The Status Of Water Use Efficiency And Productivity With A Focus On Paddy Rice In Sri Lanka

Global water demand is likely to grow in the next 20 to 30 years due to agriculture intensification, population growth, urbanization, and climate change. In Sri Lanka, one-third of the rural population depends on agriculture. Rice is the national staple food which is cultivated twice a year on more than half a million hectares of land under a range of physical and environmental conditions. Despite being self-sufficient in rice production, Sri Lanka has low levels of water productivity and water use efficiency in paddies. Furthermore, its water and food security is extremely vulnerable to climate change. The Food and Agriculture Organization of the United Nations (FAO) has been active to increase the understanding of the status of water use efficiency and water productivity in Sri Lanka through the project “Efficient Agricultural Water Use and Management Enhancement in Paddy Fields”, funded by the Japanese Ministry of Agriculture, Forestry and Fisheries (MAFF). The project objective is to identify limits and potentials of paddy rice production at national level. The project findings presented in this report are a basis for assisting the country with the evaluation of the status of water use efficiency and water productivity of paddy fields, providing technical and policy support to enhance water resources management in Sri Lanka.

In view of the projected world water demand, increased water use efficiency in irrigation is crucial to sustainably increase agricultural productivity. Paddy field systems are especially water demanding, though products such as rice is not only a staple food, but also constitutes a major social and economic activity providing public goods and is a key source of employment and income for the rural population in Zambia. The Food and Agriculture Organization of the United Nations (FAO) has been active to increase the understanding of the status of water use efficiency and water productivity in Zambia through implementing the project “Efficient Agricultural Water Use and Management Enhancement in Paddy Fields”, funded by the Japan Ministry of Agriculture, Forestry and Fisheries (MAFF). The project objective is to identify limits and potentials of paddy rice production at national level. The project findings presented in this report is a basis for assisting the country with the evaluation of the status of water use efficiency and water productivity of paddy fields, providing technical and policy support to enhance water resources management in Zambia. This report will help increasing the knowledge and building capacities of technical experts in relevant institutions, ministries and universities in Zambia. Its analysis of best practices will assist in determining the needs and existing gaps and what options are available to fill these gaps. Furthermore, the policy action matrix developed and the investment portfolio compiled will support the development of future financial plans in the country.

Today, there is an increasing worldwide interest in assessing the potential for maintaining or increasing rice yields by reducing or eliminating the use of chemicals and by decreasing irrigation requirements. The System of Rice Intensification (SRI) first developed in Madagascar and now being tested in many countries, is an example of such an approach. The system is based largely on organic farming principles and additional requirements for spacing and the transplanting of seedlings.

More irrigated land is devoted to rice than to any other crop. A method to save water in irrigated rice cultivation is the intermittent drying of the rice fields, known as alternate wet/dry irrigation (AWDI). This report reviews previous studies in AWDI, with a focus on mosquito vector control, water saving, and rice yields. Examples are provided from a number of countries.

An increasing number of regions in the world are frequently facing water shortage, and water demand is likely to grow in the next 20-30 years due to intensified agriculture, population growth, urbanization and climate change. Future demand of water by all sectors will, thus, require as much as 25 to 40 percent of water to be re-allocated from lower to higher productivity and employment-oriented activities, particularly in water stressed regions. As such, these reallocations are likely to come from agriculture due to its high share of water use. In view of the projected rise in water demand in both agriculture and non-agricultural sectors, appropriate actions that increase water use efficiency especially in irrigation are crucial to sustainably enhance agricultural production and productivity. In Zambia, rice is one of the most important cereal food and is at the centre of major socioeconomic activity for a large share of rural population. Paddy field system are especially water demanding as it needs continues inundation of the field during most of the growing season. In Zambia, there is no controlled infrastructure for paddy irrigation and nearly all of the rice is grown under paddy field system in the country rainfed lowlands. The Food and Agriculture Organization of the United Nations (FAO) has been active to increase the understanding of the status of water use efficiency and water productivity in Zambia through the project “Efficient Agricultural Water Use and Management Enhancement in Paddy Fields”, funded by the Japan Ministry of Agriculture, Forestry and Fisheries (MAFF).

The Indus and Ganges River Basin, being the most populous in the world, is under extreme pressure to sustain food security. Production resources including water are being exploited to various levels from underdevelopment to heavy overexploitation. This report provides a bird’s eye view of the basin and focuses on the nexus between agricultural production and water consumption, making it possible to pinpoint the areas with high/low water productivity and identify the factors behind this, which helps to promote informed decision making in light of environmental sustainability.