Dynamics of seepage mobile inventory in forest and agricultural soils - Results from a comparative multi-year lysimeter study

2020 ◽  
Author(s):  
Katharina Lehmann ◽  
Robert Lehmann ◽  
Kai Uwe Totsche
Keyword(s):  
Land Use ◽  
Agricultural Soils ◽  
Field Studies ◽  
Critical Zone ◽  
Soil Monitoring ◽  
Event Scale ◽  
Weather Events ◽  
Physico Chemical

<p>The mobile inventory in soil seepage is of fundamental importance for soil development and for functioning of subsurface ecosystem compartments. The mobile inventory may encompass inorganic, organo-mineral and organics, dissolved and colloidal, but also particulate matter and microbiota. Still unknown are the conditions and factors that trigger the release and export of seepage-contained mobile matter within soil, and its translocation through the subsurface of the critical zone. Long-term and high-resolution field studies that includes the mobile particulate inventory are essentially lacking. To overcome this knowledge gap, we established long-term soil monitoring plots in the Hainich Critical Zone Exploratory (HCZE; NW-Thuringia, central Germany). Soil seepage from 22 tension-supported lysimeters in topsoil and subsoil, covering different land use (forest, pasture, cropland) in the topographic recharge area of the HCZE, was collected and analyzed by a variety of analytical methods (physico-/chemical and spectroscopic) on a regular (biweekly) and event-scale cycle. With our study we proved that substances up to a size of 50 µm are mobile in the soils. The material spectra comprised minerals, mineral-organic particulates, diverse bioparticles and biotic detritus. Atmospheric forcing was found to be the major factor triggering the translocation of the mobile inventory. Especially episodic infiltration events during hydrological winter seasons (e.g. snow melts) with high seepage volume influences seepage hydrochemistry (e.g. pH, EC) and is important for transport of mobile matter to deeper compartments. Seasonal events cause mobilization of significant amounts of OC. On average, 21% of the total OC of the seepage was particulate (>0.45 µm). Furthermore, our results suggest that the formation environment and the geopedological setting (soil group, parent rock, land use) are controlling factors for the composition and the amount of soil-born mobile inventory. Our study provides evidence for the importance of the mobile inventory fraction >0,45 µm for soil element dynamics and budgets and highlights the role of weather events on soil and subsoil development and subsurface ecosystem functioning.</p>

scholarly journals Casting Activity ofScherotheca gigasin No-Till Mediterranean Soils: Role in Organic Matter Incorporation and Influence of Aridity

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Paloma Bescansa ◽  
Iñigo Virto ◽  
Oihane Fernández-Ugalde ◽  
María José Imaz ◽  
Alberto Enrique
Keyword(s):  
Organic Matter ◽  
Agricultural Soils ◽  
Nw Spain ◽  
Organic C ◽  
No Till ◽  
Physico Chemical ◽  
C Stocks ◽  
Casting Activity ◽  
Total Organic C

The behaviour of earthworms, their role in organic matter incorporation into the soil, and the influence of aridity in such processes in arid and semiarid regions have scarcely been studied. In this study, physico-chemical analyses of the casts and the surrounding no-till agricultural soils of three experimental sites representing an aridity gradient in Navarre (NW Spain) were done. The casts were formed by the activity of the only anecic species,Scherotheca gigas(Dugès, 1828), ubiquitous in no-till soils in this region. We observed a significant depletion of clay and higher concentration of total organic C and labile C in the form of particulate organic matter (POM) in the casts as compared to the surrounding soil, suggesting selective ingestion of soil byS. gigas. This, together with the observation of increased concentration in POM with increasing aridity, suggests a major role of this species in the observed progressive gains of organic C stocks in no-till soils in the region.

scholarly journals THE ECONOMICS OF DISASTER RISK AND RECOVERY:  THREE ESSAYS ON SRI LANKA

2021 ◽  
Author(s):  
◽  
Diana de Alwis
Keyword(s):  
Health Care ◽  
Land Use ◽  
Sri Lanka ◽  
Food Consumption ◽  
Health Risks ◽  
Household Income ◽  
Disaster Risk ◽  
Extreme Weather Events ◽  
Weather Events

