Impact of aerobic rice cultivation on growth and productivity of Indica and Japonica cultivars

摘要

An experiment was carried-out to examine the effects of aerobic rice cultivation on different growth, yield and its related characteristics. The study was laid out at the experimental field RE-5, Tsukuba International Center, Japan International Cooperation Agency, Japan. The main objectives of the experiment were to save the irrigation water and acquire optimum/higher yields under aerobic cultivation as compared to traditional lowland cultivation. To achieve these objectives, two Indica and one Japonica cultivars were selected to examine under both the conditions on two-factor split plot design with three replications. Under aerobic conditions, ~59% of the total irrigation water was saved and ~72% water was saved at freshwater level except rainfall as compared to lowland conditions. The Indica cultivar IR-50 showed higher grain yields (6.3ton/ha) under aerobic conditionsas compared to lowland (5.2ton/ha) and also retained higher panicle and spikelets number under aerobic conditions. On the other hand, the Japonica cultivar Fukuhibiki retained higher yields (5.2ton/ha) under lowland compared to aerobic conditions (4.9ton/ha). Whilst, an upland cultivar NERICA-10 retained higher grain yields (4.6ton/ha) under aerobic cultivations as compared to lowland (3.7ton/ha). Interactions were significant among all the cultivars underaerobic and lowland conditions, whereas IR-50 had higher nitrogen absorption under aerobic conditions than rest of the cultivars. Hence, nitrogen absorption positively sustains the grain yields and total dry mass accumulations. It is, therefore, concluded that lowland and upland cultivars are not only adaptive to aerobic conditions but also a great amount of irrigation water may be saved.