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Subject: Soil Science × Start date: 2020 × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    ASSESSMENT OF SOIL QUALITY AND NUTRIENT DYNAMICS UNDER CONVENTIONAL AND PROTECTED AGRICULTURE
    (CSKHPKV, Palampur, 24-07-18) Shabnam; Sharma, Sanjay K.
    Protected cultivation is gaining momentum especially for vegetable cultivation in Himachal Pradesh. Therefore the present study was undertaken to assess the soil quality inside polyhouses vis a vis under conventional cultivation so as to ascertain the effect of intensive cropping and the management practices being followed by farmers under these two systems. The main objectives of this study were to assess the effect of conventional and protected systems of farming on soil quality and to study N, P and K dynamics under conventional and protected systems of farming. To accomplish this, 25 sites of district Kangra were selected. All the required physical, chemical and biological parameters of soil quality were analysed and key indicators were identified using multivariate statistical analysis for computing the soil quality index. Wide variations in the soil health indicators were observed among different sites. Likewise, differences existed in the quality indicators between the samples from the protected and open conditions at number of sites. Higher salt accumulation (EC) was observed under protected conditions as compared to conventional system, though the differences in other properties were only conspicuous for some of the parameters. Among different nitrogen fractions, amino acid-N was the dominant fraction and contributed about 25 and 30% towards total-N and total hydrolysable-N, respectively. In case of P fractions, inorganic fractions constituted about 84.2% of total P. Water soluble-K, Exchangeable-K and non exchangeable-K contributed about 0.12, 0.59 and 3.05% towards total-K, respectively. As per multivariate statistical analysis techniques,organic carbon (OC), soil pH, EC, MWD and total K were found to be the most important indicators contributing towards soil quality.The mean soil qualityindex (SQI) values in Baijnath, Bhedu-Mahadev, Bhawarna, Kangra and Dharamshala blocks were 0.852, 0.816, 0.722, 0.823 and 0.794, respectively under protected cultivation. Similarly the SQI for the respective sites was computed as 0.762, 0.741, 0.759, 0.765 and 0.773 under conventional system. Overall significantly higher soil quality index was observed under protected system (0.815) as compared to the conventional cultivation (0.760). However, at two sites SQI score was lower under protected conditions than conventional cultivation. Higher gross returns were observed under protected system as compared to conventional system due to comparatively higher production. Also higher concentrations of macro as well micronutrients were observed in plant samples grown under protected system.
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    ThesisItemOpen Access
    STUDIES ON THE DISTRIBUTION OF BORON FORMS IN SOME CULTIVATED SOILS OF HIMACHAL PRADESH
    (CSKHPKV, Palampur, 24-07-18) Nazir, Gazala; Sharma, V.K.
    Understanding the spatial distribution of various forms of boron in soils helps in predicting its short- and long-term availability for sustainable crop production. In the present investigation, 202 surface soil samples, representing major soils (Alfisols, Entisols & Inceptisols) and land use types were collected from Outer and Lesser Himalayan regions of Himachal Pradesh to study the spatial distribution of B forms vis-à-vis their relationship with important soil properties. The soil samples were collected at 0-15 cm depth from cultivated soils under maize-wheat, paddy-wheat, vegetable-based & sugarcane-based cropping sequences and at 0-30 cm depth from tea gardens & orchards of mango, mandarin, apple etc. and analyzed for important soil properties and B forms using standard methods. The depth-wise distribution of those soil attributes and B forms (at 0-15, 15-30 & 30-60 cm) was also studied in the selected soils. Sand (%), silt (%), clay (%), textural class, soil pH (1:2.5), electrical conductivity (μS cm-1), organic carbon (g kg-1), cation exchange capacity {cmol(p+) kg-1}, base saturation (%) and calcium carbonate (%) in cultivated soils of Himachal Pradesh ranged from 25 to 80, 12 to 45, 6 to 32, loamy sand to clay loam, 5.2 to 7.8 (slightly acid to slightly alkaline), 40 to 372, 2.8 to 22.0, 4.1 to 16.4, 48 to 77 and 0.05 to 2.20, respectively. As regards available nutrient status, soils were medium in available N & K, low in available P & S, high in available Ca & Mg, sufficient in available Cu, Fe & Mn and deficient to sufficient in available Zn and B. Per cent soil samples deficient in N, P, S, Zn and B were 18, 45, 44, 36 and 55, respectively. Such a spatial variation in soil properties and fertility status may be explained in the light of pedo-genesis and prevailing nutrient management practices. Water soluble, exchangeable, specifically adsorbed, oxide occluded, organically bound, residual and total boron in cultivated soils ranged from 0.104 to 0.389, 0.128 to 0.393, 0.215 to 0.680, 0.567 to 2.13, 0.79 to 2.65, 20.04 to 53.16 and 22.0 to 59.14 mg kg-1 with mean values of 0.218, 0.231, 0.402, 1.26, 1.46, 34.09 and 37.67 mg kg-1, respectively. On an average, water soluble, exchangeable, specifically adsorbed, oxide occluded, organically bound and residual B constituted about 0.58, 0.61, 1.07, 3.34, 3.86 and 90.6 per cent of total B, respectively. As regards depth-wise distribution, surface soils were found rich in available and potentially available reserves of B as compared to sub-surface soils. Irrespective of land use types and soils, there were significant and positive correlations between different chemical pools of B, indicating the existence of dynamic equilibrium among them. Among all soil properties, clay, organic carbon and cation exchange capacity exhibited better correlations with each form of B. The step-wise multiple regression analysis showed that organic carbon contributed largely to different pools of boron. Soils deficient in available B had lower content of each form of B as compared to those, sufficient in available B. Further, soils with lower values of clay, organic carbon and cation exchange capacity contained less amount of soil B in each pool as compared to soils higher in these soil attributes. Therefore, former soils require relatively more attention on B mangement as compared to latter ones for sustaining soil productivity.
