Estimation of reference evapotranspiration inside fan and pad greenhouse from external climate data.

Autor: Gaafer, Amna M. A., Mohammed, Hassan I., Elfadil, Elfadil Abdelkarim Dafalla
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Zdroj: World News of Natural Sciences (WNOFNS); 2024, Vol. 54, p133-145, 13p
Abstrakt: With increasing cultivating areas using greenhouses, estimating reference crop evapotranspiration (ETo) inside a greenhouse has recently gained greater attention for the design of new greenhouses or for improving operation of existing ones. Currently, calculating ETo inside a greenhouse using the Penman-Monteith formula recommended by FAO is difficult because the wind speed in a greenhouse is very low or approximate zero. In addition estimating the inner greenhouse is confronted by lack of all needed climate input variables in many areas especially in developing countries. To simplify calculating the inner greenhouse ETo from the routinely and historically collected data outside the greenhouse in the study area by the Penman-Monteith formula (PM-56), a correction factor is proposed in this study. The parameters for constructing the proposed adjustment factor were taken from ETo values measured using class A evaporation pan, and from ETo determined through meteorological data. The first is used for developing and validating the proposed correction factor where data was collected during three years at three study sites (Abu Halima, Date Palm Shambat Site, and Khartoum University farm) with three greenhouses per site. In the second experiment one house is chosen in Shambat area during the third year and equipped with needed equipments. The second experiment was used for verification purposes. In all cases the fitted values by the correction factor agreed well according to statistical evaluation parameters (Chi-squire test, Mean Absolute Error (MAE), correlation coefficient (r2), the slope of the regression and the absolute deviation) with a measured value. Hence, the developed correction factor can be used as easy mean of calculating the ETo inside a greenhouse because historically available meteorological factors are needed. The estimations of the greenhouse indoor ETo PM from outdoor ETo PM could enhance climate-smart agriculture applications in semiarid environments while minimizing in-greenhouse meteorological data requirements. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index