Theses

Browse

Search Results

Now showing 1 - 9 of 26

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
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
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
Increasing the geranoil content of palmarosa oil by chemical methods
(Department of Soil Science and Agricultural Chemistry, Horticulture College, Vellanikkara, 1997) Mullakoya, C P; KAU; Samuel, Mathew
Palmarosa, Cymbopogon martinii (Stampf) var. motia is an important essential oil crop grown commercially in various states of peninsular India. Palmarosa oil finds extensive use in flavouring, cosmetics and toiletry. The oil is valued for the principal constituent geraniol, present in the oil to the extent of 75-82%. Besides being a high grade perfume, geraniol is the starting material for a number of synthetic aroma chemicals. Next to geraniol, the most abundant chemical component of the oil is geranyl esters, predominantly geranyl acetate. Most oils contain about 2 - 12% geranyl acetate. Several factors like the genotype, season, harvest stage, method of oil extraction etc. influence the ratio of geraniol to geranyl acetate in the oil and it is found that a reciprocal relationship exists between the geraniol and geranyl acetate content of the oil. At most times, the geraniol content of palmarosa oil produced by cultivators fall short of requirements of the user industry. The availability of an inexpensive and efficient method of hydrolytic conversion of geranyl acetate to geraniol will facilitate the farmer to undertake an on-farm quality upgradation of his product which will fetch him better price. A laboratory investigation was carried out at the Aromatic and Medicinal Plants Research Station, Odakkali, Kerala during 1994-96 to develop a method for upgrading the quality of palmarosa oil by the conversion of geranyl acetate in the oil to geraniol. Four treatments were tried for the hydrolysis of geranyl acetate, with essential oil of palmarosa type ODP-3 as the test material viz., methanolic sodium hydroxide, methanolic sodium carbonate, ammonia and aqueous sodium hydroxide. Mixing of essential oil with 5% methanolic NaOH reagent in the ratio of 1 : 4 and keeping undisturbed at ambient conditions for 30 min were the optimum conditions for the complete hydrolysis of geranyl acetate in the oil. The product of reaction analysed 90.5% geraniol and the process yielded geraniol to the extent of 78.74% of the oil taken for processing. However, treatment of the oil with methanolic sodium carbonate or ammonia did not result in hydrolysis of geranyl acetate. In the case of aqueous sodium hydroxide method of hydrolysis, refluxing the essential oil with an equal volume of 20% aqueous NaOH solution for 30 min was optimum for the complete hydrolysis of geranyl acetate in the oil. The product contained 89.35% geraniol and the quantity of geraniol yielded by the process was estimated at 86.67% of the oil taken for processing. Comparison of the methods of hydrolysis studied -revealed that in terms of geraniol content of the product, geraniol yield from the process and time: required for '\ .' .. the reaction, the aqueous sodium hydroxide method was found to be the best. The efficiency of the method for quality upqradation was tested on essential oils of different Cymbopogon types viz., ODP-1, ODP-3, C-3, OD-455 and Jamrosa. All the oils were characterised by low level of geraniol and high level of geranyl acetate and none of them conformed with ISI specifications for palmarosa oil. In case of all the oils, the treatment resulted in complete conversion of gerariyl acetate to geraniol with commensurate increase in the level of geraniol, bringing about a vast increase in their quality. By the process, oils of ODP-3 and Jamrosa were upgraded to meet the specifications for palmarosa oil. Verification of the sodium hydroxide hydrolysis method on pilot plant scale showed that it can be employed on large scale for the quality improvement of . palmarosa oils which contain appreciable amount of geranyl acetate.
Open Access
Vermicompost as a potential organic source and partial substitute for inorganic fertilizers in sweet potato (Ipomoea batatas (L.) Lam.)
(Department of Soil Science and Agricultural Chemistry,College of Agriculture, Vellayani, 1998) Suresh Kumar, S N; KAU; Ushakumari, K
