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ThesisItem Open Access 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; KAU; 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.ThesisItem Open Access Development of protocol for quality control of commercial organic manures and their evaluation(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2008) Gowri Priya; KAU; Harikrishnan Nair, KThe research project entitled “Development of protocol for quality control of commercial organic manures and their evaluation” was conducted at College of Agriculture, Vellayani during 2006-2008, with the objectives of quality evaluation of the major commercial organic manures in Kerala, development of a quality protocol for assessing quality and detecting adulteration in commercial organic manures, studying the mineralization pattern of major nutrients in selected manures and their comparative effect on crop performance. Forty four commercial organic manure products and their raw materials were collected from the manufacturers allover Kerala and their physical, chemical and biochemical characters were analysed. Standard compost manures viz., standard vermicompost, standard coirpith compost and standard city waste compost were prepared at the Instructional Farm, College of Agriculture, Vellayani and their physical, chemical and biochemical characters were analysed. The raw materials viz. bone meal, leather meal and neem cake were mixed in different proportions and the characters of the resulting organic meal mixtures were estimated. Based on these data, a protocol was developed to predict the nitrogen, phosphorus and potassium contents of the organic manures prepared by mixing bone meal, leather meal and neem cake in any ratio. A storage experiment was conducted to study the changes in quality aspects of organic manures during a period of one year. The quality parameters of market samples and the corresponding factory samples of COMs were compared. An incubation experiment was conducted to study the nutrient mineralization pattern of organic manures. A field experiment was carried out to evaluate the performance of selected organic manures using amaranthus variety Arun as test crop. The results of the investigation revealed that none among the forty four commercial organic manures conformed completely to the quality standards specified by the Fertilizer (Control) Amendment Order, 2006, of the Government of India. The colour of COMs varied depending on their raw materials (ingredients) and the odour of COMs varied depending on raw materials and the state of decomposition. The total nitrogen contents of COMs varied from 0.7 per cent to 7.87 per cent. Majority of the COMs had total nitrogen contents between 2.8 per cent and 5.85 per cent. The C/N ratio of COMs varied from 2.86 to 43.18 and only one product viz. SN 4 (Neem cake marketed by TIFFCO Fertilizers & Chemicals) had a ratio more than 20:1. All the COMs contained satisfactory level of total organic carbon. The total phosphorus content varied from 0.12 per cent to 4.57 per cent and the total potassium content in COMs varied from 0.12 per cent to 7.87 per cent. Only eighteen of the COMs had pH in the neutral range and with respect to EC, only three COMs were good for use having EC values less than 4 dS m-1. Based on heavy metal contents, the COMs P.L.meal (PL Agro Technologies Ltd.), Skymeal (Vembanad Chemicals & Fertilizers) and Haritha Super (The Gramakarshaka Fertilizer Company Pvt Ltd.) were found unsuitable for long term application to soil. The standard compost manures did not conform to the specifications of moisture content and bulk density as per Fertilizer (Control) Amendment Order, 2006. The total nitrogen content of SVC was 1.4 per cent, SCC 0.7 per cent and SCWC 2.1 per cent. All the three SCMs recorded C/N ratios below 20. SVC and SCWC had satisfactory levels of total P while SCC was poor in total P. The three SCMs did not contain enough total K to conform to the minimum limit prescribed by the Fertilizer (Control) Amendment Order, 2006. The pH of SVC and SCWC were within the neutral range of 6.5- 7.5, while SCC was more acidic with pH of 3.93. The electrical conductivity of the SCMs ranged from 0.33 to 3.4dS m-1. The total organic carbon contents of SCMs were above 30 per cent. SCMs had heavy metal contents below the maximum limits prescribed by the Fertilizer (Control) Amendment Order, 2006. The analysis of raw materials revealed that leather meal was a good source of nitrogen, bone meal and pressmud were good sources of phosphorus and pressmud was the best source for potassium. The mathematical models developed for predicting the N, P and K contents of any mixture of bone meal, leather meal and neem cake were: N estimated= 3.62088 BM+ 6.58962 LM+ 1.74407 NC+ 4.74391 (BM)x(LM) + 7.8398 (BM) x (NC) – 9.87862 (LM)x(NC), where BM is the proportion of bone meal in the mixture, LM is the proportion of leather meal in the