PG Thesis
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Item Characterisation of soil organic matter in different soil types of Kerala(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 1982) Usha, P B; Jose, A ILarge number of surface soils representing the different districts of the state were analysed in order to work out precise relationships between organic carbon, total nitrogen and available nitrogen in these soils. The soils were categorized into different groups based on soil texture and content of organic matter. Relationships between different soil properties applicable to the different categories of soil were then examined. Fractionation of soil organic matter was carried out in a limited number of soils. Also the distribution of elemental components of soil organic matter was studied in soils selected for the fractionation of organic matter. Observations on the general characteristics of soil revealed that the content of organic carbon, total nitrogen and available nitrogen showed an increasing trend with increase in acidity of soil. In general more organic carbon was seen in fine textured soils. The total and available nitrogen content of soil increased with increase in content of organic matter. The content of available nitrogen showed significant and positive correlation with total nitrogen. Since the C/N ratio increased with increase in content of organic carbon it was necessary to predict the total and available nitrogen content of soil based on precise regression equations rather than depending on a conversion factor. On an average 10.82 per cent of the nitrogen in soil was extracted as available nitrogen. The C/aN ratio was positively and significantly correlated with organic carbon and total nitrogen while it was negatively correlated with available nitrogen. On an average the percentage of humic acid, fulvic acid and humin in soil organic matter were 28.28, 36.51 and 35.21 respectively. Of the 28.28 per cent humic acid, 9.60 per cent (of organic matter) was represented by hymatomelanic acid and the remaining 18.68 per cent by the insoluble fraction of humic acid. Humic acid was found to be significantly and positively correlated with total organic carbon, total nitrogen, clay and fulvic acid. Of the total fulvic acid 12.35 per cent (of organic matter) was represented by beta humus and the remaining by the soluble fraction of fulvic acid. Fulvic acid was positively and significantly correlated with organic carbon, total nitrogen, humic acid and clay. Humic acid and fulvic acid maintained a constant proportion irrespective of the variation in content of total organic matter. Humin was also positively and significantly correlated with organic carbon and total nitrogen. The mean phosphorus, sulphur and potassium content of organic matter were 0.051, 6.96 and 0.32 per cent respectively. The C/org.P, C/org.K, C/org.S, N/org.P, N/org.K, N/org.S, Org.P/org.K, Org.P/org.S and Org.K/org.S ratios were 1672.8, 94.1, 19.23, 205.81, 9.77, 2.91, 0.07, 0.008 and 0.0073 respectively.Item Utility of an indigenous source of magnesium silicate for rice in Kuttanad soils(Division of Agricultural Chemistry, Agricultural College and Research Institute, Vellayani, 1980) Karunakara Panicker, N; Gopalaswami, VA field experiment was conducted at Kavalikari padom, Changanacherry, Kuttanad tract, to investigate the effect of 'Steatite' (Magnesium silicate) on the growth and yield characters of rice in Kuttanad soils. The samples of grain and straw from the experiment were analysed for the contents of N, P, K, Ca, Mg and Si; and the uptake of nutrients per plot computed. The influence of the treatments on the grain shattering character of Jyothi variety; incidence of pests and diseases etc., were also studied. The following results were obtained. Steatite application increased tillering and plant height. The yield of grain and straw showed increase. The increase was statistically significant at five per cent level in the case of 400 kg/ha treatment. The thousand grain weight increased significantly in all the four levels of treatments over control. The treatments resulted in decreasing the N. P. K and Ca content of grain and straw , while Mg and S1 content increased with increasing levels of the treatment.Item Assessment of nitrification rate of Kerala soils and agronomic factors influencing it(Department of Agronomy, College of Horticulture, Vellanikkara, 1989) Marykutty Zacharias; Vikraman Nair, RThe present study 'assessment of nitrification rate of Kerala soils and agronomic factors influencing it' was conducted during June 1987 to November 1988 at the College of Horticulture, Vellanikkara, Trichur. A series of laboratory incubation studies were conducted using a total of 22 soil samples including 20 samples drawn from five soil types (laterite red, alluvial, forest and black soils ) of Keralaand two from Coimbatore (red and black). The presence of Nitrosomopas was observed in 11 soil samples and that of Nitrobacters in all soil tested. The nitrification rate was high for alluvial and black soils and low for the red