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2013 - 20183
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Author: Navneet Kaur × End date: 2018 × Start date: 2010 × Type: Thesis × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Physico-chemical studies on synthesized graphene oxidemagnesium ferrite based nanocomposites and their adsorption potential for Ni (II) ion
    (Punjab Agricultural University, Ludhiana, 2018) Navneet Kaur; Manpreet Kaur
    Role of magnetic nanocomposites for the remediation of waste-water is a thrust area of research. In the present study, hybrid graphene oxide (GO) based inverse spinel magnesium ferrite (MgFe2O4) nanocomposites (NCs) with bentonite/charcoal/chitosan were synthesized using facile sonication method. p-XRD patterns confirmed the presence of spinel ferrite phase in the NCs with the crystalline size 8-32 nm. FT-IR spectra displayed absorption bands corresponding to GO, MgFe2O4 NPs and bentonite/charcoal/chitosan in the NCs along with red shift of bands corresponding to C=O, C=C and O-H stretching. TGA confirmed higher stability of NCs over pristine GO. MgFe2O4 NPs imparted appreciable saturation magnetization to the NCs (4.03-11.10 emug-1). SEM and TEM revealed high porosity and immobilization of clusters of MgFe2O4 NPs onto GO sheets in the NCs. BET surface area of the NCs ranged from 58.34 to 165.29 m2g-1 and was markedly higher than pristine MgFe2O4 NPs. Removal of Ni (II) ions was studied by batch adsorption method. Langmuir, Temkin and Freundlich models were followed in perfect way. Maximum adsorption capacity from Langmuir model ranged between71.43-111.11 mgg-1 for NCs. Kinetic data fitted pseudo-second-order equation. Thermodynamic parameters revealed spontaneous and endothermic removal using NCs; whereas using GO the removal was exothermic. Percentage removal of Ni (II) was maximum for MgFe2O4 NPs and their binary NCs with GO. Effect of co-existing ions on Ni (II) adsorption was studied in Pb-Cd-Ni-Zn system. NCs possessed higher removal potential for Pb (II) as compared to Ni (II) due to the lower hydration energy of the former. For electroplating waste-water the optimum adsorbent dose required for complete metal ion removal was higher than that for spiked water because of presence of other interfering ions.
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    ThesisItemOpen Access
    Weed control in autumn sugarcane (Saccharum spp.) based intercropping systems
    (PAU, 2013) Navneet Kaur; Bhullar, M.S.
    The investigation entitled “Weed control in autumn sugarcane (Saccharum spp.) based intercropping systems” was conducted at The Students’ Research Farm, Department of Agronomy, Punjab Agricultural University, Ludhiana during 2010-11 and 2011-12. The soil was loamy sand, normal pH and EC, low in organic carbon & available N and medium in available P & K. Experiment I consisted of 3 cropping systems {sole sugarcane, sugarcane + gobhi sarson(1:1) and sugarcane + raya(1:2)} in main plots and 6 weed control treatments {pre emergence pendimethalin 0.562 kg & 0.75 kg ha -1 , pre emergence alachlor 1.25 kg & 1.875 kg ha -1 , two hand weeding (30 and 60 DAS) and weedy check}in sub plots with 4 eplications in a split plot design. Experiment II consisted of 4 cropping systems {sole sugarcane, sugarcane + cabbage (1:1); sugarcane + peas (1:2) and sugarcane + garlic (1:3)} in the main plots and six weed control treatments {oxyfluorfen 0.176 kg & 0.234 kg ha -1 PRE, pendimethalin 0.562 kg & 0.75 kg ha -1 PRE, hand weeding (30 & 60 DAS in cabbage and peas;30, 60 & 100 DAS in garlic) and weedy check} in sub plots replicated thrice in a split plot design. In autumn sugarcane and Brassicaspecies intercropping systems, gobhi sarsonandraya intercrops exhibited good weed smothering potentialand reduced the weed count and dry matter accumulation than sole sugarcane; rayawas more effective than gobhi sarson. The cane yield under gobhi sarson and raya intercropped sugarcane were similar to that of sole sugarcane during both the years; cane equivalent yield, net profit and benefit cost ratio under the intercropping systems were higher than sole sugarcane. The intercropping of rayaand gobhi sarsonin autumn sugarcane increased the net returns by ` 61,469 and ` 26,738 ha -1 , respectively, than sole sugarcane. Pendimethalin 0.75 kg and alachlor 1.875 kg ha -1 recorded effective control of weeds in these intercropping systems and increased the seed yield of gobhi sarson by 43.6 & 37.3 per cent and raya by 16.1 & 14.1 per cent, respectively than weedy check and were at par with hand weeding. The increase in net returns with the use of these herbicides varied from ` 1,775 to ` 16,406 ha -1 as compared with weedy check. In autumn sugarcane and vegetables intercropping systems, peas exhibited partial weed suppressing ability while cabbage and garlic did not show any weed suppressing ability; weed population and dry matter accumulation under these intercropping systems were similar to that of sole sugarcane during both the years. The cane yield under these intercropping systems were similar to that of sole sugarcane, however, cane equivalent yield, net returns and benefit cost ratio of intercropping systems were higher than sole sugarcane. Sugarcane + garlic intercropping recorded the highest gross, net returns and benefit cost ratio. Averaged over two seasons, the intercropping of garlic increased the net returns by ` 1,36,548 ha -1 than sole cane; the corresponding figures for peas and cabbage intercropping systems were ` 73,860 and ` 61,388 ha -1 . Oxyfluorfen 0.234 kg and pendimethalin 0.75 kg ha -1 recorded effective control of weeds in these intercropping systems and were at par with hand weeding and significantly increased yield of cabbage, peas and garlic than under weedy check. The herbicides use increased net returns by ` 11,459 to ` 36,263 ha -1 as compared with weedy check. The three herbicides at the dose tested were safe to the sugarcane and the intercrops. The herbicides only temporarily reduced the population of soil microbes on the day of application; it recovered within 15 days after application. The residues of pendimethalin and oxyfluorfen in the intercrops produce were below detectable limit.
