Academic literature on the topic 'Kuttanad Clay'

Nitrogen through organics and inorganics application is an alternate to maintain soil health and crop productivity in the rice cropping system. With this background, field experiments were conducted in farmer’s field at Kuttalam during 2012-2013, 2013-14 to evaluate residual organics and mineral nitrogen (100%N) on growth parameters and yield of rice (Oryza sativa) in sandy clay loam and clay loam soil. The treatments consisted of residual organics viz., composted coir pith (CCP), green manures (GM), sugarcane trash compost (STC), vermicompost (VC), poultry manure (PM) and FYM applied(100%N) and a combination of above residual organics with urea@50%N besides 100% recommended dose of nitrogen (RDN) and control. The results revealed that residual organics and urea recorded higher growth parameters like plant height, chlorophyll content, leaf area index(LAI), crop growth rate (CGR), relative growth rate(RGR), net assimilation rate(NAR), No. of tillers/hill compared to their individual addition. The growth parameters were more under residual PM in combination with mineral nitrogen in both the soils. Residual PM + fertilizer nitrogen (100% N) recorded highest grain (4485, 4693 kg ha-1) and straw yield (6984, 5897 kg ha-1) in clay loam and sandy clay loam soils, respectively. The lowest grain(3292, 2993 kg ha-1) and straw yield(4998, 4003 kg ha-1) were recorded in residual GM + fertilizer (100% N) in both soils. Among organics alone, residual PM(100% N) registered highest grain yield (4025, 4048 kg ha-1) in both soils. It can be concluded that the application of poultry manure alone or in combination with N fertilizers enhanced the growth and improved soil health.

Nitrogen and boron are necessary for the metabolic activities of rice for its growth. With this perspective, a field experiment was conducted in farmer’s field during 2020 at Kuttalam, Mayladuthurai district, Tamilnadu in sandy clay loam(Padugai Series – TypicUstifluvents) to predict the response of rice (Oryza sativa) to different levels of nitrogen(N) and boron (B) application. The treatments consisted of Factor A- Nitrogen levels, 0, 75, 150, 225 kg ha-1 and Factor B- Boron levels 0, 1.5, 3.0 kg ha-1. Fifteen treatments were conducted in a Factorial randomised block (FRBD) design with three replications. The test crop was rice with a variety ADT 46. Concerning nitrogen alone, the highest grain (5344 kg ha-1) and straw yield was recorded in N3(225 kg ha-1). Among the boron levels tested, the highest grain (4695 kg ha-1) and straw yield (6509 kg ha-1) was registered in B1 (1.5 kg ha-1) in rice. The highest total nutrient uptake viz., N(88.2 kg ha-1), P(30.5 kg ha-1), K(105.0 kg ha-1) and B(172mg kg-1) were recorded in N3B1. Among the N alone, the highest total nutrient uptake viz., N(78.1kg ha-1, P(26.3kg ha-1), K (95.8 kg ha-1) and B(156.6 mg kg-1) in N3. Concerning B alone, the highest nutrient uptake viz., N(60.5, kg ha-1) , P(17.8kg ha-1) K(74.9 kg ha-1) and B(112.1mg kg-1) were registered in B1 over other B levels. The highest grain (5631 kg ha-1) was recorded in N3B1 (225 kg N ha-1 and 1.5kg B ha-1) than other interactions. The study concluded that applying nitrogen and boron is required to achieve the maximum yield of rice in sandy clay loam soil.

Rice is a rich accumulator of silicon and its supply is essential for the growth and economic yield of rice. Hence, a field experiment was conducted in sandy clay loam soil belonging to Padugai series (Typic ustifluvent) at farmers holding in Kuttalam block, Mayiladuthurai district, Tamil Nadu to assess the role of silicon in improving agronomic characters and yield of rice ADT 43, Oryza sativa. The treatments included T1 - Recommended dose of fertilizer (RDF), T2 - RDF + Potassium silicate (FS) - 0.25%, T3- RDF + FS - 0.50%, T4 - RDF +FS - 1.00%, T5­ -RDF + FS - 0.25%, T6 - RDF + FS - 0.50%, T7­ - RDF + FS - 1.00%, T8 - RDF + SA - 50 kg ha-1, T9 - RDF + SA - 100 kg ha-1 and T10 - RDF + SA- 150 kg ha-1. From T2 to T4, the foliar spray was done at tillering stage and from T5 to T7, the foliar spray was done at tillering and panicle initiation stage. The silicon was applied through FS with the rice crop. The soil application of silicon relatively recorded higher growth and yield compared to foliar application. Besides improving different agronomic characters of the rice, the soil application of 50 kg Si ha-1 registered the highest grain yield (6183.3 kg ha-1) and straw yield (6740 kg ha-1) and was comparable with a single foliar spray of 1% Si. Growth and rice yield increased with Si concentration of 0.25% to 1%. Thus, the soil application of silicon @50 kg ha-1 through potassium silicate is advocated to realize maximum rice yield.

