Productivity of rice-based cropping system in Jaffna district o f Sri Lanka leads to sustainability

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.