Browsing by Author "Sam T Kurumthottical"

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Assessment of some phosphatic sources for possible accumulation of heavy metals in chilli (Capsicum annuum L.)
(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 1998) Jidesh, C V; Sam T Kurumthottical
Rock phosphate sources collected from different locations were analysed for both phosphorus content and heavy metals namely cadmium and lead. Those sources which analysed relatively higher content of heavy metals were included for conducting a pot culture experiment using chilli (Capsicum annuum L.) as test crop. To derive meaningful comparison in the study, partially acidulated rock phosphates as well as direct water soluble source of cadmium and lead were also applied to assess their bioavailability to plants. The influence of organic matter when applied alone or in conjunction with heavy doses of heavy metals was also assessed in the study. The pot culture experiment was conducted in the Vegetable Research Farm, Department of Olericulture, Vellanikkara during the kharif season of 1996, with chilli as the test crop. The entire fertilizer management was based on package of practice (N, P and K at 70, 40 and 25 kg ha-1) recommendation. Five different sources of P selected for the pot culture experiment were (1) Maton rock phosphate, (2) Mussorie rock phosphate, (3) Gafsa rock phosphate, (4) Rajasthan rock phosphate and (5) Single superphosphate. The maximum content of cadmium (55 mg kg-1) was recorded in Gafsa rock followed by 25 mg Cd kg-1 for the Maton rock and single superphosphate analysed the least concentration of cadmium (15 mg kg-1 Highest lead content of 230.5 mg Pb kg-1 was analysed in Maton rock while lowest (38 mg kg-1) in Musoorie rock. All the other sources maintained their heavy metal concentration in between these extremes. In general, the shoot portion of test crop chilli recorded highest cadmium uptake while root portion noted the maximum lead uptake. The least uptake of heavy metals was noted in the chilli fruit, which is the edible part of the plant. This indicates that the heavy metal load in the fruit portion is much less when compared to other plant parts, irrespective of the sources used. The same trend was evident when either partially acidulated P sources or direct source of heavy metals (through water soluble salts) were applied. However, the uptake of cadmium and lead from those sources remained higher in plant parts. Application of organic matter in conjunction with a heavy dose of heavy metals to soil resulted in a significantly higher uptake of cadmium and lead in all plant parts. Analysis of the available cadmium and lead in the post-harvest soil samples indicated negligible build-up of these metals in soils. However, direct application of higher levels of heavy metals permitted higher cadmium and lead extraction in the post-harvest soil samples. Application of partially acidulated rock sources to soils, though could cause enhanced uptake of heavy metals, could not show higher residual effects of heavy metals in post-harvest soil samples.
Effect of major nutrients on the yield and quality of nuts in graft-raised cashew (Anacardium occidentale Linn.)
(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 2002) Nair Rajiv, R K; Sam T Kurumthottical
An experiment was conducted to study the "Effect of major nutrients on the yield and quality of nuts in graft raised cashew" at Cashew Research Station Madakkathara Kerala. The treatments consisted of three levels each of N, P and K on eight year old cashew trees. The salient findings are abstracted below. The study revealed that increasing levels of nitrogen significantly increased the height and spread of cashew trees, while the girth was significantly increased by the interaction effects of nitrogen and potassium. The yield parameters such as number of flushes, number of leaves per flush, number of panicles and the number of nuts per panicle were significantly enhanced by the application of nitrogen at increasing levels, while the application of phosphorus at increasing levels also significantly increased the number of nuts per panicle. The yield of cashew nuts and apples were significantly increased due to the highest level of nitrogen applications. Application of potassium at the highest level also significantly increased the apple yield per tree. Weight and volume of cashew apples was significantly increased by the application of increasing levels of potassium but nitrogen application was found to significantly decrease the weight of fruits. The juice percentage was positively and significantly influenced by the application of nitrogen and potassium. Potassium applications were found to significantly increase the nut length and weight while nitrogen applications were found to reduce the nut weight. Shelling percentage of cashew nuts was enhanced by the application of nitrogen and potassium at increasing levels. The kernel weight was increased due to the application of potassium. Ascorbic acid content of cashew apples was positively influenced due to the application of increasing levels ofNPK. The Total Soluble Solids of the apple was significantly enhanced by the application of nitrogen. Applications of nitrogen alone and in combination with phosphorus were found to increase the protein content of kernels. The carbohydrate, Non-reducing sugars and reducing sugars content of kernels were significantly enhanced by the application of different levels of nitrogen. Increase in the soil major nutrient content due to the individual effects of nitrogen, phosphorus and potassium applications were also observed. The leaf phosphorus and potassium content was enhanced specifically due to the application of increasing levels of phosphorus and potassium respectively, while the nitrogen content of leaves was positively influenced by the application of nitrogen and phosphorus. The average nutrient off-take through nuts and apples was computed to be 279.43, 4l.58 and I 86.40g of nitrogen, phosphorus and potassium respectively. The average nutrient off take per tree through nuts from an average yield of 2.89 kg tree" was found to be 93.56, 2.89 and 48.85g of nitrogen, phosphorus and potassium respectively and through apples was found to be 185.87, 38.69 and 137.54g of nitrogen, phosphorus and potassium respectively from an average yield of 18.20 kg tree". In 'general, among the major nutrients applied at different levels only nitrogen had shown exceedingly high effects in sustaining the growth, yield and quality parameters. The yield and quality parameters were also seen to be affected to a certain extent by potassium applications but the response of the crop to phosphorus was seen to be exceedingly limited.
