The demand for water in Asia is expected to increase by 50 percent over the next 20 years. To avoid the serious crisis of the looming water crisis for food security and to make more water available for the non-agricultural sector, there is an urgent need to develop and promote ways to increase water use efficiency in agriculture.
Since 50 percent of the irrigated area in Asia is planted to rice, saving water in rice-based irrigation systems deserves particular attention. In this context. and within the framework of the System-Wide Initiative on Water Management (SWIM), scientists from International Water Management Institute (lWMI) and International Rice Research Institute (IRRI) are collaborating with NARS to find ways to produce "more rice with less water".
The water shortage is being felt more urgently in China than in many other Asian countries. Recognizing the severity of the situation. China has pioneered some water saving irrigation (WSI) techniques aimed at reducing seepage and percolation at the farm level. These techniques are being widely adopted in different parts of China. However, there are a number of important, unanswered questions:
What has been the impact of WSI and other factors on water saving?
Has the introduction of WSI at farm level led to water saving in the basin?
Can WSI as practised in China be extended and successfully practised in other locations?
The focus of this study is on the first two questions.

The objective of this research is to address the technical issues underlying the successful application of WSI. These include:
(i) Quantifying the impact of WSI on water saving, rice crop yields, and fertilizer use efficiency.
(ii) Assessing the financial costs and benefits to farmers who are using these technologies, and
(iii) Identifying irrigation system and basin-wide impacts of on-farm WSI innovations in order to understand the degree to which large scale adoption of WSI will lead to system and basin-wide water savings and water productivity increases.
The research team includes scientists from IWMI, IRRI, Wuhan University of Hydraulic and Electrical Engineering (WUHEE), and Zhejiang Agricultural University (ZAU) each of which brings different strengths to address the above objectives. Through frequent field visits, meetings, and exchange of information the research team has built a strong sense of purpose and high esprit de corp.
The research has been organized around four subprojects. Sub-project 1 involves the conduct of experiments on stations in Zhanghe in Hubei Province and Jinhua in Zhejiang Province. The experimental design included treatments with and without WSI with different timing of fertiliser application. Sub-project 2 focuses on the financial assessments of WSI. A survey of 30 farms has been conducted in each of two sites in Zhanghe Irrigation District, one with and one without the adoption of WSI management Techniques. Sub-project 3 focuses on assessing the impact of WSI on water productivity, at different scales. In the same sites (with and without WSI) covered by the farm survey, water accounting studies are being conducted at the farm level and in a much larger service area with measurements taken twice daily of water inflows and outflows during the rice growing season. Sub-project 4, a seminar to be held at the end of the project will discuss the project outcomes among Chinese and international water scientists. In addition to the above sub-projects, data has been gathered on long-term trends in water allocation among sectors and rice crop yields in order to assess the factors contributing to the increase in land and water productivity over time.
Most of the first year's data is still being analysed. However, results from analysis of long-term trends in water allocation and of the first year's experiments provide some interesting results. From 1966 to 1998, despite a decline in water allocation to agriculture of 60 percent and a decline in rice area irrigated by 15 percent, total rice production has increased. This has been made possible by an almost doubling of rice yield per hectare and quadrupling of rice yield per cubic meter of water. The trends in growth in rice yield per hectare in Zhanghe District are very similar to those for Hubei and for all of China and the factor contributing to this trend reasonably well understood. The next step is to attempt to identify the contribution of factors (other than increase in yield per hectare) including WSI to the increase in the productivity of water, using the trend data, our field research results and other sources of information
Results of the first year's experiments conducted at Tuanlin Station in Zhanghe District showed yield per hectare to be somewhat lower for WSI treatments than for the normal flooding practice contrary to what is normally reported by Chinese researchers. Yields per unit of water were slightly higher, but again the level of water saving was much less than we anticipated based on other reports. We have not yet analysed the rainfall pattern for this year as compared to other years to determine how this may have affected our results.
We find a growing interest in WSI outside of China. We have discovered the practice of alternate wetting and drying in paddy rice production being practised in a number of locations. With the growing shortage of water, it is extremely important to identify the potential of WSI and related practices such as volumetric pricing of water under different situations. With the submission of this report we have also prepared a concept proposal for a follow-on study that will allow us to assess the potential of WSI under a wider range of conditions.