Lime Content Research Articles

Effect of Active Lime on the Availability of Metal Micronutrients

The low solubility of minerals containing metal micronutrients such as Fe, Zn, Cu, and Mn in alkaline or lime-rich soils adversely affects plant development in these soils, leading to significant yield losses. This study was conducted to determine the effects of active lime on metal microelement availability in calcareous soils. The analysis of 55 soil samples taken from Narlı Plain in Kahramanmaraş Province revealed a significant positive correlation (r=0.95**) between active and total lime values. The study also indicated that an average of 58% of total lime was present in the active form. Furthermore, it demonstrated that as total lime increased, the proportional amount of active lime decreased. The points where the ratio of active lime to total lime is highest are observed to have low total lime contents. As the total lime content increases, the ratio of active lime to total lime decreases. This is thought to be related to the measurement of relatively higher active lime contents as the calcium on exchangeable surfaces passes into solution when the total lime is low. Therefore, this situation calls into question the reliability of active lime analysis at low total lime contents. With the increase in total lime content, this relative effect disappears and more reliable results are obtained. While active and total lime values showed similar correlations with Mn and Cu, Fe showed a higher correlation with active lime than with total lime. Active lime did not exhibit superior predictability compared to total lime when explaining the utility of metal microelements, excluding iron.

Piping Stabilization of Clay Soil Using Lime

Construction of earth fill dams offers a cost-effective solution for various purposes. However, their susceptibility to internal soil erosion, known as piping, poses a significant risk of structural failure and resultant loss of life and property. Soil stabilization emerges as a practical technique to fortify these dams against such threats. This study investigated the impact of lime on the internal erosion properties of clay soils, focusing on CH and ML soil types. Specimens of different lime content were prepared and remolded at 95% relative compaction and optimum moisture content. Hole Erosion tests at varying lime concentrations and curing durations were adapted to conduct the investigation. This investigation aims to optimize lime content and curing time for cohesive soil stabilization against internal erosion. Findings revealed that 2% and 5% of quicklime, by dry weight of the soil, effectively stabilized CH and ML soils, respectively, against internal erosion, with a two-day curing period proving optimal. Furthermore, the addition of lime significantly enhanced erosion rate index and critical shear strength in clay soil, underscoring its efficacy in soil stabilization efforts.

Mechanical properties and microstructure of lime-treated shield tunnel muck improved with carbide slag and soda residue

Shield tunnel muck are usually discarded due to high water content and poor engineering properties, resulting in occupation of land sources and waste of soil sources. Meanwhile, large amounts of industrial waste such as carbide slag (CS) and soda residue (SR) are landfilled with a low reuse rate, which poses a threat to the natural environment. This study aims to improve waste shield tunnel muck using CS and SR and traditional lime, and the improved tunnel muck is expected to be used in subgrade filling to provide a new approach to solve this dilemma. A series of physical, mechanical, subgrade property, and microcosmic tests were conducted on shield tunnel muck improved by CS, SR and lime. The effects of different mixing proportions on the properties of improved tunnel muck were examined. The micro-improvement mechanisms of CS and SR on tunnel muck were explored. Results indicate that the addition of CS or SR can effectively improve the physical and mechanical properties of shield tunnel muck. CS plays a significantly role than SR in improving physical and mechanical properties of tunnel muck. A synergistic enhancement is observed as the combined CS and SR are added, and the optimal mixing proportion of tunnel muck to CS to SR is found to be 100:6:2 with a fixed lime content of 4 %. The alkaline environment created by the synergistic action of CS and SR promotes the dissolution of the active ions in soils, and the generated crystals and gelling products of hydration significant contribute to soil improvement. The tunnel muck improved with appropriate CS or SR content could meet the requirements for light or medium traffic load levels and can be effectively utilized as subgrade filling.

