Soil quality variation due to long term tea cultivation in upper Assam India

Abstract

SOIL QUALITY VARIATION DUE TO LONG TERM TEA CULTIVATION IN UPPER ASSAM, INDIA Tea is an important Agricultural crop of commerce and a major foreign exchange earner. Tea quotCamellia sinensisquot (L) O. kuntze, belonging to a family Theaceae is an unique crop popularly used as a beverage and is extensively cultivated in different tea growing regions of the world. There are mainly three varieties of tea plants: Assam. Camellia assamica, China, Camellia sinensis (L) O. kuntze and combod, Camellia assamica SSP lasiocalyx tea. Beside these botanical varieties, there are many strains and modern Indian clonal varieties. Leaf size is the criterion for the classification of the tea plants. Tea is classified into Assam type, characterised by the largest leaves. China type, characterised by the smallest leaves and Cambod, characterised by leaves of intermediate size. China is believed to be the first country for commercial exploitation of tea. In India, tea cultivation was started by the British in a systematic way in 1830 with seeds and plants imported from China. The largest tea producing countries are China, India, Kenya, Sri Lanka and Turkey. India is the second largest producer and the largest consumer of tea in the world and Assam alone contributes more than half of the total production of tea in India. Agro-climatic condition and other eco-biological factors largely determine the growth and yield of tea. This thesis describes the results of investigation on the changes brought in soil quality by uninterrupted tea cultivation in 20 tea estates of Sivasagar and Dibrugarh districts in Assam, India. Some selected sites have been taken up for soil collection and monitoring in each of the tea estates over a period of three years in order that a comparative study could be made about the soil quality. The thesis as a whole consists of five chapters: Introduction, Description of the Study Area, Materials and Methods, Results and Discussion, and Conclusion along with a large number of illustrations, graphs and data tables. Chapter 1