Evapotranspiration in a rice paddy field over 13 crop years

• Ikawa Hiroki

  Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization

• Ono Keisuke

  Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization

• Mano Masayoshi

  Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization Graduate School of Horticulture, Faculty of Horticulture, Chiba University

• Kobayashi Kenshi

  Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization Graduate School of Life and Environmental Sciences, University of Tsukuba

• Takimoto Takahiro

  Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization Institute for Global Change Adaptation Science, Ibaraki University

• Kuwagata Tsuneo

  Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization

• Miyata Akira

  Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization

Abstract

Evapotranspiration (ET) in rice paddy fields has been studied over the past half-century, but despite that long history of rice ET study, not much is known about their inter-annual variation. This study investigates ET in rice paddy fields during the growing season for 13 years (2002-2014) at one of the longest flux monitoring sites in Japan. The cumulative ET estimated for each growing season (120 days after transplanting) was 419±45 SD (standard deviation) mm/season (3.5 mm d⁻¹), which increased to 534±64 mm/season (4.4 mm d⁻¹) when energy balance was forced to close. This study determined that ET was correlated with meteorological conditions defined by potential evaporation (E_P), and the inter-annual variability of seasonal ET/E_P (coefficient of variation (CV) = 4.6%) was less than half the variability of ET (CV = 10.7%). For most years, the seasonal ET was reasonably estimated as the product of E_P and the overall average ET/E_P (=0.89), including years that experienced both extremely warm and cold summers. However, the errors in estimation were relatively large for 2008 (which experienced high precipitation) and 2012 (which was characterized by an extremely low leaf area index). Although the seasonal ET/E_P was relatively invariable among years, both the seasonal trends of ET and ET/E_P greatly differed between years. The inter-annual variability in ET/E_P was particularly high at the ripening stage (defined as 91-120 days after transplanting). The ET/E_P at this stage was well correlated to precipitation, and the variation was possibly caused by evaporation from intercepted rainfall. The variation in ET/E_P associated with precipitation at the ripening stage accounted for 21% of the inter-annual variation of seasonal ET/E_P.

Journal

• Journal of Agricultural Meteorology

  Journal of Agricultural Meteorology 73 (3), 109-118, 2017

  The Society of Agricultural Meteorology of Japan

Keywords

• Eddy covariance
• Evapotranspiration
• Long-term observation
• Rice paddy field

Details

• CRID: 1390282679646907264
• NII Article ID: 130005797425
• NII Book ID: AN00200732
• DOI: 10.2480/agrmet.d-16-00011
• ISSN: 18810136
• ISSN: 00218588
• NDL BIB ID: 028349140
• Web Site: http://id.ndl.go.jp/bib/028349140
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I028349140
• Web Site: https://www.jstage.jst.go.jp/article/agrmet/73/3/73_D-16-00011/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed