scholarly journals Quantifying Mechanistic Detachment Parameters Due to Humic Acids in Biological Soil Crusts

Land ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1180
Author(s):  
Atheer A. Abbood ◽  
Abdul-Sahib T. Al-Madhhachi
Keyword(s):  
Electrical Conductivity ◽  
Organic Matter ◽  
Humic Acid ◽  
Biological Soil Crusts ◽  
Exchange Capacity ◽  
Scale Model ◽  
Small Scale ◽  
Soil Erodibility ◽  
Soil Crusts ◽  
Detachment Rate

Humic acid (HA) is a material that could be used to decrease erosion and improve soil structure. It is also known that biological soil crusts (biocrusts) have a major role in soil stabilization, but the mechanism is not well understood in the presence of HA, especially with mechanistic soil detachment rate parameters (b0 and b1) of the Wilson model, where b0 is the dimensional soil detachment parameter and b1 is the dimensional soil threshold parameter. Therefore, this study intends to (1) investigate the effect of different humic acid (HA) concentrations (0%, 4%, and 8%) on mechanistic soil detachment rate parameters (b0 and b1,) in the Tigris Riversides of the Gheraiat region, Baghdad City, Iraq, of the crusted versus uncrusted soils using a small scale model of the jet erosion tests (mini-JET) at different curing periods (1 week, 2 weeks, and 3 weeks), and (2) examine the impact of HA on b0 and b1 parameters versus some soil characteristics, such as electrical conductivity, cation exchange capacity, and soil organic matter for uncrusted and crusted soils. Thirty-six undisturbed soil specimens (18 for crusted soils and 18 for uncrusted soils) were acquired from the Tigris Riverbank. On these specimens, the mini-JET was used to determine the mechanistic cohesive soil erodibility parameters b0 and b1. The results showed that the value of b0 decreased up to 60% with an increase in curing times for crusted soils until they reached their optimum values at 2 weeks. There was no consistent pattern for b1 at different curing times. As the concentration of HA increased, the value of b0 decreased up to 86% and 99% for crusted and uncrusted soils, respectively. HA significantly improved electrical conductivity, exchange capacity, and organic matter in the soil and reduced soil erodibility. This study provides the benefits of adding HA to the soils as a soil stabilizer using a low-cost technique, which is the JET instrument.

Biological soil crusts greatly contribute to small-scale soil heterogeneity along a grazing gradient

2013 ◽  
Vol 64 ◽  
pp. 28-36 ◽  
Author(s):  
L. Concostrina-Zubiri ◽  
E. Huber-Sannwald ◽  
I. Martínez ◽  
J.L. Flores Flores ◽  
A. Escudero
Keyword(s):  
Soil Heterogeneity ◽  
Biological Soil Crusts ◽  
Small Scale ◽  
Soil Crusts ◽  
Small Scale Soil

Soil Erosion in Mesic Forests: How do Biological Soil Crusts affect sediment transport and surface runoff?

2020 ◽  
Author(s):  
Corinna Gall ◽  
Martin Nebel ◽  
Dietmar Quandt ◽  
Michael Sauer ◽  
Thomas Scholten ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Surface Runoff ◽  
Dna Analysis ◽  
Soil Layer ◽  
Soil Surface ◽  
Biological Soil Crusts ◽  
Small Scale ◽  
Sediment Discharge ◽  
Soil Crusts ◽  
Disturbed Areas

<p>Soil erosion under forests occurs if forest layers get disturbed. Disturbances may arise from treefall, forest road works, skid trails or deforestation. In these disturbed areas, both an intact canopy and forest floor cover are missing, so that forest soils lack protection against water erosion. To counteract these negative effects a quick restoration of soil surface covers by vegetation is important. In particular, biological soil crusts (biocrusts) are able to quickly colonize gaps in higher vegetation and they are known to reduce soil erodibility. So far, the focus of biocrust research has been in drylands, whereas biocrusts have proven to be an important factor in mesic environments, especially as a pioneer vegetation in disturbed areas.</p><p>In this study, the natural succession of biocrusts in skid trails was observed on four different underlying substrates in a temperate European forest ecosystem (Schönbuch Nature Park in the state of Baden-Württemberg, Germany) and their influence on surface runoff, sediment discharge and nutrient relocation was investigated. Therefore, 144 micro-scale runoff plots (ROPs, 40 x 40 cm) were established with four replicates in the wheel tracks as well as in the center tracks and two replicates on undisturbed forest soil. In order to initiate splash and interrill erosion, four rainfall simulations were carried out from spring to winter with a constant intensity of 45 mm h<sup>-1</sup>. With the purpose to compare these small-scale erosion rates with a larger scale, additional turbidity sensors were installed in the catchment area. The biocrust succession was determined by regular vegetation surveys with a classification of mainly mosses and liverworts up to the species level. Additionally, DNA samples of the upper soil layer were collected to conduct DNA extractions specify other potential biocrust organisms such as lichens, cyanobacteria, fungi and algae.</p><p>First results show that surface runoff and sediment discharge are higher in the wheel track than in the center track and that both parameters are reduced with a higher developmental stage of soil surface cover. The vegetation survey demonstrates a quick development of moss-dominated biocrusts from April to October with up to ten different species in one ROP. Depending on the location of the skid trail, a quick development of the higher vegetation was observed as well. Lab work on nutrient relocation and DNA analysis is still in progress and further results will be presented at the EGU 2020.</p>

