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20172
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Subject: Soil Science and Agriculture Chemistry × End date: 2018 × Start date: 2017 × Type: Thesis × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Assessment of Different Approaches of Fertilizer Recommendation to Soybean [Glycine max (L.) Merrill.] in a Vertisol and Their Impact on Soil Properties in Northern Transitional Zone of Karnataka
    (University of Agricultural Science, Dharwad, 2017-10) Sankalpa C.P.; Math, K.K.
    A study on the effect of different fertilizer recommendation approaches on yield, quality, nutrients uptake by soybean, residual nutrients status and their transformation in soil was conducted at the Main Agricultural Research Station, University of Agricultural Sciences, Dharwad during kharif 2015 and 2016 with 12 treatments replicated thrice in RCBD. Targeted yield of 30 q ha-1 under SSNM recorded significantly higher seed yield (30.91 q ha-1) over all other treatments except 35 q ha-1 target yield under SSNM. It was because of higher number of seeds plant-1 (210.3), seed yield plant-1 (31.15 g), test weight (15.35 g), uptake of NPK and S (191.8, 24.9, 93.7 and 20.1 kg ha-1, respectively) and Zn, Fe, Mn and Cu (449.5, 1732.5, 662.0 and 152.6 g ha-1, respectively). Accordingly, B:C ratio was also highest (2.88) and least value (2.11) was recorded in 150 per cent RDF. There was significant improvement in protein (38.05 %) and oil (18.83 %) contents in seeds. The residual nitrogen and potassium status in soil at 40 DAS and at harvest were significantly higher in SSNM targeted yield of 35 q ha-1 compared to other treatments except yield target of 30 q ha-1 under SSNM while the residual phosphorus content in soil was higher in 150 per cent RDF followed by 125 per cent RDF and target yield 35 q ha-1 under SSNM. Control recorded higher residual sulphur status in soil compared to others. Similar trend was observed in different fractions of NPK and S nutrients. Enzyme activities in soil at 50 DAS were significantly higher in 30 q ha-1 targeted yield of SSNM over other treatments except targeted yield of 35 q ha-1 under the same practice. Hence, yield maximization in soybean can be achieved through target yield of 30 q ha-1 under SSNM.
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    ThesisItemOpen Access
    Characterization and Mineralogy of Soils of Kavalur Sub-Watershed (4d4a2p) of Koppal District, North Karnataka
    (University of Agricultural Science, Dharwad, 2017-06) Anjali M.C.; Hebbara, Manjunatha
    An investigation was carried-out by University of Agricultural Sciences, Dharwad to characterize soils and study mineralogy of Kavalur sub-watershed of Koppal district, Karnataka during 2015-17. Twenty two soil pedons representing larger heterogeneity were studied for their morphological, physical and chemical properties. Nine typical pedons, each representing a different soil series were selected for assessing their mineralogical properties. The sub-watershed was nearly level with moderate erosion and drainage conditions. The soils were very shallow to very deep, sandy clay loam to clay in texture and weak to moderate sub-angular blocky structure with many fine roots distributed in surface horizons. The soil consistency was predominantly hard when dry, friable when moist, moderately sticky and moderately plastic when wet. The BD, MWHC and COLE values were higher in black soils as compared to red soils and increased with depth. The pedons were slightly alkaline to alkaline in reaction and non-saline while organic carbon content was low to medium (1.56 to 5.80 g kg-1). The black soil pedons contained more free CaCO3 (58.5 g kg-1) than red pedons (23.4 g kg-1). The cationic dominance was in the order of Ca2+>Mg2+>Na+>K+. The black soil pedons had higher CEC, base saturation and ESP than red soil pedons. Taxonomically, the soils of the study area were classified under the orders Entisol, Inceptisol, Vertisol and Alfisol. The mineralogical composition of sand fraction of soils was dominated by quartz followed by feldspar, olivines, biotite mica and pyroxenes. Quartz followed by mica and feldspar as primary and smectite followed by vermiculite and kaolinite as secondary minerals dominated in silt fraction. Kaolin was dominant among secondary clay minerals followed by smectite in red soil pedons. Kaolin content decreased with depth while, smectite content increased with depth. The black soil pedons showed higher content of smectite than kaolin.