The parental material of soils in the Qilian Mountains of northwest China is mainly aeolian loess containing CaCO3 which may remain in soils under the semiarid-arid climate. To disclose the CaCO3 characteristics change with the altitude and the terrain attributes, we surveyed 18 soil profiles in an altitude sequence from 3076 m to 4510 m in the Hulugou Watershed in the Qilian Mountains, measure...

Previous studies have shown that porous hydrated calcium silicate (PS) is very effective in decreasing cadmium (Cd) content in brown rice. However, it is unclear whether the PS influences cadmium transformation in soil. The present study examined the effect of PS on pH, cadmium transformation and cadmium solubility in Andosol and Alluvial soil, and also compared its effects with CaCO3, acidic p...

4 A newly emerging microbiological soil stabilization method, known as microbially 5 induced calcite precipitation (MICP), is tested for geotechnical engineering 6 applications. MICP is a promising technique that utilizes the metabolic pathways of 7 bacteria to form calcite precipitation throughout the soil matrix, leading to an increase 8 in soil strength and stiffness. This paper investigates...

A method to simultaneously determine calcite surface area and content in soils has been developed. The proposed procedure is based on rates of CO2 production upon reaction of soil with buffered acid solutions under controlled conditions. A pressure transducer connected to a chart recorder allows determination of soil calcite dissolution rate, which is directly proportional to calcite surface ar...

In the present paper the yield and soil spatial variability in an apple orchard was studied. Apples were collected manually and placed in plastic bins along the tree rows. Yield per ten trees was weighted and the geographical position in the centre of the ten trees was recorded, using a GPS, in order to create the yield map. The orchard was divided in management zones with the Management Zone A...