Abstract: Sodic lands are not only physically and chemically degraded but are biologically degraded too. Owing to lower load of heterotrophic microorganisms, organic matter decomposing power of sodic land is considerably lower than that of normal cultivated soil (Bajpai and Gupta 1979). Truly, ameliorative and nutritive effects of organic amendments depend on the degree of their decomposition in these soils. In order to hasten the organic matter decomposition, extraneous inoculation of organic amendment with decomposing microbial inoculant may be a useful approach to augment the efficacy of organic amendments in these soils. Besides, gypsum being a non-renewable natural reserve and costly input necessitates it to be supplemented preferentially with locally available organic wastes. Taking these themes in view, present studies were undertaken. Press mud (suiphitation), water hyacinth and rice straw @ 10 t ha + decomposing bioinoculant (consortium of Aspergillus awamorii, Trichoderma ressi, Trichoderma viride and Trichuris spiralis) applied consecutively for two years integrated with gypsum @ 25% G.R. were evaluated for their ameliorative and manurial efficacy in the adaptive experiments in calcareous sodic land(pH₂₅ 10.0, ESP 68) of the hyperthermic family of petrocalcic Natrustalfs in Etawah District of Uttar Pradesh in rice-wheat green manuring sequence during 2001-2003. Press mud/water hyacinth + bioinoculant integrated with gypsum @ 25% G.R. exhibited higher crop yields than that obtained under gypsum alone @ 50% G.R. by 10-12% while rice straw amendment equated with it statistically. Bioinoculant improved performance of organic amendments by 10-15%. Organic amendment integrated with gypsum reduced pH, ESP and resulted in better carbon sequestration and microbial load. Organic amendments along with bioinoculant increased the contents of available N,P,K, Fe and Zn in soil on mean basis by 10.0, 128.5,105.4 and 73.0 per cent respectively over gypsum alone @ 50% G.R. after two years of experimentation. Average response to bioinoculant was 306 kg ha ^-1 rice and 190 kg ha^-1 in wheat with cost benefit ratio of 1:13. The effect of organic amendments on the crop yields and nutrient uptake is attributable collectively to its ameliorative and nutritive effect on soil.

Key words: Organic amendments, Bioinoculant, Gypsum, Reclamation, Productivity, Sodic Land.