scholarly journals Water repellency of clay, sand and organic soils in Finland

2008 ◽  
Vol 16 (3) ◽  
pp. 267 ◽  
Author(s):  
K. RASA ◽  
R. HORN ◽  
M. RÄTY
Keyword(s):  
Preferential Flow ◽  
Management Practice ◽  
Soil Surface ◽  
Water Repellency ◽  
Organic Soil ◽  
Water Infiltration ◽  
Organic Soils ◽  
Water Repellent ◽  
Moisture Regime ◽  
Wetting Process

Water repellency (WR) delays soil wetting process, increases preferential flow and may give rise to surface runoff and consequent erosion. WR is commonly recognized in the soils of warm and temperate climates. To explore the occurrence of WR in soils in Finland, soil R index was studied on 12 sites of different soil types. The effects of soil management practice, vegetation age, soil moisture and drying temperature on WR were studied by a mini-infiltrometer with samples from depths of 0-5 and 5-10 cm. All studied sites exhibited WR (R index >1.95) at the time of sampling. WR increased as follows: sand (R = 1.8-5.0) < clay (R = 2.4-10.3) < organic (R = 7.9-undefined). At clay and sand, WR was generally higher at the soil surface and at the older sites (14 yr.), where organic matter is accumulated. Below 41 vol. % water content these mineral soils were water repellent whereas organic soil exhibited WR even at saturation. These results show that soil WR also reduces water infiltration at the prevalent field moisture regime in the soils of boreal climate. The ageing of vegetation increases WR and on the other hand, cultivation reduces or hinders the development of WR.;

scholarly journals Spatially variable soil water repellency enhances soil respiration rates (CO<sub>2</sub> efflux)

2017 ◽  
Author(s):  
Emilia Urbanek ◽  
Stefan H. Doerr
Keyword(s):  
Soil Moisture ◽  
Soil Respiration ◽  
Soil Water ◽  
Water Distribution ◽  
Preferential Flow ◽  
Water Repellency ◽  
Water Repellent ◽  
Co2 Efflux ◽  
Soil Co2 ◽  
Soil Water Repellency

Abstract. Soil CO2 emissions are strongly dependent on water distribution in soil pores, which in turn can be affected by soil water repellency (SWR; hydrophobicity). SWR restricts infiltration and movement of water, affecting soil hydrology as well as biological and chemical processes. Effects of SWR on soil carbon dynamics and specifically on soil respiration (CO2 efflux) have been studied in a few laboratory experiments but they remain poorly understood. Existing studies suggest that soil respiration is reduced in water repellent soils, but the responses of soil CO2 efflux to varying water distribution created by SWR are not yet known. Here we report on the first field-based study that tests whether soil water repellency indeed reduces soil respiration, based on in situ field measurements carried out over three consecutive years at a grassland and pine forest site under the humid temperate climate of the UK. CO2 efflux was reduced on occasions when soil exhibited consistently high SWR and low soil moisture following long dry spells. However, the highest respiration rates occurred not when SWR was absent, but when SWR, and thus soil moisture, was spatially patchy, a pattern observed for the majority of the measurement period. This somewhat surprising phenomenon can be explained by SWR-induced preferential flow, directing water and nutrients to microorganisms decomposing organic matter concentrated in hot spots near preferential flow paths. Water repellent zones provide air-filled pathways through the soil, which facilitate soil-atmosphere O2 and CO2 exchanges. This study demonstrates that SWR have contrasting effects on CO2 fluxes and, when spatially-variable, can enhance CO2 efflux. Spatial variability in SWR and associated soil moisture distribution needs to be considered when evaluating the effects of SWR on soil carbon dynamics under current and predicted future climatic conditions.

Using X-ray radiography to image rapid water infiltration into soil

2021 ◽  
Author(s):  
John Koestel ◽  
Lorenzo Garbari ◽  
Daniel Iseskog
Keyword(s):  
Preferential Flow ◽  
Sandy Loam ◽  
Initial Moisture Content ◽  
Image Data ◽  
Water Repellency ◽  
Water Infiltration ◽  
Image Correction ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