An investigation entitled "Verrnicompost as a potential organic source and partial substitute for inorganic fertilizers in sweet potato (Ipomoea batatus (L) Lam)" was carried out at the Instructional Farm, College of Agriculture, Vellayani during the period December 1995 to April 1996. The main objectives of the study were to study the efficiency of vermicompost as an organic manure, the extent to which inorganic fertilizers can be substituted when vermicompost was used as an organic source and the feasibility of reducing the dose of vermicompost. The experiment was laid out III randomised block design with seven treatments and four replications. The treatments consists of package of practices recommendations of Kerala Agricultural University for sweet potato (cattle manure + inorganic fertilizers) and vermicompost as organic source with graded doses of inorganic fertilizers. The growth parameters like vine length and number of branches did not show any significant variation. However highest vine length and number of branches are noticed in treatment which received vermicompost as a sole source of nutrient. Significant difference was observed in vine yield and highest vine yield was obtained when vermicompost was given as a sole source of nutrients. Yield attributing characters like length and girth of tubers and number of tubers did not show any significant variation. With respect to mean tuber weight and tuber bulking rate, the treatment differed significantly and maximum effect was observed when vermicompost was applied along with half the recommended dose of inorganic fertilizers. Significant treatment effect could be observed in total tuber yield and marketable tuber yield. Vermicornpost with half or 3/4th NPK produced highest yield. From this it could be deduced that by using vermicompost as organic manure in sweet potato, it is possible to bring down the usage of chemical fertilizers. Half or 3/4th dose of vermicompost along with recommended dose of inorganic fertilizers was equally effective as that of package of practices recommendations of Kerala Agricultural University (cattle manure + recommended inorganic fertilizers) in yield and yield attributes of sweet potato. The nitrogen and phosphorus content in the leaves and vmes did not show any significant difference by applying various treatments. But in tubers the nitrogen content was maximum when 1/2 inorganic fertilizers + organic manure as vermicompost was applied. The phosphorus accumulation in tuber was maximum in the combination of full inorganic fertilizers + organic manure as cattle manure was given. The treatment combination of full inorganic fertilizers + organic manure as vermicompost resulted m maximum accumulation of phosphorus in leaves, vines and tubers. Regarding calcium, magnesium and iron contents of leaves, vines and tubers there was no significant difference among various treatments. The application of full inorganic fertilizers + organic manure as vermicompost produced maximum manganese concentration in leaf and tuber. The starch content of tubers showed a decreasing trend with the reduction in the quantity of inorganic fertilizers. But by reducing inorganic fertilizer levels, the reducing sugar percentage increased. The crude protein, crude fibre and carotene contents showed the same trend as that of reducing sugar. The plant uptake of nitrogen, phosphorus and potassium was maximum when 112 inorganic fertilizers + organic manure as vermicompost was applied. The organic carbon level after the crop showed significant difference among various treatments. The maximum organic carbon percentage was noticed when nitrogen as vermicompost + organic manure as vermicompost was given. The growth characters like vine yield, number of branches were negatively correlated with yield. The yield components like number of tubers per plant, tuber weight, uptake of nitrogen, phosphorus and potassium showed positive correlations with yield. The economics worked out show that the highest net profit was obtained when 1/2 inorganic fertilizers + organic manure as vermicompost was given. The cost of cultivation while applying this treatment was minimum and it showed a B C ratio of 2.53.
Open Access
Effect of vermicompost enriched with rock phosphate on cowpea
(Department of Soil Science and Agricultural Chemistry,College of Agriculture, Vellayani, 1999) Sailajakumari, S; KAU; Ushakumari, K
An investigation was carried out at the College of Agriculture, Vellayani during 1998 to evaluate the effect of vermicompost enriched with RP on P availability yield and quality of cowpea and the feasibility of reducing the inorganic P. The variety used was Kanakamoni. All the growth characters, yield and yield attributes studied were significantly influenced by different treatments. Nodule number per plant, weight of nodules per plant and root shoot ratio were maximum by the application of enriched vermicompost. Yield attributes like number of pods per plant, number of seeds per pod and hundred seed weight and total grain yield were significantly increased by the application of enriched vermicompost. Vermicompost primed with full RP or with half RP produced no significant difference in grain yield. Thus the results revealed that inorganic phosphoate for cowpea coufd be reduced to half• of its recommended dose by priming vermicompost with RP. Analysis of plant samples at harvest showed that maximum content of macronutrients except Mg was recorded by enriched vermicompost. It showed its superiority over other treatments for protein and P content of grain. Enriched vermicompost also