Aerobic rice is projected as a sustainable rice production technology for the immediate future to address water scarcity and environmental safety. Micronutrient deficiency, particularly iron is one of the main factors responsible for low productivity in aerobic rice. With this perspective, a field experiment was conducted at farmer’s field in 2022 at Kuttalam, Mayladuthurai district, Tamilnadu, in sandy clay loam (Padugai Series – Typic Ustifluvents) to predict the response of aerobic rice (Oryza sativa) to iron nutrition. The experiment was laid out in randomised block design with eleven treatments (Recommended dose of fertilizers (RDF) NPK only (control)(T1), (RDF) + FeSO4 @ 25 kg ha-1 (SA) (T2), RDF + FeSO4 37.5 kg ha-1 (SA)(T3),RDF+ FeSO4 @ 50 kg ha-1 (SA)(T4), RDF+ FeSO4 @ 25 kg ha-1 (SA) + FeSO4 @ 1% (FS)(T5), RDF+ FeSO4 37.5 kg ha-1 (SA) + FeSO4 @ 1% (FS)(T6) , RDF+ FeSO4 @ 50 kg ha-1 (SA) + FeSO4 @ 1% (FS)(T7), RDF+ FeSO4 @ 25 kg ha-1(SA) + Fe-EDTA @ 0.5% (FS)(T8), RDF+ FeSO4 37.5 kg ha-1 (SA) + Fe-EDTA @ 0.5% (FS)(T9), RDF+ FeSO4 @ 50 kg ha-1 (SA) + Fe-EDTA @ 0.5% (FS) (T10) and RDF + Seed priming 0.05M Fe-EDTA(T11)) and replicated thrice. The results revealed that application of FeSO4 @ 50 kg ha-1 (SA) + Fe-EDTA @ 0.5% (FS) with RDF recorded the highest growth and yield parameters and the highest grain (3438 kg ha-1) and straw yield (5078 kg ha-1) compared to other treatments including control. This study concluded that iron fertilization through the soil and foliar application could enhance aerobic rice productivity.

Kuttanad soils are low strength soft clay or silt deposits found in the Kuttanad areas of the Alappuzha district, Kerala. Due to its low load-bearing and high shrinkage characteristics, the structures and pavements constructed over were unstable. Treatment with appropriate chemical additives is one of the accustomed and economic techniques in soil stabilization practice for improving the characteristics of weak soil. Traditional stabilizing agents like cement, lime, etc. are becoming less environmentally friendly and costly. Coir pith (treated and untreated) is proposed in this study. Coir pith was treated using potassium hydroxide. Initial tests like natural water content, specific gravity, Atterberg’s limit test, hydrometer analysis, compaction test, unconfined compressive strength tests were conducted to find the properties of natural soil. Proctor compaction tests, unconfined compression tests are to be performed to investigate the effectiveness of the coir pith to control the volume change and increase the soil strength. Maximum dry density increases with treated coir pith whereas OMC decreases. UCS test results shows an increase in strength which confirm that treated and untreated coir pith are able to effectively stabilize the natural expansive soil.

AbstractThe practice of pre-compression with sand drains is a widely accepted soil stabilization method for improving soft soil deposits. The scarcity of quality sand contributed to the substitution of a more cost-effective material. An effort was made in the present investigation to utilize waste products like quarry dust (QD), coir pith (CP), fly ash (FA), and rice husk ash (RHA) as the vertical drain in clayey soils. A sand drain (SD) has been used for comparison purposes. Kuttand Clay (KC) and Cochin marine clay (CMC) was selected for the study. Tests were conducted on conventional oedometer cells with a diameter of 6 cm and a height of 2 cm using vertical and radial consolidation models. In addition, this paper demonstrated the effect of the density of drain on radial consolidation characteristics. From the analysis, it was observed that the rate of consolidation increases with the inclusion of any drain material. The radial coefficient of consolidation using sand, quarry dust, and coir pith drain shows a higher value when comparing with the other drain material, which can be owing to their high permeability. The present study can recommend that the quarry dust and coir pith drain, or maybe the combination can be a better alternative for the sand drain.

