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2010 - 20132
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Subject: Soil Science and Agricultural Chemistry × End date: 2017 × Start date: 2010 × Type: Thesis × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Studies on land degradation in the three agro-climatic zones of Belgaum District, Karnataka
    (UAS Dharwad, 2013) Prabhavathi Koraprolu; G. S. Dasog
    A study was carried out to determine the extent of different land degradation types in Belgaum district on 1: 50,000 scale using remote sensing and GIS techniques. Out of 13,44,084.60 ha of total geographical area of Belgaum district, 3,96,059.5 ha land is degraded accounting for 29.47 per cent. Among the various land degradation types, sheet erosion (23.13 %) was the dominant land degradation type followed by rill erosion (5.76 %) and barren rocky/ stony waste (0.44%). Three micro-watersheds were selected one each from Northern dry zone (Yadawad), Northern transitional zone (Hukkeri) and Hilly zone (Khanapur) for characterization, soil fertility mapping and soil loss risk assessment using USLE. The soils of Yadawad microwatershed were alkaline, low in organic carbon, available nitrogen, P2O5 and sulphur content and deficient in Zn and Fe. The soils of Hukkeri micro-watershed were neutral to slightly alkaline, low in organic carbon, available nitrogen and available phosphorus in two third of area. The entire watershed was found deficient in available sulphur, zinc and iron. The soils of Khanapur micro-watershed were slightly acidic to acidic in reaction. Available phosphorus, potassium and sulphur status was low in majority of the area. Nearly all of Yadawad micro-watershed depicted very low soil erosion risk class. Hukkeri microwatershed had very low soil erosion risk in 34.9 per cent of TGA and low soil erosion risk in 17.6 per cent of TGA. The Khanapur micro-watershed exhibited a wide range of soil erosion risk with 41.22 per cent of TGA under low soil erosion risk class with substantial extent (16.12 %) under high soil erosion risk class because of topographic variation.
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    ThesisItemOpen Access
    Effect of Nutrient Management Practices on Soil Health and Crop Response under Different Cropping Systems in a Vertisol of Northern Transition Zone of Karnataka
    (UAS Dharwad, 2010) Vidyavathi; G.S. Dasog
    A field experiment was conducted to study the “Effect of nutrient management practices on soil health and crop response under different cropping systems in a Vertisol of Northern transition zone of Karnataka” at Main Agricultural Research Station, University of Agricultural Sciences, Dharwad during 2007-08. The experiment was laid out in strip plot design with nutrient management practices as main plots and cropping systems as subplots with three replications. Among the nutrient management practices organic plots recorded significantly higher soybean (2790 kg/ha), groundnut (3709 kg/ha) and chilli (1001 kg/ha) equivalent yields where as integrated plots recorded significantly higher maize (4330 kg/ha) and potato (4723 kg/ha) equivalent yields and were found superior over inorganic plots. Both organic and inorganic fractions of nitrogen in soil increased over time under organic followed by integrated nutrient management practices during both kharif and rabi seasons. Nitrogen fractions under inorganic nutrient management practice increased up to 60 DAS and later declined. The dehydrogenase, phosphatase and urease activity were found to be maximum under integrated followed by organic nutrient management practice and their activity increased up to 30 DAS and then sharply declined. After harvest of rabi crops the soil organic carbon in organic plots increased by 32.6 per cent. Similarly, in integrated plot it increased by 17.1 per cent whereas in inorganic plot soil organic carbon decreased by 11.0 per cent over the initial value. The available N, P2O5, K2O and S content of soil increased by 19.1, 46.3, 9.6 and 54.0 per cent respectively, and DTPA extractable Zn, Fe, Mn and Cu increased by 18.6, 30.6, 36.5 and 30.0 per cent, respectively under integrated nutrient management practice over their initial values. Legume based cropping system at the end of their crop cycle improved the soil fertility status with respect to available N, P2O5, K2O, S and micronutrients content of soil.