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    ThesisItemOpen Access
    Simulating the yield of maize (Zea mays L.) under projected climate change scenarios in Punjab
    (Punjab Agricultural University, Ludhiana, 2016) Navneet Kaur; Sidhu, Prabhjyot Kaur
    The field experiment was conducted during kharif 2014 and 2015 at the Research farm, School of Climate Change and Agricultural Meteorology, PAU, Ludhiana to generate field data for the calibration and validation of the CERES-Maize model. Significantly higher plant height, leaf area index and dry matter accumulation were recorded by the maize cv. PMH 1 sown during 4th week of May which led to improved PAR interception as compared cv. PMH 2 and later sowing dates. During crop year 2015, due to lower temperature regimes, cv. PMH 1 sown during 4th week of May took more number of days to attain maturity as compared to cv. PMH 2, other sowing dates and crop year 2014. The superiority of the cv. PMH 1 over cv. PMH 2 was mainly due to longer crop duration by virtue of which it acquired better canopy architecture (more plant height and LAI) which was the main contributor towards better source to sink relation (more dry matter accumulation). This superiority was reflected in significantly higher yield attributing characters (cob length and girth, number and weight of grains per cob) and may be the reason for higher grain and biomass yield in cv. PMH 1 sown during 4th week of May as compared to other sowing dates and cultivar. The calibration and validation of the CERES-Maize model showed good agreement between the observed and simulated values with NRMSE value of 2.7 and 4.2 for anthesis and maturity respectively, and 19.7 and 17.6 grain yield and biomass yield respectively. The future simulated climatic data (temperature and rainfall) from the regional climate model viz. PRECIS (Providing Regional Climates for Impact Studies) for different agro-climatic regions, i.e. Zone II (Ballowal Saunkhri), Zone III (Amritsar, Jalandhar, Ludhiana and Patiala) and Zone V (Bathinda) of Punjab was corrected by deriving the correction factor using the difference method, Leander and Buishand method and modified difference method for the mid and end of 21st century under different SRES scenarios (A1B, A2 and B2 scenario). The analysis of the corrected data on the annual/seasonal/monthly basis revealed that we may experience hotter days and warm nights by the end of 21stcentury in Punjab. The study showed that the annual maximum and minimum temperature and rainfall by the end of 21st century are likely to increase by 2.2 to 4.6 °C, 3.5 to 6.0°C and 31 to 96 % respectively in agro-climatic zone II; by 3.0 to 6.4 °C, 3.1 to 6.5 °C and 12 to 87 % respectively in agro-climatic zone III and by 4.0 to 7.1 °C, 3.3 to 6.3 °C and 19 to 30 % respectively in agro-climatic zone V of Punjab state under various scenarios of climate change. The trend analysis of these parameters revealed there is positive linear increasing trend under different scenarios in the Punjab state. The simulation of CERES-Maize under projected climate scenarios showed the significantly decreasing duration and grain yield of maize crop in the state. The reduction in the maturity period and grain yield is more under the A1B and A2 scenario (high emission scenario) followed by B2 scenario (low emission scenario). In Punjab state, the years 2073, 2078, 2084, 2085, 2086, 2090, 2093, 2096 and 2097 under A1B scenario, years 2079, 2096, and 2097 under A2 scenario and year 2084 under B2 scenario may experience failure of maize crop (duration ≤ 70 days and grain yield < 500 kg/ha) by the end of 21st century. The higher temperatures under the A1B scenario may the cause behind more grain yield reduction as compared to other scenarios as the physiology of the crop is adversely affected under high temperature conditions.