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    ThesisItemOpen Access
    STUDIES ON NITROGEN CONTRIBUTION IN RICE GROWN UNDER SYSTEM OF RICE INTENSIFICATION
    (CSKHPKV, Palampur, 25-07-17) BAKTASH, ABDUL MATEEN; Datt, Naveen
    Azolla was grown in pots and trays in the month of February, 2016 under laboratory and field condition. Azolla was also grown in the field by making trenches (2m × 2m × 0.2m) in the month of March, 2016 and was evaluated for its biomass production in the subsequent months up to October, 2016 and has a potential of 19 t ha-1 and was also analyzed for manurial content. Azolla has nitrogen fixation rate (13.94 n moles C2H4g-1 Dwt min-1), total carbon (35 %), and total nitrogen (4.1 %), C: N ratio (9.56), protein content (25.62 %), P (1.1 %), K (4.5 %), Ca (0.20 %), Mg (0.21 %) ,S (0.49 %), Zn (38 mg kg-1), Fe (3900 mg kg-1), Mn (762 mg kg-1) and Cu (16 mg kg-1). An experiment was conducted at Water Management Farm, CSKHPKV, Palampur by taking rice crop during kharif, 2016 to study the effect of Azolla alone and in combination with graded doses of fertilizer nitrogen by taking twelve treatments and three replications in randomized block design. The soil sample before sowing of crop was taken and was analyzed for physical, chemical and microbiological properties. The representative soil was having texture silty clay loam, pH 5.5, cation exchange capacity 8.50 cmol (p+) kg-1, organic carbon 8.70 g kg-1, available N, P and K 377.5 kg ha-1, 17.8 kg ha-1 and 159.5 kg ha-1 respectively, microbial biomass carbon 113.6 μg g-1, urease activity 4.12 μg g-1 min-1 and phytase activity 0.34 μg inorganic P solid g-1 hr-1. The yield attributes of the crop were recorded, highest plant height was found in 50 kg N ha-1 + 8 t Azolla, number of tillers m-2 125 kg N ha-1 + 8 t Azolla and effective tillers m-2 were observed in treatment having 100 kg N ha-1 + 8 t Azolla and highest grains per panicle was recorded in treatment having 125 kg N ha-1 +4 t Azolla. The highest grain and straw yield was recorded in treatment having 125 kg N ha-1 + 8 t Azolla. After the harvest of crop, soil samples from each plot were taken from the depth of 0-0.15 m and analyzed for chemical, microbiological and physical properties of soil. The results revealed that an increase in pH (5.57) was observed with application of Azolla and fertilizer nitrogen combinedly. Maximum organic carbon (8.90 g kg -1) and the highest CEC [8.73 cmol (p+) kg-1] were found in treatment 125 kg N ha-1 + 8 t Azolla 1; available N (402.8 kg ha-1), P (18.87 kg ha-1) and K (169.4 kg ha-1) were recorded in treatment 125 kg N ha-1 + 8 t Azolla. Highest microbial biomass carbon (113.6 μg g-1) was found in treatment 125 kg N ha-1 + 8 t Azolla. Phytase (0.68 μg inorganic P solid g-1 hr-1) and urease (17.34 μg g-1 min-1) activity was significantly higher in treatments with 4 t or 8 t Azolla in combination with graded doses of fertilizer nitrogen than fertilizer nitrogen alone and 4 t Azolla alone. Total N, P, K content and NPK uptake was found maximum in the treatment 125 kg N ha-1 + 8 t Azolla. Build up of N was found in the treatments having 4 t Azolla, 8 t Azolla, whereas K build up was found in 100 and 125 kg nitrogen, 4 t Azolla, 100 kg N ha-1 + 4 t Azolla and 125 kg N ha-1 + 4 t Azolla . It was concluded that 50 and 100 kg of nitrogen ha-1 can be saved with the application of 4 t and 8 t Azolla ha-1. ________________________ _____________________ (Abdul Mateen Baktahs) Student Date: 25th,July, 2017 (Dr. Naveen Datt) Major Advisor Date: 25th,July, 2017 ___________________ Head