laterite soils.Item Morphological and Physico-chemical properties of the kayal soils of Kuttanad, Kerala State(Division of Agricultural Chemistry, College of Agriculture, Vellayani, 1975) Gangadhara Menon, P K; Aiyer, R SA study made on the morphological and physico-chemical characteristics of the kayal profiles of the Kuttanad region of Kerala revealed the following salient features. (1) These soils are classified under the order- ENTISOL, Sub order- Aquent and great group- Hydraquent according to the seventh Approximation. (2) Texturally they are classified mostly as silty loan or sandyclay loan, fine sand being the dominating fraction in all the profiles and layers. Only the surface soil of the Chithira kayal profile is clayey in texture with a maximum of 36.5 per cent clay. (3) The physical characteristics of the two profiles from the Rani kayal vary widely. While the profile 1 shows a decrease in clay content with increase in depth, the second profile shows a reverse trend for clay as well as fine sand. Fine sand is maximum in the middle layer of profile 1.Item Influence of Calcium and Magnesium in increasing the efficiency of fertilisers for rice and Calcium and Magnesium status of some typical rice soils of Kerala(Division of Agricultural Chemistry, Agricultural College and Research Institute, Vellayani, 1963) Thomas Varghese; Subramoney, NItem Effect of long term application of manures and fertilisers on soil properties, utilization efficiency of nutrients and quality of rice(Department of Soil Science and Agricultural Chemistry,College of Horticulture, Vellanikkara, 1992) Padmam, M K; Chinnamma, N PA study was conducted during the first crop season of 1990to assess the effect of long term application of manures and fertilizers on soil properties, utilization efficiency of nutrients and quality of rice making use of the soil and plant samples taken from the existing permanent manurial trial (dwarf indica) at the Regional Agricultural Research Station, Pattambi. This experiment was started at Pattambi during the first crop season of 1973. The soil of the experimental site is laterite. The experiment is laid out in randomised block design with four replications and eight treatments. The treatments consisted of application of entire quantity of N - 90 kg ha 1, as organic alone (cattle manure alone, .green manure alone and cattle manure + green manure) , inorganic alone (ammonium sulphate alone and NPK fertilizers) and a combination of organics with inorganics (cattle manure + NPK fertilizers, green manure + NPK fertilizers and cattle manure + green leaves + NPK fertilizers). Soil samples were collected from all the replications of the various treatments before planting, at different stages of crop growth viz., tillering, panicle initiation, 50 per cent flowering and harvest. Plant samples were also collected at the above growth stages. Data on yield of grain and straw were collected from the Regional Agricultural Research Station, Pattambi. Soil and plant samples were analysed in the laboratory to find out the effect of long term application of manures and fertilizers on physical and chemical properties of soil, uptake of nutrients and utilization efficiency of nutrients and quality of grain and straw. Results of analysis of soil samples collected before planting revealed the beneficial effect of organic matter addition on bulk density, water holding capacity and aggregate stability of soil. Long term application of manures and fertilizers singly and in combination had no significant influence on the soil reaction and CEC of the soil. The application of ammonium sulphate alone to supply 90 kg N ha continuously for the last 17 years has not changed the soil reaction considerably. Addition of organic manures at a high dose of 18 t ha for a long period of 17 years failed to increase the CEC of the soil. Results clearly indicated the favourable influence of cattle manure addition in increasing the content of organic carbon.Item Morphological and physio chemical properties of Karapadom soils of the Kuttanad region of Kerala State(Division of Agricultural Chemistry, College of Agriculture, Vellayani, 1975) Santhakumari, G; Aiyer, R SA study was mads on ths morphological and physico-chemical properties of 3 profiles of the Karapadom soils of the Kuttanad region. The study revealed many salient features of Karapadom soils The main conclusions drawn from the results obtained are summarised as follows 1. The soils can be texturally classified as clay, loamy sand, silt and silty loam* Maximum percentage of clay was recorded by the top layer of Vettikaripadom, lowest layer of Mathurpadom and sub-surface layer of Mathurvadakke padom profiles. 2. In Mathurpadom and Mathurvadakke padom absolute specific gravity Increased with increase in depth and there is no general trend in the value of apparent density. 3. Mathurpadom and Mathurvadakke padom profiles are strongly acidic when compared to Vettikaripadom which is situated on the western most boundary of Kuttanad near Punnapra. 4. Electrical conductivity increased as depth of the profile increased in Mathurpadom and Mathurvadakke padom profiles. 