Chemical reactions of organic compounds including pesticides at the interlayer and exterior surfaces of clay minerals and with soil organic matter are reviewed. Representative reactions under moderate conditions possibly occurring in natural soils are described. Attempts have been made to clarify the importance of the chemical nature of molecules, their structures and their functional groups, a...

The spread of vegetable production around Lhasa, Tibet, China, with high nitrogen fertiliser use may cause accelerated acidification which has consequences for soil productivity. In order to understand the different patterns of soil acidity in Lhasa, Tibet, China three patterns of land use were studied namely: grain, openfield vegetable, and greenhouse vegetable. Fertilizer application was high...

Farmed landscapes are engineered for productivity, and research suggests they contribute a disproportionate share of inorganic C to the Mississippi River and Gulf of Mexico. Here we use alkalinity and total organic C (TOC) measurements collected from the Raccoon River of Iowa to (i) evaluate inorganic and organic C concentrations and export patterns, (ii) compare current trends to historical co...

This study was designed to investigate the effects of different tillage systems on some parameters such as soil salinity (pH, EC, SAR), soil density and nutrients in a nested experimental design with three treatments (no tillage, reduced tillage and conventional tillage) and three replications. Chenaran city fields were selected as the case study areas. Result of the statistical analysis indica...

The aim of the study was to estimate the influence of soil pH on the uptake of copper, zinc, and manganese by Valeriana officinalis. Preliminary studies involved soil analyses to determine acidity, organic matter content, and copper, zinc, and manganese total and bioavailable forms. The study involved atomic absorption spectrometry to determine the concentration of the elements, and mineral soi...

This study analyzed the relationship between nitrogen fertilization and the biological properties of soil contaminated with zinc. The influence of various concentrations of zinc and nitrogen on the microbiological and biochemical activity of soil was investigated. In a laboratory experiment, loamy sand with pHKCl 5.6 was contaminated with zinc (ZnCl2) and fertilized with urea as a source of nit...

Based on these figures, it is no exaggeration to say that more than one-third of the Brazilian annual wealth is supported by a single natural resource: the soil. This justifies the impor‐ tance of studies on how to preserve and improve this valuable resource. According to [2], soils have natural limits to their ability to nourish plants and sustain crop productivity. The degradation of soil qua...

The Streptomyces populations inhabiting five acidic forest soils were examined. It was found that lowering the pH of a medium selective for streptomycetes (starch-casein agar) to the pH of the particular soil horizon being plated influenced both the total numbers and types of streptomycetes that were isolated from the soils examined in this study. On the acidified medium both the numbers of str...

Widespread decreases in rainfall throughout the Murray-Darling Basin, superimposed on the significant allocation of water for irrigation, resulted in an order of magnitude reduction in flow over the period from 2004-2009. This resulted in a dramatic shift in flow regimes and water quality in the lower River Murray, and in particular substantial decline in the water level of the Lower Lakes at t...