Browsing by Author "Jayant Kumar Lal"
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ThesisItem Open Access Characterization of soil hemic substances and meeting plant Nutrient Needs through Waste Recycling(Birsa Agricultural University, Ranchi, 1998) Jayant Kumar Lal; B. MisraThe present investigation was aimed to characterize the soil humic substances isolated from major soil series of Bihar plateau and to study the effect of incorporation of organic wastes on humification and mineralization of available nutrients. Field experiments were conducted to evaluate the effects of in incorporation of crop residues in situ on crop yields and soil proper tips. The determination of optical densities of humic acids ((HA) and fulvic acids (FA) at different wavelengths indicated that optical density decreased with increasing wavelengths. Considerable variation in optical density of humic acids and fulvic acids preparations derived from different soils was recorded. Eq/E ratio of fulvic acids of different soils were, in general, wider than that of humic acids. The highest E_{A} / E_{A} ratios of both HA and FA of soil was recorded at pH 6.0. Between the two dynamic fractions of organic matter humic acid dominated over fulvic acid in carbon content (23.87 to 36.38 per cent in humic acid and 16.57 to 27.25 per cent in fulvic acid). The lowest ratio of HA-C/FA-C (0.889) in Pusara soil was indicative of an advanced stage of oxidative decomposition and greater humification, while highest value (1.81) on Lachmipur soil was due to high condenation and aromatization. Total acidity of fulvic acids (7.59 to 10.38 m.e. a ^ - 1 ) of all the soils under study was higher than that of humic acids (6.44 to 8.91 m.e. g). Contribution of carboxylic group (32.12 to 45.75 per cent) in total acidity of fulvic acids was higher than that in humic acids (19.87 to 40.53 per cent) but reverse trend was observed in case of phenolic hydroxyl group. Analysis of organic wastes under study indicated that subabul leaves contained highest nitrogen (3.24 %) and calcium (4.4%) whereas waterhyacinth was rich in potassium content (2.89%). Ipomea tops and lentil straw contained the high Mg and S, respectively. Micronutrient analysis showed high 2n (160.72 mg g ^ - 1 ) and Cu (45.9 mg k * g ^ - 1 ) in Lantana tops, Fe (1863.20 mg kgin Ipomea tops and Mn in waterhyacinth (1071.98 mg forall k * o ^ - 1 , . Incubation studies indicated a significant increase in soil reaction, organic carbon content and microbial biomass in presence of crop wastes in soil. Mean C*D_{2} evolution was significantly higher during 0-30 days of incubation (1.884 g k * g ^ - 1 ) , indicating higher rate of decomposition duirng this stover treated soil followed by that in lentil straw. Humic acid- carbon decreased and fulvic acid carbon increased as incubation proceeds. Results further showed that incorporation of organic wastes increased the nutrient status of soil. Among the organic wastes, incorporation of subabul leaves released highest amount of available nutrient in soil. Field experiments revealed that in situ incorporation of crop residues significantly increased the grain and stover/straw yield of maize and wheat grown in sequence. The highest crop yields and nutrient uptake were recorded in the plot receiving 100% NPK+ crop residue. Apparent nitrogen) recovery and nitrogen use efficiency were higher in the treatment receiving both fertilizer and crop residues. Incorporation of crop residues enhanced the available. nutrient status of soil and microbial biomass and thus helped to sustain soil health with increased crop productivity. It is concluded that (1) There is greater humification and oxidative decomposition in upland light textured soil where as high condensation and aromatization takes place in forest soils of south Bihar, (ii) Organic wastes can serve as a potential source of plant nutrients and has capacity to ameliorate soil acidity to some extent, (111) It significantly increased organic carbon content, microbial activities and microbial population, (iv) In situ incorporation of crop residues significantly increased the crop yield and nutrient uptake as well as improved the soil physical, chemical and biological environment.ThesisItem Open Access Physico - Chemical And Microbiological Characterization of Fly Ash And Its Effect on Nutrient Uptake by Soybean Crop(Birsa Agricultural University, Ranchi, 1994) Jayant Kumar Lal; B. MishraThe present investigation was aimed to characterize the flyash obtained from different sources (Bokaro Steel Plant, Patratu Thermal Power Plant and Rourkela Steel Plant) and to quantify the growth performance and nutrient uptake by soybean (Glycine max L.) grown on soil amended with flyash. Apart from these, its effect on the soil environment was studied. Results indicate that flyash with high water holding capacity (MHC) and nutrient content could serve as a source of plant nutrients and as an amendment for acid soils. The WHC of flyash varied from 64 to 78 per cent, pH from 5.6 to 8.0 and organic carbon from 0.17 to 1.7 per cent. Besides these properties, fly ashes were rich in total as well as available P and K, but poor in nitrogen. It was also poor in microbial population compared to that in native soil. A pot experiment was conducted with soybean in an acid upland soil (pH 4.9) amended with five levels of Bokaro flyash (0, 4, 8, 16 and 32 per cent) and 100% level of fly ash. The results show that maximum dry matter yield of soybean plants 15 days of sowing was at 4% level of flyash(0.255g plant-1).