5. In the three profiles, the organic carbon varies from 0.79 to 4.09 per cent and nitrogen varies from 0.11 to 0.3 per cent. She carbon nitrogen ratio of the profiles varies from 6.58 to 18.33Item Evaluation and suitability rating of ten major soil series of the command area of Kallada Irrigation project(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Tavanur, 1992) Premachandran, P N; Aiyer, R SThe present study was undertaken covering the ten identified important soil series of the command area of Kallada Irrigation Project, with the objective of evaluating the soils based on their morphological and physico chemical characteristics. The soil series selected are Mannar, Adoor, Sooranad, Palamel, Mylom, Erath, Bharanikavu Kallada, Pooyappally and Kunnamkara. Profile pits were dug in the typical areas identified and the morphological features observed were recorded as per soil Survey Manual (1970). The salient features of the area in respect of location, physiography, drainage, vegetation and land use were also recorded. The physical and chemical properties of the soil samples collected were determined by standard analytical procedures. These soil series have been evaluated on the basis of land evaluation and rating of productivity parameters The productivity parameters considered in the present study include soil texture, depth, soil reaction, drainage, cation exchange capacity, base saturation, electrical conductivity, coarse fragments, slope and nutrient status. For each parameter, a range of scale is prepared, and numerical values assigned based on principles of land evaluation. Productivity of the soil has been calculated by multiplying the ratings of the individual parameters and expressed as percentage. The ten soil series selected for study have been classified as per the comprehensive soil classification system – Soil Taxonomy. Five soil series namely Kallada, Mannar, Erath, Pooyappally and Kunnamkara are grouped under Entisol. four series namely Bharanikavu, Palamel, Mylom and Sooranad under Inceptisol and Adoor series under Ultisol. The land capability classification of these soils shows that the Kallada soil series comes under class IIe, Sooranad, Mylom, Erath, Pooyappally and Kunnamkara series under class IIw, Palamel, Bharanikavu, major part of Adoor and a portion of Kallada under class IIIe and Mannar serious under class IIIsc. A portion of Adoor series is grouped under class IVe. The irrigability classification of these soils revealed that the Mannar series comes under class 2s, Kallada under class 2t, Sooranad, Mylom, Erath, Pooyappally and Kunnamkara under class 2d, Adoor, Palamel, Bharanikavu and a portion of Kallada series under class 3t. A portion of Adoor series in grouped under the irrigability class 4t. The productivity rating of these soil series gives the following results. The Kunnamkara soil series with a rating of 38.7 percent rank first for paddy. The study shows that the Earth soil series is the least productive for paddy. Coconut, tapioca and banana. The Palamel series having a rating of 31.4 percent, with good rating class is the most suitable for coconut. The kallada soil series ranks top both for tapioca and banana with rating of 27.6 and 38.8 percent respectively.Item Rock dust as a nutrient source for coleus (solenostemon rotundifolius (POIR) morton)(Department Of Soil Science And Agricultural Chemistry,College of Agriculture, Vellayani, 2008) Divya S S Rose; Shehana, R SThe effect of application of rock dust at different rates alone as well as in combination with FYM and chemical fertilizers and the resultant effect on growth and yield of Coleus (Solenostemon rotundifolius) var. Sreedhara was evaluated by conducting a laboratory incubation study and field experiment at College of Agriculture , Vellayani during 2006- 2007. The results of the incubation study revealed that increasing the rate of application of rock dust resulted in an increase in the available nutrient contents of soil. Application of rock dust in conjunction with an equal quantity of FYM also enhanced the availability of all the major as well as minor nutrients. The pattern of release of available N was found maximum during 30th day of incubation and for P, the highest value was recorded during 120th day of incubation. The release of K was found to increase over time reaching the maximum during the later part of the study. The pattern of solubilisation of micronutrients viz. Fe, Mn and Zn revealed that there was a gradual increase in their concentration from the start of experiment, reaching the highest values during the later stages of incubation. Application of rock dust at a higher rate i.e.12 t ha -1 along with an equal quantity of FYM resulted in the maximum release of almost all the nutrients viz. N, P, K, Fe, Mn, and Zn through out the incubation period. Addition of rock dust along with an equal quantity of FYM resulted the percentage increases from 7 to 17.5, 19.50 to 29.22, 22.95 to 45.38, 10.47 to 14.14 15.58 to 26.36 and 1.3 to 8.6 respectively for