Soft soil deposits of coastal regions and lowland areas pose many geotechnical problems but it is indispensable to utilize these grounds to meet the growing demand for infrastructure with ever increasing urbanization and industrial development. Soft soils are generally associated with high compressibility and low strength characteristics which augment the risk of huge settlements and foundation failure. It is essential to understand the complex behaviour of the ground consisting of soft clays as construction and maintenance of infrastructure in these areas is challenging. Marine sediments mostly possess open microstructure irrespective of the differences in their mineral composition and sedimentation environment. Also this particular microstructure in marine sediments is generally accompanied by the presence of a great amount of organic residues and fragments of marine organisms. Formation of pyrite is also possible because of the presence of decomposable organic matter, dissolved sulfate and reactive iron minerals. These soils due to their inherent mineralogy and microstructure have high void ratios and consequently high water holding capacity which explains the reason for their low shear strength and high compressibility characteristics. And often the formation environment is conducive for incorporation of organic content in the soft clay deposits which further aggravates the problem. A complete characterization of the soil can enhance the understanding of soil behavior and therefore can play a crucial role in suggesting suitable and sustainable ground improvement method. Soft clay deposits of Kuttanad area in Kerala, India extending to varying depths below the ground level, present a challenge as a foundation soil due to low bearing capacity and high settlement. Geologically Kuttanad is considered as a recent sedimentary formation. In the geological past, the entire area was a part of the Arabian Sea. Presently Kuttanad area covers an area of about 1,100 km2. Many intriguing reports of distresses to structures founded on this soil are available. An over view of specific characteristics of soft clays along with the comprehensive description of soft clays from various parts of the world is presented in the introductory Chapter. Deep soil mixing and mass stabilization methods are found to be relatively advantageous in reducing differential settlements and in achieving expeditious construction. A more detailed review of literature on Kuttanad soil problems and various ground improvement methods adopted are presented. The different ground improvement techniques attempted are soil reinforcement, stone columns, preloading etc. Soil mixing can be relatively advantageous over the other conventional ground improvement methods. Laboratory studies carried out earlier with different binders such as cement, lime and lime fly ash combinations did not exhibit appreciable improvement in soil strength. It is reasoned that the lack of understanding of the soil characteristics is responsible for the limited success of these attempts. Based on the review of literature the detailed scope of the work is presented at the end of Chapter 1. The method of collection of the soil from Kuttanad region, methods adopted for characterization of soil, characteristics of various binders used and testing procedures adopted for assessing the geotechnical behavior with and without binders are described in Chapter 2. In order to characterize the soil for understanding its behaviour under different conditions as well as to gauge its response to different stabilizers, a detailed physico¬chemical, mineralogical, morphological and fabric studies are carried out and presented in Chapter 3. An attempt has been made to explain the role of components of soils such as organic substances, pyrite and sesquioxides for variations in its properties with change in water content. The high water holding capacity of the soil reflected in its Liquid limit along with relatively low plasticity characteristics of the soil has been explained as due to the presence of minerals such as metahalloysite and gibbsite, the flocculated fabric, porous organic matter and water filled diatom frustules (amorphous silica). Based on the study conducted on the plasticity characteristics of Kuttanad soil under different conditions of drying and treatment, it was brought about that the organic content plays a dominant role in particle cementation and aggregation causing a substantial reduction in plasticity upon drying. Further, the presence of minerals such as pyrite and iron oxides also account for the plasticity changes. The significant changes in soil properties upon drying have also been successfully explained in Chapter 4. Attempts made to stabilize the soil using conventional chemical stabilizers are described in Chapter 5. The effect of binders on the strength improvement of soil has been explained based on the changes occurring in the composition, fabric and physico-chemical characteristics of soil upon addition of the binders. Lack of strength development in soil with lime has been attributed to the inherent composition of the soil hindering the formation of pozzolanic compounds and unfavourable modification of the fabric. On the other hand the soil responded well to cement stabilisation. The influence of various parameters such as Water/Cement (W/C) ratio, Initial water content, curing period and additive dosage on the strength development of cement treated soil has been examined. Cement improved the strength of the soil by binding the soil particles without depending on the interaction with the soil. It was observed that the role of initial water content is insignificant and the strength improved with reducing W/C ratio. The dependence of strength development with cement addition on the fabric at different W/C ratios has been assessed. Also the role of other additives such as Lime, Sand, Fly Ash, Ground granulated blast furnace slag, Silica fume and Sodium silicate to enhance the strength of cement treated soil has been analysed in Chapter 5. It was shown that only Sodium Silicate (NS) along with cement meets with good success. The studies on the undrained shear strength and compressibility characteristics of cemented soil carried out to understand the strength and deformation behaviour of the cemented soil are presented in Chapter 6. It is clear from the compressibility characteristics of the cemented soil that there is a well defined yield stress demarcating the least compressible pre-yield zone and more compressible post yield zone. Generally the yield stress increases with reducing water cement ratio. It is interesting to note that the post yield compressibility of the cemented soil is controlled more by the fabric of soil than by cementation effect. The study on the undrained shear behavior of cemented soil revealed that the cohesion intercept and angle of internal friction increases with addition of cement. However the impact of cementation is reflected more as increase in cohesion intercept with increasing cement content. The uniqueness of failure envelope observed for the cemented soil irrespective of whether the confining stress is above or below the yield stress has been explained in detail. A case study on the performance of embankment founded on Kuttand soil improved with Deep mixed cement columns (DMCC) has been evaluated through numerical simulations using FLAC 2D and this forms the subject matter of Chapter 7. For this work the soil properties of the Kuttanad soil determined by experimental investigations have been used. The simulation results showed that the introduction of DMCC columns improved the factor of safety against failure and reduced settlements. This study clearly endorses the analysis and the results of the test carried out on Kuttanad soil. The final chapter summarizes the details of the work carried out which brings out the importance of characterization of the soil in terms of soil components, physico-chemical environment as well as the micro structure of the soil in predicting the behaviour of the soil in changing environment and to understand the stabilization response of the soil with different binders which intern helps to select appropriate binder and or binder combinations.

