Polycyclic aromatic hydrocarbon (PAH) contamination exists at numerous sites and poses a substantial risk to public health and the environment. Electrokinetic remediation technology has the potential to treat PAH-contaminated soils, but the effect of soil heterogeneities such as layers, lenses, and mixtures of different soils on the electrokinetic process has not been adequately studied. This s...

In conservation tillage systems, at least 30% of the soil surface was covered by crop residues which generally contain significant amounts of nitrogen (N). However, little is known about the multi-seasonal recoveries of the N derived from these crop residues in soil-crop systems, notably in northeastern China. In a temperate agro-ecosystem, 15N-labeled maize residue was applied to field surface...

22 In terrestrial environments, soil organic matter (SOM) is the largest organic carbon 23 (C) pool. The quantity and quality of organic carbon in soils can be affected by 24 vegetation through influencing the inputs and outputs of SOM. We examined how 25 storage and quality of C in SOM were affected by vegetation under grass cover or 26 single and a polyculture plot of Betula pendula, Alnus gl...

The mineralization of the herbicide 3-(4-isopropylphenyl)-1,1-dimethylurea (isoproturon) was reduced after the dry and hot summer 2003 in a soil profile placed in a field lysimeter. A different isoproturon mineralization pattern remained in soil material taken at two different soil depths (0–5 cm and 15–20 cm), although soil material was re-equilibrated at adequate climatic conditions. Special ...

The effects of elevated atmospheric CO(2) (560 p.p.m.) and subsequent plant responses on the soil microbial community composition associated with trembling aspen was assessed through the classification of 6996 complete ribosomal DNA sequences amplified from the Rhinelander WI free-air CO(2) and O(3) enrichment (FACE) experiments microbial community metagenome. This in-depth comparative analysis...

ABSTRACT Background: This work investigated radioactive contamination in soils of the pine forest in the territory adjacent to Semipalatinsk test site. Materials and Methods: Thirty samples from the soil were collected from six different a soil profile was laid out (research areas). Activity concentrations of 137Cs and 241Am were determined using a Canberra GX-2020 solid-state gamma-spectromet...

Measuring changes in soil carbon levels is a difficult task. Uncertainty about soil carbon measurement, monitoring, and verification is affecting agriculture’s role as an offset provider under a cap-and-trade program. There is ample evidence that skepticism is warranted. Soil carbon varies significantly at short distances—the carbon difference between samples collected within a meter can easily...

This paper investigates the power of the stream X machines ba sed on cooperating distributed grammar systems which replaces relations by functions The case of regular rules is considered The deterministic case is introduced in order to allow the application of some already deve loped testing strategies Some conditions for getting equivalent stream X machines in the derivation mode are studied

introduction: nitrogen (n) is one of the most important growth-limiting nutrients for dryland wheat. mineral nitrogen or ammonium (nh4+) and nitrate (no3−) are two common forms of inorganic nitrogen that can serve as limiting factors for plant growth. nitrogen fertilization in dryland area can increase the use of soil moisture, and improve wheat yields to some extent. many researchers have been...

Soil properties change with depth. Layers of soil that are nearly parallel with the soil surface and that are distinguishable from adjacent layers are called soil horizons. Horizons are visible on the vertical wall of a pit dug into the soil; the entire series of horizons visible on this wall is known as a soil profile. An idealized soil profile is illustrated in Figure 1. Soil classification r...