Theses

Browse

Search Results

Now showing 1 - 9 of 36

Open Access
Effect of Vermicompost on the yield and quality of tomato (lycopersicon esculentum Mill.)
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 1996) Pushpa, S; KAU; Prabhakumari, P
An investigation was carried out at the Instructional Farm, attached to the College of Agriculture, Vellayani to evaluate the Effect of vermicompost on the yield and quality of tomato. The experiment was laid out in Randomised Block Design with ten treatments and three replications. Biometric observations viz. height of the plant, number of leaves and number of floweres were greately influenced by the application of vermicompost compared to farm yard manure. Yield attributes like mean fruit weight and girth of fruits were also found to be significantly influenced by the vermicompost application. Vermicompost application has got a significant influence on the yield of tomato. Plants receiving 25t vermicompost along with full dose of inorganic fertilizers produced maximum yield followed by the plants receiving 25 t farm yard manure along with full dose of inorganic fertilizers. Germination count and viability was maximum when vermicompost was used as the organic source. Maximum germination count and viability was observed when 100t ha-1 vermicompost was used. Vermicompost application has also got a significant influence on fruit qualities. Protein, and carbohydrate content were more in vermicompost treated plants compared to farm yard manure application. Chemical properties of the soil was significantly influenced by the application of vermicompost. pH, organic carbon, available N, P2O5, K2O, Ca and Mg was maximum when 25t vermicompost along with full dose of inorganic ferilizers was used. However availability of micronutrients Mn, Cu, Zn was more in 100t vermicompost applied plots. Application of vermicompost increased the uptake of nutrients by plants. Maximum uptake of all nutrients viz. N, P, K, Ca, Mg, Mn, Cu and Zn was found in plants treated with 25t vermicompost along with full dose of inorganic fertilizers. Correlation studies showed that nutrient uptake was significantly and positively correlated with availability of nutrients. Yield and nutrient uptake of plants were significantly and positively correlated with availability of nutrients and so vermicompost can be effectively used for increasing the fruit yield and quality of fruits in tomato.
Open Access
Quality and fatty acid composition of coconut oil in relation to varietal variation and mineral nutrition
(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 1994) Geetha Kumari, V S; KAU; Ranjendran, P
Coconut is a perennial oil seed crop with a large number of cultivars having widely varying growth and yield characteristics. It is both an agricultural and industrial crop with immense economic importance. A variety of edible oils are available in the market today with wide variations in quality parameters and nutritional characteristics. Although product quality is influenced by many factors associated with production, harvesting, curing and processing; quality is influenced to a greater extent by the genetic parameters and chemical composition. Assessment of quality parameters and fixing standards for the nutritional aspects are to be considered with top priority for the development of new varieties/cultivars along with the yield attributes. Considering the afore mentioned facts in view, it was felt essential to study the effect of varietal variation and mineral nutrition on the oil content, quality and fatty acid composition of coconut oil. Nuts collected from different varieties/cultivars from RARS, Pilicode, Instructional farm, Vellayani and palms of an ongoing fertilizer trial of the CRS, Balaramapuram, were subjected to chemical analysis to study the above aspects. The results of the analysis were summarised and appropriate conclusions drawn. The effect of varietal variation on the oil content and quality parameters like acid value, saponification value and iodine value were found to be significant. Minor quality parameters like Reichert – Meissel and Polenske value also showed considerable differences among the varieties. The fatty acid composition of oil from selected varieties also had shown considerable variation. The effect of mineral nutrition on the oil quality and fatty acid composition of coconut oil were found to be insignificant. The oil content was not influenced by nitrogen and phosphorus while potassium had a significant but negative effect on oil content. The influence of N, P and K fertilizers on the quality parameters like acid value, saponification value and iodine value was not significant in general. Minor quality parameters like Reichert – Meissel and Polenske value showed variation due to fertilizer treatments. The fatty acid composition of oil from selected treatments. The fatty acid composition of oil from selected treatments were also influenced by mineral nutrition. From the results of the study it can be concluded that quality parameters of coconut are much influenced by varietal differences than by mineral nutrition. Thus it is evident from the study that the genetic variability has got a greater role to play in modifying quantity parameters and chemical composition of the most important tropical adible oil namely coconut oil. Selection and breeding should be directed towards tailoring new varieties with higher oil content, quality indices and fatty acid composition.
Open Access
Distribution of extractable in soils of selected major land resource area of Kerala
