Development of irrigation control method based on evapotranspiration from the plant canopy

基于植物冠层蒸散量的灌溉控制方法的开发

• 批准号: 18580257
• 负责人: TAKAKURA Tadashi
• 金额: $ 2.13万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2006
• 资助国家: 日本
• 起止时间: 2006 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18580257/
• 关键词: Energy balance; Penman-Monteith equation; Evapotranspiration; 熱収支式; 蒸発散測定; 法線面日射; ペンマンーモンティス法

A simple heat balance equation for the plant canopy model from which the Penman-Monteith equation was derived is used to estimate evapotranspiration from a plant canopy. Incoming radiation downward and upward, air temperature and wind speed above the canopy are the only four factors to be measured. Estimated evapotranspiration is in good agreement with the values measured by an accurate scale in wet and dry conditions. The present method was simple and considered for irrigation control in greenhouses.It was found that the cosine law for a flat sensor causes an error since the surface of a plant canopy which receives the sun's energy is not flat. In order to develop an economical solarimeter to measure solar radiation received by the surface normal to the direct solar radiation, a photodiode was placed at the bottom of an opaque white ping-pong ball which had a hole for the photodiode at the bottom. It was concluded that this solarimeter can be used to form better control strategies for greenhouse environment control.It was proved that the system can be used without any problem in greenhouses. In the open field, the effect of precipitation should be taken into account. Four sensors to detect wetness have been used to determine when irrigation should be started after rain fall with a potentiometer to measure soil water content. It was concluded that the timing can be determined by the developed instrument itself by judging when evapotranspiration starts.

用一个简单的植物冠层模型的热量平衡方程来估算植物冠层的蒸散量。向下和向上的入射辐射、冠层上方的气温和风速是唯一需要测量的四个因素。估算的蒸散量与在干湿条件下通过精确尺度测量的值吻合良好。本方法简单，并考虑在温室灌溉控制。它被发现，余弦定律的平面传感器造成的误差，因为植物冠层的表面接收太阳的能量是不平坦的。为了开发一种经济的太阳辐射计来测量由垂直于直接太阳辐射的表面接收的太阳辐射，将光电二极管放置在不透明的白色乒乓球的底部，该乒乓球在底部具有用于光电二极管的孔。研究结果表明，该系统可以为温室环境控制提供更好的控制策略，在温室环境中应用是完全可行的。在露天场地，应考虑降水的影响。四个传感器检测湿度已被用来确定何时灌溉应开始后，降雨与电位计测量土壤含水量。结果表明，该仪器可以通过判断蒸发蒸腾开始的时间来确定蒸发蒸腾的时间。

项目成果

Plant solarimeter for energy balance.

用于能量平衡的植物日光计。

• 发表时间: 2008
• 期刊: Acta Horticulturae (In press)
• 作者: Hossain;M.Z.;T. Takakura
• 通讯作者: T. Takakura

Evapotranspiration rate measurement by energy-balance equation in a single-span greenhouse

单跨温室蒸散速率的能量平衡方程测量

• 发表时间: 2007
• 期刊: ASABE Paper No.74020
• 作者: T. Takakura;C. Kubota;S. Sase;M. Hayashi;M. Ishii;K. Takayama;H. Nishina;K. Kurata;G. A. Giacomelli
• 通讯作者: G. A. Giacomelli

Plant solarimeter for energy balance

用于能量平衡的植物日照计

• 发表时间: 2008
• 期刊: Acta Horticulturae in press
• 作者: Takakura;T.
• 通讯作者: T.

植物日射計の試作

植物总辐射表原型

• 发表时间: 2007
• 期刊: 日本農業気象学会2007年春季大会講演要旨
• 作者: T.Takakura;C.Kubota;S.Sase;M.Hayashi;M.Ishii;K.Takayama;H.Nishina;K.Kurata;G.A.Giacomelli;高倉 直
• 通讯作者: 高倉 直

Evapotranspiration rate measurement by energy-balance equation in a sigle-spangreenhouse.

单跨温室蒸散速率的能量平衡方程测量。

• 发表时间: 2007
• 期刊: ASABE Paper No.74020
• 作者: Takakura;T.;Kubota.;C.;Sase;S.;Hayashi;M.;Ishii;M.;Takayama;K.;Nishina;H. and Kurata. K.
• 通讯作者: H. and Kurata. K.