<p>Dramatic increase of economic losses from Natural disasters derail economic and human development in many places. This dissertation sheds light on natural disaster risk and short-term and long-term household wellbeing after disasters. It is composed of three empirical studies of Sri Lanka. The first study examines the impacts of frequently occurring extreme weather events on individual health and health care cost using national household data. The analysis shows that local floods and droughts impose a significant risk to health when individuals are exposed directly and their communities indirectly to these hazards. These risks are associated with the land-use in the affected regions and the status of access to sanitation and hygiene. Health risks due to flood and drought cause a considerable economic burden on the private and public health care sectors. Finally, we learn that recurring extreme weather events may potentially be sources of significant health risk and economic cost to a rapidly growing developing country that call for alternative policies focusing on the socio-economic environment, and land use to manage these health risks. The second study estimates a difference- in- difference (DID) model to examine the 2004 Indian Ocean tsunami’s long-term impacts on household wellbeing in Sri Lanka. The study finds a strong association between area-wide tsunami disaster shock and increases in household income and consumption in the long-term. The increase in consumption is much smaller than the observed increase in income; the study reveals an increase in food consumption and only a marginal increase in non-food consumption. The third study analyses the 2004 tsunami recovery’s impact on income distribution across households in the long-term in Sri Lanka using quantile difference-in-difference methods and inequality measures. Recovery of household income is observed across the entire distribution of affected households. The income recovery is skewed to low-income households; the affected regions appear more income-equal ex-post compared to the unaffected regions. A similar pattern appears for consumption. Finally, the findings in the second and third studies show a potential for a long-lasting and successful recovery from a catastrophic disaster.</p>

scholarly journals Patterns of spatial methane distribution in the upper layers of permafrost in Central Yakutia

2017 ◽  
pp. 105-112
Author(s):  
M. Yu. Cherbunina ◽  
D. G. Shmelev ◽  
A. V. Brouchkov ◽  
V. S. Kazantsev ◽  
R. N. Argunov
Keyword(s):  
Field Studies ◽  
Methane Content ◽  
Central Yakutia ◽  
The Difference ◽  
The Moment ◽  
Methane Distribution ◽  
The Right ◽  
Ice Complex

The article presents the results of long-term field studies of methane in the upper part of permafrost for the different geomorphological levels of Central Yakutia. Patterns of spatial distribution of methane content across different landscapes were found. The highest concentrations of methane are found in alas deposits, the major role of methane in the conservation there goes to the moment of freezing the thermokarst lake draining. The difference in methane content in the sediments of the Late Pleistocene Ice Complex on the left and the right bank of the river Lena was identified. That is likely caused by the conditions of ice complex formation.

Land Use and an Archaeological Perspective on Socio-Natural Studies in the Wadi Al-Hasa, West-Central Jordan

2004 ◽  
Vol 69 (3) ◽  
pp. 389-412 ◽  
Author(s):  
J. Brett Hill
Keyword(s):  
Land Use ◽  
Environmental Research ◽  
Active Engagement ◽  
American Antiquity ◽  
Human Environment ◽  
West Central ◽  
Central Jordan ◽  
Archaeological Perspective

In recent years environmental archaeologists have emphasized evidence for human-caused degradation, and attention has been focused on the role of our discipline in debates over contemporary socioenvironmental problems. In a recent American Antiquity forum, van der Leeuw and Redman (2002) argue that current environmental research would benefit from an archaeological perspective on these problems, and that our discipline would benefit from more active engagement in the larger debate. I present research supporting the claim that archaeology has unique and compelling insights to offer socio-natural studies. I make arguments based on spatial statistical and GIS analyses of past land use in the Wadi al-Hasa, west-central Jordan, that environmental degradation in the form of soil erosion has been a problem for agropastoralists in that region for several millennia. Furthermore, I argue that an archaeological perspective on long-term patterns of land use provides information at a scale and resolution that makes it highly suitable for studies of human-environment dynamics. Archaeology's unique data and perspective create an opportunity to contribute in a more explicit manner to the study of contemporary environmental issues that currently lack long-term focus at a scale and resolution that is meaningful to humans.