(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 1997) Sathyanarayanan, R; KAU; Abdul, Hameed
The investigation was carried out to assess the total and available micronutrients in soils of selected major land resource areas (MLRAs) of' Kerala. The micronutrients investigated in the present study were iron, manganese, zinc, copper and boron. The study was intended to establish the pattern of the distribution of micronutrients both vertically and spatially in eight MLRAs viz, Palode, Vellayani, Trivandrum, Mannar, Kottarakkara, Thakazhy, Ramankary and D-Block soil series of Kerala. Three extractables viz DTPA, EDTA and ammonium acetate were used in the analysis. The available boron content in these soils was also determined by hot water extraction method. All the micronutrients showed great variation in their distribution in the various horizons of the profiles. The micronutrients content of the soils estimated were correlated with soil properties like pH, organic carbon, CEC and clay content. They were found to be positively and significantly correlated with organic carbon, CEC and clay content while it was significantly and negatively correlated with pH. The significant correlations revealed that the micronutrient availability in these soils were influenced greatly by the soil properties mentioned above. From the results obtained, it was observed that micronutrients like iron and manganese were well supplied in all the profiles studied. The micronutrients were found to decrease with depth except in Ramankary, D-Blockand Thakazhy series where it showed an irregular trend with depth due to the peculiar hydrologic and oxidation-reduction conditions existing in these soil series. The available and total micronutrients content in the surface soils from places around the profile sites did not show any significant variation among places. In almost all the samples very high iron content was recorded.
Open Access
Leaf litter dynamics in acacia and eucalyptus plantations
(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 1997) Moossa, P P; KAU; Venugopal, V K
An investigation entitled “Leaf litter dynamics in Acacia and Eucalyptus plantations” was undertaken to study the leaf litter production, litter decomposition and nutrient release characteristics, and impact of Eucalyptus and Acacia monoculture plantations on the soil physico-chemical and biological characteristics during 1994-97. One hectare each of Acacia auriculiformis, Eucalyptus tereticornis and a moist deciduous forest coming under the Kulathupuzha range of Kerala Forest Department were selected for the study. Field experiment were conducted to determine the leaf litter production and decomposition characteristics of plantation and natural forest. Leaf litter collected at monthly intervals showed that highest litter production was in Acacia (9.4 t ha-1 year-1) followed by natural forest (6.67 t ha-1 year-1) and Eucalyptus (4.68 t ha-1 yaer-1). Pattern of litter production was unimodal in Acacia and natural forest while in Eucalyptus it was bimodal. Chemical analysis of litter samples of plantations and natural forest revealed that with respect to nutrient content fresh and leaf litter of Acacia and Eucalyptus is superior to natural forest whereas litter quality in terms of water soluble components, polyphenols, lignin and cellulose were superior in natural forest. Annual dry matter loss of leaf litter by decomposition followed the order natural forest > Acacia > Eucalyptus. Nutrient release pattern of major and micro nutrients were also worked out for the leaf litter during the process of decomposition and natural forest litter recorded the highest mobility for all the nutrients on decomposition. Improvement in soil physico-chemical properties were noticed due to leaf litter decomposition in the monoculture plantation and natural forest. Biological activity in terms of earthworm and nematode under monoculture plantation was significantly lower than that of adjacent natural forest. Microbial content of soil below the litter bag during different months of decomposition were low in Eucalyptus and Acacia. Chemical analysis of the profile samples of various plantations revealed lower nutrient status in respect of major and micronutrients compared to natural forest. The physical properties of the soil also recorded as unfavourable change in the monoculture plantations as compared to the adjacent natural forest. Proximate anlysis of soil organic matter and humus characterization of the soil organic matter separated from various plantations indicated a low rate of humification and condensation under Eucalyptus. Low humic acid and fulvic acid content in humus and dominance of fulvic acid over humic acid was also noticed in Eucalyptus plantations. Functional group analysis of humic acid and fulvic acid showed that humic material separated from natural forest contained higher quantity of total acidity, contributed by COOH and phenolic group compared to plantation soils. UV, IR, DTA and TGA analysis of humic acid and fulvic acid separated from various plantations showed no variation with respect to natural forest. Allelopathic effect of fresh leaf and leaf litter extract of various plantations on the germination and growth of rice and cowpea followed the order Eucalyptus > Acacia > natural forest and as the concentration decreased from 1: 2 to 1: 10, the allelopathic inhibition also decreased significantly. Allelopathic effect of soil extract also followed the order Eucalyptus > Acacia > natural forest. Thus it can computed that though the leaf litter production and litter quality of monoculture plantations are comparable with that of natural forest, leaf litter decomposition and nutrient released were significantly lower than that of natural forest. Soil physico-chemical properties, soil fertility and biological activities were also adversely affected by monoculture plantations.