registered significant increase in soil available N, P and K after the experiment. ./ 2 Uptake of macronutrients was significantly influertced by different treatments. Enriched vermicompost registered maximum mean value for the uptake of all the macro nutrients. Priming of vermicompost with full RP or with half RP produced no significant difference in uptake of any macro or micronutrients. Grain yield was positively and significantly correlated with the growth characters. Yield and yield attributes showed positive and significant correlation with nutrient uptake. The study indicated the superiority of vermicompost enriched with RP on yield and quality of cowpea. P recommendation for cowpea can be reduced to half by priming vermicompost with RP.
Open Access
Effect of vermicompost/ vermiculture on physico-chemical properties of soil
(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 1996) Rajalalekshmi, K; KAU; Pushkala, S
A study was undertaken to assess the effect of application of vermin compost / vermin culture on physic – chemical properties of soil and yield of chilli making use of the soil and plant samples taken from the trial conducted at College of Agriculture, Vellayani. The experiment was conducted during the period from December 1994 to April 1995. The soil of the experimental site was sandy loam. (fine loamy kaolinitic isohypothermic Typic Kandiustults). The experiment was laid out in randomized block design with four replications and six treatments. The treatments consisted of FYM + NPK fertilizers, vermin compost + NPK fertilizers, vermin culture with local worms and with Eudrillussps, vermin culture with above sps. Of worms + basal dose of NPK fertilizers. Soil samples were collected from all the replications of the various treatment before planting, at maximum flowering stage and at harvest. Plant samples were also collected at the above growth stages. Soil and plant samples were analysed in the laboratory to find out the effect of application of vermi compost / vermin culture on physic – chemical properties of soil and content of nutrients in plant parts viz. leaf, shoot and root. Results of preliminary analysis of soil samples collected before the experiment revealed the beneficial effect of application of vermin compost/vermin culture on physic – chemical properties of soil. Physical properties of soil such as bulk density and particle density were found to be much reduced in plots treated with earthworms while porosity was increased in them. Percent of water stable aggregates in plots with insitu application of worms was found to be more than 50 percent but an optimum mean weight diameter of above 0.50 mm was recorded by all treatments. Water stable aggregates with greater than 0.25 mm size had helped to retain more moisture due to the increased intraggregate spaces. The moisture content in soil was found to be more due to the coverage of organic wastes on soil surface. Water holding capacity and hydraulic conductivity were also much influenced by the presence of earthworms. The increased infiltration rate with insitu application of worms to soil indicated the improvement in water permeability of the soil as compared to plots without worms. But surface compaction of soil was found to be not much affected by the application of vermin compost / vermin culture and it showed negative correlation. Application of organic manures either as farmyard manure or vermin compost with inorganic fertilizers had significant influence on soil reaction and organic carbon content of the soil. Organic carbon content was found to be increased with increasing nitrogen rates at both depths of 0 – 15 cm and 15 - 30 cm. Available nutrient contents of the soil viz. available nitrogen, phosphorus and potassium and exchangeable calcium and magnesium were influenced significantly due to different treatments at maximum flowering stage and at harvest. Application of vermin compost + NPK increased the availability of nutrients in soil while application of vermin culture alone with local worms or Eudrillussps. Had resulted in a lower value. Regarding the nutrient content in plant parts such as leaf, shoot and root, all the nutrient contents were highest in the plot treated with vermin compost + NPK fertilizers followed by farmyard manure + NPK. Significant correlation existed between available nutrient in soil and plant nutrient content. Maximum yield and growth parameters were also recorded by the treatment receiving application of vermin compost + NPK fertilizers and the results thus clearly indicate that application of vermin compost along with NPK is essential to maintain high yields. Application of vermin culture alone with local worms or Eudrillussps. Or together with basal dose of fertilizers also failed to give higher yields. Thus by adopting vermin culture technique only the physical properties of soil can be improved while its effect on chemical properties is negligible. So combined application of vermin compost/vermi culture with inorganic fertilizers is found to be better for improving the soil productivity and fertility.
