Thumbnail Image

Theses

Browse

2007 - 20085
Reset filters
Subject: Soil Science and Agriculture Chemistry × Author: KAU × End date: 2008 × Start date: 2007 × Type: Thesis ×
Reset filters

Search Results

Now showing 1 - 5 of 5
  • Thumbnail Image
    ThesisItemOpen Access
    Availability indices of potassium in an ultisol under coleus cultivation
    (Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 2007) Santhosh, C; KAU; Mariyam, K A
    A field experiment was carried out in the main campus of College of Horticulture, Kerala Agricultural University, Vellanikkara to study the availability indices of potassium in an Ultisol under the coleus cultivation. The experiment was laid out in a randomized block design with eight treatments and three replications. The treatments consisted of eight different levels of potassium. All other crop management practices were done uniformly in all plots as per the recommendation of KAU. Observations on biometric parameters as well as yield attributes were recorded during the cropping period. The soil, shoot and tuber were analysed for the various nutrients. The quantity of potassium extractable by various reagents was also estimated at these three stages. The Q/I parameters were estimated for the soil under study and the thermodynamic parameters related to K supplying power of soil were worked out. Tuber number and tuber yield were significantly influenced by the potassium application up to 60 kg K2O ha-1. The size of the tuber was not significantly affected with potassium application. Available potassium status that increased linearly with the levels of K did not affect the availability of P where as availability of N increased during the active growth stage of the coleus. Available potassium increased significantly with the levels of K application. Availability of exchangeable Al and Mn in soil got reduced with the increased levels of K. Even though the nitrogen and potassium content in shoot increased with the levels of K application at active stages of crop growth it had not reflected in the final yield. Calcium and aluminium absorption were found to reduce with increase in available K. Nitrogen and phosphorous content in the tuber reduced towards the harvest of crop. Calcium and magnesium content in tuber was influenced by K application where as K content in tuber was not increased with the levels of K. At all stages of analysis the quantity of K extracted with all reagents increased with the levels of potassium application in the soil. The water soluble, exchangeable and non-exchangeable potassium were reduced from initial stages towards harvest indicating the crop utilization and the presence of dynamic equilibrium between the various forms of potassium. Correlation studies conducted between yield attributes and quantity of K extracted revealed positive correlation between tuber yields and tuber number with water soluble and exchangeable K. The quantity-intensity parameters estimated at temperatures viz. 25°C and 40°C showed that the desorption of potassium is more at higher temperature indicating the higher availability of K in summer season. The potassium adsorption of soil under study followed the Freundlich adsorption isotherm both at 25°C and 40°C.
  • Thumbnail Image
    ThesisItemOpen 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 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.
  • Thumbnail Image
    ThesisItemOpen Access
    Yield maximisation in rice (Oryza sativa L) in the acid sulphate soils of Kuttanad through systematic approach in fertilizer use
    (Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2007) Annie, Koruth; KAU; Venugopal, V K
    Cereals are the world’s major source of food for human nutrition. Among these, rice is very important and represents the staple diet for more than two-fifths (2.4 billion) of the world’s population, making it the most important food crop of the developing world. Rice is the staple food of Kerala and is the only cereal crop of significance to the food basket of the State. Kuttanad is the rice bowl of Kerala producing nearly 30% of the State’s rice output. The entire area is now planted with high yielding rice varieties adopting all improved agricultural practices including higher doses of fertilizers and pesticides. The problems associated with the application of heavy doses of fertilizers, leading to nutrient imbalance and economic loss to the farmer is a major constraint. Therefore improvement in soil health through balanced fertilization, leading to productivity increase and economic benefit to the farmer, will have a measurable impact on rice production in the state. With a view to realize the maximum economic yield in rice by optimizing the nutritional status of the soil, a series of experiments were undertaken under the present study entitled “Yield