OPTIMIZATION OF RICE FIELD CROPPING PATTERN IN WAY KETIBUNG IRRIGATION AREA AT SOUTH LAMPUNG DISTRICT
ABSTRACT: Land use changing in
Way Ketibung Irrigation Area from rice field cropping to rubber and palm oil
planting were one of causes to decline rice field production at its irrigation
area. The changingof land use were caused by lack of water availability .
Therefore, it is necessary efforts to optimize irrigation area in order to
increase rice production.
Based on cropping schedule which used by Way Ketibung Irrigation Area the
farmer had define cropping season, rainy cropping season (rendeng, MT I) and
dry cropping season (gadu, MT II). The 1 st class of rainy cropping season was
started on 1 st week of September and on 1 st week of January to the 1 st class
of dry cropping season. Whereas, the 2 nd class of rainy season began on 2 nd week
of September and on 2 nd week of January to the 2 nd class of dry season.
Cropping pattern which based on its cropping schedule that the farmers have
done was not suitable, because only a few one could apply the schedule to crop
rice field. It is due to the water availability could not serve the amount of
water to its cropping pattern.
Field observation and hydrologic analysis using suitable approach methods
produced the optimized cropping pattern that approximated by reliable discharge
has 80 % probability in occurs (Q 80 ) and Net Farm Requirement (NFR). The
optimized cropping pattern of Way Ketibung Irrigation Area defines the cropping
season. The 1 st class of rainy cropping season begins on 2 nd December and 2
nd April to 1 st class of dry cropping season. Whereas, The 2 nd class of rainy
cropping season begins on 1 st January and 1 st May to 2 st class of dry
cropping season. Water balance analysis describe surplus and deficit of water,
therefore could be generated cropping pattern rotation as; The rainy cropping
season (MT I) : 1 st class begin on 2 nd week of December with 821 hectares
(100 %), 2 nd class begin on 1 st week of January with 612 hectares (100 %).
The dry cropping season (MT II) : 1 st class begin on 2 nd week of April with
50 % of 821 hectares, 2 nd class begin on 1 st week of May with 50 % of 612
hectares.
KEYWORDS: Daerah irigasi, Way
Ketibung, sawah, padi, musim tanam, neraca air, debit andalan, pola tanam
Penulis: Wayan Susana
Kode Jurnal: jptsipildd140795
