Page 210 - Enzymes in Tropical Soils

198 Enzymes In Tropical Soils

GLOSSARY

Acidification is to make a reaction medium to have a lower pH. For example, soil
acidification is to make the soil pH lower by using S powder or naturally by
root excretion of organic acids or by producing CO 2 during root respiration.

Activation Energy is a measure on the magnitude of all forces that must be
surmounted during a reaction process (Sparks, 1989). This energy barrier
separates the reactant state from the product state (Castellan, 1983). To
form the products, the reactants must have sufficient energy to overcome
this energy barrier. Without enough energy to surmount the energy barrier,
the reactants will stay at their origiinal states and the products will never
exist.
Adsorption is a chemical process by which an ion is attached to a solid with an
opposite charge. For example, the adsorption of a cation by the negative
charges of soil organic matters.
Alkalination is to make a medium to have a higher pH. For example, soil
alkalination is to make the soil pH higher by a liming materials such as calcite
or dolomite. In general it is referred to as liming.
Arylsulfatase is an organic substance produced by microorganisms, earthworms, or
plant roots acting as a biocatalyst functioning to accelerate the detachment
2-
of S from organic S to form inorganic SO 4 available for plant root
absorption.

Abdul Kadir Salam - 2014