Intrinsic Sorptivity and Water Infiltration into Dry Soil at Different Degrees of Saturation

2007 ◽  
Author(s):  
K. E. Schulte ◽  
P. J. Culligan ◽  
J. T. Germaine
Keyword(s):  
Water Infiltration ◽  
Dry Soil

scholarly journals Numerical Simulation of Unstable Preferential Flow during Water Infiltration into Heterogeneous Dry Soil

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 909
Author(s):  
Luis Cueto-Felgueroso ◽  
María José Suarez-Navarro ◽  
Xiaojing Fu ◽  
Ruben Juanes
Keyword(s):  
Numerical Simulation ◽  
Correlation Length ◽  
Soil Structure ◽  
Preferential Flow ◽  
Soil Heterogeneity ◽  
Water Infiltration ◽  
Intrinsic Permeability ◽  
Relative Permeabilities ◽  
Flow Through ◽  
Dry Soil

Water infiltration and unsaturated flow through heterogeneous soil control the distribution of soil moisture in the vadose zone and the dynamics of groundwater recharge, providing the link between climate, biogeochemical soil processes and vegetation dynamics. Infiltration into dry soil is hydrodynamically unstable, leading to preferential flow through narrow wet regions (fingers). In this paper we use numerical simulation to study the interplay between fingering instabilities and soil heterogeneity during water infiltration. We consider soil with heterogeneous intrinsic permeability. Permeabilities are random, with point Gaussian statistics, and vary smoothly in space due to spatial correlation. The key research question is whether the presence of moderate or strong heterogeneity overwhelms the fingering instability, recovering the simple stable displacement patterns predicted by most simplified model of infiltration currently used in hydrological models from the Darcy to the basin scales. We perform detailed simulations of constant-rate infiltration into soils with isotropic and anisotropic intrinsic permeability fields. Our results demonstrate that soil heterogeneity does not suppress fingering instabilities, but it rather enhances its effect of preferential flow and channeling. Fingering patterns strongly depend on soil structure, in particular the correlation length and anisotropy of the permeability field. While the finger size and flow dynamics are only slightly controlled by correlation length in isotropic fields, layering leads to significant finger meandering and bulging, changing arrival times and wetting efficiencies. Fingering and soil heterogeneity need to be considered when upscaling the constitutive relationships of multiphase flow in porous media (relative permeability and water retention curve) from the finger to field and basin scales. While relative permeabilities remain unchanged upon upscaling for stable displacements, the inefficient wetting due to fingering leads to relative permeabilities at the field scale that are significantly different from those at the Darcy scale. These effective relative permeability functions also depend, although less strongly, on heterogeneity and soil structure.

High‐Resolution Shortwave Infrared Imaging of Water Infiltration into Dry Soil

2017 ◽  
Vol 16 (13) ◽  
pp. 1-10 ◽  
Author(s):  
Morteza Sadeghi ◽  
Wenyi Sheng ◽  
Ebrahim Babaeian ◽  
Markus Tuller ◽  
Scott B. Jones
Keyword(s):  
High Resolution ◽  
Infrared Imaging ◽  
Water Infiltration ◽  
Dry Soil ◽  
Shortwave Infrared

Comparative study of the impact of two mechanical perforation densities on the behavior of a sandy soil

2012 ◽  
Vol 8 (1) ◽  
pp. 37-48
Author(s):  
S. Chehaibi ◽  
K. Abrougui ◽  
F. Haouala
Keyword(s):  
Soil Water ◽  
Sandy Soil ◽  
Water Infiltration ◽  
Cone Penetration ◽  
Initial State ◽  
Soil Water Infiltration ◽  
Good Improvement ◽  
The Impact ◽  
Positive Effect ◽  
Resistance To Penetration

