Assessment of Emitter Discharge in Drip Irrigation as Affected by Biogas Effluent

2012 ◽  
Author(s):  
Mohamed Abouzeid Rashad ◽  
Mohamed Ali Abdel-Hadi ◽  
Samy Abl El-Malik Abd El-Azeem
Keyword(s):  
Drip Irrigation ◽  
Emitter Discharge

Application of the steady-state principle of constant-head well permeameter to indirect subsurface drip irrigation

2009 ◽  
Vol 89 (5) ◽  
pp. 671-676 ◽  
Author(s):  
Z Weixia ◽  
C Huanjie ◽  
Z Zhenhua ◽  
S Zhijie
Keyword(s):  
Steady State ◽  
Hydraulic Conductivity ◽  
Drip Irrigation ◽  
Discharge Rate ◽  
Saturated Hydraulic Conductivity ◽  
Subsurface Drip Irrigation ◽  
Equilibration Time ◽  
Constant Head ◽  
Subsurface Drip ◽  
Emitter Discharge

Indirect subsurface drip irrigation (ISDI) is a method of increasing the irrigation water use efficiency of drip irrigation without the need to bury irrigation tubes and wet the soil surface. A major problem of ISDI is the mismatch between emitter discharge rate and water-conducting device dimension, which will result in over-filling of application water. In this paper, we propose to use the steady-state principle of constant-head well permeameter (CHWP) to quantify the relationship between emitter discharge rate and water-conducting device dimension for ISDI. CHWP tests and ISDI tests were carried out in a 300 m2 winter wheat fallow to verify its feasibility. The steady-state characteristic of these two methods was also studied using long-term infiltration. Results indicate that the equilibration time (110 min) in the ISDI tests was greater than that in the CHWP tests (30 min). The steady ponded depth in ISDI had a smaller variation than the steady water discharge rate in the CHWP. When using the steady-state principle of CHWP to design ISDI systems, there was significant linear correlation between predicted and measured ponded depth values (R2 = 0.8379). The soil field-saturated hydraulic conductivity calculated by these two tests was approximately equal. These results demonstrate that the steady-state principle of CHWP could be used to select appropriate irrigation systems for ISDI, and ISDI provides another technique to obtain the field-saturated hydraulic conductivity. Key words: Constant-head well permeameter, field-saturated hydraulic conductivity, indirect subsurface drip irrigation, steady-state

scholarly journals Experimental and Numerical Analysis of Drip Tape Layout for Irrigation of Sugarcane in Latosol

2015 ◽  
Vol 9 (1) ◽  
pp. 265-271 ◽  
Author(s):  
Kai Huang ◽  
Desuo Cai ◽  
Jinchuang Jinchuang ◽  
Wei Pan
Keyword(s):  
Point Source ◽  
Soil Water ◽  
Drip Irrigation ◽  
Water Movement ◽  
Discharge Rate ◽  
Single Point ◽  
Critical Parameters ◽  
Irrigation Uniformity ◽  
Emitter Discharge ◽  
Soil Water Movement

A laboratory soil column experiment was first conducted to analyze water movement in latosol of sugarcane field under drip irrigation from single-point source at different emitter discharge rates. Next, a mathematical model of soil water movement under drip irrigation from single-point source was built using Hydrus-3D, which could accurately simulate the shape of the wetted soil volume and the distribution of volumetric water content in the experiment. Further, a Hydrus- 3D model of soil water movement under drip irrigation from double-point source was built and then used to analyze the effects of critical parameters on irrigation uniformity. Results showed that emitter spacing affected irrigation uniformity greatly, but emitter discharge rate did not. According to the irrigation uniformity, project cost and operational management patterns, appropriate drip tape parameters for irrigation of sugarcane in latosol were determined: emitter discharge rate 1.38 L/h, emitter spacing 30 cm, and single-emitter irrigation volume 9.0 L.

scholarly journals Evolution of the spherical cavity radius generated around a subsurface drip emitter

2010 ◽  
Vol 7 (2) ◽  
pp. 1935-1958 ◽  
Author(s):  
M. Gil ◽  
L. Rodríguez-Sinobas ◽  
R. Sánchez ◽  
L. Juana
Keyword(s):  
Drip Irrigation ◽  
Spherical Cavity ◽  
Water Distribution ◽  
Subsurface Drip Irrigation ◽  
Positive Pressure ◽  
Irrigation Performance ◽  
Cavity Radius ◽  
Soil Pressure ◽  
Subsurface Drip ◽  
Emitter Discharge

