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Subject: Soil Sciences × Author: Basumatary, Danswrang × End date: 2017 × Start date: 2017 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    LAND EVALUATION FOR CROP INTENSIFICATION IN BUMNOI-MORNOI WATERSHED OF KOKRAJHAR DISTRICT OF ASSAM USING REMOTE SENSING AND GIS TECHIQUES
    (AAU, Jorhat, 2017-07) Basumatary, Danswrang; Dutta, Marami
    The present study was undertaken in Bumnoi-mornoi watershed of Kokrajhar district of Assam in order to characterize and prepare soil resource maps, to study soil site suitability and to find out the related constraints for crop production. Altogether six profiles and twenty two surface samples were collected from two different physiographic units viz., alluvial plain and flood plain. The samples were analyzed for various morphological and physic-chemical properties. The dominant hue of soil colour was 10YR, except in sub surface C horizon of P1 (AP) where it was 7.5YR. Colour value ranged from 3 to 6 and chroma from 1 to 6. Yellowish red (2.5YR 4/6) to reddish yellow (7.5YR 7/6) mottles were observed in the soils. Wide variations were observed in soil textural class varying from sand to clay loam. The structure of the soil varied from medium, weak to moderate sub angular blocky at the surface to very fine to medium, week to moderate sub angular blocky, massive and single grain structure. Organic matter content in the soil varied from 0.07 to 3.13 g kg-1, the highest being observed in the surface Ap horizon of P3. Soil pH varied from 4.7 to 6.2. Sand, silt and clay contents in these soils varied from 23.3 to 89.2, 9.9 to 60, and 1.8 to 22.1 per cent, respectively. Among the exchangeable cations, Ca2+ was the dominant cation followed by Mg2+, Na+ and K+. CEC of the soils varied from 3.5 to 10.2 cmol (p+) kg-1. Available N varied from 13.44 to 448.0 kg ha-1, available P2O5 varied from 0.92 to 55.70 kg ha-1 and available K2O varied from 137.2 to 451.0 kg ha-1, respectively. The studied soils were classified as Aquic Dystrudepts (P1), Oxyaquic Dystrudepts (P2, P4), Typic Dystrudepts (P3), Aquic Udorthents (P5) and Fluvaquentic Epiaquepts (P6). The productivity of the soils for crop production varied from poor to good in alluvial plain, and poor to average in flood plain. Potential productivity varied from average to good in alluvial plain and flood plain, respectively. The co-efficient of improvement (CI) values indicated that the productivity of the alluvial plain and flood plain soils can be increased to maximum extend of 2.22 to 1.88, respectively. Soil site suitability assessment showed that the soils were moderately suitable (S2) to permanently unsuitable (N2) for Sali rice, Ahu rice, Potato and Maize. Soils were found to be very suitable (S1) to permanently not suitable (N2) for Banana. For pineapple, the soils were found to be very suitable (S1) to moderately suitable (S3). Various thematic and soil site suitability maps along with potential productivity maps of the study area were prepared using remote sensing and GIS techniques.