maximisation in rice (Oryza sativa L.) in the acid sulphate soils of Kuttanad through ‘systematic approach’ in fertilizer use”. This involved preliminary soil analysis, nutrient fixation study and green house nutrient survey to demarcate the nutrient constraints and also to optimize the soil nutrient status. The critical level of P & K for the soils of Kuttanad were also done since the basic concept of systematic approach is based on the critical level of nutrients in soil. Pot culture studies were undertaken to find out the critical level of P & K using maize as indicator crop. The soil test values of P & K were correlated with the per cent yield and a significant correlation was obtained only for P with yield. A quadratic relationship was observed with per cent yield and soil test P values. This relationship gave a critical level value of 11.17 mg I' 1 for P. But in the case of K, no such relationship was obtained. Fixation study conducted for P, K, Cu, Zn, Mn, S & B to find out if any of the applied plant nutrients, fixed or complexed abnormally with the soil indicated P, K, Zn, S & B as the limiting nutrients, and the optimum quantities of these limiting nutrients were determined as 224 mg f 1 P, 122 mg l"1 K, 5.8 mg f 1 Zn, 2 mg I' 1 S & 1.52 mg I' 1 B. The green house nutrient survey conducted to arrive at the optimum treatment revealed that, for formulating the optimum treatment, lime @ 0.07 g CaCC>3 100 ml' 1 soil, Ca @ 822.4 mg I'1, Mg @ 349 mg f 1, P, K, Zn, S & B at the above concentrations, Mo @ 2 mg I' 1 & N @ 100 mg I' 1 has to be added. There were 16 treatments. This experiment was conducted with Sorghum as indicator crop and the relative yield calculated from the biomass yield, recorded on the 45th day of planting revealed P only as the limiting nutrient for this particular soil. The quantity of P to be added to the optimum treatment was 224 mg I'1, which is 602 kg P ha'1. Since this is a very high and uneconomic dose for farmers to adopt, the Package of Practices Recommendations: Crops (POP) for medium duration rice variety, 45 kg P2O5 ha’1 was opted as the base and since P is the limiting nutrient, two higher doses, 60 & 75 kg P2O5 ha' 1 were tested as the three levels of P application. As balanced fertilization is a must for the rice crop, three levels of K were also included. Since K was not limiting, the POP recommended dose and two lower levels were tested, i.e., 15, 30 & 45 kg K2O ha'1. Thus the design for the field experiment was 3x3 Factorial RBD with an absolute control. Total 9+1 treatments. N @ 90 kg ha' 1 was applied to all treatment plots. The main effect of P & K and their interactions were studied. The field experiment was laid out for two consecutive seasons, Puncha (Rabi) 2004-05 (Nov. ’04 - March ’05) and Additional Crop (,Khan/) 2005 (May ’05 to Oct. ’05) in the experimental field of Rice Research Station (RRS), Moncompu, Kuttanad, Kerala. The medium duration rice variety, Uma (MO. 16) released from RRS, Moncompu with an average grain yield of 4.5 - 5.0 t ha' 1 was used for the experiment. The effect of these treatments on dry matter yield of shoot & root, soil & plant nutrient content and nutrient uptake of N, P & K at the critical stages of rice growth were studied. Biometric observations, yield and yield components were also recorded. For P, the limiting nutrient, significant differences in the phosphorus content of plant were observed when different doses of P were applied. The P content and uptake of grain and straw were not influenced during the Puncha season, while during the Additional Crop season it was significantly influenced by the varying doses of P. All the control plots recorded a significantly lower P content and uptake & low P soil status compared to treated plots on an average during both seasons. An increase in the application of K doses, resulted in a significant increase in the K status of soil during Puncha season, while during the Additional Crop season, this was not noticed and the treated plots were on par with control. With an increase in applied K, there was a significantly corresponding increase in K content in plant during the Puncha season, while during the Additional Crop season this was not so. The K content and uptake of grain and straw was not influenced during both seasons by the different doses of K but the treated plots recorded a significantly higher uptake
  • Thumbnail Image
    ThesisItemOpen 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, K
    The 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.
  • Thumbnail Image
    ThesisItemOpen Access
    Quantity - intensity relations of phosphorus with reference to its bioavailability in lateritic soils
    (College of Horticulture, Vellanikkara, 2008) Geetha, P; KAU; SureshKumar, P
    Five 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.