Zoysa, A.K.N.Wickramaratne, A.C.R. De W.Munasinghe, P.S.Dissanayake, S.M.Tea Research Institute of Sri Lanka2016-03-032016-03-032003TRI Update, 8(2):p.6https://dl-tri.nsf.gov.lk/handle/1/1718Soil and FertilizerHumussoil fertilityhumic acidsfield productivityutilization of fertilizerArticle