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20045
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Subject: Soil Science × End date: 2004 × Start date: 2004 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Influence of temperature on decomposition of wheat straw and nutrient release in mollisols
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2004-08) Joshi, Ganga; Mishra, B.
    A laboratory experiment was conducted to study the influence of temperature on decomposition of wheat straw and nutrient release in Mollisols. For this study representative samples of three soils viz. Phoolbagh clay loam, Haldi loam and Patherchatta sandy loam were taken and wheat straw was applied @ 4.544 g/kg soil. The soils were incubated at 15, 25 and 35°C for 90 days. The evolution of carbon dioxide from soils was measured quantitatively following the alkali trap method. The soils differed significantly with regard to CO2 evolution. Haldi loam showed the highest CO2 evolution while Patherchatta sandy loam recorded the lowest, irrespective of temperature. The rate of CO2 evolution from all the soils was highest during the first six days of incubation and lowest at the end of incubation period. The CO2 evolution at 35°C was significantly greater than at 25 and 15°C at all dates of observation. At the end of incubation period in Phoolbagh clay loam 24.6, 38.4 and 59.6 percent carbon from added wheat straw was lost at 15, 25 and 35°C, respectively. In Haldi loam the corresponding values of wheat straw carbon loss was 22.4, 37.9 and 52.7 percent and in Patherchatta sandy loam 21.1, 31.8 and 45.3 percent, respectively. Out of two mathematical models viz. power function model and first order kinetic model the power function model showed better fitness with wheat straw carbon loss data with lower RMSE and higher R2 values than first order kinetic model. The half life of wheat straw in Mollisols varied from 371 to 426 days at 15°C, 130 to 238 days at 25°C and 50 to 95 days at 35°C. After decomposition of wheat straw in soils available P and K content increased moderately whereas, the available N level decreased over initial level. The increase in available P and K of the soils due to wheat straw was more at 35°C than at 25 and15°C. It was concluded that decomposition of wheat straw in the soils was slow and temperature dependent. The rate of decomposition followed power function model. Available P and K status of the soils were moderately increased by wheat straw incorporation.
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    ThesisItemOpen Access
    Effects of nutrient management systems on potassium fractions and some soil properties under humid subtropical climate
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2004-01) Chander Pal; Singh, H.N.
    The study entitled as above was conducted on experimental plot, which has been under “All India Coordinated Research Project on Long Term Fertilizer Experiments” for the last 33 years at Pantnagar. Under these trails, the crop rotation being followed Since 1971 as Paddy-wheat-cow pea. Six profiles of more than 1 m depth i.e. (0-20, 20-41, 41-69, 69-96 and 96-120 cms. were opened to evaluate the effect of selected nutrient management systems viz. NPK+FYM, NPK, NP, N, control and natural fallow on potassium fractions and some soil properties of Aquic hapludoll soil. A comparision between cultivated (NPK+FYM, NPK, NP, N and control) and uncultivated (natural fallow) plots showed that use of chemical fertilizers lead to increase acidity, accumulation of salts, depletion of nutrients and deterioration of soil structure, ultimately leading to poor soil health. Among all the treatment, NPK+FYM application was found to have significant positive effect on potassium fractions viz. Water soluble, available , exchangeable, fixed, lattice and total potassium and some soil properties viz pH, electrical conductivity, cation exchange capacity, organic carbon and calcium carbonate equivalent. Thus use of chemical fertilizers in combination with FYM was found suitable for sustaining good soil health and crop production.
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    ThesisItemOpen Access
    Effect of INM on production potential of wheat and residual soil properties under maize-wheat cropping sequence in a mollisol
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2004-06) Dwivedi, Rama; Shri Ram
    A field experiment was conducted during the year 2002-2003 at the Crop Research Centre of G.B. Pant University of Agriculture and Technology, Pantnagar to study the effect of INM on production potential of wheat and residual soil properties under maize-wheat cropping sequences in a Mollisol. The experiment consisted of twelve treatments (T1 to T12) with three replications. Maximum values of growth parameters and yield attributing characters and yield were found with 100% of recommended dose of NPK fertilizers. Remarkably higher values of grain and straw yields and nitrogen, phosphorus and potassium uptake by succeeding wheat crop were observed under those treatments in which FYM @ 10 tonnes/ha was incorporated in combinations with biofertilizers and chemical fertilizers in comparison to treatments receiving chemical as well as biofertilizers alone in various combinations. Maximum grain (41.30 q/ha) and straw (68.67 q/ha) yield as well as nutrients uptake of wheat were found with the application of 100% NPK of recommended dose of fertilizers to both maize and wheat crops. Physical and chemical properties viz., soil organic carbon contents, bulk density, root density, water holding capacity etc. were improved with the treatments in which FYM @ 10 t/ha was incorporated alongwith chemical and biofertilizers as compared to application of chemical fertilizers alone in various combinations. Thus sustainable and economical productivity can be obtained by substituting a part of inorganic fertilizer and combined application of FYM, green manure, inoculation by Azotobacter and PSB which improve soil fertility and organic carbon status and simultaneously physico-chemical properties of soil.