Soft soil deposits of coastal regions and lowland areas pose many geotechnical problems but it is indispensable to utilize these grounds to meet the growing demand for infrastructure with ever increasing urbanization and industrial development. Soft soils are generally associated with high compressibility and low strength characteristics which augment the risk of huge settlements and foundation failure. It is essential to understand the complex behaviour of the ground consisting of soft clays as construction and maintenance of infrastructure in these areas is challenging. Marine sediments mostly possess open microstructure irrespective of the differences in their mineral composition and sedimentation environment. Also this particular microstructure in marine sediments is generally accompanied by the presence of a great amount of organic residues and fragments of marine organisms. Formation of pyrite is also possible because of the presence of decomposable organic matter, dissolved sulfate and reactive iron minerals. These soils due to their inherent mineralogy and microstructure have high void ratios and consequently high water holding capacity which explains the reason for their low shear strength and high compressibility characteristics. And often the formation environment is conducive for incorporation of organic content in the soft clay deposits which further aggravates the problem. A complete characterization of the soil can enhance the understanding of soil behavior and therefore can play a crucial role in suggesting suitable and sustainable ground improvement method. Soft clay deposits of Kuttanad area in Kerala, India extending to varying depths below the ground level, present a challenge as a foundation soil due to low bearing capacity and high settlement. Geologically Kuttanad is considered as a recent sedimentary formation. In the geological past, the entire area was a part of the Arabian Sea. Presently Kuttanad area covers an area of about 1,100 km2. Many intriguing reports of distresses to structures founded on this soil are available. An over view of specific characteristics of soft clays along with the comprehensive description of soft clays from various parts of the world is presented in the introductory Chapter. Deep soil mixing and mass stabilization methods are found to be relatively advantageous in reducing differential settlements and in achieving expeditious construction. A more detailed review of literature on Kuttanad soil problems and various ground improvement methods adopted are presented. The different ground improvement techniques attempted are soil reinforcement, stone columns, preloading etc. Soil mixing can be relatively advantageous over the other conventional ground improvement methods. Laboratory studies carried out earlier with different binders such as cement, lime and lime fly ash combinations did not exhibit appreciable improvement in soil strength. It is reasoned that the lack of understanding of the soil characteristics is responsible for the limited success of these attempts. Based on the review of literature the detailed scope of the work is presented at the end of Chapter 1. The method of collection of the soil from Kuttanad region, methods adopted for characterization of soil, characteristics of various binders used and testing procedures adopted for assessing the geotechnical behavior with and without binders are described in Chapter 2. In order to characterize the soil for understanding its behaviour under different conditions as well as to gauge its response to different stabilizers, a detailed physico¬chemical, mineralogical, morphological and fabric studies are carried out and presented in Chapter 3. An attempt has been made to explain the role of components of soils such as organic substances, pyrite and sesquioxides for variations in its properties with change in water content. The high water holding capacity of the soil reflected in its Liquid limit along with relatively low plasticity characteristics of the soil has been explained as due to the presence of minerals such as metahalloysite and gibbsite, the flocculated fabric, porous organic matter and water filled diatom frustules (amorphous silica). Based on the study conducted on the plasticity characteristics of Kuttanad soil under different conditions of drying and treatment, it was brought about that the organic content plays a dominant role in particle cementation and aggregation causing a substantial reduction in plasticity upon drying. Further, the presence of minerals such as pyrite and iron oxides also account for the plasticity changes. The significant changes in soil properties upon drying have also been successfully explained in Chapter 4. Attempts made to stabilize the soil using conventional chemical stabilizers are described