Open Access
Characterisation of the gravels in the major soil series of Trivandrum district
(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 1996) Suraj, John; KAU; Subramonia Iyer, S
Soil gravels are different in their morphological, physical, chemical and mineralogical features; as well as in their origin. In the major soil series of Trivandrum district, soil gravel inclusions make up a considerable part of the soil mass. Presence of soil gravels interferes with the cultivation operations, reduce soil volume and quantity of available water. In soil textural determinations and the soil fertility evaluation, presence of soil component greater than 2mm is usually disregarded and ignored. In order to gather information on the nature and properties of soil gravels, their genesis and distribution and their specific contribution to soil fertility; an integrated and systematic morphological, physical, chemical, mineralogical and micromorphological characterisation and interpretation of soil gravels of the representative profiles of the major soil serious of Trivandrum district namely Palode, Nedumangad, Varkala, Thonnackal and Trivandrum series were attempted. All the series except Thonnackal were gravelly throughout; Palode, Varkala, and Trivandrum series showed an increase in gravel content with depth but no specific profile pattern was observed at Nedumangad and Thonnackal. Palode series is unique with all the different gravel fractions (2mm to 2.5 cm, 2.5 to 7.5 cm and 7.5 to 25 cm). Another uniqueness of the Palode series is the presence of gneissic cobbles. Cobbles were absent in all the other series. Combination of grayels different in morphology and genesis are present at Palode and Trivandrum series. Gravel consolidation and soil hardening were observed maximum at Varkala series and least at Thonnackal series. Higher total phosphorus and potassium content of gravels indicate that gravels are the potential source of phosphorus and potassium for crop production. Acid insoluble content of gravels are in the increasing order Varkala< Trivandrum Quartz content of the finer gravels are in the increasing order at Varkala Palode and Nedumangad series contain multiglaebular microgravels and multimicrogravelly coarse gravels and cobbles. The gravels of Varkala are dominantly nodular than concretionary. The uniqueness of the Thonnackal series is the presence of rubefied less hard kaolinitic gravels. The gravels of the Trivandrum series are nodular, plinthic to petroplinthic with bigger angular skeletons. The preponderance of gravels with geodic internal morphology in the lower horizons and pseudomorphic in the surface horizons are direct expressions of geogenic and pedogenic origin of gravels. The observation of nucleic type of gravels in the last horizon of Thonnackal series is indicative of its detrital origin from microgravels of nearby landscapes. The preponderance of quartz both in the soil and gravels is obviously due to the acid igneous and metamorphic parent material. The hardened plinthite gravel ie., the petroplinthite gravel is proposed in the soil taxonomy to differentiate Entisols and Inceptisols from Oxisols and Ultisols. The comparative gravel contribution to available nitrogen content of the soil is in the increasing order Palode A multilocational field experiment based on the information gathered in the present study is desired to be taken up to reveal the effect of gravels on the performance of crops in the actual field situation.
Open Access
Evaluation of maton rockphosphate in the acid rice soils of Kerala
(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 1997) Suja, Thomas; KAU; Sushama, P K
A study conducted at College of Horticulture during the period 1994 – 96 so as to assess the effectiveness of Maton rockphosphate (MTRP) as a source of P compared with single super phophate (SSP), diammonium phosphate (DAP) and Mussoorie rockphosphate (MRP). In addition to the above sources a control treatment (with no P fertiliser) and another treatment with SSP at the rate of 45 kg P2o5 ha-1 given twice (conventional practice) were also included. The P release from all the sources were monitored with an incubation experiment. In order to evaluate the response of fertilisers two continuous pot culture experiments were undertaken using Jaya variety of rice. Two acid rice soils of Kerala, viz., Kuttanad alluvium and laterite were used for the study. The variations in pH of the soil types indicated that there was increase with advancement of periods under waterlogging irrespective of the treatments including the control. Available N was high in Kuttanad alluvium as compared to laterite and was found to decrease with periods of incubation. The content of available P gradually increased with period of incubation, reached a peak at 120 days for water soluble phosphates (SSP and DAP) and 180 days for rockphosphates, irrespective of the soil types. Comparing the two extractants, Mathewstriacid extracted more available P than that of the Bray solution in both the soil types. Available K decreased with periods of incubations. In general, Kuttanad alluvium recorded higher content of available nutrients as