lnfra - Red Spectra of Soils

Department of Chemistry, University of Allahabad, Allahabad-211002 (India)

Manuscript received 25 October 1975; revised 3 May 1976; accepted 30 December 1976

Fifty representative soil samples collected from semi-desert, arid, semi-arid, semi-humid, humid-temperate and per-humid soil-climatic regions of India were processed for taking their infrared curves by KBr-mull technique using Perkin-Elmer Infra-Red Spectrophotometer, model no. 137. The infrared curves of each soil sample have been studied in the wavelength region, 2.5$\mu$ to  15.0$\mu$ . Previously, Functional groups, Si-OH (bonded and unbonded water-peaks) ; Si-OH (absorbed water-peak) ; Si-O (silica-peak) ; Al-O (alumina-peak) ; Si-H (pH-peak) and Si-C (carbon complex-peak), were assigned to this wavelength region. The common characteristic peaks of the functional group observed in the I.R. curves of soils belonging to different soil-climatic regions were noted.  The total number of peaks, total number of strong, medium and weak peaks and distribution of these peaks in different infrared regions of  IR-curves between wavelengths 2.70$\mu$  to 8.0$\mu$ , 8.5$\mu$  to 10.3$\mu$ and 11.0$\mu$ to 15.0$\mu$  were also observed and discussed.