Nitrogen fertiliser replacement by single and multi-strain rhizobial inoculants for black gram, green gram and soybean cultivation in Sri Lanka
C.S Hettiarachchi,
C.L Abayasekara,
P. Saravava Kumar,
S. Rajapakse,
S.A. Kulasooriya,
E.M.H.G.S. Ekanayake,
R.K.G.K. Kumara,
H.M.A.C. Gunaratne