Rajapakse, R.M.S.S.Yatawatte, S.T.Tea Research Institute of Sri Lanka2016-03-032016-03-031998TRI Update, 3(1):p.2-3https://dl-tri.nsf.gov.lk/handle/1/1663FertilizerEarth worm castsPlant nutrientsorganic fertilizercost of manuringArticle