in Chapter 5. The effect of binders on the strength improvement of soil has been explained based on the changes occurring in the composition, fabric and physico-chemical characteristics of soil upon addition of the binders. Lack of strength development in soil with lime has been attributed to the inherent composition of the soil hindering the formation of pozzolanic compounds and unfavourable modification of the fabric. On the other hand the soil responded well to cement stabilisation. The influence of various parameters such as Water/Cement (W/C) ratio, Initial water content, curing period and additive dosage on the strength development of cement treated soil has been examined. Cement improved the strength of the soil by binding the soil particles without depending on the interaction with the soil. It was observed that the role of initial water content is insignificant and the strength improved with reducing W/C ratio. The dependence of strength development with cement addition on the fabric at different W/C ratios has been assessed. Also the role of other additives such as Lime, Sand, Fly Ash, Ground granulated blast furnace slag, Silica fume and Sodium silicate to enhance the strength of cement treated soil has been analysed in Chapter 5. It was shown that only Sodium Silicate (NS) along with cement meets with good success. The studies on the undrained shear strength and compressibility characteristics of cemented soil carried out to understand the strength and deformation behaviour of the cemented soil are presented in Chapter 6. It is clear from the compressibility characteristics of the cemented soil that there is a well defined yield stress demarcating the least compressible pre-yield zone and more compressible post yield zone. Generally the yield stress increases with reducing water cement ratio. It is interesting to note that the post yield compressibility of the cemented soil is controlled more by the fabric of soil than by cementation effect. The study on the undrained shear behavior of cemented soil revealed that the cohesion intercept and angle of internal friction increases with addition of cement. However the impact of cementation is reflected more as increase in cohesion intercept with increasing cement content. The uniqueness of failure envelope observed for the cemented soil irrespective of whether the confining stress is above or below the yield stress has been explained in detail. A case study on the performance of embankment founded on Kuttand soil improved with Deep mixed cement columns (DMCC) has been evaluated through numerical simulations using FLAC 2D and this forms the subject matter of Chapter 7. For this work the soil properties of the Kuttanad soil determined by experimental investigations have been used. The simulation results showed that the introduction of DMCC columns improved the factor of safety against failure and reduced settlements. This study clearly endorses the analysis and the results of the test carried out on Kuttanad soil. The final chapter summarizes the details of the work carried out which brings out the importance of characterization of the soil in terms of soil components, physico-chemical environment as well as the micro structure of the soil in predicting the behaviour of the soil in changing environment and to understand the stabilization response of the soil with different binders which intern helps to select appropriate binder and or binder combinations.

Kuttanad clays are low strength, soft, organic clay deposits found in the Kuttanad areas of the Alappuzha district, Kerala. Lots of failures have been reported to the structures built over it due to its swelling - shrinking characteristics. To enhance the load-bearing capacity and decrease the settlement characteristics, the addition of appropriate stabilizing agents is considered the most efficient technique in soil stabilization applications. Soil stabilization techniques using traditional stabilizers in mass projects have become costly due to the increase in the cost of materials like cement, lime, fly ash, etc. Moreover, cement production also accounts for global warming due to the emission of carbon gas. Hence studies are going on regarding the effectiveness of using non-traditional materials that can react faster as stabilizing agents and thus reducing the cost of construction. This paper focuses on studying the suitability of a non-traditional nanotechnology-based organo-silane compound in the treatment of Kuttanad clay soils. Observations were made for the variation in the strength characteristics of the soil such as maximum dry density, optimum moisture content, Unconfined Compressive Strength (UCS), California Bearing Ratio (CBR) strength of samples stabilized with varying dosages of nanochemical for curing periods up to 28days.