Search results for "ORGANIC MATTER"

Soil organic matter and soil nitrogen fractions as affected by crop rotation in rainfed Mediterranean conditions

2005

Responses to increases in temperature of heterotrophic micro-organisms in soils from the maritime Antarctic

2015

Understanding relationships between environmental changes and soil microbial respiration is critical for predicting changes in soil organic carbon (SOC) fluxes and content. The maritime Antarctic is experiencing one of the fastest rates of warming in the world and is therefore a key location to examine the effect of temperature on SOC mineralization by the respiration of soil micro-organisms. However, depletion of the labile substrates at higher temperatures relative to the total SOC and greater temperature sensitivity of recalcitrant components of the SOC confound simple interpretations of the effects of warming. We have addressed these issues by testing the hypothesis that respiration by …

Geochemical characterization of soil organic matter and variability of a postglacial detrital organic supply (chaillexon lake, france)

1998

Humus in World Soils

1996

Publisher Summary This chapter discusses the soil humus and total organic carbon (OC) content. It reviews the results concerning the changes in soil organic matter (SOM) chemical nature regardless of the technical methods used. Information about C cycling and storage in soils is also given. Soil humus is characterized by its amounts and properties such as water retention capacity, aggregation and cementing agent, and the ability to absorb both nutrients and contaminants. The uncontrolled decrease in soil humus content affects soil water regime, aeration, fertility, and purifying capacity. The chapter focuses on the main soil types and the areas of the world where they are found, and conside…

Selenium and heavy metals content in some Mediterranean soils

2010

Abstract The study of metal contents in industrial, agricultural or/and polluted soils compared with natural or unpolluted soils is currently necessary to obtain reference values and to assess soil contamination. Nonetheless, very few works published appear in international journals on elements like Se, Li and Sr in Spanish soils. This study determines the total levels of Se, Li, Sr, As, Cd, Co, Cr, Cu, Ni, Pb, V, Zn, Fe, Mn and Ba in 14 natural (unpolluted) soils (Gypsisols, Leptosols, Arenosols and Acrisols), 14 agricultural soils (Anthrosols, Fluvisols and Luvisols), and 4 industrial–urban affected-surface soil horizons (Anthrosols and Fluvisols) of Eastern Spain. The geochemical baselin…

Impact of Innovative Agricultural Practices of Carbon Sequestration on Soil Microbial Community.

2011

This chapter deals with the impact on soil microbiology of innovative management techniques for enhancing carbon sequestration. With in the MESCOSAGR project, the effect of different field treatments was investigated at three experimental sites differing in pedo-climatic characteristics. Several microbiological parameters were evaluated to describe the composition of soil microbial communities involved in the carbon cycle, as well as to assess microbial biomass and activity. Results indicated that both compost and catalyst amendments to field soils under maize or wheat affected microbial dynamics and activities, though with out being harmful to microbial communities.

Soil humic acids formation and characteristics in a xeric mollisol reforested with two tree species

2002

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…

Effects of length and application rate of rice straw mulch on surface runoff and soil loss under laboratory simulated rainfall

2021

Abstract Forest land affected by deforestation yields high soil and water losses. Suitable management practices need to be found that can reduce these losses and achieve ecological and hydrological sustainability of the deforested areas. Mulch has been found to be effective in reducing soil losses; straw mulch is easy to apply, contributes soil organic matter, and is efficient since the day of application. However, the complex effects of rice straw mulch with different application rates and lengths on surface runoff and soil loss have not been clarified in depth. The current paper evaluates the efficiency of rice straw mulch in reducing the hydrological response of a silty clay loam soil un…

Short-term changes in soil Munsell colour value, organic matter content and soil water repellency after a spring grassland fire in Lithuania

2014

Abstract. Fire is a natural phenomenon with important implications on soil properties. The degree of this impact depends upon fire severity, the ecosystem affected, topography of the burned area and post-fire meteorological conditions. The study of fire effects on soil properties is fundamental to understand the impacts of this disturbance on ecosystems. The aim of this work was to study the short-term effects immediately after the fire (IAF), 2, 5, 7 and 9 months after a low-severity spring boreal grassland fire on soil colour value (assessed with the Munsell colour chart), soil organic matter content (SOM) and soil water repellency (SWR) in Lithuania. Four days after the fire a 400 m2 plo…

Wildland fire ash: Production, composition and eco-hydro-geomorphic effects

2014

Abstract: Fire transforms fuels (i.e. biomass, necromass, soil organic matter) into materials with different chemical and physical properties. One of these materials is ash, which is the particulate residue remaining or deposited on the ground that consists of mineral materials and charred organic components. The quantity and characteristics of ash produced during a wildland fire depend mainly on (1) the total burned fuel (i.e. fuel load), (2) fuel type and (3) its combustion completeness. For a given fuel load and type, a higher combustion completeness will reduce the ash organic carbon content, increasing the relative mineral content, and hence reducing total mass of ash produced. The hom…