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20213
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Subject: Soil Sciences × End date: 2021 × Start date: 2021 × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Effect of varying levels of boron and sulphur on yields and nutrient uptake of linseed and sunflower grown in a mollisol
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-12) Bungla, Prerna; Pachauri, S.P.
    The laboratory and greenhouse experiments were conducted in the micro-nutrient Laboratory and net house of Department of soil science, College of agriculture, GBPUAT, Pantnagar in the year of 2018-2019 to study the leaching behavior of B and S in the presence of either nutrient in soils of varying textures. In pot culture experiment, the effect of B and S application on yields, nutrient concentration and uptake of B and S by linseed and a residual crop of sunflower. Two soils of different textures i.e. sandy loam and clay loam were collected from different depths (0-15, 15-30, 30-45, 45-60 and 60-90 cm) in NBCRC, Pantnagar. These soil samples were packed depth-wise in plastic pipes of 1 inch diameter and 110 cm length. All columns were packed with slightly moist soil at natural bulk density. The lower most pipe was covered with a perforated polythene sheet tied with tight rubber band. Boron and S sources were added as borax and ammonium sulphate (2 mg B kg-1 and 60 mg S kg-1) to the uppermost layer of soil. Soil columns were subjected to 6 cm irrigation at specified time intervals. Boron and sulphur were analyzed in the percolated water samples every 24 h until leaching stopped. Relatively higher amounts of B were lost from the sandy loam soil than clay loam soil and S application delayed the leaching loss of B in sandy loam soil. The kinetics of B and S losses in both the soil could be satisfactorily accounted by a first order kinetics. Pot culture experiment was laid out in a factorial completely randomized design with combinations of six levels of boron (0, 0.5, 1.0, 1.5, 2.0 mg B kg-1 soil and 2 foliar sprays of 0.2% borax at 30 and 45 DAS) and six levels of sulphur (0, 10, 20, 30, 40 and 60 mg S kg-1 soil) with three replications. Linseed (cv. Neelum) and a residual crop of sunflower (cv. Shresta) were taken as test crops and all the treatments were basally applied to linseed only. Two foliar sprays of 0.2% borax were done in sunflower crop at 30 and 45 DAS. The highest total dry matter (6.45 g pot-1), seed yield (2.30 g pot-1), stover yield (4.16 g pot-1), S concentration, B uptake and S uptake was observed under a treatment combination receiving 2 mg B and 60 mg S kg-1 soil. The highest B concentration in seeds and stover of linseed was observed under a treatment combination receiving foliar spray of B and 60 mg S kg-1 soil. The highest total dry matter (48.81 g pot-1), seed yield (13.69 g pot-1) and stover yield of sunflower (35.12 g pot-1) was recorded under a treatment combination receiving 2 mg B and 60 mg S kg-1 soil applied to linseed crop. The highest B concentration in seeds and stover and highest concentration of S in stover of sunflower was noted under a treatment combination receiving foliar spray of B in sunflower and 60 mg S kg-1 soil applied to linseed crop. The highest B uptake of sunflower was recorded under a treatment combination receiving two foliar sprays of 0.2% borax and 60 mg S kg-1 soil applied to linseed crop. The highest S uptake by sunflower was observed under a treatment combination receiving 2 mg B and 40 mg S kg-1 soil applied to linseed crop.
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    ThesisItemOpen Access
    Studies on mesoporous nanosilica and reduced graphene oxide as anocomposites of iron and zinc and their effects on growth, yield of crops and soil quality in mollisols of sub Himalayan region
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-08) Durgude, Shubham Anil; Shri Ram
    Synthesis of nanocomposites, characterization and pot culture studies were conducted for evaluate of mesoporous nano silica (mNs) and reduced graphene oxide (rGO) based nanocomposites of iron (Fe) and zinc (Zn) with rice and wheat crops in zinc deficient alluvial soils belonging to the mollisols of sub-Himalayan region. This greenhouse experiment includes fifteen treatments consisted T1:Absolute control, T2: Control / NPK – Zn, - Fe (no zinc & iron applied), T3:NPK + ZnSO4 ( 20 Kg/ha) + FeSO4 (5 kg/ ha) Basal (Silica/Graphene applied in maximum quantity), T4: NPK + 10 ppm Zn (mNs) + 1 ppm Fe (mNs) Foliar, T5:NPK + 20 ppm Zn (mNs) + 3 ppm Fe (mNs) Foliar, T6: NPK + 30 ppm Zn (mNs) + 5 ppm Fe (mNs) Foliar, T7:NPK + 1 ppm Zn (mNs) + 0.5 ppm Fe (mNs) Soil application, T8:NPK + 2 ppm Zn (mNs) + 1 ppm Fe (mNs) Soil application, T9:NPK + 5 ppm Zn (mNs) + 2 ppm Fe (mNs) Soil application, T10: NPK + 10 ppm Zn (rGO) + 1 ppm Fe (rGO) Foliar, T11:NPK + 20 ppm Zn (rGO) + 3 ppm Fe (GO) Foliar, T12:NPK + 30 ppm Zn (rGO) + 5 ppm Fe (rGO) Foliar, T13:NPK + 1 ppm Zn (rGO) + 0.5 ppm Fe (rGO) Soil application, T14:NPK + 2 ppm Zn (rGO) + 1 ppm Fe (rGO) Soil application and T15:NPK + 5 ppm Zn (rGO) + 2 ppm Fe (GO) soil application in completely randomized block design (CRD) with three replications. Synthesis and characterization of nanocomposites conducted in Nanotechnology unit, College of Basic Science and Humanities, G.B Pant University of Agriculture and Technology, Pantnagar and Indian Institute of Technology, Bombay (Maharashtra) respectively. The characterization revealed successful synthesis of wanted nanocomposites through physico-chemical dimensions with average particles size ranging