Behavior of soil erodibility parameters due to biological soil crusts using jet erosion tests

2020 ◽  
Vol 153 ◽  
pp. 105903 ◽  
Author(s):  
Zahraa E. Hashim ◽  
Abdul-Sahib T. Al-Madhhachi ◽  
Lubna A. Alzubaidi
Keyword(s):  
Biological Soil Crusts ◽  
Soil Erodibility ◽  
Soil Crusts

Effects of type of flow, plants and addition of organic carbon in the removal of zinc and chromium in small-scale model wetlands

2007 ◽  
Vol 56 (3) ◽  
pp. 199-205 ◽  
Author(s):  
D. Paredes ◽  
M.E. Vélez ◽  
P. Kuschk ◽  
R.A. Mueller
Keyword(s):  
Organic Matter ◽  
Removal Rate ◽  
Typha Latifolia ◽  
Surface Flow ◽  
Synthetic Wastewater ◽  
Scale Model ◽  
Small Scale ◽  
Significant Difference ◽  
The Impact ◽  
Small Scale Model

Constructed wetlands are used for the treatment of wastewater containing metals. In order to clarify the role of plants, flow and the impact of organic matter, an investigation of three factors, each at two different levels, was carried out in small-scale model wetlands. The evaluated factors and levels were: type of flow (subsurface and surface); presence of plants (planted with Typha latifolia and unplanted) and addition of organic matter (with and without). Eight different experimental units were run for a year. The units were fed with synthetic wastewater containing chromium (VI) (1.5 mg L−1), zinc (1.5 mg L−1), macro, micronutrients and organic matter (to those units in which this factor was being investigated). Subsurface flow wetlands showed a significantly higher rate of chromium removal in comparison with surface flow systems (97 and 60 mg m−2 d−1, respectively). Planted systems removed significantly more chromium compared to unplanted systems (85 and 76 mg m−2 d−1, respectively), and the addition of organic matter increased the removal rate in a comparison with the units without it (88 and 69 mg m−2 d−1, respectively). Similar results were found for zinc; however, the addition of organic matter made no significant difference to zinc removal.

scholarly journals Small Scale Spatial Variability of Apparent Electrical Conductivity within a Paddy Field

2009 ◽  
Vol 2009 ◽  
pp. 1-7 ◽  
Author(s):  
W. Aimrun ◽  
M. S. M. Amin ◽  
M. H. Ezrin
Keyword(s):  
Electrical Conductivity ◽  
Paddy Field ◽  
Seasonal Variability ◽  
Management Practices ◽  
Exchange Capacity ◽  
Small Scale ◽  
Soil Features ◽  
Zone Management ◽  
Central Regions ◽  
Water Holding

Quick variability description is an important component for zone management practices. Precision farming requires topping up of only the nutrients that are lacking in the soil to attain the highest yield with the least input. The apparent soil electrical conductivity (ECa) sensor is a useful tool in mapping to identify areas of contrasting soil properties. In nonsaline soils,ECais a substitute measurement for soil texture. It is directly related to both water holding capacity and Cation Exchange Capacity (CEC), which are key ingredients of productivity. This sensor measures theECaacross a field quickly and gives detailed soil features (one-second interval) with few operators. Hence, a dense sampling is possible and therefore a high-resolutionECamap can be produced. This study aims to characterize the variability of soilECawithin a Malaysian paddy field with respect to the spatial and seasonal variability. The study was conducted at Block C, Sawah Sempadan, Selangor, Malaysia, for three continuous seasons. SoilECawas collected after harvesting period. The results showed that deepECavisualized the pattern of the former river routes clearly as continuous lines (about 45 m width) at the northern and central regions of the study area. This exploration has shown different maps with higher contrast as compared to the existing soil series map for the study area. Seasonal variability test showed that theECathat was acquired during rainy season (collected after harvest in December to January) has the highest value as compared to another season.

Climate and small scale factors determine functional diversity shifts of biological soil crusts in Iberian drylands

2014 ◽  
Vol 23 (7) ◽  
pp. 1757-1770 ◽  
Author(s):  
Laura Concostrina-Zubiri ◽  
David S. Pescador ◽  
Isabel Martínez ◽  
Adrián Escudero
Keyword(s):  
Functional Diversity ◽  
Biological Soil Crusts ◽  
Small Scale ◽  
Scale Factors ◽  
Soil Crusts
Sign in / Sign up

Export Citation Format

Share Document