Open Access
Interrelations of humans with the fertility components of wetland soils
(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 1996) Sreedevi, K; KAU; Alice, Abraham
Surface soil samples from the major wetland soil types of Kerala were studied to establish the relationship between soil organic matter and its fractions with the total and available nutrients and other physicochemical characters. Destruction of organic matter has resulted in a substantial drop in the status of almost all nutrients and an appreciable change in soil properties. The SOM separated from the soils were fractionated and the correlation between soil characters and the SOM and its fractions were determined. Regression equations relating soil properties which were significantly correlated with SOM and its fractions were also derived in each soil type. The study has revealed that CEC,WHC,SOM, lime requirement, buffering capacity as well as total and available nutrients in all the four soil types showed considerable degree of variability between samples in each soil type. The content of SOM was highest in Kayal soils (8.03%) and lowest in lateritic alluvial (2.24%) soils with Kari and Karappadam soils with intermediate values of 7.58 and 6.81% respectively. Fractionation of organic matter has shown that humification of SOM was maximum in Karappadam soils, followed by Kayal, Kari and lateritic alluvial soils. The degree of degradation of humified organic matter was high in all the soil types except Kari soils, as evidenced from the HA/FA ratios. The SOM in Kayal soils may probably exist as a stable clay humus complex which has resulted in its lower contribution to CEC, lime requirement and nutrient status. All the four soil types were acidic and the contribution of SOM to free acidity was maximum in Karappadam soils (18.4%) followed by Kayal (17.2%) and lateritic alluvial soils (4.2%). Inspite of the high content of SOM, its contribution to free acidity in Kari soils was only 7.1%, probably due to the low deprotonation of SOM at low pH values. pH in all soil types is negatively correlated to SOM and its fractions. The Kari, Karappadam and Kayal soils are highly buffered when compared to lateritic alluvial soils and the slope of the buffer curves for these soils showed a drastic drop due to the destruction of organic matter. The contribution of SOM to lime requirement ranged from 13.9 to 25.5% which is evident from the drastic drop in lime requirement values consequent to the destruction of organic matter. Maximum contribution of SOM to WHC was shown by lateritic alluvial soils (49.8%). In Kari, Karappadam and kayal soils, the contribution was 24.7, 29.4 and 25.3% respectively.WHC is positively related to SOM and its fractions in all the soils. CEC was highest in Kari soils and lowest lateritic alluvial soils. The contribution of SOM to CEC was maximum in Kari soils (27.2%) and least in Kayal soils (9.7%). CEC of all soils except Kayal soil showed significant positive and linear relationship with SOM as well as with its components. The lack of such a relationship in Kayal soil is attributed to the existence of stable clay-humus complexes. Karappadam soils showed the highest content of total nitrogen and lateritic alluvial soils the lowest. Available nitrogen was highest in Kari soils and lowest in Karappadam soils. In all the four soil types, SOM contributed to more than 90% of total and available nitrogen and it is positively correlated to total and available nitrogen. Total phosphorous was highest in Kayal soils and lowest in Kari soils. Inspite of the lowest content of SOM in Kari soils, it made the maximum contribution to total phosphorous (35.2%). In the Kayal soils the contribution of SOM to total phosphorus was minimum and representing only 5.4%. The available phosphorous in all the soil types showed maximum degree of variability (85.1 to 160.8%) between samples and the contribution of SOM to available phosphorus was also very low. It showed a negative correlation with SOM and its fractions in Kari, Karappadam and Kayal soils probably due to the strong linkage of phosphorus to humus via iron and aluminium bridges. In lateritic alluvial soils, the relationship between SOM and available phosphorus was positive. The total and exchangeable potassium, calcium and magnesium are positively correlated to SOM and its fractions. However these are influenced only to a very low degree by the SOM content. The pattern of relationship of each soil property with SOM is the same as that with its fractions and hence, in studies on soil organic matter, the derivation of relationship between soil properties and soil organic matter alone is sufficient to bring out the interaction between soil organic matter and components of soil fertility.

Theses

Browse

Thesis Type

Type

Author

Date

Subject

Search Results