Abstract. The emitter discharge in subsurface drip irrigation can be affected by soil properties. A positive pressure develops at the emitter outlet where a spherical cavity is assumed to form. In steady-state conditions, the pressure in the soil relates to soil hydraulic properties, the emitter discharge, and the cavity radius. This pressure in the soil is very sensitive to the cavity radius. In this paper, the development of the cavity around the emitter outlet was measured for various emitter discharges in laboratory tests carried out in containers with uniform loamy soils. A trend between soil pressure and emitter discharge was established that illustrates the performance of buried emitters in the field. Its application to the prediction of water distribution in subsurface drip irrigation units and its effect on the estimation of irrigation performance is also shown.

scholarly journals Evolution of the spherical cavity radius generated around a subsurface drip emitter

2010 ◽  
Vol 7 (6) ◽  
pp. 1983-1989 ◽  
Author(s):  
M. Gil ◽  
L. Rodríguez-Sinobas ◽  
R. Sánchez ◽  
L. Juana
Keyword(s):  
Drip Irrigation ◽  
Spherical Cavity ◽  
Water Distribution ◽  
Subsurface Drip Irrigation ◽  
Positive Pressure ◽  
Irrigation Performance ◽  
Cavity Radius ◽  
Soil Pressure ◽  
Subsurface Drip ◽  
Emitter Discharge

Abstract. The emitter discharge in subsurface drip irrigation can be affected by soil properties. A positive pressure develops at the emitter outlet where a spherical cavity is assumed to form. In steady-state conditions, the pressure in the soil relates to soil hydraulic properties, the emitter discharge, and the cavity radius. This pressure in the soil is very sensitive to the cavity radius. In this paper, the development of the cavity around the emitter outlet was measured for various emitter discharges in laboratory tests carried out in containers with uniform loamy soils. A trend between soil pressure and emitter discharge was established that illustrates the performance of buried emitters in the field. Its application to the prediction of water distribution in subsurface drip irrigation units and its effect on the estimation of irrigation performance are also shown.

scholarly journals Emitter discharge variability of subsurface drip irrigation in uniform soils: effect on water-application uniformity

2008 ◽  
Vol 26 (6) ◽  
pp. 451-458 ◽  
Author(s):  
M. Gil ◽  
L. Rodríguez-Sinobas ◽  
L. Juana ◽  
R. Sánchez ◽  
A. Losada
Keyword(s):  
Drip Irrigation ◽  
Subsurface Drip Irrigation ◽  
Water Application ◽  
Subsurface Drip ◽  
Emitter Discharge

scholarly journals Evaluation of Root Water Uptake and Urea Fertigation Distribution under Subsurface Drip Irrigation

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1487 ◽  
Author(s):  
Mohamed Galal Eltarabily ◽  
Khaled M. Bali ◽  
Abdelazim M. Negm ◽  
Chihiro Yoshimura
Keyword(s):  
Drip Irrigation ◽  
Nitrate Concentration ◽  
Sandy Loam ◽  
Irrigation Event ◽  
Subsurface Drip Irrigation ◽  
Soil Types ◽  
Silty Loam ◽  
Loam Soil ◽  
Subsurface Drip ◽  
Emitter Discharge

Shallow groundwater contamination by nitrate is frequent in agricultural lands in Egypt because of the use of urea fertilizers. The urea transformation process in the vadose zone was simulated using a HYDRUS-2D model, Software package for simulations of 2D movement of water, heat, and multiple solutes in variably saturated media, for subsurface drip irrigation. The root water and nutrient uptake were assessed for three soil types (sandy loam, loam, and silty loam) with three emitter discharge levels (1.0 L h−1, 1.50 L h−1, and 2.0 L h−1), for a comparison of three fertigation strategies (A) at the beginning, (B) at the end, and (C) at the middle of the irrigation cycle. The extension of the wetted area mainly depends on soil hydraulic conductivity. The high emitter discharge with a short irrigation time is suitable for shallow-rooted crops. The cumulative flux was highest for silty loam soil and the lowest was for the sandy loam soil (1891, and 1824 cm3) for the 2 L h−1 emitter discharge within the 35 days simulation. The cumulative drainage significantly differs among soil types with little effect of emitter discharge. It recorded 1213, 295, 11.9 cm3 for sandy loam, loam, silty loam, respectively. Urea transformation is controlled by hydrolysis and nitrification as well as the adsorption coefficient of ammonium. Nitrate distribution is mainly governed by soil type rather than the emitter discharge where the sandy loam soil is more highly susceptible to nitrate leaching than to silty loam. Nitrate concentration has recorded the minimum possible level when applying the urea fertilizer at the beginning of the irrigation event for sandy loam and loam soil while for the silty loam soil, urea application at the middle of the irrigation event is more effective. Urea application at the end of the irrigation event gives the highest accumulated leached nitrate concentration below the root zone and should be avoided (the worst strategy).

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