Impact assessment of landfill on soil health and water quality in a waste disposal site
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2017) Fasila, E K; Sam T Kurumthottical
The study entitled “Impact assessment of landfill on soil health and water quality in a waste disposal site” was undertaken with an objective to assess the impact of dumping Municipal Solid Waste (MSW) on soil and water quality, spatial variability in the level of biological and chemical contamination along the leachate zone and identification of a few bioremediators and their possible effectiveness in decontaminating the landfill materials. As a part of this study, geo-referenced sampling points have been identified initially for dumped waste materials (from the existing two landfill sites), soil (from two depths) and leachate samples along the leachate flow zone at a regular interval of 50 m within the plant area and ground water samples outside the area were collected. All the samples were monitored from these geo-referenced sampling points in three successive seasons, viz., pre-monsoon, monsoon and post-monsoon. The values for all the physico-chemical parameters in landfill materials were high during pre-monsoon period and only a marginal variation observed in heavy metal content in three seasons of study. Soil samples were acidic in reaction and a reduction in N, P, K and heavy metals were observed as the depth of sampling increased. Comparatively high values were observed in all parameters during pre-monsoon period than the other two seasons both in soil and leachate samples. Fe, Al and Hg content in leachates were very high and the concentrations of Fe, Al, Pb, Cd and Hg in ground water exceeded the acceptable level insisted by BIS. The leachate samples also recorded a high value for biological oxygen demand, chemical oxygen demand and coliform count than the ground water samples. Fifteen profusely growing weed species were identified and collected along the leachate flowing zone and the shoot and root portions were analyzed separately for various heavy metals to assess their selective retention capacities. Most of the weed species except Sphagneticola trilobata, Commelina diffusa, Ricinus communis, and Mikania micrantha were found to retain more toxic metal load in the root portion than the shoot portions. Among them, Alternanthera tenella was identified as the best hyper accumulator with respect to its gross uptake of the metals like Mg, Mn, Pb, Cd, Ni, Co and Cr. Hence, this plant was selected for the sand culture study along with other established hyper accumulator plants namely; Indian mustard, sunflower, globe amaranth and marigold analyzed for selective retention capacity under four graded doses of lead, cadmium and nickel. This study identified three best plants species (sunflower, globe amaranth and marigold) showing highest hyper accumulation capacities and hence they were carried forward to another pot culture study employing contaminated and degradable landfill materials for the final revalidation of claims. The experiment consisted of ten treatments and the treatments where the growing medium was re-constituted with different proportions of degradable landfill materials and virgin soil with and without the AMF inoculation. The plants which were grown for three months were analyzed separately for root and shoot portions for the exact quantum of selective retention status of metals like Al, Zn, Cu, Fe, Pb, Cd, Ni, Co, Cr and Hg. Lower levels of metal accumulation was recorded in all the plant parts where AMF had been inoculated in the media than its pairing treatment without inoculation, indicating the specific effect of AMF in preventing the uptake of heavy metals by plants and at the same time permitting the absorption of other ions needed for growth. Sunflower had been adjudged as the best plant that removed maximum load of studied heavy metals from the contaminated growing media except nickel and chromium. Similarly globe amaranth had been specifically identified as an excellent accumulator of nickel. Marigold was identified to be efficient accumulator of chromium. From the investigation it can be concluded that the soil and water bodies near the dumpsite sufficiently contaminated with the heavy metals like Zn, Mn, Cu, Fe, Pb, Cd, Ni, Co, Cr and Hg. As the distance from the dumpsite increased the extent of various chemical and biological contaminations showed a decreasing trend. Sunflower, globe amaranth and marigold were found to be effective hyper accumulators for the area in decontaminating the soils.
Management of banana bract mosaic virus (BBrMV) symptoms in banana with micronutrients
(Department of Soil Science and Agriculture, College of Agriculture, Vellayani, 2015) Sangeetha, S S; Sam T Kurumthottical