available N, P, K, Fe, Mn and Zn when compared to the application of rock dust alone. The results from the field experiment conducted to evaluate the efficiency of rock dust revealed that the plant growth characters like number of branches per plant at 90 DAP and plant spread at 60 DAP showed significant variation due to the application of rock dust @ 10 t ha -1 mixed with equal quantity of FYM and kept for 15 days before the field application. Leaf chlorophyll concentration was increased by 47.36 per cent due to the application of rock dust when compared to POP recommendation. Yield component like number of tubers per plant was also increased by 14.81 per cent due to the application of rock dust. Application of rock dust @ 10 t ha -1 along with equal quantity of FYM and 50 per cent of the chemical fertilizers NPK @ 30:30:50 kg ha -1 also produced yield (17.26 t ha -1, B. C ratio 2.63) equivalent to POP (19.55 t ha -1, B. C ratio 2.39). This treatment also produced the highest number of tubers per plant, dry matter content of plant parts and total dry matter production. The highest yield of 19.55 t ha -1 was obtained for POP recommendation. But application of rock dust along with half the recommended dose of NPK and FYM also produced the similar yield as (17.26 t ha -1) that of POP recommendation. This shows that partial substitution (50 per cent) of chemical fertilizers with rock dust can be recommended to the farmers where ever it is locally available. The starch content and cooking quality of the tubers were also favoured by the application of rock dust @ 10 t ha -1. Starch content increased by 35.02 per cent due to the application of rock dust. Priming rock dust with FYM two weeks prior to field application resulted in the maximum release of P, K, Ca, Mg, Fe, Mn and Zn from rock dust. Rock dust application resulted in the percentage increases of 34.55 to 43.12, 47.96 to 58.49, 20, 17.55 to 55.00, 74.50 to 78.69 and 20 for P, K, Mg, Fe, Mn and Zn respectively when compared to the application of inorganic fertilizers for coleus. Rock dust @ 10 t ha-1 along with equal quantity of FYM resulted in the highest returns per rupee invested (B.C ratio 2.89). It can be concluded from the results of the study that the present recommended dose of in organic fertilizers for coleus can be reduced to half provided it is applied along with rock dust @ 10 t ha -1 . 100 per cent substitution of chemical fertilizers with rock dust 10 t ha -1 and FYM 10 t ha -1 can be recommended for coleus wherever rock dust is locally available.Item Fertility investigations and taxonomy of the soils of regional agricultural research station, Pattambi(Department of soil science and agricultural chemistry, College of Horticulture, Vellanikkara, 1995) Deepa, K P; Chinnamma, N PThe Regional Agricultural Research Station, Pattambi has entered it seventh decade of activities. The total area of the station is 63.64 ha and it includes both upland and low land. A detailed survey of the soil in the area of the station has not been made by the Soil Survey Department and hence a taxonomic classification of the soil and fixing of the soil serious as per the soil taxonomy has not been done so far. Therefore the present study was formulated to find out of the morphological and Physico-chemical characteristics of soil profiles of selected blocks, to analyse the surface soil samples from all the blocks for fertility parameters, to classify the soils under taxonomy and to prepare the soil fertility map of the station. The soils had predominantly red hues. Good structural development was noticed in all soils except in ill drained areas. Coarse fragments formed a predominant part in the soil samples collected. In general the soils were acidic in nature. Organic carbon content was low irrespective of crops grown. The nitrogen content of all soils were also low. No regular pattern of distribution with depth was obtained for total reserves of N, P2 O5, K2 O, CaO, MgO and Na2O which were low. Total Fe2 O3 content was fairly high. The cation exchange capacity calculated by NH4 OAC method was low for all the soils. Among the exchangeable bases, Ca formed the predominant cation. With regard to the available nutrient content of soils, nitrogen status of the soul worked out based on the organic carbon content showed that it was high in C block, low in blocks I and IX and medium in the remaining 19 blocks. Nutrient index worked out for available P content showed that it was medium in 12 blocks i.e., E, M, K, I, II, III, IV, V, VI, VII, IX, X and high in the remaining 10 blocks. For available K, the nutrient index values indicated that it was low in 10 blocks and medium in 12 blocks. Based on the nutrient indices, the fertility map of the station was prepared. Based on the profile soil sample analysis, classification of the soils under soil Taxonomy was attempted upto the subgroup level. Among the nine profiles, only 3 i.e., F, I and V fell under Inceptisols and the remaining 6 i.e., F, I and V fell under Inceptisols and the remaining 6 i.e., B, C, I, VIII, IX and X were under Entisols.