1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Carrier based slow release fertilizer formulations for sustained nutrient release and enhanced crop production(Department of soil science and agricultural chemistry,Vellayani, 2023-08-10) Farha, M K.; Gladis, RItem Nutrient economy through seed coating with vermicompost in cowpea(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 1998) Meera, A V; Prabhakumari, PAn investigation was carried out at the Instructional Farm, attached to the College of Agriculture, Vellayani to evaluate "Nutrient economy through seed coating with vermicompost in cowpea". The experiment was laid out in Completely Randomised Design with nine treatments and three replications. The variety used was Kanakamoni. The treatments include coating of seeds with Rhizobium, vermicompost and a combination of both and also uncoated seeds supplied with either farmyard manure or vermicompost as organic source. Biometric observations like height of plant, number of leaves, seedling girth and number of fruiting branches were not significantly influenced by any of the treatments. However, root characters like root length, root spread and number of effective nodules were found to be significantly influenced by the different treatments. Coating of seeds with vermicompost significantly influenced the grain yield of cowpea and also the number of pods plant-l. Coating seeds with vermicompost combined with the application of full inorganic fertilizers and farmyard manure as organic source recorded the highest grain yield. From the analysis of grain samples, it is inferred that only K and Ca content of grain was significantly influenced by the different treatments. Phosphorus solubilisation capacity of soil was not significantly influenced by any of the treatments. N fixing capacity of soil was significantly influenced by the vermicompost coating of seeds during 30 DAS and 45 DAS. Soil analysis for available nutrients revealed that the different treatments had significant influence on the Ca, Mg, Zn, Cu and Mn content in soil. Use of vermicompost coated seeds produced the maximum uptake of N, P and K at maximum flowering stage and at harvest. Soil application of vermicompost recorded the highest uptake of Ca, Mg, Cu and Mn during maximum flowering stage. Plant analysis for nutrient content indicated that the content of all the nutrients except P was significantly influenced by the different treatments during maximum flowering stage. Yield was positively and significantly correlated with the height of plant, root characters and availability and uptake of nutrients. In the present study, a superiority is shown by vermicompost inoculated plants where farmyard manure was given as the organic source indicating that at times of scarcity of vermicompost, seed treatment could serve the purpose.Item Nutrient uptake efficiency of cassava (Manihot Esculenta Crantz) as influenced by vesicular arbuscular mycorrhizal (Vam) association and rock phosphate application(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 1991) Narayanan, S; Saifudeen, NItem Efficiency of rock phosphate in the acid rice soils of Kerala(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 1992) Visakha, L; Sundaresan Nair, CInvestigations were conducted to assess the suitability of Rajasthan rock phosphate for rice in two acid rice soils viz. Vellayani kayal soil and Moncompu soil respectively. The study also included a study on fractionation of the soil P collected at periodical intervals from these two locations for the different forms of P. The results are summarized below: 1. At both the locations a significant increase in height of plants, number of tillers, panicle length, thousand grain weight etc. was obtained by the application of phosphatic fertilizers over control. But between the different phosphatic forms no significant difference could not be observed. 2. In both the locations application of rock phosphate both Rajasthan rock phosphate as well as Mussoorie rock phosphate has been found to be as good as super phosphate in enhancing the yield of rice grain. 3. In both the locations the treatments with different forms of P increased the P content of grain and straw. This indicates that, the rock phosphate applied in acid soils while increasing the yield significantly increase the P content in plants also. In general, the treatments with phosphate fertilizers increase both the Ca and Mg content of grain and straw. The increase is much more marked in the case of calcium. 4. At both the locations the total P content of the soil is found to be significantly enhanced by the phosphatic fertilizer treatments. The highest total P content was recorded 20 days after transplanting and there is a progressive decrease in total P with time. 5. At Vellayani, super phosphate is found to be significantly superior to the other two rock phosphate in enhancing the available P status of the soil. But there is no significant difference between the two forms of rock phosphate in enhancing the available P. At Moncompu all the phosphatic treatments ie. super phosphate, mussoorie rock phosphate and Rajasthan rock phosphate were found to be equally good in enhancing the available P. The difference in response might be due to the difference in pH of the two soils. The highest available P content was recorded at 40th day at Vellayani and on 60th day at Moncompu.Thus there is variation in the period of submergence required for the attainment of peak value in available P in the two soils. Soil to soil variation is partly responsible for this. 6. Fe- P fraction of the soils treated with phosphatic fertilizers increase with period. Maximum Fe- P was recorded by super phosphate. However between the two rock phosphate there is no significant difference. Maximum Fe- P was recorded at 40th day of water logging. At Moncompu all the phosphatic fertilizer treatments significantly enhance the Fe- P content. All the phosphatic fertilizer forms significantly increase the Al- P fraction over control. But there is considerable variation in the behaviour at the two locations. The treatments significantly enhance the Al- P level at Moncompu than at Vellayani. The peak Al- P was recorded at 40th day at both the locations. There is progressive decrease in reductant soluble P and occluded P as the period progresses. The pattern was followed irrespective of soil types. The progressive decrease in reductant soluble P is accelerated by phosphatic fertilizer treatment in kayal and Moncompu soils. Same is the case with occluded P. The treatments with phosphatic fertilizers increase the Calcium P fractions in all the soils. Application of Mussoorie rock phosphate and Rajasthan rock phosphate as well as super phosphate enhance the Ca- P fraction. There is not much difference between the locations in enhancing the Ca-P fraction with respect to the treatments. Saloid fraction reach a peak value by 60 days of water logging. The results of the present study indicate that Rajasthan rock phosphate compares very well with super phosphate and Mussoorie rock phosphate under water logged situations. Its lower cost will substantially contribute towards reducing the input cost of phosphates under acid rice soil conditions. The studies on the pattern of dissolution give an indication that its solubilization and conversion to more available forms can be put to greater advantage in the growing of a rice crop by synchronizing the peak period of utilization of phosphate by the rice crop with the peak period of availability by shifting the basal application of rock phosphate by about 10 to 15 days perior to transplanting or sowing, in situations where such a practice is feasible.