between 30-80 nm. Seed germination study showed that different exposure levels of nano iron and zinc recorded remarkable increase in seed germination and vigour in rice and wheat. Application of mesoporous nano silica and reduced graphene oxide i.e. @30 ppm Zn + 5 ppm Fe showed better results as compared to all treatments. The column study revealed the slow release properties of prepared nanocomposites as compared to conventional fertilizers (iron sulphate and zinc sulphate). The mesoporous nanosilica based nanocomposites showed comparatively extended (slow) release pattern during 100 consecutive days of application as compared to conventional fertilizers of iron and zinc. In greenhouse studies, growth parameters, yield contributing characteristics, yields and nutrients uptake by rice and wheat crops were significantly higher with iron and zinc application as foliar through mesoporous nanosilica @ 30 ppm zinc and 5 ppm of iron over conventional fertilization. Application of @ 30 ppm zinc and 5 ppm through mesoporous nanosilica as foliar application recorded 53% increase rice yield and 20% increase wheat yield as compared to conventional fertilizer application of ZnSO4 and FeSO4. Significant increase in soil available zinc was observed with application of iron and zinc nanoparticles through mNs @ 5 ppm of zinc and 2 ppm of iron as basal application. Soil microbial population viz. bacteria, fungi and actinomycetes were significantly higher with application of iron and zinc nanoparticles through mNs @ 5 ppm of zinc and 2 ppm of iron as basal application. Dehydrogenase activity got severely reduced with application of nanoparticles of iron and zinc @ 5 ppm of zinc and 2 ppm of iron though reduced graphene oxide (rGO) as basal application. The quality of rice and wheat grains found increased positively in terms of test weight, total protein in rice and gluten in wheat with application of nanoparticles of iron and zinc @ 30 ppm zinc and 5 ppm through mesoporous nano silica (mNs) via foliar mode. The macronutrient viz. NPK use efficiency along with fertilizer use efficiency of iron and zinc nanofertilizers found significantly increased with application of nanoparticles of iron and zinc @ 30 ppm zinc and 5 ppm through mesoporous nano silica (mNs) as foliar when compared with conventional fertilizer application. Thus use of nanomaterials for making nanocomposites of iron and zinc are helpful to increase crop productivity along with grain and soil quality.
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    ThesisItemOpen Access
    Characterization of biochars prepared from different plant wastes and their use as source of micronutrients
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-02) Labanya, Rini; Srivastava, P.C.
    Six biochars were prepared from three different plant biomasses at two incineration temperature. They were characterized in the laboratory. A pot experiment was also conducted in the net house of Department of Soil Science, G.B.P.U.A.&T., Pantnagar to study the effect of different biochar addition and micronutrients + S doses on dry matter yield, nutrient concentration, nutrient uptake by hybrid Maize (Zea mays L., cv. NMH-589) and soil properties after maize harvest (60 d). Treatments imposed were six different biochars (0.5 t/ha) along with a control (no biochar addition) and four graded levels of different micronutrients+ S (equivalent to 0, 50, 75 and 100 percent) in an asymmetrical factorial completely randomized design with three replications. The present study revealed that biochars were highly carbonaceous residues and the properties of biochars change with the nature of source and also with the increase in the incineration temperature. The concentrations of Zn, Cu, Fe, Mn and B in the biochars were found to be significantly increased with the increase in the incineration temperature from 300 to 450 °C. The adsorption kinetics of micronutrients and S on biochars conformed best to the pseudo-first order kinetics. The concentration dependent adsorption-desorption studies of biochars revealed that they followed Freundlich isotherm model. An increase in incineration temperature significantly increased the adsorbed amount of Zn, Cu, Fe, Mn and B onto biochars but decreased the percent desorption of these micronutrients. The interaction effect of biochar source and incubation temperature had varying effects on adsorption and percent desorption of micronutrients and S. Pot experiment revealed that with application of wheat biochar (W300) and 75 percent of micronutrients+ S doses the highest dry matter yield was obtained. The Zn and Fe uptakes were found to be significantly influenced by the biochar addition, different micronutrients+ S doses and interaction effect of these two variables. Application of 50%, 75% and 100% micronutrients+ S doses significantly increased Mn and B uptake of maize. The interaction effect of biochar addition and application of different micronutrients+ S doses failed to significantly influence Cu, Mn, B and S uptake of maize crop. After the harvest of maize, higher soil pH and EC were recorded under biochar addition and different micronutrients + S doses. The soil organic C showed a significant but minor increase only under the application of the W300 biochar. The highest DTPA extractable Fe, Mn content and 0.15% CaCl2 extractable S content were recorded in treatment combination receiving P300 biochar with application of 100 % micronutrients+ S dose. Thus, biochar can be considered as a good source and carrier of micronutrients and S to improve maize biomass yield and the soil quality.