Venkatesan. S

Impact of Chemical Fertilisers on Certain Enzymes in Tea: Research in the Area of Heavy Metals in Soils and Their Impact on Enzymes in Tea Venkatesan. S

studies on urease activity provided informations on optimum interval that should be maintained between two successive splits of NK (urea based) fertiliser application. This information would be of immense use for the planting community of south India to increase fertiliser use efficiency. The positive correlation coefficient obtained between NR activity and productivity index of tea reveals an important information that NR activity could be used as productivity index of tea under south Indian conditions. This could be of immense use for plant breeders to predict the yield potential of different clones even at initial stages of selection program. The inhibiting ability of various metals is different in different solis towards the enzymes studied. Cu, Mn, Fe and Mo are applied frequently in tea plantations for various reasons. But they are all proved to inhibit the enzyme activities responsible for N, P and S transformations. Enzyme activity can be recogonised as a good proxy for soil health, it can be concluded that the tea plantations keep better soil health in terms of enzyme activity when compared to near by forest soils.