Plants with different photosynthetic pathways could produce different amounts and types of root exudates and debris which may affect soil respiration rates. Therefore, wetland vegetation succession between plants with different photosynthetic pathways may ultimately influence the wetland carbon budget. The middle and lower reaches of the Yangtze River has the largest floodplain wetland group in...

The presence of a suitable substrate(s) in soil may release physiologically active concentration of a plant hormone ethylene (C2H4) as a result of microbial activity. We isolated three strains of fungi (Aspergillus clavatus, Penicillium commure and Thamridium elegans), from the maize rhizosphere soil, capable of producing C2H4 in the soil from L-methionine (10 mmol l). The plate and soil inocul...

Microbes are susceptible to contaminant effects, and high concentrations of chemical in soil can impact on microbial growth, density, viability and development. As a result of relative sensitivity of microbes to contaminants, toxicity data are important in determining critical loads or safe levels for contaminants in soil. Therefore the aim of this study was to assess the impact of phenanthrene...

Theories suggest that rapid microbial growth rates lead to quicker development of metal resistance. We tested these theories by adding hexavalent chromium [Cr(VI)] to soil, sowing Indian mustard (Brassica juncea), and comparing rhizosphere and bulk soil microbial community responses. Four weeks after the initial Cr(VI) application we measured Cr concentration, microbial biomass by fumigation ex...

The global terrestrial heterotrophic respiration is estimated at about 60 Gt C yr-1 (Schlesinger, 1991). Plant litter produced during senescence processes and plant residues left on site after harvest operations are the primary substrate for heterotrophic respiration in plant-soil ecosystems. They constitute both of aboveground and belowground plant parts. Substrate quality, together with the p...

Atrazine chlorohydrolase (AtzA) was discovered and purified in the early 1990s from soil that had been exposed to the widely used herbicide atrazine. It was subsequently found that this enzyme catalyzes the first and necessary step in the breakdown of atrazine by the soil organism Pseudomonas sp. strain ADP. Although it has taken 20 years, a crystal structure of the full hexameric form of AtzA ...

A simple, inexpensive method for measurement of respiration (CO, evolution) under a continuous air-flow was calibrated against an i.r. gas analyzer. Regression equations were developed to apply the method to general soil respiration measurement in the laboratory. The substrate-induced respiration technique was modified. By using 120% PWHC as a standard soil water condition during incubation, in...

Decomposition of soil organic matter (SOM) is limited by both the available substrate and the active decomposer community. The understanding of this colimitation strongly affects the understanding of feedbacks of soil carbon to global warming and its consequences. This study compares different formulations of soil organic matter (SOM) 5 decomposition. We compiled formulations from literature in...

The effect of Indigenous microorganisms (IMO’s) on the native soil was investigated in the present study. Supplementation of IMO’s suspension to the soil alters the physico-chemical, biological and enzyme properties of the soil. These alternations include decreases in P from 7.2 to 6.8, increase in electrical conductivity 0.36 to 1.21 (μmohs/cm), water holding capacity 0.36 to 2.2ml/g of soil o...