Search Results

You are looking at 41 - 50 of 778 items for :

  • "evapotranspiration" x
  • All content x
Clear All
Free access

David R. Bryla, Thomas J. Trout, and James E. Ayars

crops are needed. A dependable method to estimate crop water requirements is a simple procedure whereby water lost by soil evaporation and plant transpiration, referred to collectively as crop evapotranspiration (ET c ), is calculated by multiplying

Full access

Esmaeil Fallahi, Bahar Fallahi, and Michael J. Kiester

this treatment, the trees were irrigated once a week at the full rate of evapotranspiration (ETc) for apple starting in 2002. During the period of this study (2008–11), ETc values for fully mature trees were used. Method for ETc calculation is described

Free access

Reagan W. Hejl, Benjamin G. Wherley, James C. Thomas, and Richard H. White

evapotranspiration (ET a )] and deficit irrigation (0.3 × ET a ). ET a was determined by weighing and calculating the mean mass change of three fully watered (1.0 × ET a ) lysimeters within each of the three water source treatments. Irrigation was then supplied at

Full access

Tim R. Pannkuk

(ASABE) has recently defined mixed-species landscape water use normalized to reference evapotranspiration as plant factors, rather than crop coefficients ( ASABE, 2012 ; Beeson et al., 2014 ; Sun et al., 2012a ). The new S623 Standard attempts to define

Free access

Jack D. Fry, Steven C. Wiest, and Ward S. Upham

Evapotranspiration from tall fescue, perennial ryegrass and zoysiagrass turfs during the summers of 1992-3 was compared to evapotranspiration estimates from an evaporation pan, a black Bellani plate, and several empirical combination models, Actual measurement of turf water use was made with small weighing lysimeters. Soil was maintained at field capacity. Data were collected on 51 dates between June and September. Tall fescue was clipped weekly at 7.6 cm whereas ryegrass and zoysiagrass were clipped 3 times weekly at 2.5 cm, Although differences between the grass species existed, in general the rankings of estimate precision were Bellani plate > evaporation pan > empirical models when compared with measured evapotranspiration rates.

Full access

Janet S. Hartin, David W. Fujino, Lorence R. Oki, S. Karrie Reid, Charles A. Ingels, and Darren Haver

al., 2017 ). A summary and brief review of these UC-led studies follows. Evapotranspiration adjustment factor (ETAF) study . California implemented water conservation legislation that required reductions in urban and agricultural water usage ( CDWR

Free access

Julián Miralles-Crespo, María J. Sánchez-Blanco, Alejandra Navarro G., Juan J. Martínez-Sánchez, Jose A. Franco L., and Sebastián Bañón A.

) followed by a fourth one during which the plants died (August). To confirm plant death, it was irrigated for 2 weeks and when it was seen that the leaves remained dry and produced no new shoots, it was considered dead. Evapotranspiration determination. The

Free access

Toshio Shibuya, Yoshiaki Kitaya, Toyoki Kozai, and Masaichi Nakahara

Net photosynthetic and evapotranspiration rates of tomato (LAI = 2.3) and lettuce (LAI = 6.6) plug sheets were estimated based on measurements of the weight of plug sheets and vertical profiles of CO2 concentration above the plug sheets. The measurements were continued in situ for several days in a greenhouse when plugs were at transplant stage. The maximum net photosynthetic rates of tomato and lettuce plug sheets were 0.8 and 2.0 mg CO2/m2 per sec on a plug sheet area basis, respectively. The maximum evapotranspiration rates of those sheets were 100 mg·m–2·s–1. Net photosynthetic and evapotranspiration rates of tomato and lettuce plug sheets increased linearly with an increase in solar radiation flux, with a correlation coefficient of 0.9.

Free access

Daniel I. Leskovar, Shinsuke Agehara, Kilsun Yoo, and Nuria Pascual-Seva

strategies on quercetin content of onion remains largely unknown. Previous investigations have not evaluated the interactive effects of PD and deficit irrigation rates using specific growth-stage crop coefficients as a tool for evapotranspiration

Full access

Esmaeil Fallahi

at 70% of ET c . Rainfall in both experiments was comparable. Table 1. Precipitation, evapotranspiration (ET), depth of applied water, and total volume of applied water per tree in ‘Pacific Gala’ apple from 2004 to 2007. Effects of rootstock on leaf