ABSTRACT. A comparative study of organic and conventional farming system at two planting fields was conducted in Sabah Tea Plantation to determine the effect of management practices on soil nitrogen and pH, as well as leaf size and major polyphenol and caffeine content. Soil and leaves samples were from two selected fields; B29 (conventional field) and NO3 (organic field) in Sabah Tea Plantation, and were analyzed using UV spectrophotometer and high performance liquid chromatography methods. Organic farming system resulted in significantly higher soil pH (4.14), leaf length (15.14 cm), leaf width (7.33 cm) as well as major polyphenol content in tea shoot (172.42 mg/g) as compared to conventional farming system with soil pH (3.38), leaf length (13.19 cm), leaf width (5.58 cm) and major polyphenol content in tea shoot (107.03 mg/g). On the other hand, conventional farming system produced higher levels of ammonium (332.4 kg/ha) and nitrate (39.0 kg/ha) content in soil as compared to organic farming system (45.2 and 19.2 kg/ha, respectively). No significant difference in caffeine, epicatechin, epicatechin gallate and epigallocatechin content in leaves was observed between the two farming systems. The study provides some basic knowledge on soil nitrogen and pH level as well as tea major polyphenol and caffeine content in tea shoot of organic and conventional farming in Sabah Tea Plantation.
KEYWORDS. Caffeine, Conventional, Nitrogen, Organic, Polyphenol