extractable" moisture is defined as the difference between the
maximum moisture content observed in any soil horizon and that at maturity.
The ability of a crop to extract moisture from a given depth interval will depend
largely upon the root proliferation with that depth interval, and thus "extractable"
moisture values will reflect the root distribution. It can be seen from Table
5 that at Tel Hadya and Brida there was no meaningful difference between
treatments. The difference between sites represent the different soil moisture
charateristics of the two soils.
The same picture holds true at Jindiress when comparing the three wintersown
crops, but a contrasting picture emerges when comparing winter sowing
with spring sowing. Table 4 indicates that the recharge front under spring-sown
149