**4.3 Water-efficient irrigation regimes to increase water productivity**

Mao Zhi (2000) stated that rice is one of the most important food crops contributing over 39% of the total food grain production in China. Out of 113 million hectares of area sown under food crops 28% is covered by rice. The traditional irrigation regime for rice, termed as "continuous deep flooding irrigation" was applied in China before 1970s. Since 1980s, the industry water supply, urban and rural domestic water consumption has been increasing continuously. The shortage of water resources became an important problem and many water efficient irrigation regimes for rice have been tested, advanced, applied and spread in different regions of China.

Based on the results of experiment and the experience of spread of these new irrigation regimes, the following conclusions were drawn by the author:

