Browsing by Author "Sumam George"

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Biological characterization of Onattukara soils under coconut based cropping system
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2015) Anila T Sasi; Sumam George
Biological indicators of soil health as influenced by plant nutrient sources
(Department of soil science and agricultural chemistry, College of agriculture, Vellayani, 2013) Mekha, M G; Sumam George
The research project entitled ‘Biological indicators of soil health as influenced by plant nutrient sources ’ was undertaken to study the changes the major biological properties of a soil undergo when the major nutrients to a crop grown on it are supplied organically or inorganically or in their different combinations and to employ them as tools for evaluating the health of that soil. The investigations consisted of laboratory studies and two field trials at the Instructional Farm, College of Agriculture, Vellayani with Amaranthus var.Arun during May 2012 to July 2012 in two soil types of Vellayani, red loam and lateritic. The ten treatments were laid out in RBD with three replications. The treatments consisted of T1 (Urea+ Rock phosphate+ Muriate of potash) (KAU POP, 2007), T2 (Urea+ Rock phosphate+ Wood ash), T3 (Urea+ Bone meal+ Muriate of potash), T4 (Urea+ Bone meal + Wood ash), T5 (Oil cake+ Rock phosphate+ Muriate of potash), T6 (Oil cake +Rock phosphate +Wood ash) , T7 (Oil cake+ Bone meal+ Muriate of potash) , T8 (Oil cake+ Bone meal+ Wood ash), T9 (KAU Organic POP, 2009), T10 (Control ) The biometric observations viz., plant height, number of leaves, number of branches, stem girth, root length and root volume were all significantly influenced by different treatments. Significant differences were observed among yield attributing characters like leaf weight plant -1, stem weight plant -1,shoot biomass plant -1, root biomass plant -1, biomass yield plant -1 and total yield plot -1. The highest yield plot -1 was recorded by the treatment combination T1 in both soils. With respect to quality characters the treatment combination T5 recorded the highest value for vitamin C and -carotene content in both soils. For crude protein content treatment T6 recorded the highest value in red loam soil and T8 in lateritic soil to both of which T5 was on par. Oxalate content and nitrate content were also influenced by different treatments .T9 registered significantly higher population of earthworm and soil respiratory activity in both soils. Soil microathropod and soil microbial population (bacteria, actinomycetes and fungal) were maximum in the treatment combination T6. In both soils urease activity was maximum for T4 and dehydrogenase activity maximum for T8, phosphatase activity showed maximum values for T2 in red loam soil and T8 in lateritic soil. Soil organic carbon and available N, P, K content in the soils were significantly influenced by various treatments. Regarding Carbon mineralization potential estimated as the organic C content of the soil T5 recorded maximum value in red loam soil and T9 in lateritic soil. The treatment combination T¬6 registered highest values for nitrogen mineralization potential in red loam soil while T1 for lateritic soil.T7 recorded highest values for available P content in both soils and available K content in lateritic soil. Economic analysis of various treatments showed that the combination of inorganic sources of plant nutrients T1 generated higher profit compared to all other treatments in both soils. Taking into account the favourable effect exerted on biological properties of soil, yield and yield attributes treatment T6 which is a combination of N and K in organic form and P in inorganic form to supply the recommended dose of major nutrients to the crop can be adjudged to be the best treatment for economic production of amaranthus in both red loam and lateritic soils of Vellayani. Considering quality of the crop treatment T5 which supplied N alone organically was found to be best.
Biological profile of ferralitic alluvial paddy soils under long term differential fertilizer application
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2014) Nikhil, K; Sumam George
Evaluation of latex sludge as a phosphorus source in crop production
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2004) Simi Sathyaseelan; Sumam George
Liming in karappadam soil of Kuttanad
(Kerala Agricultural University, 1987) Chandrasekharan Nair, K; Sumam George; Annie Koruth
Nutrient fixation in the poonthalpadam soils of Kerala
(Kerala Agricultural University, 1986) Sumam George; Alice Abraham
Standardisation of plant part as an index of potassium status in banana, musa (AAB Group) nendran
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 1994) Sumam George; Padmaja, P
A field experiment in Musa (AAB group) Nendran, the most popular commercial fruit crop of Kerala was undertaken from August, 1991 to May, 1992 with seven graded levels of K as treatments replicated thrice. The soil, medium in N and P and high in K status belonged to the taxonomic class ‘loamy kaolinitic isohyperthermic aeric tropic fluvaquents’. The effects of higher levels of K on all important growth characters of the crop like height of pseudostem, girth of pseudostem at different heights from the ground level, total number of leaves, number of functional leaves, total leaf area, leaf area index and total dry matter production were more pronounced from the shooting stage of the crop after the plants had received the full dose of K supply. Uptake of major nutrients N, P and K showed increasing trend with increase in K supply. Uptake of Ca showed a negative relationship with increasing K application while Mg uptake showed an inconsistent pattern. Uptake of micronutrients Fe, Mn, Cu and Zn were maximum at K3 level of application (225 g K2O plant-1). Soil content of available K increased while exchangeable Ca and Mg contents decreased at higher levels of K supply. The maximum bunch yield of 26.18 t ha 1-which was significantly higher than all other treatments was recorded at K3 level (225 g k2O plant-1) This level also resulted in maximum values for all the yield attributing characters like number of hands bunch-1, number of finger bunch-1, weight of hand, length of finger, girth of finger and weight of finger. By adopting this recommendation a net fertilizer saving of 75g K2O plant-1 Can be achieved which is equivalent to 312.5 kg of muriate of potash costing Rs. 2000 at the present market rate. Over and above this, increase in yield obtained by doing so is 4500 kg ha-1. Additional income that could be generated by the way of sale of this at the rate of Rs. 8 kg-1 works out to Rs. 36000. Thus a total saving of Rs. 38000 ha-1 can be achieved by following the suggested recommendation. Path coefficient analysis of yield attributes showed that the character number of finger bunch-1 is having the maximum direct effect on yield followed by girth of fruit and weight of fruit. Quality characters of the fruit namely total and non reducing sugars, shelf life and flesh peel ratio showed significant and positive trend towards K nutrition. Correlation coefficient were worked out between bunch yield and important crop characters. Balance sheet of nutrients in soil after harvest of the crop was worked out to assess the final soil status of nutrients in relation to the initial status. Petiole of the third leaf up to shooting stage of the crop and that of the flag leaf there after was selected as the index of K status of the plant as the K content of the same was found to hold the maximum relationship with bunch yield at all the growth stages. The critical K levels in the petiole for maximum yield as well as maximum response to fertilizer application at each stage were determined which were found to be 1.30 per cent and 1.02 per cent respectively at early vegetative stage, 1.28 per cent and 1.06 per cent respectively at late vegetative stage, 1.80 per cent and 1.36 per cent respectively at shooting stage, 2.43 per cent and 1.98 per cent respectively at post shooting stage, 2.50 per cent and 1.80 per cent respectively at bunch maturation stage and 2.47 per cent and 1.80 per cent respectively at harvest stage. The critical K content in soil for economic yield worked out to 286.5 kg K2O ha-1 at early vegetative stage, 276.5 kg K2O ha-1 at late vegetative stage, 271.o kg K2O ha-1 at shooting stage, 239.o kg K2O ha-1 at post shooting stage, 245.0 kg K2O ha-1 at bunch maturation stage and 236.0 kg K2O ha-1 at harvest stage. Graphs were plotted relating petiole K content to soil K content at important growth stages of the crop based on quadratic regression models to provide information on soil K content at a particular stage if the petiole K content at that stage is known. Linear regression models were developed relating soil K content to fertilizer dose to find out the quantity of fertilizer to be applied to bring the soil level to the critical level.
Sulphur and boron nutrition and their foliar diagnosis in sesame
(Department of Soil Science and Agricultural Chemistry,College of Agriculture, Vellayani, 2010) Jeena Mathew; Sumam George
A laboratory cum field experiment was conducted to study the effect of S and B on the growth, yield and quality of sesame var. Thilarani and to standardize the foliar diagnosis of these elements in Onattukara sandy loam soil. The study included an incubation study and two field experiments. The treatments comprising the different levels of S and B laid out in 42factorial RBD. The treatments were T1(S0B0), T2(S0B1), T3(S0B2), T4(S0B3), T5(S1B0), T6(S1B1), T7(S1B2), T8(S1B3), T9(S2B0), T10(S2B1), T11(S2B2), T12(S2B3), T13(S3B0), T14(S3B1), T15(S3B2), T16(S3B3). The different levels of S were S0 (0 kg ha-1), S1 (7.5 kg ha-1), S2, (15 kg ha-1) and S3 (30 kg ha-1) and B0 (0 kg ha-1), B1(2.5 kg ha- 1), B2 (5 kg ha-1) and B3 (7.5 kg ha-1). The incubation study was conducted at College of Agriculture, Vellayani to understand the dissolution and release pattern of S and B from their sources gypsum and borax respectively in Onattukara sandy soil. The results revealed that the release of S and B was maximum at the 30th DOI. Increasing levels of S and B has a positive influence on the S content of the soil. T16 (S3B3) recorded the highest value at all the sampling stages for S whereas in the case of B, the treatment combinations which received B at the highest levels in combination with S3 or S2 showed the highest value. The field experiments were laid out at ORARS, Kayamkulam in 42 factorial RBD having two replications using Thilarani as the test crop. It was observed that application of S and B favourably influenced the yield and yield attributes of sesame. T16 was found to be the treatment which gave the highest grain yield and oil yield in both the years and was found to be on par with T14 (S3B1). S3 was the superior S level. As for the different levels of B, B1 can be inferred as the best level. The content of saturated fatty acids such as palmatic and stearic acid showed a decreasing trend with increasing levels of S and B whereas the content of the unsaturated fatty acids showed an increasing trend. The quality attributes of oil such as acid value, iodine value and saponification value was also studied and it was found that there is a decreasing trend with regard to acid and saponification value and an increasing trend for iodine number. The grain protein content also showed an increasing trend with the increase in rate of application of S and B. Regarding the content and uptake of N, P, K, S, B, Fe, Mn, Cu and Zn, a favourable influence for the different levels of S and B was recorded. Results regarding the S and B use efficiency and their apparent recovery showed that with increase in levels of S, an increasing trend was observed for S. In the case of B, increase was noticed up to B1 (2.5 kg ha-1) and there after showed a decreasing trend. This positive influence was also reflected on the available nutrient status of the soil such as organic carbon content, available N, P, K, S, B and DTPA extractable micronutrients. Correlation studies conducted to standardize the part and stage of sampling for the foliar diagnosis of sesame showed petiole at 30 DAS and 20 DAS in the case of S and B respectively. The same stages were found for the soil sampling also for both the nutrients. The critical nutrient level in the part standardised for these two nutrients were standardized using the graphical method proposed by Cate and Nelson (1965). In the case of S, it had been standardized as 0.088 per cent and for B, it had been found to be 28 mg kg-1. The critical nutrient level in soil was also estimated using the scatter diagram technique and was found to be 23 kg ha-1 at 30 DAS for S and 1.4 ppm at 20 DAS for B. Hence the application of S @ 30 kg ha-1 and B @ 2.5 kg ha-1 could faourably enhance growth of sesame with regard to the growth characters, yield and yield attributes and the quality aspects. Moreover, analysis of the plant and soil samples at the critical stages fixed for the respective nutrients will provide the necessary data for the sustainable management of the crop in Onattukara sandy loam soil.