Nitrogen is one of the most important ecosystem nutrients and often its availability limits net primary production as well as stabilization of soil organic matter. The long-term storage of nitrogen-containing organic matter in soils was classically attributed to chemical complexity of plant and microbial residues that retarded microbial degradation. Recent advances have revised this framework, ...

In the last decades an increasing number of natural and synthetic compounds have been recognized as endocrine disruptors (EDs) because of their hormone-like activity and capacity to alter the normal hormonal functions of animals and humans. Among EDs, there are phenolic compounds widely present in terrestrial and aquatic systems, such as bisphenol A, 4-nonylphenol (NP), 4-tert-octylphenol, estr...

Regional distributions of organic content are an important aid in developing basin evolution and hydrocarbon generation models. An approach to evaluate hydrocarbon source rocks using resistivity, sonic, density, neutron and natural gamma ray logs is developed. Organic matter, as a constituent in sedimentary rocks, has a relatively low density, slow velocity, and is high in hydrogen content. Sou...

abstract saturated water content is one of the important parameters which its measurement is necessary in estimation of soil water retention and unsaturated hydraulic conductivity curves. in several researches, saturated water content is assumed to be equal to soil total porosity. in some others, its value is estimated by pedotransfer functions using readily available parameters, such as bulk d...

introduction drought stress is one of the most yield reduction factor of lima bean where effects on the more than 60% of bean world production. in this regard, solutions that help increase productivity with high water efficiency in this region can change the agricultural crop production. one of the solutions is using organic materials (acid humic). humic acid with linkage of water molecules and...

the gulf of mannar, located between india and sri lanka, is a shallow embayment of the bay of bengal. the gulf, which has been declared a bio-reserve is a highly productive area endowed with rich marine fauna including corals. in order to study the origin and nature of the sediments and paleo-environment, 2.6 m length core was collected with 5cm interval at 1320m water depths. textural studies ...

The burial of organic carbon in marine sediments removes carbon dioxide from the ocean-atmosphere pool, provides energy to the deep biosphere, and on geological timescales drives the oxygenation of the atmosphere. Here we quantify natural variations in the burial of organic carbon in deep-sea sediments over the last glacial cycle. Using a new data compilation of hundreds of sediment cores, we s...

Introduction Natural variations of the C/C ratio have been frequently used over the last three decades to trace C sources and fluxes between plants, microorganisms, and soil. Most of these studies have used the natural C labelling approach, i.e. natural δC variation after C3 – C4 vegetation changes. In this mini-review, we focus on C fractionation in processes at the interface between roots, mi...

Soil physical structure causes differential accessibility of soil organic carbon (SOC) to decomposer organisms and is an important determinant of SOC storage and turnover. Techniques for physical fractionation of soil organic matter in conjunction with isotopic analyses (dC, dN) of those soil fractions have been used previously to (a) determine where organic C is stored relative to aggregate st...