The effects of mechanical perforation densities by extracting soil cores through an aerator Vertidrain with a working width of 1.6 m and equipped with hollow tines spaced of 65 mm, were studied on a sandy soil of a grassy sward in the Golf Course El Kantaoui in Sousse (Tunisia). The mechanical aeration was performed at two densities: 250 and 350 holes/m2. The cone penetration resistance and soil water infiltration were measured. These parameters were performed at initial state before aeration (E0) and then on the 10th, 20th and 30th day after aeration. These results showed that perforation density of 350 holes/m2 had a positive effect on the soil by reducing its cone resistance to penetration compared to the initial state (Rp = 14.8 daN/cm2). At 5 cm depth the decrease in resistance to penetration was 34% and 43% on the 10th and 20th day after aeration, respectively. However, on the 30th day after aeration the soil resistance to penetration tended to grow and its value compared to the initial state decreased only by 21 and 26%, respectively, at 5 and 15 cm of depth only by 10% and 9% with 250 holes/m2 density. The soil water infiltration made a good improvement after aeration compared to the initial state. This parameter increased from 4.8 cm/h to 8.3, 10.9 and 13.1 cm/h with 250 holes/m2 density and to 10, 12.9 and 14.8 cm/h with 350 holes/m2 density on the 10th, 20th and 30th day following the aeration.

DYNAMICS OF BARLEY FLAVONOID AND PRODUCTIVITY UNDER UF-A RADIATION

1970 ◽  
pp. 14-18
Author(s):  
L. I. Goncharova ◽  
P. N. Tsygvintsev ◽  
О. А. Guseva
Keyword(s):  
Grain Yield ◽  
Defense Mechanisms ◽  
Antioxidant Defense ◽  
Malonic Dialdehyde ◽  
Growth Period ◽  
Negative Effects ◽  
Uv Spectrum ◽  
Quantum Energy ◽  
Dry Soil ◽  
Universal Mechanism

The effect of increased UV-A radiation during the ontogeny of barley plants of the Vladimir variety in the vegetation experiment was studied. Changes in the content of malonic dialdehyde, flavonoids and grain yield were revealed. UV-A radiation as compared to UV-B radiation, has lower quantum energy and can have both positive and negative effects on plant regulatory and photosynthetic processes. One of the most damaging effects of increased levels of UV-A radiation is oxidative stress, which causes lipid peroxidation of biological membranes. The existence of a plant cell in such conditions is possible only thanks to a system of antioxidant defense mechanisms. The accumulation of phenolic compounds under the action of UV radiation is a universal mechanism of protection against photodamage, which was formed in the early stages of the evolution of photoautotrophic organisms. Flavonoids are localized in the epidermis of plant tissues and act as an internal filter. The content of flavonoids is determined by the genotype and due to ontogenetic patterns. Plants were grown in a greenhouse, in vessels containing 4.5 kg of air-dry soil. The repetition is threefold (3 vessels in each variant). Sowing density - 13 plants in each vessel. As a source of UV-A radiation used lamps Black Light BLUE company Philips. Plants were irradiated for 5 hours a day from 10 to 15 hours at 13, 25, 34, 43 and 52 stages of organogenesis. The magnitude of the daily biologically effective dose of UV-A radiation was 60.7 kJ / m2. The solar part of the UV spectrum in the vegetation experiment was absent in the greenhouse. The nature of changes in the content of flavonoids under the action of UV-A irradiation during the growing season of plants with the dynamics of the oxidative process has been established. The first maximum was observed during the vegetative growth period, the second - at the earing stage. The data obtained indicate that flavonoids have ontogenetic conditionality and perform photoprotective functions. The increase in their content under the action of UV-A radiation is accompanied by an increase in resistance to photodamage, which is confirmed by the formation of grain yield.

