0000000000073068
AUTHOR
Anna Benedetti
Humic substances along the profile of two Typic Haploxerert
Abstract In Vertisols, organic matter contributes to soil colour by formation of organo-mineral complexes and affects morphological, physico-chemical, biological and biochemical properties. Turbation may affect the chemical and structural composition of the most stabilised fractions of soil organic matter (SOM), i.e., humic substances (HS). The objectives of this study were to: (1) characterise SOM in two Vertisols (V1 and V2) developed under Mediterranean climate in Italy, using some HS characteristics as indicators of SOM turnover in Vertisols, and (2) explore possible differences related to the pedomorphologic conditions of the area under which two soils have formed. SOM evolution along …
Improving soil and water conservation and ecosystem services by sustainable soil management practices: From a global to an Italian soil partnership
The UN Sustainable Development Goals (SDGs) identify the need to restore degraded soils in order to improve productivity and the provision of ecosystem services. The aim is to support food production, store and supply clean water, conserve biodiversity, sequester carbon, and improve soil resilience in a context of climate change. Within this framework, in order to achieve the SDGs and to correct land management in the long-term, soil management is considered mandatory. The reduction of land degradation should be based on various sustainable soil management practices that improve and maintain soil organic matter levels, increase water infiltration, and improve soil water management. This tec…
Energy use in the A and B horizons of the soil under a pine and a cedar stand
Publisher Summary This chapter discusses a study that compares organic carbon content, availability of substrates, and microbial metabolism in two afforested sites in Sicily (Italy) developed under the same climatic and physical conditions but underlying different tree species. Given the key role of the soil microbiota in promoting energy exchanges and transformations in the soil profile, an analysis of the microbial activity and of organic carbon pools was performed on twenty profiles. The parameters considered in this study were based on microbial activity, organic carbon fractions, and kinetics of organic C mineralization. In the two systems studied, the competition for available energy …
Soil humic acids formation and characteristics in a xeric mollisol reforested with two tree species
Publisher Summary The study discussed in this chapter examines the influence on humic acids (HAs) characteristics of different plant species—Pinus halepensis Miller and Cedrus atlantica (Endl) Carriere—used in the restoration of a Mollisol under xeric conditions. The area studied is in Sicily (Italy), and two stands were compared 40 years after planting. The differences among soil profile developments in the two stands were investigated by chemical and biochemical methods to understand the different levels at which the processes of pedogenesis acted in the study area. The chapter analyzes some chemical and spectroscopic characteristics of HAs, separated from two selected pedons. The results…
Spatial microbial community structure and biodiversity analysis in "extreme" hypersaline soils of a semiarid Mediterranean area
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…
Compartmentalization of gypsum and halite associated with cyanobacteria in saline soil crusts
The interface between biological and geochemical components in surface crust of a saline soil was investigated using X-Ray Diffraction (XRD), and variable pressure scanning electron microscopy (SEM) in combination with Energy Dispersive X-ray Spectrometry (EDS). Mineral compounds such as halite and gypsum were identified crystallized around filaments of cyanobacteria. A total of 92 genera were identified from the bacterial community based on 16S gene pyrosequencing analysis. The occurrence of the gypsum crystals, their shapes and compartmentalization suggested that they separated NaCl from the immediate microenvironment of the cyanobacteria, and that some cyanobacteria and communities of su…
Salinity and Bacterial Diversity: To What Extent Does the Concentration of Salt Affect the Bacterial Community in a Saline Soil?
In this study, the evaluation of soil characteristics was coupled with a pyrosequencing analysis of the V2-V3 16S rRNA gene region in order to investigate the bacterial community structure and diversity in the A horizon of a natural saline soil located in Sicily (Italy). The main aim of the research was to assess the organisation and diversity of microbial taxa using a spatial scale that revealed physical and chemical heterogeneity of the habitat under investigation. The results provided information on the type of distribution of different bacterial groups as a function of spatial gradients of soil salinity and pH. The analysis of bacterial 16S rRNA showed differences in bacterial compositi…