Page 190 - Ilmu Tanah

The Chemistry and Fertility of Soils under Tropical Weeds 177

Dissolution A chemical process in which precipitate or mineral dissolve forming all
the related species at concentrations lower than those needed to compensate
the related solubility constant.

Drying An action of draining water from paddy field.

Electron Acceptor A chemical compound that may be reduced after receiving
electron(s) from an electron donor encountering oxidation in a redox reaction.

Electron Donor A chemical compound donating electron(s) after encountering
oxidation in a redox reaction.

Environmental Weeds Weeds existing in non-agricultural lands which may
negatively affect plant biodiversity.

Equilibrium Constants the constant values indicating the relationship between the
activities of products relative to the activities of reactants of the related steady
state chemical reactions.

Exchangeable Cation The adsorbed cations on the soil exchange-sites
exchangeable with other cations in soil water.

Exchangeable K The adsorbed K on the soil exchange-sites exchangeable with other
cations in soil water.

Excretion The release of organic and inorganic substances including organic acids,
+ -
enzymes, H , and OH by plant roots.

Free Ion A charged elemental species does not associate with any other elemental
2+ 3+ - - -
species such as Pb , Fe , Cl , NO 3 , or H 2 PO 4 .

Flooding The submerging of paddy field with irrigation water.

Heavy Metals A group of trace elemental metals with relatively high density of
3
more than 5 g cm .
Integrated Weed Control The control of weeds by wisely considering all methods
of weed control depending on the existing and magnitude of weed problem in
the field.

Abdul Kadir Salam and Nanik Sriyani – 2019