Effects of Water Management on Greenhouse Gas Emissions in Rice Paddy Field.

FAO（Food and Agriculture Organization of the United Nations）reported that about 870 million people are estimated to have been undernourished (in terms of dietary energy supply) in the period 2010–12. This figure represents 12.5 percent of the global population, or one in eight people. The highest region of the prevalence of undernourishment was Africa and the figure was 22.9% but the number of undernourishment population was most was Asia, and the figure was 563 million people. So many people of Asia regard rice as Staple food, to find rice cultivation which increase amount of rice yields connects to decrease the prevalence of undernourishment mainly in Asia.The vast majority of these, 852 million, live in developing countries, where the prevalence of undernourishment is now estimated at 14.9 percent of the population. (FAO, 2012)

Method of water management is one of the factors affecting the yield of rice.

To investigate the effects of water management on the rice yields of IR24 cultivar and green house gas emission. We applied three different water managements in 2013 and two different water managements in 2014. Water management in 2013 were (ⅰ) Continuous Flooding (CF), （ⅱ）Two days Intermittent irrigation(TI) and (ⅲ)Four days Intermittent irrigation(FI). TI and FI started intermittent irrigation from one week after transplantation. Water management in 2014 were (ⅰ) Continuous Flooding (CF) and (ⅳ)Compound, combination of flooding and intermittent irrigation. Compound started intermittent irrigation from one month after transplantation.

Result of 2013 experiment showed that yield by both TI and FI decreased 46% compared to CF. On the other hand, as a result of 2014 experiment, yield by Compound increased 4% compared to CF.

This result indicates that starting intermittent irrigation one week after transplantation leads big decrease of yield.

FAO（Food and Agriculture Organization of the United Nations）reported that about 870 million people are estimated to have been undernourished (in terms of dietary energy supply) in the period 2010–12. This figure represents 12.5 percent of the global population, or one in eight people. The highest region of the prevalence of undernourishment was Africa and the figure was 22.9% but the number of undernourishment population was most was Asia, and the figure was 563 million people. So many people of Asia regard rice as Staple food, to find rice cultivation which increase amount of rice yields connects to decrease the prevalence of undernourishment mainly in Asia.The vast majority of these, 852 million, live in developing countries, where the prevalence of undernourishment is now estimated at 14.9 percent of the population. (FAO, 2012)

Method of water management is one of the factors affecting the yield of rice.

To investigate the effects of water management on the rice yields of IR24 cultivar and green house gas emission. We applied three different water managements in 2013 and two different water managements in 2014. Water management in 2013 were (ⅰ) Continuous Flooding (CF), （ⅱ）Two days Intermittent irrigation(TI) and (ⅲ)Four days Intermittent irrigation(FI). TI and FI started intermittent irrigation from one week after transplantation. Water management in 2014 were (ⅰ) Continuous Flooding (CF) and (ⅳ)Compound, combination of flooding and intermittent irrigation. Compound started intermittent irrigation from one month after transplantation.

Result of 2013 experiment showed that yield by both TI and FI decreased 46% compared to CF. On the other hand, as a result of 2014 experiment, yield by Compound increased 4% compared to CF.

This result indicates that starting intermittent irrigation one week after transplantation leads big decrease of yield.