Comparison studies of unsaturated flow below annual and perennial plants

Values of unsaturated water content determined with neutron moisture measurements (NMM) reveal different water profiles below different plantings. In the extremes, calibration requires a linear and logarithmic response (using the Lambert-W function) along with the normal submersion in a drum of water. Nevertheless a post-calibration with a hydraulic push sampler was used for confirmation. Data were collected at six pastures near the Western Australia coast near Geraldton, with four replicates through the profile. The sites have mostly sandy soils and receive 300–500 mm of rainfall annually. Findings generally showed that, if there was sufficient water, as in 2006, the perennials were able to use the water evenly throughout the vertical profile. Otherwise, with low rainfall, as in 2009, perennials struggle to survive and use less water than the annuals. Modelling of the soil water movement, plant growth and calibration/recalibration is and will be used to get a maximum likehood fit. Clearly, in desert conditions and little or no vegetation, rainfall tends to build up deep in the profile, increase salinity in groundwater, and create waterlogging. Any vegetation is helpful; perennials more so; provided they have sufficient water and are not significantly harvested.

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Soil Water Movement of Mining Waste Rock and the Effect on Plant Growth in Arid, Cold Regions of Xinjiang, China

Water ◽

10.3390/w13091240 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1240

Author(s):

Zizhao Zhang ◽

Qianli Lv ◽

Zezhou Guo ◽

Xuebang Huang ◽

Ruihua Hao

Keyword(s):

Numerical Model ◽

Plant Growth ◽

Water Balance ◽

Water Content ◽

Soil Water ◽

Water Movement ◽

Mining Waste ◽

Waste Rock ◽

Mine Lands ◽

Reconstructed Soil

Understanding the water movement in reconstructed soil and its efficacy on local vegetation is critical for the ecological reclamation of mine lands. This study employed field experiments and a numerical model to investigate the water movement in reconstructed soil and evaluate the effects of mining waste rock on plant growth in an arid and cold region of Xinjiang. Water contents and matrix potentials were monitored over 1-year period. A numerical model was established based on the observed data to calculate soil water balance and irrigation demand. The results show that the soil water content at a shallow depth could be more vulnerable to the climate variability in uncompacted and compacted soil. The water content at the depth of 50 cm with 30 cm-thick covering soil was the lowest; meanwhile, the barrels with 50 cm- and 70 cm-thick covering soil without compaction had the highest water content. Moreover, the water content of the uncompacted soil could be lower than that of the counterpart attributed to the variation in soil porosity. To maintain the water content as an optimized value to grow a certain plant species in the long run, irrigation could be implemented according to the water balance over time in mine lands.

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A bench-scale assessment of the effect of soil temperature on bare soil evaporation in winter

Hydrology Research ◽

10.2166/nh.2020.044 ◽

2020 ◽

Vol 51 (6) ◽

pp. 1349-1357

Author(s):

Peigui Liu ◽

Yan Xia ◽

Manting Shang

Keyword(s):

Soil Temperature ◽

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Water Movement ◽

Bare Soil ◽

Soil Evaporation ◽

Factors Affecting ◽

Bare Soil Evaporation ◽

Soil Water Movement

Abstract To quantitatively evaluate in the laboratory the effect of soil temperature on bare soil evaporation, this study uses two indoor soil columns and homogenized sand as an example to carry out the experimental study of soil temperature on bare soil evaporation in winter. The results show that the soil temperature directly affects the change in bare soil evaporation and that the effect decreases as the soil temperature decreases. Because of the influence of soil temperature, the soil water movement accelerates, and the soil water content increases. At a depth of 50 cm, the average difference in soil water content between groups A and B was 7.61%. The soil evaporation when considering the soil temperature was obviously greater than that without considering the soil temperature. This shows that in a laboratory environment where the soil temperature is higher than the room temperature in winter, the effect of the soil temperature on bare soil evaporation is significant. Soil temperature directly affects soil water movement and distribution, which is one of the important influencing factors affecting bare soil evaporation.

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Laboratory Experiments on the Effect of Microtopography on Soil-Water Movement: Spatial Variability in Wetting Front Movement

Applied and Environmental Soil Science ◽

10.1155/2012/679210 ◽

2012 ◽

Vol 2012 ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

Leif Sande ◽

Xuefeng Chu

Keyword(s):

Soil Water ◽

Smooth Surface ◽

Laboratory Experiments ◽

Unsaturated Flow ◽

Water Movement ◽

Experimental Studies ◽

Soil Profiles ◽

Wetting Front ◽

Front Movement ◽

Soil Water Movement

The effect of microtopography on soil-water movement is a topic of interest for a range of disciplines, with experimental studies investigating the relationship between the two lacking. Laboratory experiments were conducted by simulating rainfall across packed soil surfaces to investigate the effect of microtopography on wetting front movement within experimental soil profiles. In small soil box experiments, the observed wetting fronts for soil profiles showed considerably deeper movement beneath a smooth surface than depressions for 12–60 min rainfalls. For large soil box experiments, the wetting front reached moisture sensors installed at 5 and 10 cm depths and corresponding to various rough and smooth surface features at significantly different times, with movement being most rapid beneath the smooth surface. Wetting front movement was “quicker” beneath surface peaks than depressions for the rough surface as attributed to 2D/3D unsaturated flow. This study provides valuable experimentally based insight into the effect of microtopography on soil-water movement.

