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  • ThesisItemOpen Access
    CHARACTERIZATION OF SOILS AND SOIL ORGANIC MATTER FRACTIONS OF SELECTED TREE PLANTATIONS
    (University of Agricultural Sciences, Dharwad, 2014-06) JEETENDRAPRAKASH; Dr. MANJUNATHA HEBBARA
    A study was conducted at Main Agricultural Research Station, UAS, Dharwad, Karnataka to characterize soils and soil organic matter fractions under teak (Tectona grandis), sisso (Dalbergia sissoo), catechu (Acacia catechu), bamboo (Dendrocalamus strictus), eucalyptus (Eucalyptus tereticornis) and casuarina (Casuarina equisetifolia) tree plantations. Irrespective of tree species, soils under tree plantations registered lower pH and higher electrical conductivity values over control (cultivated land). The pH of surface soils (0-30 cm) remained lower than subsoil (30-60 cm). The lowering of pH was to a greater extent under bamboo (Dendrocalamus strictus) compared to all other plantations. Soil organic carbon and total N were more under tree plantations than control. The C:N ratio did not vary much among tree species and cultivated land. Tree species registered higher available status for nitrogen, phosphorus and potassium compared to cultivated land. Among different tree plantations, soils under the canopy of bamboo (Dendrocalamus strictus) followed by Sissoo (Dalbergia sissoo) registered significantly higher organic carbon content and available status of N, P2O5 and K2O. Soils under Dendrocalamus strictus registered higher DTPA extractable iron and manganese contents whereas higher copper and zinc contents were recorded in soils under Eucalyptus tereticornis. Cultivated land recorded lower heavy metal (Cd, Cr, Ni, Pb) contents compared to tree plantations. Among different tree plantations Dendrocalamus strictus recorded higher CEC, humic acid and fulvic acid contents. The humic and fulvic acids extracted from Dendrocalamus strictus plantation recorded the highest total acidity and E4/E6 ratio. Irrespective of tree species, humic acid had higher iron content followed by zinc, copper and manganese. Higher copper and manganese contents were recorded in humic acid compared to fulvic acid. The chromium concentration was the highest in leaf litter of all plantations as compared to other heavy metals. The leaf litter of Dalbergia sissoo had higher nitrogen, phosphorus and potassium contents over other trees.