INFLUENCE OF CULTIVATION DEGREE OF SOD-PODZOLIC SOIL ON RESPONSIVENESS OF SOWING PEAS TO NITROGEN NUTRITION LEVEL

2020 ◽  
Keyword(s):  
Podzolic Soil ◽  
Nitrogen Nutrition ◽  
Maximum Yield ◽  
Mineral Nitrogen ◽  
Degree Of Saturation ◽  
Cultivated Soil ◽  
Combined Use ◽  
Dry Soil ◽  
Microbial Preparation ◽  
Harvest Maturity

The article presents the results of a vegetation experiment on studying an effect of increasing doses of nitrogen (factor С - N0; No.o5; No.io; N015; No.2o; N0,25 g/kg of absolutely dry soil) and pre-sowing inoculation of seeds with biological preparation "Risotorphine" (factor В - no inoculation; by inoculation) on the formation of vegetative mass and grain yield ofpeas at cultivating in the conditions of a poorly cultivated (factor A0) and of a medium cultivated (factor A f sod-podzolic soil. Cultivation degree of soil was expressed by such criteria as power of an arable horizon, value of metabolic acidity and content of mobile phosphorus, a degree of saturation of soil with bases. For experience tab there were used Mitscher-lich cups with a capacity of 5 kg of absolutely dry soil (a.d.s.), in 16 repetitions of options. The experiments were conducted in the conditions of vegetation site on the territory of University Scientific Centre "Lipogorie" of FSBEI Perm GATA, guided by a science-based methodology. When harvesting peas for a green mass more intensive development and productivity of plants (23.3 and 58.9, 40.0, 78.8 g/cup, respectively) in the phase of stem branching and budding a beginning offlowering that is recorded for its use on the background of inoculation, usage of mineral nitrogen in a dose of 0.10 g/kg on a poorly cultivated soil and 0.15 g/kg a.d.s. on a medium cultivated soil. Applying of higher doses of nitrogen has a depressing effect on development of assimilating surface of pea plants on a poorly and a medium cultivated soil. When raising pea plants before harvest maturity of grain: in the conditions of a poorly cultivated soil for yield at the level of 7.92 g/cup, the process of carrying on only an inoculation of seed with microbial preparation "Rizotorfin" can be considered; in the medium cultivated soil varieties, plant peas impose higher requirements for the level of mineral nutrition the maximum yield in the experiment (which 9.22 g/cup), noted at a combined use of inoculation and mineral nitrogen in a dose of 0.20 g/kg a.d.s.

Effect of Chemical and Tillage Summer Fallow upon Water‐Infiltration Rates

1955 ◽  
Vol 47 (5) ◽  
pp. 235-236 ◽  
Author(s):  
O. K. Barnes ◽  
D. W. Bohmont ◽  
Frank Rauzi
Keyword(s):  
Water Infiltration ◽  
Infiltration Rates ◽  
Summer Fallow

Traditional Urine-diversion Practices in Sub-urban Hanoi, Vietnam: Replaced or Promoted?

2010 ◽  
Vol 5 (3) ◽  
Author(s):  
H. Harada ◽  
N. T. Dong ◽  
S. Matsui ◽  
S. Fujii
Keyword(s):  
Northern Vietnam ◽  
Urine Diversion ◽  
Disinfection Process ◽  
History Of ◽  
Interview Survey ◽  
Agricultural Use ◽  
Dry Soil ◽  
Human Wastes ◽  
Farming Households ◽  
Current Practices

Northern Vietnam has a history of using urine diversion (i.e., UD) toilets with agricultural use of excreta. This study tried to identify the current practices of UD toilets in suburban Hanoi, Vietnam. An interview survey to 120 households showed that UD toilets were used by 26.7% of households, of which most were double-vault UD toilets. Human wastes were used by 73.0% of vault toilets. It was interpreted that they are still recognized as not wastes but fertilizers especially by farming households in recent sub-urban Hanoi. Double-vaults UD toilets were used in significantly old houses compared to flush toilets with p<0.001. Results indicated the gradual replacement of double-vault UD toilets by water-flush toilets. All households with vault toilets applied additives such as ashes, dry soil and sawdust into vaults, and 24.3% of them applied ashes after every defecation event. Out of 33 vault toilets, 30 retained faeces for a period longer than six months and 28 did for a period longer than 12 months. Still, the application of ashes after every defecation event can be suggested to enhance the disinfection process in vaults, resulting sanitary use of excreta for agriculture.

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