1. Organic matter decomposition is the main process by which carbon (C) is lost from terrestrial ecosystems, and mycorrhizal associations of plants (i.e. arbuscular mycorrhizas (AM) and ectomycorrhizas (ECM)) may have different indirect effects on this loss pathway. AM and ECM plants differ in the soil decomposers they promote and the quality of litter they produce, which may result in differen...

The pH and buffer capacity of two soils increased or remained constant after incubation with different amounts of plant material (lucerne chaff) at field capacity and when air dry. For both soils, the pH changes were greater at field capacity, whereas the buffer capacities were independent of the water treatments. The pH changes observed could be explained in terms of the organic anion concentr...

abstract soil organic matter and its components are important factors in formation and stability of aggregates and subsequently soil structure. however data regarding organic matter distribution in soil aggregates is scarce, particularly in arid soils of central iran. the objective of this study was to investigate the distribution of organic carbon (oc), total nitrogen (tn), and carbohydrates i...

the potential risk of metal accumulation in periurban agricultural areas is a matter for concern.the climate characteristics and carbonate content of calcareous agricultural mediterranean soils typical inthese areas favour metal accumulation at the surface level; however there is also a risk of potential metalmobility. our study focuses on the soil properties affecting metal mobility in these s...

A hot topic in recent decades, the application of organic amendments to arid-degraded soils has been shown to benefit microbially-mediated processes. However, despite the importance of soils for global sustainability, a gap has not been addressed yet in soil science: is there any connection between ecosystem-community processes, cellular functionality, and microbial lifestyles (i.e. oligotrophy...

Mobilization of unavailable phosphorus (P) to plant available P is a prerequisite to sustain crop productivity. Although most of the agricultural soils have sufficient amounts of phosphorus, low availability of native soil P remains a key limiting factor to increasing crop productivity. Solubilization and mineralization of applied and native P to plant available form is mediated through a numbe...

Cultural methods such as crop fertilization can affect susceptibility of plants to insect pests by altering plant tissue nutrient levels. Research shows that the ability of a crop plant to resist or tolerate insect pests and diseases is tied to optimal physical, chemical and mainly biological properties of soils. Soils with high organic matter and active soil biology generally exhibit good soil...

Several factors effect on sorption of polycyclic aromatic hydrocarbons (PAHs) in soil. Coexistence of metals and organic matter of soil are among important affecting factors on sorptive behavior of PAHs. This research investigated the effect of organic matter content and heavy metals (lead, nickel and zinc), on sorption of phenanthrene onto kaolinite. For this purpose, sorption of the organic m...

Improved predictions on the fate of organic pollutants in surface environments require a better understanding of the underlying sorption mechanisms that control their uptake by soils. In this study, we monitored sorption of nine aromatic compounds with varying physicochemical properties (hydrophobicity, electron-donor/acceptor ability and polarity), including two polycyclic aromatic hydrocarbon...

The Viking missions showed the martian soil to be lifeless and depleted in organic material and indicated the presence of one or more reactive oxidants. Here we report the presence of Mars-like soils in the extreme arid region of the Atacama Desert. Samples from this region had organic species only at trace levels and extremely low levels of culturable bacteria. Two samples from the extreme ari...