Simple equation for estimating actual evapotranspiration using heat units for wheat in arid regions

Abstract

Available online xxxKeywords: Evapotranspiration Growing degree days Spring wheat WUE HUE Neutron probe a b s t r a c t Estimation of actual evapotranspiration (ET a ) is an important part of agricultural water management in local and regional water balance studies. At the field scale, ET a is important in irrigation planning and scheduling and is an integral part of field management decision support tools. The conventional approach of estimating actual evapotranspiration is difficult and needs more calculations and extensive data on soil-plant-atmosphere. A field experiment was conducted to simplify the measurement and calculation of actual evapotranspiration by using thermal units (heat units) for spring wheat crop under trickle irrigation system in sandy soil. Two irrigation methods were applied; the first one (A) using the crop evapotranspiration (ET c ) that depends on whether parameters, and the second (B) is the depletion from field capacity which dependent on soil parameters. Three varieties of wheat namely Sids12, Misr2 and Gemmeza10 were cultivated on sand soil and treatments arranged in complete randomized block design with three replicates. Application of treatment (B) resulted in highly significant increase in yield production of Gemmeza10 and Misr2 as compared to treatment (A). Grain yield of different wheat varieties grown under treatment (B) could be ranked in the following descending order: Misr2 > Gemmeza10 > Sids12. While under treatment (A) it could be arranged in the following descending order: Misr2 > Sids12 > Gemmeza10. On the other hand, the overall means indicated non-significant difference between all wheat verities. The highest values of water and irrigation use efficiency as well as heat use efficiency were obtained with treatment (B). The equation used in the present study is available to estimate ET a under arid climate with drip irrigation system. journal h omepage: http :/ / www .e lsev ie r. co m/ lo cate/ j rras 1

Evaluation of Crop Coefficient, Cumulative and Dynamic Evapo-Transpiration of Winter Wheat under Deficit Irrigation Treatments in Weighing Lysimeter in Beijing, China

“…Salama et al (2015) also noted that estimating evapotranspiration is an important part of agricultural water management in local and regional water balance studies. Lysimeters are the most reliable research tool for direct measurement of ET c (Trajkovic, 2010).…”

Comparison of the Reference Evapotranspiration among Empirical Methods and Penman-Monteith in Semiarid Region of Northeastern Brazil

“…Evapotranspiration is the simultaneous process of water transfer to the atmosphere both by soil water evaporation and plant transpiration. The study of this parameter is essential for adequate irrigation management, water resources planning and management, and rational agricultural water use (Salama et al, 2015;Pandey et al, 2016;Yang et al, 2019). The determination of evapotranspiration is as well important for the studies of hydrology, climatology, and meteorology (Djaman et al, 2018).…”

Feedstock availability and moisture content data processing for multi-year simulation of forest biomass supply in energy production

“…6 uses net irradiance (R n, in W m -2 ), ground heat flux (G, in W m -2 ), dry air density (ρ a , in kg m -3 ), the specific heat capacity of air (c p , in J kg -1 K -1 ), the vapor pressure deficit of air (e s -e a, in Pa), the rate of change of saturation specific humidity with air temperature (Δ, in Pa K -1 ), the psychrometric constant (γ, in Pa K -1 ), and surface and aerodynamic resistances (r s and r a , in s m -1 ) to calculate the energy rate of water evaporation (E, in g s -1 m -2 ) multiplied with the latent heat of vaporization (λ, in J g -1 ). Due to complications and the need for several parameters, this equation has been simplified in many different ways (Linacre 1977;Salama et al 2015;Gallego-Elvira et al 2012). Linacre (1977) This includes R as a daily range of temperature and R ann as the difference between the mean temperatures of the coldest and hottest months (values in °C).…”