optimal use of water resources is essential to decrease cost and maximize available water resources. subsurface drip irrigation can increase irrigation and water use efficiency. this irrigation method distributes water into the soil, leaving the surface of the soil dry and decreasing evaporation. in the design of subsurface drip irrigation (sdi) systems, the dimensions of the wetted onion deter...

Agricultural irrigation in the middle reaches of the Heihe River Basin consumes approximately 80% of the total river water. Whether the irrigation depth matches the water uptake depth of crops is one of the most important factors affecting the efficiency of irrigation water use. Our results indicated that the influence of plastic film on soil water δ(18)O was restricted to 0-30 cm soil depth. B...

Thèse présentée et soutenue le 28 octobre 2005 devant le jury composé de : Je remercie enfin mes parents et mes frères pour leur soutien. A Véro, Charlotte et Claire : merci d'exister et d'avoirété toujours l` a.

according to the low efficiency of irrigation and drainage networks and water distribution in iran, simulating water flow and sensitivity structures and networks is considered as a new approach to evaluate the performance hydroelectric projects in the country. in this study, because of reduced water supply and distribution, especially in downstream irrigation and drainage networks varamin to ev...

The great challenge of the agricultural sector is to produce more food and/or more revenue from less water, which can be achieved by optimal irrigation management. A task of primary importance is the problem of intraseasonal irrigation scheduling under limited seasonal water supply. On the intraseasonal level, a limited amount of water is to be distributed over a number of irrigations, taking i...

Capillary rise from shallow groundwater can decrease the need for irrigation water. However, simple techniques do not exist to quantify the contribution of capillary flux to crop water use. In this study we develop the Agricultural Water Productivity Model for Shallow Groundwater (AWPM-SG) for calculating capillary fluxes from shallow groundwater using readily available data. The model combines...

shallot (allium altissimum regel.) is a medicinal, industrial and perennial plant that has underground tubers. it is one of the most important allium species in iran, which normally grows in semi-cold to very cold highlands. because of being a wild plant, shallot is encounter with water deficit during its growth season. therefore evaluation of water requirement of shallot is important. in order...

abstract to optimal use of available water, irrigation scheduling is important to over scarcity of water resources in arid and semi-arid area. in this research to estimate of maximum allowable deficit (or: management allowed depletion) and irrigation scheduling of fodder mays based on canopy-air temperature difference, a field study was conducted in agricultural faculty of karaj. the lower limi...

Drought stress (DS) is an important limiting factor for crop growth and production in some regions of the world. Limitation in water availability precludes optimal irrigation in some production regions. Therefore, investigations on the interaction of other factors to mitigate the DS to varying degree are important. Two field experiments were conducted in the experimental farm of the National Re...

Introduction. This experimental study is to compare radiographs based on the penetration depth of the irrigant following three final irrigation techniques. Material and Method. A sample of sixty teeth with single roots were prepared with stainless steel K files followed by mechanized Ni-Ti files iRace® under irrigation with 2.5% sodium hypochlorite. Radiopaque solution was utilized to measure t...