1Krishi Vigyan Kendra, Pilibhit-262 001 (U.P.).S.V.B.P.U.A. & T., Meerut.
2Research Station Sui, Champawat (Uttaranchal), G.B.P.U.A. & T., Pantnagar.
3Directorate of Extension, S.V.B.P.U.A. & T., Meerut, 250 110U.P..
Soybean rhizobial isolates were collected from 92 different locations in the hills of Uttarakhand and plains of Uttar Pradesh. After preliminary screening, eleven isolates were tested for effectiveness against soybean varieties based on increase in N content in plants over the uninoculated control. S2, S6, S12 and S16 were grouped as efficient, while S3 and S17 as moderately efficient rhizobia. Efficient rhizobia isolates recorded better nodulatlons and higher grain yield of different soybean varieties. Among the four efficient isolates, 512 was found superior to others in terms of nodulation and grain yield. This isolate proved better than other isolates at four other centres of All India Co-ordinated Research Project on soybean. In field studies on Mollisol with high native rhizobial population, S12 also reecorded higher number of nodules, nodule dry weight, plant biomass and grain yield of PK 416 (medium maturing) and PK327 (early maturing).
Soybean, native rhizobia, isolates, nodulation North Indian soils