&lt;p&gt;While the basic processes of water infiltration into soil are well understood, their details are difficult to quantify due to the opaque nature of soil. In this study, we investigated the potential and limitations of X-ray radiography to measure the water front progression in a narrow sample (15 &amp;#215; 15 &amp;#215; 1 cm) filled with dry soil under simulated rainfall of high intensity (53 mm/h). The temporal resolution of the acquired infiltration movies was 133 milliseconds. We evaluated three different kinds of soil samples. i) Bare samples filled with a 1:1 mixture of a sandy loam and peat. ii) The same soil-peat mixture, but cropped with &lt;em&gt;Trifolium incarnatum&lt;/em&gt;, &lt;em&gt;Trifolium repens&lt;/em&gt;, &lt;em&gt;Lathyrus odoratus&lt;/em&gt; and &lt;em&gt;Lupinus regalis&lt;/em&gt;, all of them plants that have been reported to induce water repellency; prior to the experiments, the plants were harvested and only the roots remained in place. iii) Sandy loam soil that had been incubated for four weeks in an outside garden plot. Due to time limitations of the project, the incubation period was in early spring, which meant that plant growth in the samples was negligible. All three sample types were replicated five times, resulting in 15 individual samples. We carried out the infiltration experiments in four-fold replications, from which it follows that we collected 60 individual infiltration movies. After each infiltration round, the samples were placed in a drying room to reset them to a similar initial moisture content. The experiments aimed at testing i) whether the infiltration patterns of the four consecutive infiltration runs conducted on each sample remained identical and ii) to document differences in infiltration patterns between bare, cropped and incubated samples. We found that increasing X-ray scattering with increasing soil water contents made it challenging to evaluate the image data quantitatively. Advantages of our setup are that X-ray captures the complete water content at a specific depth and that sample boxes with irregularly shaped walls can be used to prevent preferential flow along the walls. Preliminary analyses of the data showed that the infiltration fronts in the bare and the incubated samples were less uniform than the ones for the cropped samples. In contrast, the likelihood of observing the same infiltration pattern in all four consecutive infiltration runs was larger for the bare and the incubated samples. The latter fact may have been caused by the interaction with root exudates in the cropped samples that may have been redistributed or mineralized during the wetting-drying cycles. We conclude that the here presented setup has large potential to investigate unstable infiltration phenomena into soil after an image correction approach has been developed that removes X-ray scattering artifacts. Alternatively, scattering may be suppressed by using a collimator during image acquisition.&lt;/p&gt;

Induced uneven spatial distribution of agrochemicals due to preferential flow in water repellent soils and its remediation by surfactant

2020 ◽  
Author(s):  
Felix Abayomi Ogunmokun ◽  
Rony Wallach
Keyword(s):  
Spatial Distribution ◽  
Soil Water ◽  
Soil Profile ◽  
Preferential Flow ◽  
Sandy Soils ◽  
Water Repellency ◽  
Treated Wastewater ◽  
Water Repellent ◽  
Soil Water Repellency ◽  
Mediterranean Countries

&lt;p&gt;Soil water repellency is a common feature of dry soils under permanent vegetation and drought conditions. Soil-water hydrology is markedly affected by soil-water repellency as it hinders infiltration, leading to enhanced surface runoff and soil erosion. Although this phenomenon was primarily ascribed to sandy soils, it has been observed in loam, clay, and peat soils in dry and humid regions. One detrimental effect of soil water repellency on plants is the reduction of soil water availability that stems from the non-uniform water retention and flow in preferential pathways (gravity-induced fingers) with relatively dry soil volume among these paths. It was recently discovered that prolonged irrigation with treated wastewater, a widely used alternative in Israel and other Mediterranean countries due to the limited freshwater, triggers soil water repellency which invariably resulted in preferential flow development in the field. Due to climate change events, the use of treated wastewater for irrigation as a means of freshwater conservation is expected to widen, including in countries that are not considered dry.&lt;/p&gt;&lt;p&gt;While a vast amount of research has been devoted to characterizing the preferential flow in water repellent soils, the effect of this flow regime on the spatial distribution of salt and fertilizers in the root zone was barely investigated. Results from a commercial citrus orchard irrigated with treated wastewater that includes the spatial and temporal distribution of preferential flow in the soil profile measured by ERT will be demonstrated. The associated spatial distribution of salinity, nitrate, phosphate, and SAR in the soil profile will be shown as well.&amp;#160; We investigated the efficacy of two nonionic surfactants application to remediate hydrophobic sandy soils both in the laboratory and field. The effect of the surfactant application to the water repellent soils in the orchards on the spatial distribution of soil moisture and the associated agrochemicals will be presented and discussed.&lt;/p&gt;

Managing soils to enhance the potential for bioremediation of water repellency

Soil Research ◽  
2005 ◽  
Vol 43 (7) ◽  
pp. 803 ◽  
Author(s):  
Margaret M. Roper
Keyword(s):  
Management Practices ◽  
Crop Yields ◽  
Water Repellency ◽  
Water Infiltration ◽  
Most Probable Number ◽  
Water Repellent ◽  
Gradual Decline ◽  
Kaolinite Clay ◽  
Probable Number ◽  
Degrading Bacteria

