ISHS Acta Horticulturae 278: Symposium on Scheduling of Irrigation for Vegetable Crops under Field Condition
THE WATER CONSUMPTION OF AGRICULTURAL CROPS: HOW CROP COEFFICIENTS ARE AFFECTED BY CROP GEOMETRY AND MICROCLIMATE |
| Authors: | C. Stanghellini, A.H. Bosma, P.C.J. Gabriels, C. Werkhoven |
| Abstract:
A theoretical equation for crop coefficients is derived in the present work. It is shown that the ratio of crop evapotranspiration to reference evaporation is, by no means, constant. It is, in fact, a function of leaf area, a number of crop parameters and the prevailing weather. The relationship with respect to weather is discussed in the first place, and the predicted trend (larger crop coefficients in "humid" weather) is shown to be detectable in original experimental values of the crop coefficient of two crops as different as grass and tomato. Further, the influence of leaf area and its seasonal trend is taken into account. It is observed that it might be due to good luck that crop coefficients are "almost" constant. The conclusion is that, whenever knowledge of a number of crop-specific parameters is available, a "theoretical" transpiration formula is likely to deliver better estimates of crop water requirement than calculations based on crop coefficients. It is suggested, therefore, that some hydrological research could better be aimed at establishing the needed crop-specific parameters. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
