scholarly journals The effect of hysteresis on soil water dynamics during surface trickle irrigation in layered soils

2013 ◽  
Vol 15 (3) ◽  
pp. 351-365 ◽  
Keyword(s):  
Numerical Model ◽  
Soil Water ◽  
Water Distribution ◽  
Root Zone ◽  
Distribution Patterns ◽  
Irrigation Efficiency ◽  
Water Dynamics ◽  
Trickle Irrigation ◽  
Soil Water Dynamics ◽  
Soil Water Distribution

<p>In this study, the development of a numerical model simulating surface drip irrigation from equidistant line sources in stratified soils under various conditions is being presented. The developed numerical model was used to investigate the effects of hysteresis, discharge rate, and soil hydraulic properties on soil water dynamics in stratified soils under surface trickle irrigation. Soil water dynamics were simulated for two sequences of soil layers and for two drip lines discharge rates. Soil water distribution patterns, for all conditions examined, were computed first neglecting hysteresis by using the boundary wetting curve only and second considering hysteresis to evaluate the effect of hysteresis on the obtained results. The numerical results showed that hysteresis has a profound effect on the computed soil water distribution patterns and that the draining process progresses more quickly when hysteresis is neglected than when hysteresis is considered. The inclusion of hysteresis results in reduced water losses under the root zone. Moreover, this reduction seems to be more significant in the case that a fine soil is located below a coarse soil. The results also showed that the irrigation efficiency is higher in the same case; however, irrigation efficiency is generally high in all the examined cases of stratified soils.</p>

Numerical routine for soil water dynamics from trickle irrigation

2020 ◽  
Vol 83 ◽  
pp. 371-385 ◽  
Author(s):  
Ángel del Vigo ◽  
Sergio Zubelzu ◽  
Luis Juana
Keyword(s):  
Soil Water ◽  
Water Dynamics ◽  
Trickle Irrigation ◽  
Soil Water Dynamics

In-situ soil water dynamics under different irrigation methods in North East India

2017 ◽  
Vol 4 (2) ◽  
Author(s):  
JOY K DEY ◽  
LALA IP RAY ◽  
Y. MARWEIN
Keyword(s):  
Soil Water ◽  
Drip Irrigation ◽  
Clayey Soil ◽  
Root Zone ◽  
Soil Layer ◽  
Water Dynamics ◽  
Soil Water Dynamics ◽  
Irrigation Methods ◽  
North East

Availability of in-situ soil water plays a major role in exploiting the potential yield of crops under irrigated conditions. Depending on type of irrigation, variations of soil water is mostly observed at different soil depths within the root zone. The deviation of soil water at the edaphic zone becomes a deciding factor in assuring optimum yield. As availability of irrigation water is a great concern during non-rainy season, water saving irrigation techniques need to be adopted to maximize the productivity under hilly terrain. An experiment was laid out with potato as a test crop under the valley region of Meghalaya plateau on sandy clayey soil to study in-situ soil water dynamics under three different irrigation methods viz. furrow, micro-sprinkler and gravity-fed drip. Irrigation was scheduled at every weekly basis to restore back the soil water required to achieve the field capacity. Mean value of soil water up to 15 cm depth was 21.75, 22.65 and 23.45%, however, range (minimum to maximum) was 16.21-29.17; 15.56-29.21 and 17.84-28.97% for furrow, micro-sprinkler and gravity-fed drip irrigation, respectively. Co-efficient of variation was found to be the maximum (4.65%) for furrow over other two types of irrigations during the weekly interval. Deviation of in-situ soil water was found to vary rapidly at upper layer (30 cm) under furrow method of irrigation; but at deeper soil layer rapid variation was not observed. Water use efficiency of potato was evaluated to be 14.66, 18.78, 20.63 kg ha-1 mm-1 for furrow, micro-sprinkler and gravity-fed drip irrigation, respectively.

scholarly journals Evaluating the Effects of Mulch and Irrigation Amount on Soil Water Distribution and Root Zone Water Balance Using HYDRUS-2D

Water ◽  
2015 ◽  
Vol 7 (12) ◽  
pp. 2622-2640 ◽  
Author(s):  
Ming Han ◽  
Chengyi Zhao ◽  
Gary Feng ◽  
Yingyu Yan ◽  
Yu Sheng
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Water Distribution ◽  
Root Zone ◽  
Irrigation Amount ◽  
Soil Water Distribution ◽  
Zone Water

scholarly journals Energy states of soil water – a thermodynamic perspective on soil water dynamics and storage-controlled streamflow generation in different landscapes

2019 ◽  
Vol 23 (2) ◽  
pp. 971-987 ◽  
Author(s):  
Erwin Zehe ◽  
Ralf Loritz ◽  
Conrad Jackisch ◽  
Martijn Westhoff ◽  
Axel Kleidon ◽  
...  
Keyword(s):  
Free Energy ◽  
Soil Water ◽  
Riparian Zone ◽  
Root Zone ◽  
Energy State ◽  
Local Equilibrium ◽  
Water Dynamics ◽  
Soil Water Dynamics ◽  
Streamflow Generation ◽  
Energy States

Abstract. The present study confirms that a thermodynamic perspective on soil water is well suited to distinguishing the typical interplay of gravity and capillarity controls on soil water dynamics in different landscapes. To this end, we express the driving matric and gravity potentials by their energetic counterparts and characterize soil water by its free energy state. The latter is the key to defining a new system characteristic determining the possible range of energy states of soil water, reflecting the joint influences of soil physical properties and height over nearest drainage (HAND) in a stratified manner. As this characteristic defines the possible range of energy states of soil water in the root zone, it also allows an instructive comparison of top soil water dynamics observed in two distinctly different landscapes. This is because the local thermodynamic equilibrium at a given HAND and the related equilibrium storage allow a subdivision of the possible free energy states into two different regimes. Wetting of the soil in local equilibrium implies that free energy of soil water becomes positive, which in turn implies that the soil is in a state of storage excess, while further drying of the soil leads to a negative free energy and a state of storage deficit. We show that during 1 hydrological year the energy states of soil water visit distinctly different parts of their respective energy state spaces. The two study areas compared here exhibit furthermore a threshold-like relation between the observed free energy of soil water in the riparian zone and observed streamflow, while the tipping points coincide with the local equilibrium state of zero free energy. We found that the emergence of a potential energy excess/storage excess in the riparian zone coincides with the onset of storage-controlled direct streamflow generation. While such threshold behaviour is not unusual, it is remarkable that the tipping point is consistent with the underlying theoretical basis.

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