Environmental Engineering Reference
In-Depth Information
Table 24.2
Land area (in sq. km) according to land types
(from Alam et al. 1999)
principal crops are aus, paddy and jute. Aus plan-
tation requires irrigation at the beginning of the
season for land preparation and transplantation if
the monsoon arrives late. After the monsoon ar-
rives natural rainfall supplies the crop. This prac-
tice is observed tomaintain the planting time. Aus
is normally grown on the higher F0, F1 and F2 land
types.
.
The Kharif-II season refers to late monsoon and
early post-monsoon. Transplanted aman paddy
is the main crop in the Kharif-II season. Aman is
sown during the monsoon and harvested post-
monsoon. At a later stage of crop growth supple-
mentary irrigation is often required to prevent
yield losses in case of water shortage. Most vari-
eties of aman are normally grown in higher F0, F1
and F2 land types while the deep-water varieties
can be grown in the lower F3 lands.
.
Rabi (dry season) consists of the cool winter
months when crops such as wheat, pulses and
oilseeds are grown, or the hot pre-monsoon when
Land type
Generalized area (1990)
F0 land
44,409
F1 land
32,708
F2 land
15,829
F3 and F4 land
14,311
Urban area
1539
the high rainfall and flooding conditions are par-
ticularly suitable for rice cultivation, and since
rice is also the staple food, rice cultivation occu-
pies around 80%of the cropped area in the country
(Brammar 2002). There are generally two main
cropping seasons (Kharif and Rabi) and three
rice-growing seasons (aus, aman and boro). The
Kharif season further comprises an early part and
later part.
.
The Kharif-I season corresponds to the pre-
monsoon and early monsoon (wet season). The
J
F
M
A
M
J
J
A
S
O
N
D
Kharif - I
Kharif - II
Rabi - Boro
Rabi - Boro
Crop Seasons
Land type (Flood
Depth)
Rabi - Dry
Rabi - Dry
Aus
Highland
TransplantedAman
HYV Boro
Wheat
(0cm)
Aus
Medium Highland (0-
90cm)
HYV Boro
Wheat
Transplanted Aman
Mixed Aus
Medium Lowland (90-
180cm)
HYV Boro
Wheat
Deepwater Aman
Lowland
(>180cm)
Very lowland/
Bottomland
(>300cm/
permanently wet)
HYV Boro
Local Boro
Fig. 24.3
Cropping patterns in relation to seasonal flooding, climate and natural disasters. From Brammar (2002).
