Comparison of Calculations for Crop Transpiration
It is significant to research crop evapotranspiration, including plant transpiration and soil evaporation, for field water cycle. There are some techniques to obtain transpiration index. In this paper, comparisons of three techniques for calculating evapotranspiration of grape under alternate partial root zone drip irrigation were curried. The results showed that cumulative transpiration can be calculated by sap flow and Penman-Monteith. Compare to water balance, the relative error was not beyond 10％. Considered the relationship of delay lag between the variety of sap flow of grape vine and the change of the transpiration, the modified coefficient K related with (Rn — G) was introduced. The results showedthere was a good correlation between the modified temporal sap flow and the transpiration rate. The correlation coefficient is 0.8344, and the slop of correlation equation is 0.9038.
transpiration water balance Penman-Monteith sap flow
Zhou Qing-yun Wang Yang-ren Sun Shu-hong
Hydraulic Engineering Department,Tianjin agricultural university,Tianjin, China, 300384
国际会议
山东淄博
英文
367-371
2011-05-27（万方平台首次上网日期，不代表论文的发表时间）