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    ThesisItemOpen Access
    Chemical characterization of FYM-alkali extract and its efficacy evaluation as Zn-humate
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2004-07) Kar, Dipankar; Ghosh, D.
    The humic and fulvic acid fractions of humic substance extracted from well decomposed FYM were characterized after isolation, purification and lyopholyzation for oxygen containing functional groups and degree of humification (E4/E6). Potentiometric titrations were carried out with different organo metallic (Fe3+, Mn2+, Cu2+, Zn2+) complexes. The efficacy of Zn-organo complexes to supply Zinc was evaluated in a greenhouse experiment with maize crop. Fulvic acid contained more oxygen but less nitrogen and carbon than humic acid. Higher amount of oxygen containing functional group (COOH) resulted in more acidity (8.7 me/g) and exchange capacity of fulvic acid as compared to humic acid (6.1 me/g). Lower E4/E6 ratio of humic acid (7.19) than fulvic acid (9.67) indicated the more aromatic and condensed nature of humic acid. The potentiometric titration curves of different metal organo complexes followed the same order for both humic and fulvic acids. The drop in pH followed the order Fe3+>Cu2+>Zn2+>Mn2+ which indicated the order of their affinity in complex formation and stability index. Zinc concentration in plant increased with increasing Zn level and the highest Zn concentration was observed when Zn was applied as Zn-fulvate at the level of 10 mg Zn/kg. Dry matter production was increased with increasing Zn levels. The highest dry matter was produced when critical Zn concentration in plant reached 39 ppm which was reached at the level 10 mg Zn as ZnSO4, 5 mg Zn as Zn-humate, 2.5 mg Zn as Zn-humate-falvate and 1 mg Zn as Zn-falvate per kg soil.
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    ThesisItemOpen Access
    Effect of fertilizers, fym and microbial inoculants on growth and yield of fenugreek (Trigonella foenum-graecum L.) in a mollisol
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2004-06) Adak, Tarun; Sachan, R.S.
    Field experiments were conducted during Rabi, 2001-02 and 2002-03 to evaluate the effect of fertilizers, FYM and microbial inoculants on growth and yield of fenugreek (Trigonella foenum-graecum L.) in a Mollisol. The treatments replicated thrice in a randomized block design consisted of T1 (Control), T2 (30 : 60 : 40 N, P2O5 and K2O kg/ha), T3 (NPK + Sinorhizobium meliloti), T4 [NPK + PSB (Bacillus megaterium)], T5 (NPK+ Sinorhizobium + PSB), T6 (NPK+ Sinorhizobium + PSB +FYM @ 5.0 t, 30% moisture per hectare), T7 (50% N + 100% P+ 100% K + Sinorhizobium), T8 (50% N+ 67% P + 100% K + Sinorhizobium + PSB), T9 (25% N + 50% P + 75% K + Sinorhizobium + PSB + FYM @ 5.0 t, 30% moisture per hectare) and T10 (Sinorhizobium + PSB + FYM @ 15 t, 30% moisture per hectare). The effect of various INM treatments on yield attributing characters, yield, nutrient uptake and post harvest soil fertility indices were observed. The results conclusively established the positive role of various sources of nutrition in not only enhancing the growth and yield of fenugreek but also in contributing towards conserving the soil fertility, which in tern, may prove highly beneficial on a long-term basis. The highest seed yield was recorded in the treatment T2 (NPK) during the year 2001-02 and in T6 during 2002-03. The T6 treatment was found to be the best among other treatments regarding all growth parameters, test weight (12.13 and 13.14 g), uptake of total N (245.05 and 203.84 kg/ha), total P (12.89 and 10.67 kg/ha), total K (210.60 and 112.17 kg/ha) and micronutrient cations (Zn-0.19, Fe-1.16, Mn-0.17 and Cu-0.04 kg/ha respectively). Post harvest soil fertility status was also highest in the same treatment with organic carbon content (1.28 and 1.30%), available N (256.90 and 257.30 kg/ha), P (29.78 and 26.78 kg/ha), K (224.02 and 224.75 kg/ha) and micronutrient cations (0.95, 6.60, 10.10 and 1.88 mg/kg of Zn, Fe, Mn and Cu). The hypothesis of adjusting the recommended NP doses (to the extent of 15 kg N/ha and 20 kg P2O5/ha) with microbial inoculants (Sinorhizobium and PSB) was found to be correct. The production of comparable yield of fenugreek in this Mollisol, under the organic farming mode by raising the FYM dose to about 15 t, 30% moisture per hectare along with biofertilizers and without the addition of chemical fertilizers was also found to be feasible.