Abstract:
The study was carried out in Jaffna district of Sri Lanka from July to December 2004 to
evaluate the present rice based cropping system in terms of its productivity and
sustainability. Sample farmers were selected randomly from five Agrarian Service
Centres where rice based cropping system is being practiced. Selected farmers were
interviewed by using a questionnaire. In Jaffna district rice is being cultivated in 9000
ha as a rain-fed crop, of which nearly 2000 ha of land is cultivated with vegetables and
cash crops with the help of lift irrigation from dug wells. In this system, cropping
sequence, cropping index, use of inputs and level of management and productivity
varies among different Agrarian Service Centres (ASC). This variation is mainly due to
the soil fertility and quantity and quality of water available in the dug well for
irrigation. Farmers practice different cropping sequences based on the availability of
water for irrigation and soil type. Farmers from Uduvil, Tholpuram and
Chavakachcheri divisions adopt high cropping intensity (>2) by cultivating more than
one crop after harvesting paddy in the same field. In Ampan and Puloly divisions
farmers cultivate only one crop after harvesting paddy and their cropping index is
always two or less than two. In these two divisions inadequate irrigation water and
water quality were identified as major problems. These areas are closer to sea coast and
facing the problem of sea water intrusion into the dug wells during the dry periods and
over extraction of ground water will also affect the quality of the irrigation water in
these divisions. Use of organic manures to maintain the soil fertility is also reduced due
to its high price and limited availability. Production of vegetables and cash crops gives
better revenue compared to the legumes and oil seed crops. Production capacity and
income obtained from rain-fed rice is very much lower than that of vegetables and cash
crops followed by rice in this system. Present rice based cropping system in Jaffiia
district appears to be sustainable in terms of its productivity. However, on a long term
basis this system may not be sustainable if proper technology is being adopted to
improve water management and soil fertility. For better water management to increase
water use efficiency, selection of short duration crops, cropping sequences, timely
cultivation and modernizing the irrigation by introducing sprinkler system are the
available choices. To improve soil fertility proper crop residue management, addition of
organic manures such as farmyard and green manures are important.
