Determination of crop and soil evaporation coefficients for estimating evapotranspiration in a paddy field  

作　　者：Yan Haofang Zhang Chuan Hiroki Oue Peng Guangjie Ransford Opoku Darko 

机构地区：[1]Research Center of Fluid Machinery Engineering and Technology,Jiangsu University,Zhenjiang 212013,China [2]Institute of Agricultural Engineering,Jiangsu University,Zhenjiang 212013,China [3]United Graduate School of Agricultural Sciences,Ehime University,3-5-7 Tarumi,Matsuyama,790-8566,Japan [4]Department of Water Management,Delft University of Technology,Delft,2600GA,the Netherlands

出　　处：《International Journal of Agricultural and Biological Engineering》2017年第4期130-139,共10页国际农业与生物工程学报（英文）

基　　金：supported by the Natural Science Foundation of China(51509107,51609103);the Key Laboratory of Agricultural Water Resources,the Chinese Academy of Sciences(No.KFKT201605);Natural Science Foundation of Jiangsu province(BK20140546,BK20150509);the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry(2015,No.311);Jiangsu University Senior Professional Scientific Research Fund Project(14JDG015,14JDG017,12JDG097);Jiangsu Universities Engineering Discipline Construction Project(1033000001).

摘　　要：Accurate estimation of evapotranspiration is important in efficient water management for improving water use efficiency.In order to obtain evapotranspiration and evaporation beneath the canopy using the Food and Agriculture Organization(FAO)method,pan evaporation was used instead of reference evapotranspiration calculated by the Penman-Monteith equation with detailed meteorological data.The total crop coefficient and soil evaporation coefficient were determined using actual measured daytime evapotranspiration and evaporation by the Bowen ratio energy balance and lysimeter,respectively,in a rice paddy field in Japan.The average evapotranspiration was 5.3 mm/d,4.4 mm/d,7.4 mm/d and 6.3 mm/d and crop coefficient was 0.79,1.18,1.01 and 0.86 for the initial stage,development stage,middle-season stage and late-season stage,respectively.The evaporation was low and almost constant with an average value around 0.77 mm/d when the leaf area index(LAI)reached 3.The proposed average crop coefficients for different growing stages were applied to estimate daytime evapotranspiration and found suitable.A simple soil water evaporation coefficient model was developed using leaf area index for practical use and it was found that it could accurately estimate evaporation.

关 键 词：EVAPOTRANSPIRATION EVAPORATION paddy field LYSIMETER leaf area index(LAI) Bowen ratio energy balance 

分 类 号：S15[农业科学—土壤学]