Water repellency can significantly reduce crop and pasture establishment and production in sandy soils. Management practices that increase the rate of water infiltration into dry soils following the first rains at the end of the dry season were investigated. In the laboratory, addition of water to water repellent soil and maintenance of warm moist conditions produced a gradual decline in water repellency. This was supported by results in the field which showed that under daily irrigation there was a gradual decline in water repellency over time. However, under dryland conditions, other mechanisms to increase water infiltration had to be found. In the laboratory, after the addition of lime and kaolinite clay, there was an initial rapid decline in repellency, indicative of a physical mechanism, followed by a more gradual decline suggesting a biological response. In the field, under dryland conditions, the addition of lime and kaolinite clay resulted in a reduction in water repellency, and in the case of lime, this effect increased with the size of application. Estimates of the numbers of wax-degrading bacteria in the treated soils, using a most-probable-number assay, showed at least a 10-fold increase in lime-treated sands, but not in the clay-treated sands. The results suggest that lime may provide a viable alternative for increasing the wettability of soils by physical mechanisms and by promoting microbial activity by bacteria responsible for wax degradation, resulting in more consistent plant germination and establishment, and increased crop yields.

Impact of crop residue retention and tillage on water infiltration into a water-repellent soil

Biologia ◽  
2015 ◽  
Vol 70 (11) ◽  
Author(s):  
Philip R. Ward ◽  
Margaret M. Roper ◽  
Ramona Jongepier ◽  
Shayne F. Micin
Keyword(s):  
Crop Residue ◽  
Water Repellency ◽  
Water Infiltration ◽  
Soil Tillage ◽  
Water Repellent ◽  
Residue Removal ◽  
Growing Seasons ◽  
Water Repellence ◽  
The Impact ◽  
Residue Retention

AbstractWater repellence is a condition in which soils become hydrophobic and do not readily absorb water. The condition causes problems in agricultural production relating to water availability for seed germination and plant growth. In this research we assess the impact of disturbing the soil by a single annual soil tillage (compared with no-till) and crop residue retention (compared with residue removal by burning) on the severity of water repellency, and on water infiltration during and immediately after rainfall, for 5 discrete rainfall events over an 18-month period covering two crop growing seasons. Soil tillage and crop residue removal were associated with decreased severity of water repellency. Despite this, soil tillage resulted in less infiltration of rain water, especially in the crop inter-row spaces, one hour after the commencement of rainfall, and 6 hours after the conclusion of rainfall. Where a single soil tillage was performed, soil in the inter-row spaces absorbed 19-30% of incident rainfall, compared with 58-78% in undisturbed soils. This was observed for a rainfall event 11 months after soil tillage, indicating that soil tillage has a long-lasting impact on pathways of water entry into the soil.

scholarly journals Analysis of persistent macroaggregates on the surface of agricultural soils

2021 ◽  
Author(s):  
Tian Tian ◽  
Joann K. Whalen ◽  
Pierre Dutilleul
Keyword(s):  
Soil Moisture ◽  
Digital Images ◽  
Agricultural Soils ◽  
Soil Surface ◽  
Organic Soil ◽  
Organic Soils ◽  
Biological Processes ◽  
Time Intervals ◽  
Natural Rainfall ◽  
Cumulative Rainfall

In humid regions, the number of macroaggregates on the soil surface could decline because of rainfall disturbance, or increase due to rainfall-activated chemical and biological processes. We took digital images of macroaggregates at the surface of clay and organic soils six times during a 68-d period with 264 mm natural rainfall. Based on the constant or increasing number of surface macroaggregates during the five time intervals, rainfall did not disturb macroaggregates. Macroaggregate persistence was positively correlated with cumulative rainfall (both soils) and soil moisture (organic soil), so we infer that rainfall promoted macroaggregate assemblage through chemical and biological processes.

