Browsing by Author "Prakash, N. B"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
ThesisItem Open Access CHARACTERIZATION AND UTILIZATION OF DIFFERENT SILICON SOURCES FOR RICE (Oryza sativa L.)(UNIVERSITY OF AGRICULTURAL SCIENCES GKVK, BENGALURU, 2016-04-04) SANDHYA, T.S; Prakash, N. BDifferent Si sources used in this study varied greatly in their physico - chemical properties and behavior in acidic, neutral and alkaline soils. Total Si content of the Si sources ranged from 2.20 - 34.84 per cent and alkalinity to Si ratio (A/Si) ranged from 1.29- 9.08. The relative Si extracted by various extractants irrespective of Si sources was in the order of HCl + HF (112.13 %) > 0.5 M HCl (79.22 %) > 5 % citric acid (55.51 %) > 0.5 M acetic acid (51.95 %) >0.005 M H2S04 (42.56 %) > NaOAc (33.58 %) > 0.5 M N&OAc (29.30 %) > 40mM P buffer (28.34 %) > Na2C03 + N& N03 - l (21.98 %) > Na2C03 + NH4 N03 - 2 (19.32 %) > distilled water - 2 (11.94 %) > 0.01M CaCh (4.80 %) > distilled water - 1 (3.52 %). Si extracted from different Si sources with Na2C03+ N&NOr 2 method noticed higher correlation with total Si uptake by rice treated with Si @ 250 and 500 kg Si ha-1 in all the three soils. Application of Si sources significantly increased both CaCh and acetic acid extractable Si in all the three soils. 0.01M CaCh extractable Si was found to be the ideal measure for plant available Si in soils treated with different Si sources. In acidic and neutral soil, significant correlation was obtained between R- PASc (relative increase in plant available Si) and RUSic (relative uptake of Si) at 60 DAI (r = 0.660** and 0.693** respectively). In alkaline soil, significantly high correlation was obtained at 120 DAI (r = 0.732**). Similar trend was obtained with R- PASc and relative uptake in these soils. Application of calcium silicate and rice hull @ 500 kg Si ha-1 in field experiments recorded the highest grain and straw yield in acidic and alkaline soils respectively.ThesisItem Open Access CHARACTERIZATION OF BIOCHAR, NUTRIENT RELEASE AND ITS EFFECT ON GROWTH AND YIELD OF AEROBIC RICE(UNIVERSITY OF AGRICULTURAL SCIENCES GKVK, BENGALURU, 2015-10-10) AKSHATHA, M. K.; Prakash, N. BAn experiment was conducted to characterize biochar, nutrient release and its effect on growth and yield of aerobic rice at UAS, GKVK, Bengaluru in 2014. Three different biochars viz., wood (WB), bamboo (BB) and rice husk biochar (RHB) and four levels of application (2, 4, 8 and 16 t ha-1) were the treatments. An incubation study was conducted to know the nutrient and Si release from different biochars in acidic, neutral and alkaline soil at field capacity moisture regime. Among different sources, application of WB recorded higher pH and exchangeable bases while RHB recorded higher available P2O5 and 0.01 M CaCl2 - Si in all soils. Independent of biochar type, increased rate of application increased the pH, available P2O5, exchangeable bases and 0.01 M CaCl2 - Si content of soils. Significant decrease in DTPA extractable Fe and Mn were observed with application of WB in acidic and neutral soil while with RHB in alkaline soil. In a pot culture study, significantly higher yield of straw and grain were recorded with the application of RHB @ 8 and 4 t ha-1 in acidic and neutral soil, respectively while WB @ 4 t ha-1 in alkaline soil. Si and other nutrients content in straw and grain increased with application rates of biochar. With the application of different sources and levels of biochar in different soils, yield responses of straw and grain ranged from -36.56 to 55.18 per cent and -51.00 to 46.47 per cent respectively.ThesisItem Open Access EVALUATION OF DIFFERENT DIATOMITE COMPOUNDS ON SOIL PROPERTIES, GROWTH AND YIELD OF AEROBIC RICE(UNIVERSITY OF AGRICULTURAL SCIENCES GKVK, BENGALURU, 2015-11-04) ANITHA, M. S; Prakash, N. BAn incubation, green house and field experiments were conducted to know the effect of different grades (DE-1, DE-2, DE-3, DE-4 and DE-5) and levels (250, 500, 750, 1000 and 1500 kg ha-1) of diatomite (DE) on soil properties, growth and yield of aerobic rice in acidic (Hassan) and alkaline (Mandya) soil. The study revealed that, there was a significant increase in pH of acidic and decrease in pH of alkaline soil compared to control irrespective of application rates of DE under field capacity was recorded over the incubation period. Among the different grades, DE-3 and DE-4 recorded significantly higher acetic acid-Si and CaCl2-Si content at 30 days after incubation in both the soils. Irrespective of different grades of DE, increased rate of application increased the N, P2O5, K, Ca, Mg and S in both the soils. In a pot culture experiment, significantly better performance of rice, increase in the availability and uptake of Si by rice was noticed with the application of DE-4 @ 750 kg ha-1 and DE-4 @ 1000 kg ha-1 in acidic and alkaline soil, respectively. The results of field experiment revealed that, application of DE-4 @ 750 kg ha-1 and DE-3 @ 500 kg ha-1 recorded higher yield of aerobic rice at Hassan and Mandya, respectively. Application of DE-3 @ 500 kg ha-1 and DE-4 @ 750 kg ha-1 recorded higher content and uptake of Si and all other nutrients by rice straw at both the locations. Lower BD and high percentage of maximum water holding capacity and water stable aggregate were recorded with the application of DE-3 @ 500 kg ha-1 at Hassan and DE-4 @ 500 kg ha-1 at Mandya. In a green house with moisture stress experiment, application of DE-4 @ 300 kg ha-1 at 100 per cent FC recorded significantly higher straw weight and leaf relative water content, decreased proline content and electrolyte leakage in both acidic and alkaline soil. Treatment receiving DE-4 @ 300 kg ha-1 at 100 per cent FC recorded higher content and uptake of Si and other nutrients by rice straw in both the soils compared to 100 and 50 percent FC alone.