Mboyerwa, Primitiva Andrea2023-07-102023-07-102022http://www.suaire.sua.ac.tz/handle/123456789/5346Conference PaperRice (Oryza sativa L.) is one of the most important grain crops for more than 50% of the world’s population, providing approximately 20% of total energy intake for humans (Muthayya et al., 2014). • Rice is also the largest consumer of water among all crops (Deng et al., 2021; Bouman and Tuong , 2001). • The water productivity of rice is lower than those of other crops (Kumar and Rajitha, 2019). • In Tanzania, about 90% of rice is grown under continuous flooding (CF), a practice that requires large amounts of water with less productivity (Katambara et al 2013; FAO, 2012) and contribute to emission of greenhouse gas emission ( Methane, carbon dioxide and nitrous oxide (Adounkpe et al .,2021). • Water productivity of rice that ranges from 0.1 to 0.14 kg m−3 has been recorded in Tanzania, which is lower when compared to 0.60–1.60 kg m-3 in other parts of the world (Najmuddin et al .,2018). • On average, 2500 liters of water is used, ranging from 800 liters to more than 5000 liters to produce one kg of rice (Najmuddin et al .,2018;Bouman and Tuong 2001). By 2025, 15–20 million ha of irrigated rice is estimated to suffer from some degree of water scarcity (Bouman and Tuong, 2001). • Alternate wetting and drying (AWD) irrigation practice has been demonstrated to provide advantages in terms of reducing water use and increasing crop productivity. • In addition to water, nitrogen is one of the most important nutrients that determine rice yields (Zhang et al., 2021, Djaman et al., 2018; Saito et al., 2015); its deficiency is a limiting factor for sustainable rice production. • However, the use of N fertilizer is generally inefficient, and the average apparent recovery efficiency of N fertilizer is about 33% for rice globally (Zhang et al., 2021).enRiceCropNitrogen managementGas emissionGreenhouseConferencce Proceedings