Nitrate transformation in soil samples of forest and tea (Camellia sinensis) plantations

Abstract

A comparison was made in 1992 in the rate of nitrate transformation between soil samples from tea [Camellia
sinensis (L.) O. Kuntze] plantations from 3 tea-growing regions (Assam 26°44'N 94° 10'E, Dooars 26°54'N 88°55'E,
Nilgiris 11°21' N 76°49" E) and corresponding forest land, by estimating the quantity of nitrate, ammonium and volatilized
nitrogen recovered from soil samples amended with potassium nitrate. In all the 3 regions of the forest samples and in several samples of Assam plantation, 85-100% of the nitrate added to the forest samples remained unaltered for 24 hr. The nitrate-reducing activity, although a distinctive characteristic of tea-plantation samples, was related neither to the age of the tea plantation nor to the yield of tea in the respective sections.