this paper reports the results of using three empirical methods (makkink, priestley-taylor and hargreaves) for estimating the reference evapotranspiration (et0) in the semi-arid region of tensift al haouz, marrakech (center of morocco). the penman-monteith equation, standardized by the food and agriculture organization (fao-pm), is used to evaluate the three empirical methods. the obtained et0 ...

In this research, to evaluate the effect of superabsorbent polymer and drought stress on the number and leaf area of Lettuce, experimental  research was conducted in a completely randomized design factorial with two treatments of irrigation regime at three levels (60, 80 and 100 percent of crop water requirement) and four superabsorbent hydrogel application (0, 4, 6 and 8 g per kg of soil) in t...

Crop water requirement is essential for agricultural water management, which is usually available for crop growing stages. However, crop water requirement values of monthly or weekly scales are more useful for water management. A method was proposed to downscale crop coefficient and water requirement from growing stage to substage scales, which is based on the interpolation of accumulated crop ...

in order to study the effects of drought stress on yield and yield components of safflower genotypes, a split plot based on randomized complete block design with four replications was performed at the research field, islamic azad university, arak, iran during summer of 2009. irrigation treatments included three levels of 100, 75 and 50% crop water requirement and four levels of safflower genoty...

water is the most important factor for agriculture development in iran. accordingly the optimal consumptione of water is very important. using pressurized irrigation system is one of the methods to improve agricultural water management. the objecttives of this research were to compare two irrigation methods of furrow and trickle irrigation systems impacts on quantity and quality characters of s...