Event-driven dynamics of the total mobile inventory in soils - Results from a comparative multi-year lysimeter study

2021 ◽  
Author(s):  
Katharina Lehmann ◽  
Robert Lehmann ◽  
Kai U. Totsche
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Winter Season ◽  
Critical Zone ◽  
Field Scale ◽  
Undisturbed Soil ◽  
Event Scale ◽  
Event Driven ◽  
Sampling Procedures

&lt;p&gt;A diverse size- and matter spectrum of inorganic, organo-mineral and organic substances, and dissolved, colloidal, but also larger particulate matter, including microbiota, is mobile in soil and potentially involved in matter interchange between surface and subsurface ecosystems. Specifically including the widely neglected particulate fractions, conditions and field-scale factors controlling the long-term seasonal and episodic dynamics of the &amp;#8220;total mobile inventory&amp;#8221; (Lehmann et al., 2021), in undisturbed soil and its translocation through the subsurface of the Critical Zone is almost unknown. To overcome this knowledge gap, we established long-term soil monitoring plots in the Hainich Critical Zone Exploratory (HCZE; NW-Thuringia, central Germany). Soil seepage from 22 tension-controlled lysimeters in topsoil and subsoil, covering different land use (forest, pasture, cropland) in the topographic recharge area of the HCZE, was collected and analyzed by a variety of analytical methods (physico-/chemical and spectroscopic) on a regular (biweekly) and event-scale cycle. Atmospheric forcing was found to be the major factor triggering the translocation of the mobile inventory, mainly causing considerable seasonality in the solute signature (e.g., sulphate) and seepage pH. However, episodic high-flow (infiltration) events rather than seasonality caused mobilization of significant amounts of particulates, for instance, after snow melts or rainstorms. Noteworthy, particulate organic carbon translocated during the winter-season infiltration events, accounted for up to 80% of annual fluxes. On average, 21% of the total OC of the seepage was particulate (&gt;0.45 &amp;#181;m). Our study provides field-scale evidence for the importance of the mobile inventory fraction &gt;0.45 &amp;#181;m for soil elemental dynamics and budgets. We, thus, suggest involving suspended fractions in environmental monitoring programs, although requiring adapted sampling procedures.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;References:&lt;/p&gt;&lt;p&gt;Lehmann, K., Lehmann, R., &amp; Totsche, K. U. (2021). Event-driven dynamics of the total mobile inventory in undisturbed soil account for significant fluxes of particulate organic carbon. Science of The Total Environment, 143774.&lt;/p&gt;

Time to re-think agricultural phosphorus modelling for the 2020s  

2021 ◽  
Author(s):  
Jennifer M. Davies ◽  
Victoria Janes-Bassett ◽  
Martin Blackwell ◽  
Andrew Burgess ◽  
Jessica Davies ◽  
...  
Keyword(s):  
Production Systems ◽  
Agricultural Soils ◽  
Widespread Application ◽  
Disciplinary Boundaries ◽  
The Past ◽  
Soil Systems ◽  
To Come ◽  
Phosphorus Modelling

&lt;div&gt; &lt;p&gt;Phosphorus (P) is critical to our food production systems with many crop systems dependent on continual inputs to meet yield demands. However, a consequence of the widespread application of P to agricultural soils in the past 60 years has led to concerns about the long-term sustainability of P fertiliser supply and to P being transferred from soil systems to watercourses, causing diffuse pollution. This highlights the multi-scaled and interdisciplinary nature of the past, present and future of P management.&amp;#160;&amp;#160;&lt;/p&gt; &lt;/div&gt;&lt;div&gt; &lt;p&gt;The aim of this research is to define a starting framework to consider the best ways to develop a model that addresses the contemporary understanding of P processes, integrating the needs of the crop, with biogeochemical and hydrological modelling considerations, going beyond P transfer to the role of P in both food and water challenges.&amp;#160;&amp;#160;&lt;/p&gt; &lt;/div&gt;&lt;div&gt; &lt;p&gt;So, this review explores some of the current P models and the future opportunities for expanding their representation of P processes in agricultural systems. This goes beyond nesting existing models and reshapes approaches to posing research and modelling questions to achieve P models that cross disciplinary boundaries and have meaning and usability in practice. As part of this contribution, we welcome modellers and P scientists to come forward and help drive this complex issue of P in agriculture.&amp;#160;&lt;/p&gt; &lt;/div&gt;

Weakening mechanisms and the role of easy slip horizons in thrust belt development: a microstructural approach