Ongoing succession of biological soil crusts increases water repellency — a case study on Arenosols in Sekule, Slovakia

Biologia ◽  
2013 ◽  
Vol 68 (6) ◽  
Author(s):  
Sylvie Drahorad ◽  
Daniel Steckenmesser ◽  
Peter Felix-Henningsen ◽  
Ľubomír Lichner ◽  
Marek Rodný
Keyword(s):  
Soil Surface ◽  
Water Repellency ◽  
Biological Soil Crusts ◽  
Water Infiltration ◽  
Water Conductivity ◽  
Surface Stability ◽  
Surface Protection ◽  
Soil Crusts ◽  
Surface Sealing ◽  
Successional Stages

AbstractAfter soil surface disturbances biological soil crusts (BSC) cover rapidly the topmost soil millimeters. Depending on BSC age, development of soil water repellency, water infiltration and soil surface stability are influenced by this thin surface sealing. Within this study disturbed, early- mid- and late successional stages of BSC development were examined along a recovery transect. The results show an increase in water repellency and a decrease in water sorptivity and conductivity with ongoing BSC succession. Penetration resistance data shows very stable thin surface protection by cyanobacteria in early successional BSC that is non-repellent. Later successional stages show increased water repellency and lower water conductivity. We conclude that BSC development induces changes in surface structure and wettability. The soil surface wettability is strongly linked to the BSC community composition.

Soil water repellency in north-eastern Greece with adverse effects of drying on the persistence

Soil Research ◽  
2005 ◽  
Vol 43 (3) ◽  
pp. 281 ◽  
Author(s):  
Apostolos K. Ziogas ◽  
Coen J. Ritsema ◽  
Klaas Oostindie ◽  
Louis W. Dekker
Keyword(s):  
Soil Water ◽  
Water Repellency ◽  
Soil Samples ◽  
Water Infiltration ◽  
Agricultural Fields ◽  
Water Repellent ◽  
Soil Water Repellency ◽  
Kiwi Fruit ◽  
Soil Matrix ◽  
North Eastern

Many soils may be water repellent to some degree, challenging the common perception that soil water repellency is only an interesting aberration. When dry, water repellent soils resist or retard water infiltration into the soil matrix. Soil water repellency often leads to the development of unstable wetting and preferential flow paths. In the present study the persistence of water repellency was examined on samples from topsoils in Thrace, north-eastern Greece, using the Water Drop Penetration Time (WDPT) test. The soil samples were collected from agricultural fields throughout the prefectures of Xanthi and Rodopi. Six sites were selected for intensive sampling of water repellency and soil moisture content in transects. Water repellency was measured on field-moist soil samples and after drying the samples at increasing temperatures, to study the influence of drying temperature on the persistence of soil water repellency. Measurements of soil samples taken in agricultural fields under different crops, e.g. winter wheat, tobacco, clover, olive groves, kiwi fruit, and vineyards, in the area of Thrace, revealed that 45% of the locations exhibited actual water repellency during dry periods. Drying of samples from the Sostis site resulted in wettable soil, whereas drying of samples from the Mitriko site increased repellency. Therefore, water repellency should preferably be measured on samples taken in the field under dry conditions in order to reveal and determine the highest persistence of water repellency that might occur in the field.

scholarly journals Peculiarities of Infiltration Measurements in Water-Repellent Forest Soil

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 472
Author(s):  
Tomáš Orfánus ◽  
Anton Zvala ◽  
Malvína Čierniková ◽  
Dagmar Stojkovová ◽  
Viliam Nagy ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Forest Soil ◽  
Forest Floor ◽  
Water Repellency ◽  
Water Infiltration ◽  
Water Repellent ◽  
Runoff Generation ◽  
Field Methods ◽  
Single Ring ◽  
Guelph Permeameter

The paper deals with measurements of water infiltration carried out on a well-developed forest floor formed by needle-leaf litter of Norway spruce. Three field methods (tension disk permeameter, single-ring infiltrometer and Guelph permeameter) were used to determine the soil hydraulic conductivity. The results were strongly influenced by the water repellency at the interface between the O- and A-horizons. This interface was severely water repellent during the hot and dry summer season, regardless of the generally humid mountain climate of the High Tatras foothill. The single-ring method paradoxically provided lower hydraulic conductivity (3.2 × 10−4 ± 1.3 × 10−4) compared to the tension disk permeameter (8.5 × 10−4 ± 3.3 × 10−4) due to the presence of the water-repellent O/A-interface. This effect was also observed with the Guelph permeameter method, which gave the lowest value (5.6 × 10−5 ± 4.3 × 10−5). Abrupt retardation of infiltration on the water-repellent interface may generate shallow subsurface runoff (as was proved by the irrigation experiment) or litter splash during extreme rainfall events and promote water flow to deeper soil horizons through preferential pathways. The observed effects of the forest floor on rainfall infiltration will depend on the seasonal variability of soil water repellency. Although the forest floor is a source of hydrophobic substances that cause water repellency at the O/A-interface and can trigger runoff generation, at the same time its cohesive duff layer protects the forest soil from erosion.

Sign in / Sign up

Export Citation Format

Share Document