Wetting front advance patterns and water losses by deep percolation under the root zone as influenced by pulsed drip irrigation
Department of Natural Resources Management & Agricultural Engineering, Agricultural University of Athens, 11855 Athens, Greece Agricultural Water Management
(Impact Factor: 2.29).
05/2007; 90(1-2):160-163. DOI: 10.1016/j.agwat.2007.02.005
The increased use of trickle irrigation is seen as a way to improve the sustainability of irrigation systems around the world. However, soil hydraulic properties, trickle discharge rate and irrigation frequency are often not adequately incorporated in the design and management of trickle irrigation systems. The influence of the before-mentioned factors on the wetting front advance and on the water losses by deep percolation under the root zone was studied for surface trickle irrigation. For this purpose a cylindrical flow model incorporating evaporation from the soil surface and water extraction by roots was used. The results show that, for both types of soils used in this study and for the two discharge rates, the vertical component of the wetting front was greater for the pulse than for the continuous irrigation for a time equal to irrigation duration. However, this difference was practically eliminated for a longer time.
Available from: irrigation.org.au
- "There is still extensive debate in the literature, and in practice, about the value of high frequency pulse irrigation in field vegetable production (Cote et al. 2003; Elmaloglou and Diamantopoulos 2007; Mostaghimi et al. 1981). The current rationale for most growers attempting pulse irrigation is to achieve maximum lateral spread from the drip tape, and thus reduce the amount of drip tape they require in their crop. "
Available from: El-Sayed Ewis
- "The volume of wetted soil and its shape is primarily a function of the soil texture and structure, application rate, and number of emitters. So, it is essential to know the effect of the water application technique (discharge rate, continuous or intermittent application) on the amounts of water distributed to the various parts of the wetted soil volume [Elmaloglou & Diamantopoulos, 2007]. Water trickling from a point source takes place in the soil and moves downwards and sideways. "
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ABSTRACT: Abstrat To investigate solute transport in soils, detailed information about the spatial distribution of solutes is required. Many attempts have been made to determine wetting pattern under trickle irrigation using sophisticated mathematical and numerical models. These methods require detailed information concerning soil physical properties besides too complicated calculations for routine use. This study was carried out to investigate the feasibility of using image-analysis technique to derive soil wetting area and depth and to develop an image processing algorithm to derive soil wetting front map. A digital image analysis technique is proposed as a potential alternative method for visualizing and quantifying flow patterns in soils with a high spatial resolution. The method was applied in two soil types (sandy and sandy clay loam). The results of the proposed method showed that the image analysis technique gives reasonably good estimates of the wetting front map (depth and area). This potential approach to characterize flow patterns allows an objective comparison of soil infiltration patterns in the field. This proposed method could be generalized to quantify and easily derive soil flow patterns which are an important issue for precision irrigation farming and agricultural management.
Available from: ca.uky.edu
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