The rate of nonexchangeable NH/ release from soils can have a significant effect on N dynamics and environmental quality. Nonexchangeable NH/ is that N fraction which is fixed in the interlayers of clay minerals. The objective of this study was to determine the kinetics of nonexchangeable NH4 release from two topsoils from Germany [Giessen Ap (Aqualf) and Hungen Ap (Alfisol)] and from two subso...

nonexchangeable soil-k release rate can significantly affect k dynamics and it's bioavailability during plant growth. in this study, twelve soil samples taken from different wheat cropping regions of iran were incubated with nabph4 to (i) investigate the kinetics of nonexchangeable k release and (ii) to compare the ability of various kinetic equations (zero-, first- and second-order, parab...

Abstract Potassium fertilization can change K forms available in the soil, as well influence plant absorption of it and yield but, mainly, affect grape composition. The aim current study was to investigate impact potassium (K) on production juice (must) composition a Cabernet Sauvignon cultivar. Grapevines were treated with 0, 50, 100, 150 200 kg ha-1 year-1 K2O. Leaf contents, per area, total ...

The effects of microtubule inhibitors on cellular accumulation of 4'demethylepipodophyIlotoxin-9-(4,6-0-ethyIidine-/î-D-glucopyranoside) (VP-16) and subsequent epipodophyllotoxin-induced DNA single-strand breaks were investigated in human leukemia K562 cells. At concentra tions of 0.05-20 MM.vinblastine, vincristine, and maytansine similarly increased the steady-state cell concentration of VP-...

The effects of microtubule inhibitors on cellular accumulation of 4'-demethylepipodophyllotoxin-9-(4,6-O-ethylidine-beta-D-glu copyranoside) (VP-16) and subsequent epipodophyllotoxin-induced DNA single-strand breaks were investigated in human leukemia K562 cells. At concentrations of 0.05-20 microM, vinblastine, vincristine, and maytansine similarly increased the steady-state cell concentration...

abstract low molecular weight carboxylic acids (lmw) play an important role in improving the bioavailability of soil nutrients. nonexchangeable soil k, trapped between the interlayers of clay minerals, is an important source of k for plants in many soils. the objectives of this study were to determine the effect of selected lmw organic acids on the release of k from micaceous minerals and to in...

In soils of tropical climate regions the high acidity and the presence of exchangeable aluminum (Al), associated to low fertility, are the main restrainting factors for agricultural production. A laboratory experiment was conducted using 26 soils of different Brazilian regions, to investigate soil acidity components, giving emphasis to Al and their relations with chemical properties. The pH cor...