in this study, the batch equilibrium method was used to conduct metribuzin adsorption/desorption experiments with eight soils from different regions of iran. the results indicated that the organic carbon (oc) content, clay content, cation exchange capacity (cec), and ph had a combined effect on the metribuzin adsorption on soil. under the experimental conditions, the adsorption amount of metrib...

Phytoextraction of soil Cd and Zn may require reduction in soil pH in order to achieve high metal uptake. Reducing the pH of high metal soil, however, could negatively affect soil ecosystem function and health. The objectives of this study were to characterize the quantitative causal relationship between pH and soil biological activities in two Zn and Cd contaminated soils and to investigate th...

Soil pH declined from 5.9 to 5.0 in 8 years beneath plantations of Eucalyptus saligna (Sm.) in Hawaii. In stands of Albizia falcataria, (L.) Fosberg, the soil pH change was more dramatic, declining from 5.9 to 4.6. We measured several components of soil acidity beneath four mixtures of the two tree species to gain insight on the processes responsible for the decline in soil pH. These components...

the streptomycetes are gram positive bacteria with a filamentous form that present in a wide variety of soil including composts, water and plants. the most characteristic of streptomycetes is the ability to produce secondary metabolites such as antibiotics. they produce over two-thirds of the clinically useful antibiotics of natural origin (e.g., neomycin and chloramphenicol. another characteri...

Soil acidity is a major constraint on plant productivity. Arbuscular mycorrhizal (AM) fungi support plant colonization in acidic soil, but soil acidity also constrains fungal growth and diversity. Fungi in extreme environments generally evolve towards specialists, suggesting that AM fungi in acidic soil are acidic-soil specialists. In our previous surveys, however, some AM fungi detected in str...