scholarly journals Study of the Wet Bulb in Stratified Soils (Sand-Covered Soil) in Intensive Greenhouse Agriculture under Drip Irrigation by Calibrating the Hydrus-3D Model

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 600
Author(s):  
Antonio Jesús Zapata-Sierra ◽  
José Roldán-Cañas ◽  
Rafael Reyes-Requena ◽  
María Fátima Moreno-Pérez

The development of the wet bulb under drip irrigation in sand-covered soils presents a different behavior compared to the one observed in homogeneous soils. Moreover, the presence of a very active crop imposes a series of variations that have not been fully characterized. The aim of this work is to present the data acquisition methodology to calibrate and validate the Hydrus-3D model in order to safely define the evolution of moisture in wet bulbs generated in stratified “sanded” soils characteristic of greenhouses with intensive pepper crop under drip irrigation. The procedure for collecting and processing moisture data in stratified soils has been defined. Soil permeability; retention curve, texture, and bulk density have been measured experimentally for each material. It has been found that the inclusion of a previous day in the simulation improves model predictions of soil moisture distribution. In soils with less gravel, a lower average stress and a more homogeneous moisture distribution were observed. It has been proved that the Hydrus-3D model can reproduce the behavior of sand covered soils under intensive greenhouse growing conditions, and it has been possible to verify that the predictions are adequate to what has been observed in the field. In view of the results, the Hydrus-3D model could be used to establish future irrigation strategies or to locate the optimal placement point of tensiometers that control irrigation in sandy soils for intensive agriculture.

2013 ◽  
Vol 33 (2) ◽  
pp. 249-257 ◽  
Author(s):  
Alberto Colombo ◽  
Lívia A. Alvarenga ◽  
Myriane S. Scalco ◽  
Randal C. Ribeiro ◽  
Giselle F. Abreu

The increasing demand for water resources accentuates the need to reduce water waste through a more appropriate irrigation management. In the particular case of irrigated coffee planting, which in recent years presented growth with the predominance of drip irrigation, the improvement of drip irrigation management techniques is a necessity. The proper management of drip irrigation depends on the knowledge of the spatial pattern of soil moisture distribution inside the wetted strip formed under the irrigation lines. In this study, grids of 24 tensiometers were used to determine the water storage within the wetted strip formed under drippers, with a 3.78 L h-1 discharge, evenly spaced by 0.4 m, subjected to two different management criteria (fixed irrigation interval and 60 kPa tension). Estimates of storage based on a one-dimensional analysis, that only considers depth variations, were compared with two-dimensional estimates. The results indicate that for high-frequency irrigation the one-dimensional analysis is not appropriate. However, under less frequent irrigation, the two-dimensional analysis is dispensable, being the one-dimensional sufficient for calculating the water volume stored in the wetted strip.


Author(s):  
A. Selvaperumal ◽  
E. Sujitha ◽  
I. Muthuchamy

Drip irrigation system uniformity can preserve a higher crop yield and deplete the initial investment of cost. The experiment was conducted at precision farming development centre research farm, Tamil Nadu Agricultural University, Coimbatore, to evaluate the uniformity coefficient and soil moisture distribution under drip irrigation system. The experiment was designed under Factorial Randomized Block Design (FRBD) which included three fertigation levels 80%, 100% and 120% of Recommended Dose of fertilizers which were replicated thrice. The Coefficient of Variation (CV) was obtained as 0.0207 per cent kept at a constant pressure of 50.66 kPa, Statistical Uniformity (SU) as 97 per cent and Coefficient of Uniformity (CU) as 0.9518. As the elapsed time increased, the rate of increase of wetted zone diameter decreased. A high R2 value of 0.97 shows the goodness of fit for the horizontal movement. The mean soil moisture distribution 39.2 per cent was observed below the emitter at the depth of 10 cm immediately after irrigation.


2020 ◽  
Vol 20 (3) ◽  
pp. 761-772 ◽  
Author(s):  
Arpna Bajpai ◽  
Arun Kaushal

Abstract The wetting pattern of soil under trickle (drip) irrigation is governed by soil texture, structure, initial water content, emitter spacing, discharge rate and irrigation frequency. For efficient management of trickle irrigation moisture distribution plays an important role. The degree of soil wetted volume in an irrigation system determines the amount of water required to wet the root zone. This article helps in understanding moisture distribution for different lateral spacing, emitter spacing, emitter discharge rates and drip line installation depth for trickle irrigation under various soil conditions all over the world. This review reveals that soil moisture distribution and uniformity within the soil profile were affected by the distance between emitters rather than the distance between drip lines. In drip irrigation systems, the less the dripper spacing, the greater the moisture distribution as well as water use efficiency and crop yield. The radial spread of moisture was greater at lower water application rates, whereas the vertical spread was greater at higher water application rates. The vertical movement of soil moisture was greater than the horizontal movement under surface as well as subsurface drip irrigation systems. Deeper drip tape installations had a potential risk of not providing moisture to shallow rooted crops.


Author(s):  
A. Selvaperumal ◽  
E. Sujitha ◽  
I. Muthuchamy

Drip irrigation system uniformity can preserve a higher crop yield and deplete the initial investment of cost. The experiment was conducted at precision farming development centre research farm, Tamil Nadu Agricultural University, Coimbatore, to evaluate the uniformity coefficient and soil moisture distribution under drip irrigation system. The experiment was designed under Factorial Randomized Block Design (FRBD) which included three fertigation levels 80%, 100% and 120% of Recommended Dose of fertilizers which were replicated thrice. The Coefficient of Variation (CV) was obtained as 0.0207 per cent kept at a constant pressure of 50.66 kPa, Statistical Uniformity (SU) as 97 per cent and Coefficient of Uniformity (CU) as 0.9518. As the elapsed time increased, the rate of increase of wetted zone diameter decreased. A high R2 value of 0.97 shows the goodness of fit for the horizontal movement. The mean soil moisture distribution 39.2 per cent was observed below the emitter at the depth of 10 cm immediately after irrigation.


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