Search results for "Soils"
showing 10 items of 157 documents
Cárcavas y regueros generados en suelos sódicos : Petrer (Alicante, España)
2013
Este articulo pretende mostrar las interacciones entre los procesos de piping y la formacion de carcavas y regueros en diferentes sub-sistemas (laderas y rellenos de fondo de valle) de una pequena cuenca del SE espanol. Se analiza la influencia de diversas propiedades del los suelos y regolitos en el desarrollo de formas asociadas al piping. Los sistemas reguero-tunel de las laderas de badlands estan principalmente relacionados con la ratio de absorcion de sodio (SAR) y la conductividad electrica (CE) de los suelos. En contraste, en los rellenos de fondo de valle estas propiedades quimicas interactuan con las discontinuidades en el gradiente hidraulico introducidas por las terrazas de culti…
The “Soil Genetic Erosion”: a new threat for soils?
2015
During the 1990’s the concept of pedodiversity started to be diffused in the scientific literature and the decrement of the soil diversity in space and time - particularly due to human activity - has been seen as a sort of underhand problem affecting soil ecosystems, considering that different soil types face gradual or drastic reduction or complete loss of their unique “genetic features”. Pedodiversity has received considerable recent interest, especially as peculiar aspect of biodiversity and has been assessed by several authors by applying diversity indices used in ecology. This paper takes into consideration the influence of human activities on the loss of pedodiversity in a Mediterrane…
Long-term effects of metal-containing farmyard manure and sewage sludge on soil organic matter in a fluvisol
2005
Abstract Our aim was to establish the long-term effects of repeated applications after 20 y of organic amendments (farmyard manure at 10 t ha −1 y −1 , and urban sewage sludge at two different rates, 10 t ha −1 y −1 and 100 t ha −1 every 2 y) on the quality of a sandy and poorly buffered soil (Fluvisol, pH 6). Chemical characteristics and biodegradability of the labile organic matter, which is mainly derived from microbial biomass and biodegradation products of organic residues, were chosen as indicators for soil quality. The organic C content had reached a maximal value (30.6 g C kg −1 in the 100 t sludge-treated soil), i.e. about 2.5 times that in the control. Six years after the last a…
An extra-urban soil cadastre for Italy: a first guide for the introduction of soil information
2020
Assuming a positive outcome of the parliamentary procedure for laws and, thus, the transformation of the official cadastre for buildings and land into a soil cadastre (urban, extra-urban and cadastre for the conservation of natural or semi-natural soil diversity) would start a new era for pedology. Finally, after many decades of activity to expand soil culture in Italy, almost all Italian families would be in contact with a soil specialist. Land use and redefined plots would be handled with greater care and responsibility. Experts in agricultural and forestry and biodiversity conservation would have a new impetus in their activity. Furthermore, economists will also have to address new issue…
BIOCHARS IN SOILS: TOWARDS THE REQUIRED LEVEL OF SCIENTIFIC UNDERSTANDING
2017
The special issue on Biochar as an Option for Sustainable Resource Management Key priorities in biochar research for future guidance of sustainable policy development have been identified by expert assessment within the COST Action TD1107. The current level of scientific understanding (LOSU) regarding the consequences of biochar application to soil were explored. Five broad thematic areas of biochar research were addressed: soil biodiversity and ecotoxicology, soil organic matter and greenhouse gas (GHG) emissions, soil physical properties, nutrient cycles and crop production, and soil remediation. The highest future research priorities regarding biochar’s effects in soils were: functional …
Contamination of soil by copper affects the dynamics, diversity, and activity of soil bacterial communities involved in wheat decomposition and carbo…
2009
ABSTRACT A soil microcosm experiment was conducted to evaluate the influence of copper contamination on the dynamics and diversity of bacterial communities actively involved in wheat residue decomposition. In the presence of copper, a higher level of CO 2 release was observed, which did not arise from greater wheat decomposition but from a higher level of stimulation of soil organic matter mineralization (known as the priming effect). Such functional modifications may be related to significant modifications in the diversity of active bacterial populations characterized using the DNA stable-isotope probing approach.
Different Type Clay Amendments for Lead Immobilization in Contaminated Soils
2014
Contamination with lead in soil is a crucial problem in industrial and military sites. Immobilization of lead by natural and modified clay as soil amendment can be an effective solution to this problem. Quaternary and Devonian clays were chosen for modification with NaCl, CaCl2, FeOOH and Ca10(PO4)6(OH)2 in different proportions of Ca/P equimolar ratio to test and compare immobilization efficiency of lead (II) on raw and modified clays by using a batch leaching test. The aim of the study is to compare different types of raw and modified clays as soil amendments by lead immobilization properties.
Spatial microbial community structure and biodiversity analysis in "extreme" hypersaline soils of a semiarid Mediterranean area
2015
In recent years specific attention has been paid on the biotechnological potential of microorganisms in extreme soils, in particular in saline soils. Salinity is one of the most widespread soil degradation processes on the Earth, and saline soils can be defined as extreme soils or border line habitats in which several factors, as high salt content, may limit the growth of organisms. In this study, the physical, chemical and microbiological soil properties were investigated in the shallower horizon of natural saltaffected soils in Sicily (Italy). The main aim of the research was to evaluate the structure and diversity of bacterial and archaeal communities by terminal-restriction fragment len…
The effect of alternating different water qualities on accumulation and leaching of solutes in a Mediterranean cracking soil
2002
The relevance of bypass flow on water flow, solute or pesticide transport is becoming increasingly recognized. Recent investigations proved that soil salinization may be influenced by bypass flow, i.e. the rapid transport of water and solutes via macropores and/or shrinkage cracks to subsoil and groundwater. This paper explores the role of bypass flow in the process of accumulation and leaching of solutes, as well as of sodium, in a Mediterranean cracking soil irrigated with saline/sodic waters. The results of bypass flow experiments performed on undisturbed soil cores showed that leaching of solutes occurred in concomitance with bypass fluxes when a low salinity solution was alternated wit…
Design Procedures for Soil-Lime Stabilization for Road and Railway Embankments. Part 1-Review of Design Methods
2012
AbstractWhen selecting the appropriate materials for constructing road infrastructures, an important way for minimizing both the economical and environmental impact is to make use of lime for treating soils that are not suitable for road or railways construction.Advances in lime stabilization technique allowed the successful use of this technique also for improving the bearing capacity of the subgrade, with noticeable savings on both aggregate and disposal charges.In this paper a review of internationally adopted design methods for soil-lime mixture is presented, in order to compare testing methods and requirements of the adopted criteria, as discussed in Part 2.