compared to laterite. In both the soil types the most dominant P fraction was Fe – P followed by AI – P and Ca – P. While evaluating the pot culture experiment it was observed that available nutrient content decreased with advancement of crop growth. Even after the harvest of second crop, the residual effect of MTRP was recorded to be high. There was maximum uptake of P at the second crop season as compared to the first crop irrespective of the soil types. The leachate loss decreased with crop growth in both the soil types. But the maximum leachate loss was recorded for N followed by K and P. The grain yield as well as the relative yield was found to be maximum for the laterite soil on comparison to Kuttanad alluvium for the first and second crop of rice. In Kuttanad alluvium, DAP and MTRP yielded better in the first and second crop respectively. While in laterites SSP was found to be better in grain yield as compared to other sources, The source, DAP was superior to others in straw yield for both the soil types with increase in levels of P application, there was increase in grain and straw yield.
Open Access
Soil nutrirent dynamics in cocoa
(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 1995) Smitha, B; KAU; Wahid, P A
An investigation on the dynamics of soil nutrients in the rootzone of cocoa (Theobroma cacao) was conducted during 1993 – 94 at the College of Horticulture, Vellanikkara. Soil and leaf samples were taken from cocoa trees under the Cadbury – KAU Co – operative Cocoa Research Project, Vellanikkara. Cocoa variety used for the study was forastero. The soil of the site was laterite (Oxisol). The treatments consisted of factorial combinations of N, P and K fertilizers each at two levels (with and without), two levels (with and without) of irrigation and shade and seven age groups namely 1, 3, 4, 5, 6, 9 and 12 years. Soil samples were also collected from an uncropped and unfertilized area nearby. The impact of long – term inorganic fertilization, irrigation and shade and age of the tree on soil chemical characteristics as well as foliar nutrition of cocoa influenced by long – term inorganic fertilization, irrigation and shade were assessed. Continuous application of urea for a period of nine years increased soil acidity and availability of P, S, Fe and Mn. It also increased total soil P and Fe. But it resulted in depletion of available K, Ca, Mg, Zn and Zn and Mn reserves of the soil. Long – term application of superphosphate resulted in the build – up of available and total P in soil. It also improved the status of soil available Ca, S and soil reserves of Ca and S. But it depleted soil available and total K, available and total Zn, available Mg and Cu and total Mn. Muriate of potash application increased the available and total K content of the soil. On the other hand it caused depletion of available P, Ca, S, Mn, Cu and soil Ca and Mg reserves. Interactions among urea, superphosphate and muriate of potash were also significant with regard to the fertility of the cocoa rootzone is concerned. Increasing soil acidity due to urea application, enrichment of S and Ca due to superphosphate application, and decrease in available P and S due to muriate of potash application were highly influenced by depth. Regular irrigation over a period of five years resulted in reducing the availability of P, Ca, Mn and Cu. It also reduced the total P and Mn in soil. But available K, Zn, S and total S tended to increase with irrigation. In the irrigated plots, total and available P were significantly lower in the surface layers compared to that in unirrigated plots. Provision of shade for a period of 13 years resulted in the build – up of soil organic carbon, available P, Fe and soil reserves of P, Ca, S, Fe, Zn and Mn. On the other hand it decreased the concentrations of available and total K, available S, and Zn and total Mg. Irrigation x shade interaction significantly influenced the available P content of soil. Urea application increased the foliar concentrations of N, Fe, Mn and Cu, but it decreased the leaf K content significantly. Long – term superphosphate application reduced Zn content of cocoa leaf. Application of muriate of potash increased leaf K content, but depressed foliar mg content significantly. Leaf N and K contents of cocoa were highly influenced by N x K interactions. N x P interaction significantly affected foliar Zn concentration of cocoa. Foliar Zn recorded higher values in plants receiving no nitrogen and phosphorus. Irrigation resulted in increased foliar concentrations of almost all nutrients except that of Ca and Mg. Foliar Ca content was higher in unirrigated plants. Effects of irrigation on leaf Mg was not significant. Cocoa trees under shade recorded higher concentrations of N, P, Mg, Fe and Mn and Cu in their foliage while K content was higher in open grown plants. Irrigation x shade interaction significantly influenced foliar N content. Shaded and irrigated conditions resulted in highest foliar N content. Nutrient dynamics in rootzone of cocoa over a period of 12 years of crop growth and fertilization could be described by linear or quadratic model. The linear model was found to be a better fit for available and total K, available and total Mg, available Cu and total Zn. In the case of available and total P, available and total Ca, available Zn, total S and total Cu the changes in concentrations with time could be described by a quadratic model. Available Mn content of the soil showed steady increase with age up to nine years followed by a sharp decrease.