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Modeling Soil Water Movement in Pedostructure

10.13031/2013.20766 ◽

2006 ◽

Author(s):

Rabi H. Mohtar ◽

Erik Braudeau

Keyword(s):

Soil Water ◽

Water Movement ◽

Soil Water Movement

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Simulating soil-water movement under a hedgerow surrounding a bottomland reveals the importance of transpiration in water balance

Hydrological Processes ◽

10.1002/hyp.6619 ◽

2008 ◽

Vol 22 (5) ◽

pp. 577-585 ◽

Cited By ~ 14

Author(s):

Z. Thomas ◽

J. Molénat ◽

V. Caubel ◽

C. Grimaldi ◽

P. Mérot

Keyword(s):

Water Balance ◽

Soil Water ◽

Water Movement ◽

Soil Water Movement

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Discontinuous finite volume element method of two-dimensional unsaturated soil water movement problem

Advances in Difference Equations ◽

10.1186/s13662-019-2395-7 ◽

2019 ◽

Vol 2019 (1) ◽

Author(s):

Fan Chen ◽

Zhixiao Xu

Keyword(s):

Soil Water ◽

Finite Volume ◽

Unsaturated Soil ◽

Water Movement ◽

Optimal Error Estimate ◽

Two Dimensional ◽

Fully Discrete ◽

Volume Method ◽

Movement Problem ◽

Soil Water Movement

AbstractIn this paper, a numerical approximation method for the two-dimensional unsaturated soil water movement problem is established by using the discontinuous finite volume method. We prove the optimal error estimate for the fully discrete format. Finally, the reliability of the method is verified by numerical experiments. This method is not only simple to calculate, but also stable and reliable.

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Unsaturated soil water movement in hysteretic and water repellent field soils

Journal of Hydrology ◽

10.1016/0022-1694(95)02996-6 ◽

1996 ◽

Vol 184 (3-4) ◽

pp. 153-173 ◽

Cited By ~ 34

Author(s):

J.C. van Dam ◽

J.H.M. Wösten ◽

A. Nemes

Keyword(s):

Soil Water ◽

Unsaturated Soil ◽

Water Movement ◽

Water Repellent ◽

Field Soils ◽

Soil Water Movement

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Environmentally Friendly Soil Water Conservation Techniques

International Journal of Engineering and Advanced Technology - Regular Issue ◽

10.35940/ijeat.a2045.109119 ◽

2019 ◽

Vol 9 (1) ◽

pp. 5513-5520

Keyword(s):

Plant Growth ◽

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Water Use ◽

Water Scarcity ◽

Water Retention ◽

Direct Method ◽

Environmentally Friendly ◽

Cultivated Plants

The conservation of water resources through their optimal use is a compulsory for countries with water shortages in the arid and semi-arid regions, and it should be in an environmentally friendly manner to avoid the serious consequences of the use of environmentally harmful substances, the implications of which are currently evident from climate change, pollution of water bodies, soils, etc. Since Egypt is one of those countries suffering from water scarcity and uses about 82.5 percent of its water consumption in agriculture, according to data of the Ministry of Irrigation in 2010, so this research is focusing on the use of new methods to increase the efficiency of irrigation water, to achieve high productivity of agricultural crops with less water use that will certainly help to alleviate or solve the water scarcity issue. The study used a physical based model, to simulate the methods used to increase sand soil properties to ensure larger water retention index. Within this work, soil have been sampled from different areas, to simulate the behavior of arid lands, under different water retention techniques. Soil was exposed to different techniques, as it was mixed with soil additives in different quantities and different types. Physical barriers of cohesive soil and polyethylene sheets were used in addition to studying the effect of mulch on water storage capacity in noncohesive soil. Water retention have been measured using the direct method of determination soil water content by oven drying and the volumetric water content (𝞱v ) with time graphs have been plotted in groups, as well as the cultivated plants have been monitored as to measure the influence on plants growing and irrigation efficiency. And the experiment showed that the use of rice straw (RS) and wheat straw (WS) in the powder condition have a significant effect in increasing in the soil water content and even to the plant growth, the WS obtained 𝞱v values approaching the loam soil at times and slightly less in the case of RS, when the percentage of RC and WS was 30% to the sandy soil volume/volume (v/v). Also the use of mulch of RS showed a noticeable increase in 𝞱v and significant improvement of plant growth to that without mulch. These proven technologies can be used in sandy land targeted for reclamation to reduce water use in agriculture.

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