Soil Hydraulic Properties Affecting Discharge Uniformity of Gravity-Fed Subsurface Drip Irrigation Systems

The use of subsurface drip irrigation (SDI) is increasing for many reasons, including its many agronomic advantages and the ability for safe application of wastewater to crops. In contrast to surface drip irrigation, soil hydraulic properties may affect SDI performance, particularly for new SDI systems designed to operate under low pressure (e.g., 2 m of head). This work introduces a new approach for solving problems of predicting discharge in SDI laterals. We accomplish this by coupling models of head loss in laterals and soil impacts on dripper discharge. The coupled model enables an evaluation of the performance of SDI laterals while changing inputs, such as the lateral diameter, length and slope, dripper nominal discharge and exponent, inlet pressure head, soil hydraulic properties, and soil spatial variability. This model is used to determine the coefficient of variation of discharge for two numerical comparisons.

[1]  A. Warrick.  Soil Water Dynamics , 2003 .

[2]  Naftali Lazarovitch,et al.  System‐Dependent Boundary Condition for Water Flow from Subsurface Source , 2005 .

[3]  D. Russo.  A Stochastic Approach to the Crop Yield-Irrigation Relationships in Heterogeneous Soils: I. Analysis of the Field Spatial Variability1 , 1986 .

[4]  S. L. Rawlins,et al.  Prospects for high-frequency irrigation. , 1975, Science.

[5]  Pedro L. Luque-Escamilla,et al.  New Algorithm for Hydraulic Calculation in Irrigation Laterals , 2001 .

[6]  Gideon Sinai,et al.  Application of Conditioner Solution by Subsurface Emitters for Stabilizing the Surrounding Soil , 2004 .

[7]  Alon Ben-Gal,et al.  Phosphorus Availability under Continuous Point Source Irrigation , 2003 .

[8]  Crop Yield as Influenced by Irrigation Uniformity , 1987 .

[9]  U. Shani,et al.  Soil-limiting flow from subsurface emitters. I: Pressure measurements , 1996 .

[10]  U. Shani,et al.  Soil-limiting flow from subsurface emitters. II: Effect on uniformity , 1996 .

[11]  D. Or,et al.  Drip Irrigation (Applied Agriculture) , 1999 .

[12]  D. R. Nielsen,et al.  Predictions of the Soil Water Flux Based upon Field-measured Soil-water Properties1 , 1977 .

[13]  J. W. Radin,et al.  Water Uptake by Cotton Roots during Fruit Filling in Relation to Irrigation Frequency , 1989 .

[14]  C. R. Camp,et al.  Subsurface drip irrigation : A review , 1998 .

[15]  J. Philip,et al.  What happens near a quasi-linear point source? , 1992 .

[16]  B. Bar-Yosef,et al.  Advances in Fertigation , 1999 .

[17]  Uri Shani,et al.  Subsurface Drip Irrigation in Gravel-Filled Cavities , 2004 .