2020 ◽  
Author(s):  
Aimee Guida Barroso ◽  
Eddie Dempsey ◽  
Bob Holdsworth ◽  
Nicola De Paola
Keyword(s):  
Field Studies ◽  
Fine Grained ◽  
Progressive Development ◽  
Diffusive Mass Transfer ◽  
Thrust Tectonics ◽  
Thrust Zone ◽  
Shallow Crust ◽  
Geometric Processes

&lt;p&gt;The Late Silurian Moine Thrust Zone (MTZ) of the NW Highlands of Scotland has long been fundamental to the understanding of the nature and processes that occur during thrust tectonics in the upper continental crust. This complex imbrication zone formed during final Scandian stages of the Caledonian orogeny when collision of Baltica and Laurentia led to WNW-ESE tectonic foreshortening of &gt;100km. The MTZ juxtaposed greenschist to amphibolite facies Neoproterozoic metamorphic rocks of the Moine Supergroup over sequences of little metamorphosed Cambro-Ordovician and Neoproterozoic sedimentary rocks and their Neoarchean to Paleoproterozoic gneissic basement in a zone ranging from &lt;1km to &gt;20km wide.&lt;/p&gt;&lt;p&gt;The mechanical problems represented by thrust wedges being transported over such great distances without losing their internal cohesion has highlighted the role played by detachment structures and the need for mechanisms that create significant weakening along basal detachments that allow overthrusts to accommodate major horizontal displacements in the shallow crust. Field studies and use of section balancing techniques have highlighted that a substantial proportion of the displacement seems to be accommodated along detachments that follow specific stratigraphic levels.&lt;/p&gt;&lt;p&gt;Other than the Moine Thrust Mylonites and the mylonitised parts of the Cambrian Quartzites, relatively little is known about the grain scale deformation and potential weakening processes that have occurred in other parts of the MTZ. New lithological descriptions of the fault rocks and sedimentary protoliths observed in the Assynt, Durness and Eriboll areas are presented here and provide detailed microstructural evidence for the long-term weakening mechanisms that were operating at the time. These mechanisms are consistently related to the onset of grain size reduction, triggered by both chemical enhanced and geometric processes. These include feldspar alteration to fine phyllosilicates associated with cataclasis and dynamic recrystallization of quartz.&lt;/p&gt;&lt;p&gt;Pressure solution, evidenced by changes in the shape of minerals along cleavage surfaces and the presence of dissolution seams and caps, is widespread throughout the studied rock sequences. The profuse occurrence of this grain-scale mechanism makes it very likely that syn-deformational fluid-influx lead to the destruction of load bearing microstructural frameworks and the development of interconnected weak layers due to alteration, explaining the occurrence of detachments within impure layers of the predominantly quartzose Pipe Rock and Salterella Grit members. The progressive development of these interconnecting fine-grained weak layers resulting from incongruent diffusive mass transfer is enhanced in the more mineralogically heterogeneous units of the Cambro-Ordovician sedimentary sequence (in particular, Fucoid Beds dolomitic siltstones and Durness limestones) explaining the consistently observed slip localization in these horizons.&lt;/p&gt;

Nitrate leaching to groundwater

1982 ◽  
Vol 296 (1082) ◽  
pp. 477-489 ◽  
Keyword(s):  
Land Use ◽  
Potable Water ◽  
Agricultural Land ◽  
Agricultural Soils ◽  
Research Effort ◽  
Groundwater Resources ◽  
Agricultural Land Use ◽  
Supply Industry ◽  
Land Use Practices

Groundwater provides over 30% of developed supplies of potable water in Britain. The outcrops of the important aquifers form extensive tracts of agricultural land. Groundwater resources largely originate as rainfall that infiltrates this land. During the 1970s, growing concern about rising, or elevated, groundwater nitrate concentrations, in relation to current drinking water standards, stimulated a major national research effort on the extent of diffuse pollution resulting from agricultural land-use practices. The results presented derive from intensive and continuing studies of a number of small groundwater catchments in eastern England. It is in this predominantly arable region that the groundwater nitrate problem is most widespread and severe. The distribution of nitrate in the unsaturated and saturated zones of the aquifers concerned is summarized. These data have important implications for the water-supply industry, but their interpretation is discussed primarily in relation to what can be deduced about both the recent and long-term histories of leaching from the more permeable agricultural soils.

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