Please use this identifier to cite or link to this item: http://krishikosh.egranth.ac.in/handle/1/5810041685
Authors: SANDHYA, K.
Advisor: Prakash, N. B.
Title: BIOGEOCHEMISTRY OF SILICON IN DIFFERENT RICE ECOSYSTEMS OF KARNATAKA
Publisher: UNIVERSITY OF AGRICULTURAL SCIENCES GKVK, BENGALURU
Language: en
Type: Thesis
Pages: 318
Agrotags: null
Abstract: In order to understand biogeochemistry of silicon (Si), plant available Si (PAS) content was analysed in soils of different agro climatic zones of Karnataka besides conducting pot and field experiments to know the efficacy of different sources of Si and its bioavailability in rice ecosystem. Plant available Si content ranged from 1.41-82.89 mg kg-1 as extracted by calcium chloride (CCSi) and 6.69-370.24 mg kg-1 as extracted by acetic acid (AASi). Pearson’s correlation coefficient worked out for soil analytical data revealed a significant positive correlation between PAS and soil pH, silt, clay, cation exchange capacity and negative correlation with sand content. XRay Diffraction analysis of the soil samples revealed the presence of quartz, feldspars, amphibole, phyllosilicates as primary minerals and smectite, kaolinite, illite, vermiculite as clay minerals in various proportions. AASi was positively correlated with Al2O3, Fe2O3, MnO and TiO2 demonstrating the extractant assessed the fraction of Si adsorbed on the surface of oxides or oxy-hydroxides and clays while, CCSi for immediate dissolved Si. Application of diatomite @ 300 kg ha-1 significantly increased the grain yield and numerical increase in other yield attributes in the field experiment. Budgeting of Si in a rice ecosystem revealed that majority of the biogeochemical cycle of Si was controlled by uptake, dissolution and contribution by irrigation water. Bioavailability of Si for rice in acidic, neutral and alkaline soil revealed that application of calcium silicate, diatomite and rice husk biochar significantly increased the yield parameters. Higher Si uptake was noticed in neutral soil followed by acidic and alkaline soil. In acidic and neutral soil, application of calcium silicate significantly increased the nutrient status of soil whereas rice husk biochar in alkaline soil and justifies the variability in reactivity of the sources in different soils rather than total Si content.
Subject: Soil Science and Agriculture Chemistry
Theme: BIOGEOCHEMISTRY OF SILICON IN DIFFERENT RICE ECOSYSTEMS
These Type: Ph.D
Issue Date: 29-12-12
Appears in Collections:Theses

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