[Plant transpiration in a maize/soybean intercropping system measured with heat balance method].
In an experimental field with maize/soybean strip intercropping, the transpiration of maize and soybean plants was measured with sap flow gauge based on heat balance method. In the intercropping system, the diurnal change of the sap flow rates of the plants fitted single-peak curve in sunny day and multi-peak curve in cloudy day. The plant sap flow rates were affected by many environmental factors, among which, solar radiation was the most important meteorological factor. The daily sap flow per maize or soybean plant showed significant correlations with solar radiation, air temperature, relative humidity, wind speed, and soil heat flux. During the observation period (June 1-30, 2008), the mean daily transpiration of maize plant (1.44 mm x d(-1)) was about 1.8 times of that of soybean plant (0.79 mm x d(-1)). Maize transpiration and soybean transpiration contributed 64% and 36% to the total transpiration of the intercropping system, respectively. Due to the spatial variation of stem diameter and leaf area, it would be necessary to install more sap flow gauges to accurately measure the sap flow of maize and soybean plants.
Gao
Yang
Y
Ministry of Agriculture Key Laboratory for Crop Water Requirement and Regulation, Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences, Xirnxiang 453003, Henan, China. gylcx0944@yahoo.com.cn
Duan
Ai-wang
AW
Qiu
Xin-qiang
XQ
Zhang
Jun-peng
JP
Sun
Jing-sheng
JS
Wang
He-zhou
HZ
D000383:Agriculture / Q000379:methods*; D018526:Plant Transpiration / Q000502:physiology*; D013025:Glycine max / Q000254:growth & development* / Q000502:physiology; D013814:Thermal Conductivity; D003313:Zea mays / Q000254:growth & development* / Q000502:physiology