PG Thesis

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Subject: search.filters.subject.Cation exchange capacity

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    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, V
    A 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.
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    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 S
    A 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.
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    Optimization of soil environment and crop response for magnesium nutrition in ultisol
    (Department of Soil Science and Agricultural Chemistry College of Horticulture, Vellanikkara, 2019) Soniya, V P; Bhindhu, P S
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    Evalulation of soil and water quality in potta watershed of pazhayannur block in Thrissur district
    (Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 2017) Raghunath, H N; Betty Bastin
    An investigation entitled ‘Evaluation of soil and water quality in Potta watershed of Pazhayannur Block in Thrissur district” was undertaken in the department of Soil Science and Agricultural Chemistry, College of Horticulture, Kerala Agricultural University during the Year 2016-17. An intial survey was carried out in the different reaches of the watershed to identify the water resources, crops. Vegetation, manures, fertilizers and pesticides used. Based on the data generated, thirty Soil samples were samples were collected from each reach. Soil samples were collected only during the pre-monsoon season (April to May, 2016) and post-monsoon November to December, 2016) season. The soil samples were characterized for texture, bulk density, particle density, water holding capacity (WHC), pH, electrical conductivity (EC), organic carbon (OC), cation exchange capacity (CEC), available nutrients (N, P, K, Ca, Mg, S, Fe, Mn, Zn, and Cu) and heavy metals (Pb, Ni, Cr, and Cd) and heavy metals (Pb,Ni,Cr and Cd). Water samples were analyzed for chemical properties like pH, EC, TSS, cations, (Na+ , Ca2+ , K+, Mg2+) anions (CI-1, SO42-, CO32-, HCO3- and NO3- )heavy metals Cd, Pb, Cr, and Ni). The texture of soils in all the three reaches were found to be sandy loam. Soils from all the reaches were acidic and the pH varied from 3.47 to 6.80 with very low electrical conductivity(0.021 to 0.170 dS m-1). Cation exchange capacity of the soil samples varied between 4.15 to 8.97 c mol (p+) Kg-1. in the soil samples of upper reach was deficient in soil OC. Deficiency of available N in all reaches and that of P in upper and lower reaches was observed. The highest deficiency of K was noticed in the soil samples of upper reach. All the reaches were deficient in secondary nutrients (Ca and Mg). The available heavy metals in the soil was found to be below toxic level and their contents decreased in the order of Pb > Ni > Cr > Cd. Micronutrients (Fe, Mn, Zn and Cu) were found to be sufficient and their contents followed the order Mn > Fe>Cu > Zn Significant differences were observed between upper and middle reached in the content of soil available N, P and K. The association of soil properties showed that the soil organic carbon (SOC) was significantly and positively correlated with soil water holding capacity and available nitrogen in all the reaches, whereas it was negatively correlated with the bulk density of soil. During both pre and post – monsoon periods, PH of the water samples ranged between acidic to neutral values (5.62 to 7.47). electrical conductivity of water samples ranged from 0.14 to 0.54 dS m-1 . The content of cations, viz.,Ca and Mg were high in post-monsoon season while Na and K were high in pre-monsoon season. Analysis of anionic composition of water samples showed that the content of anions viz., bicarbonates, chlorides and nitrates were higher in post monsoon compared to pre-monsoon. The heavy metals like lead, chromium and cadmium were found to be below detectable level in all the water samples collected during both pre and post –monsoon seasons. Water samples registered significant differences in the contents of Ca, Mg, HCO3- between pre and post –monsoon seasons . The quality of water from all the reaches can be rated as good and suitable for irrigation. Further studies can be focused on the assessment of the impact of different soil conservation measures on the soil health. Soil test based fertilizer recommendations including various organic resources have to be adopted by the farmers.
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    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 P
    A 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.
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    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 S
    The 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.