Environmental Engineering Reference
In-Depth Information
fish. And the boy whipping the oxen reminds them:
''Thresh for yourselves, thresh for yourselves. . . . Chaff
to eat for yourselves, and barley for your masters. Don't
let your hearts grow weary! It is cool.''
Besides chaff, oxen were fed the barley and wheat
straw and grazed on wild grasses of the flood plain and
on the cultivated Vicia sativa. Cattle were also seasonally
driven to graze in the delta marshes. For plowing, oxen
were harnessed by double head yokes to wooden plows,
soil clods were broken by wooden hoes and mallets, and
the scattered seed was trampled into the ground by
sheep. Records from the Old Kingdom indicate not only
large numbers of oxen but also substantial cow, donkey,
sheep, and goat herds. Minimum populations support-
able by predynastic farming were 1-1.3 people/ha of
cultivated land (Hassan 1984). Subsequent millennia
saw a substantial increase of these densities owing to
greatly extended cultivation achieved by tree cutting,
conversion of grasslands, diking, and drainage. There was
no dynastic cultivation of summer crops because regular
canal irrigation had only a marginal role.
The Nile's very small gradient (1:12,000) made radial
canalization possible only in the Faiyum depression, and
the absence of effective water-lifting devices limited dy-
nastic irrigation techniques largely to regulation of high
floodwaters, such as building higher and stronger levees,
blocking off drainage channels, or subdividing flood
basins (Butzer 1984). Sh¯d¯f, fit for just small-plot irri-
gation, is verified from the fourteenth century
B
.
C
.
E
.; ani-
mal waterwheels came only during Ptolemaic times
(c. 300
B
.
C
.
E
.). Butzer's (1976) reconstruction of ancient
Egypt's demographic history has the Nile valley's popula-
tion density rising from 1.3 people/ha of arable land in
2500
B
.
C
.
E
. to 1.8 people/ha in 1250
B
.
C
.
E
. and 2.4 peo-
ple/ha in 150
B
.
C
.
E
.
6.7 Long-term increases of population densities per hectare
of arable land. From Smil (1994).
animals. October and November seeding followed the
receding Nile waters, and harvests followed after 150-
185 days.
Agricultural practices in place at the time of the first
dynasty (3300
B
.
C
.
E
.) changed little during the subse-
quent five millennia (Erman 1894). Harvesting was done
with wooden sickles, and the straw was cut high above
the ground, sometimes just below the heads. This prac-
tice made for easy harvesting, easier transport of the
crop to the threshing floor, and cleaner threshing. Stand-
ing straw was cut later for weaving, brickmaking, or as
kiln fuel. Inscriptions from Paheri's tomb express elo-
quently the energetic constraints and realities of the day
(James 1984). An overseer prods the laborers: ''Buck
up, move your feet, the water is coming and reaches the
bundles,'' but their reply, ''The sun is hot! May the sun
be given the price of barley in fish!'' sums up perfectly
both their weariness and their awareness that grain
destroyed by water may be compensated by flood-borne