Open Access
Fertility investigation and taxonomy of the soils of banana research station Kannara
(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 1995) Sreerekha, L; KAU; Marykutty, K C
Taxonomy and fertility investigation of the soils of Banana Research Station, Kannara, was the main intension of the present investigation. Representative surface soil samples were collected from each block of this research station, namely A, B, C, D, E and F for investigating the fertility status of soil. Profiles considered for the study were P1 and P2 in A block, P3, P4 and P5 in B block, P6 and P7 in C block, P8 in D block, P9 in E block, and P10 in F block. Profiles were excavated to study the characteristics of each of the horizons in the soil profile and classify the soils of each block. After the collection and preparation of soil samples, laboratory analyses were carried out as per the standard methods. With an increase in depth, profile samples showed an increasing intensity of colour of the horizons and increase in clay content whereas a decreasing trend was noticed for apparent density, absolute density, water holding capacity and pore space. Soils were acidic and low electrical conductivity values were observed. Organic carbon and total nitrogen decreased with depth. Total P2o5 content was lower than total K2o. Low reserves of total nutrients were observed for other elements also. Sesquioxide content was very high and intermediate layers showed maximum accumulation. In surface as well as profile samples the predominant cation was calcium followed by magnesium. A general increase of CEC and ECEC with depth was observed. Oxalate extractable iron content was lower than the dithionite extractable iron. Distribution of total iron was irregular. Surface soil showed wide variation in texture. Clay content showed significant positive correlation with water holding capacity whereas silt and organic carbon failed to impart any influence upon the same. Phosphorus fixing capacity was high for all the samples. DTPA extractable micronutrients were more than the adequate amount. Based on the soil test values fertilizers were recommended for various blocks. Nitrogeneous fertilizers can be reduced by 5 to 10 per cent. Applications of phosphatic fertilizers can be reduced by 75 per cent in most of the blocks. Potassium fertilizers can also be reduced considerably. Nutrient indices were calculated and a soil fertility map was drawn. Classification of pedons of various blocks according to soil taxonomy has been attempted and found that P1 of A block belongs to the order Entisol. P2 (A block), P3, P4 and P5 (B block), P6 and P7 (C block), P9 (E block) and P10 (F block) belong to the order Alfisol. P8 of D block belongs to the order Inceptisol. By this investigation, the classification of soil profiles were done and the fertility status of each block was found out. In accordance with the soil test values, fertilizer recommendations were made. Thus, by reducing the inputs, cost of cultivation could be reduced considerably.
Open Access
Vertical movement of nitrogen in major rice soils of Kerala
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 1995) George Abraham, T; Kau; Pushkala, S
An experiment was conducted at the College of Agriculture, Vellayani, to assess the leaching and runoff losses of applied fertilizer nitrogen in typical, major rice growing soils of kerala, with varying physical and chemical properties. Undisturbed vertical columns were used for the leaching study. The runoff study was conducted as a pot experiment using surface soil samples. The study revealed that the Onattukara soil recorded the highest leaching loss of applied nitrogen (56.10%). Kayal soil showed the lowest leaching percentage of 24.21. The quantity of leachate collected per unit time was also found to be the maximum in the case of Onattukara soil (185.51 ml/hr) and least in the case of Kayal soil (155.60 ml/hr). Correlation studies revealed that the leaching loss of nitrogen was negatively correlated with organic matter (-0.5593), cation exchange capacity (-0.4560), clay (-0.5864), bulk density (-0.3213) and water holding capacity (-0.5544). The leaching loss was positively correlated with the quantity of leachate collected per unit time (+0.8876). In the case of Onattukara and kole soils, the loss of nitrogen through leaching was observed till the fifth day. For Kari soils, the loss stopped completely by the 10th day. The Karappadam and Pattambi soils showed leaching till the 15th day. However, in the case of Kayal soils, the leaching loss continued through the whole period of the study. In all cases, maximum amount of leaching occurred during the first five days after fertilizer application and after that the loss was in negligible quantities. In the case of runoff study also, Onattukara soil showed the highest runoff loss of applied nitrogen (40.41). The least loss was shown by karappadam soil (15.70%). The runoff loss was found to decrease with increase in number of days. Even though, Karappadam soils showed the lowest runoff loss of applied nitrogen, it had the highest percentage difference in runoff loss (77.8%) and the least was shown by Onattukara and Pattambi soils (63.5%). Correlation studies revealed that the runoff loss of fertilizer nitrogen was found to be negatively correlated with the oprganic matter (-0.1248), cation exchange capacity (-0.0324), clay (-0.4135), water holding capacity 9-0.6723) and bulk density (-o.4659).

Theses

Browse

Thesis Type

Type

Author

Date

Subject

Search Results