Effect of Irrigation on the Yield and Root Distribution of Taro (Colocasia esculenta L. Schott) at the Field in Ise Plain, Japan

Abstract

Field experiment was conducted in 2022 and 2023 to examine the effects of irrigation to taro at the Andosol field in Ise plain, Japan. In 2022, we conducted furrow irrigation only two times because of frequent and large amount of rainfall. There is no significant difference in soil water content, matric potential, and yield between furrow irrigation and control plots. In 2023, we prepared three experimental plots. In the first plot, no irrigation was conducted (control plot). Furrow irrigation was conducted in the second plot (furrow-irrigation plot). Irrigation was conducted with perforated pipes in the third plot (perforated-pipe plot). According to the long-term precipitation data monitored at the meteorological station about 9 km north from the study site, the drought in this year may occur once in 5 years. Yields were significantly increased by irrigation. However, there is no significant difference in yield between furrow-irrigation and perforated-pipe plots, although there is large difference in soil moisture conditions observed by the sensors installed at the middle of furrows. According to the result of root-distribution measurement, substantial number of roots in furrow irrigation plot was located not only center of the furrow but also near the edge of the furrow, which might absorb irrigation water supplied from the edge of the furrow.