manure and NC is the proportion of neem cake in the mixture. P estimated= 8.41214 BM+ 0.37157 LM+ 0.41953 NC- 2.73548 (BM) x (LM) + 10.15749 (BM) x (NC) – 8.72905 (LM) x (NC) K estimated= 0.38543 BM+ 0.01872 LM+ 1.19747 NC+ -0.04393 (BM) x (LM) + 2.98573 (BM) x (NC) – 5.64704 (LM) x (NC) The model could be used for finding out adulteration of organic manures with inorganic fertilizers to boost their nutrient contents. Different ratios of bone meal, leather meal and neem cake were worked out to prepare organic manures with different levels of N, P and K. The results of the storage study showed that the organic carbon content of organic manures decreased from the initial value during the storage period of one year. The changes in nitrogen, phosphorus, potassium and sodium contents of organic manures showed varying patterns during storage. Comparison of quality of market and factory samples of COMs revealed that the organic carbon and nitrogen content of all the market samples were significantly less than their corresponding factory samples while P and K contents showed varying patterns. The mineralization patterns of major nutrients from the organic manures in incubation experiment indicated that in general, the available nitrogen and phosphorus contents in soils treated with organic manures increased upto 30-45days after incubation and decreased thereafter. The mineralization pattern of potassium from organic manures in soil showed pronounced variation. The treatment with Karshaka Agromeal Grade I (SN 26) recorded higher contents of N, P and K. In the field experiment the highest yield in the first crop was in the treatment with NPK fertilizers + Karshaka Agromeal Grade I. The control treatment with no fertilizers and manures recorded the lowest yield. The application of organic manures was found to improve the quality aspects of the crop. The highest content of available N in soil after harvest of first crop was recorded in T10 (NPK fertilizers + SVC) and lowest available N content was observed in T4. The available phosphorus content after harvest of first crop was highest in T7 (NPK fertilizers + Golden meal) and the lowest value of available P2O5 was observed in T6 (NPK fertilizers +Skymeal). The available potassium content after harvest of first crop was highest in T10 and the lowest content of available potassium was obtained from T14. Application of organic manures was found to raise the pH of the soil in treatment plots. The electrical conductivity of soil was significantly influenced by the different treatments. The highest yield, total dry matter production, total marketable yield and total yield per plant of the second crop was recorded in T7 (NPK fertilizers +Golden meal) and the lowest was in T14. The highest B: C ratio of 1.31 was recorded in T4 and the lowest value was recorded in T14 (absolute control) which had a B:C ratio of 0.90.ThesisItem Open Access Quantity - intensity relations of phosphorus with reference to its bioavailability in lateritic soils(College of Horticulture, Vellanikkara, 2008) Geetha, P; KAU; SureshKumar, PFive benchmark soils of lateritic origin were collected and used for the present study of Q-I relations, dynamics and transformations of P. Samples of these soils were collected from Kunnamangalam (Calicut), Angadippuram (Malappuram), Vellanikkara (Thrissur), Pattambi and Thirumittakkodu(Palakkad) . The soils were characterized with respect to pH, EC, CEC and exchangeable cations, AEC, available nutrient status ( Organic carbon, available P, K, Fe, Mn, Cu and Zn) and P fixing capacity The inorganic P fractions viz. soluble P, Al bound P Fe bound P, sesquioxide occluded P, and Ca bound P as well as organic P was estimated. The equilibrium phosphate potential and buffer power of these soils were estimated from the Q/I curve. Among the five soils, Vellanikkara soil series recorded the lowest available P and soluble P fraction, the highest P fixing capacity and highest adsorption maximum as per Langmuir equation Based on the above characteristics this soil was selected for pot culture experiments to grow cowpea as a test crop using three different amendments (Pongamia, Cleistanthus, and lime) three levels of labeled phosphatic fertilizer and two methods applications. Available P and fractions of phosphorus in the soil was estimated at three stages. P content as well as 32P counts in the plants were also estimated. A and L values were computed at 15 and 30 days after sowing. It can be concluded from the present study that application of different amendments dictated the transformation of P in soil. The available P, soluble P and %Pdff could be improved significantly. A different trend in radioactive phosphorus activity in available P as well as in A and L values indicated that the applied P though contributing to the available pool in amended soils, this might be routed through the inorganic fraction Ca-P and not directly coming to the soluble/labile pool.