A procedure to determine the exchanger-phase composition (and thus the Na/Ca selectivity) of calcareous and gypsiferous soils was developed and tested on three soils and three phyllosilicate minerals. The procedure corrects for anion exclusion and mineral weathering by measuring the Cl, SO,,, and HCO3 in the soil solution and in the extracting solution. Anion exclusion was found to be significa...

Zinc (Zn) availability and mobility in soils is controlled by its interaction with the soil matrix and amendments. Contradicting evidence has been reported for factors influencing Zn behavior in soils. The aim of this study was to investigate the Zn sorption in selected acid, calcareous and gypsiferous soils with different background electrolytes (Na+, K+ and H2PO4, NO3 and Cl backgrounds). Iso...

This paper reviews the main methodologies and techniques that have been used to characterize gypsum in soils, especially in gypsiferous soils of semiarid and arid regions and range from the identification of gypsum in soil surveys in the field to the study of gypsum in the laboratory. Many methods of gypsum identification and determination have been developed, each one with its own limitations....

zinc (zn) availability and mobility in soils is controlled by its interaction with the soil matrix and amendments. contradicting evidence has been reported for factors influencing zn behavior in soils. the aim of this study was to investigate the zn sorption in selected acid, calcareous and gypsiferous soils with different background electrolytes (na+, k+ and h2po4, no3 and cl backgrounds). iso...

Abstract The aim of this paper was to study the kinetics Boron adsorption by using concepts and different concentrations Boron. A number laboratory experiments were conducted on three samples gypsum soils which taken from some fields Tikrit University Al-Alam city. soil contained low medium with concentration (62) g.kg -1 (134) gm.kg respectively College Agriculture’s field at Tikrit, third hig...

pedogenesis and clay mineralogy of soils and rock samples were studied in a transect of calcareous, gypsiferous, saline soils and sediments of bakhtegan lake bank in southern iran. the main objectives of study were to determine the occurrence of clay minerals and factors controlling their distribution pattern and relative abundance in soils and parent materials. the soil parent material is high...

Pedogenesis and clay mineralogy of soils and rock samples were studied in a transect of calcareous, gypsiferous, saline soils and sediments of Bakhtegan lake bank in southern Iran. The main objectives of study were to determine the occurrence of clay minerals and factors controlling their distribution pattern and relative abundance in soils and parent materials. The soil parent material is high...

1. At the heart of the body of research on biodiversity effects on ecosystem function is the debate over whether different species tend to be functionally singular or redundant. When we consider ecosystem multi-function, the provision of multiple ecosystem functions simultaneously, we may find that seemingly redundant species may in fact play unique roles in ecosystems. 2. Over the last few dec...