Mix optimization and mechanical properties evaluation of lime-fly ash-stabilized loess in various engineering applications

Determining a rational mix ratio for lime-fly ash-stabilized loess (LFSL) can achieve multiple benefits of economy, environmental protection, and engineering quality improvement. This research was designed to optimize the mix ratios of LFSL applied in the pavement structure, subgrade, slopes, and foundations by conducting the unconfined compressive strength (UCS) test, California bearing ratio (CBR) test, resilient moduli (MR) test, triaxial test and uniaxial consolidation test on LFSL and lime-stabilized loess (LSL). Combined with the initial consumption of lime (ICL) test result and relevant specifications, the optimized mix ratios are as follows: 2% lime + 11.82% fly ash and 2% lime + 3.95% fly ash can reach the strength requirement of road base and subbase, respectively; 2% lime + 3.84% fly ash in building foundations and subgrade and 2% lime + 3.55% fly ash in slopes can reach the equal improvement effect of the LSL with 8% lime content. Three-factor comprehensive models were established and fitted in well with the experimental results of the LFSL with 2% lime content. Moreover, the development of correlations between UCS and other mechanical indices offers a shortcut for engineering property estimation. Finally, based on the abundant literature on LSL, another approach to estimating engineering quality was proposed for the LFSL with 2% lime content, which enhances the universality and practicability of the estimation models further.

Impact of regenerative farming practices on soil quality and yield of cotton-sorghum system in semi arid Indian conditions.

Regenerative agricultural practices, i.e. organic and natural farming, are rooted in India since ancient times. However, the high cost of production, lack of organic pest control measures and premium price of organic produces in chemical agriculture encourage natural farming. In the present study, the quality improvement of calcareous soils under organic (OGF) and natural (NTF) management was compared with integrated conventional (ICF) and non-invasive (NIF) farming practices with cotton-sorghum crops over three consecutive years. A total of 23 soil attributes were analyzed at the end of the third cropping cycle and subjected to principal component analysis (PCA) to select a minimum data set (MDS) and obtain a soil quality index (SQI). The attributes soil organic carbon (SOC), available Fe, pH, bulk density (BD) and alkaline phosphatase (APA) were selected as indicators based on correlations and expert opinions on the lime content of the experimental soil. The SQI was improved in the order of OGF (0.89) > NTF(0.69) > ICF(0.48) > NIF(0.05). The contribution of the indicators to SQI was in the order of available Fe (17-44%) > SOC (21-28%), APA (11-36%) > pH (0-22%), and BD (0-20%) regardless of the farming practices. These indicators contribute equally to soil quality under natural (17-22%) and organic (18-22%) farming. The benefit:cost ratio was calculated to show the advantage of natural farming and was in the order of NTF(1.95-2.29), ICF (1.34-1.47), OGF (1.13-1.20) and NIF (0.84-1.47). In overall, the natural farming significantly sustained the soil quality and cost benefit compared to integrated conventional farming practices.

Mechanism of improvement and best-fit models for the prediction of geotechnical properties of lime stabilized expansive soil used in pavement subgrade

The performance of a pavement mainly depends on the quality of the subgrade layer. Expansive soils (ES) are extensively found worldwide including Pakistan. The inadequate strength and swelling behaviour of these soils are the main problems in any road construction project. Several researchers in the last decades have attempted to improve expansive soil utilizing various materials such as lime, brick kiln dust and fly ash. The purpose of this research was to evaluate the effect of lime on the engineering properties of the ES of a highway subgrade in the Sialkot region of Pakistan. The influence of different lime dosages (0%, 2%, 4% and 6%) at curing ages (1, 7, 14 and 28 days) has been examined by pH tests, plasticity tests, compaction tests, unconfined compressive strength (UCS), free swell index, and California Bearing Ratios (CBR). A field CBR and plate load test (PLT) on the natural soil and optimum lime-treated soil with various curing periods have been carried out for applicability as subgrade material. The test findings demonstrated that higher lime dosages increased the strength and ultimate bearing capacity (𝑞𝑢𝑙𝑡) of improved ES and at the same time decreased the free swelling index (FSI), optimum moisture content (OMC), maximum dry density (MDD) and permanent deformation of the subgrade soil. The UCS values of soil treated with 2%, 4% and 6% lime increased almost by 324%, 523%, and 249% for unsoaked samples and 285%, 351% and 231% for soaked samples respectively as compared to the plain soil at 28 days curing period. The laboratory CBR values significantly increased 2.35-8.50 times and field CBR improved 5.6 times as compared to the plain soil. The 𝑞𝑢𝑙𝑡 of lime-treated soil increased by 162% as compared to the plain soil and permanent deformation reduced from 33 mm to 2 mm after 28 days. Furthermore, equations were developed to estimate the best fit for the prediction of various geotechnical parameters and coefficient of determination (R2 ) values for all equations were found higher than 0.90. From the results, it has been concluded that adding the optimum lime content of 4% by weight satisfies the requirement for the subgrade construction of highways and the developed expressions can provide a scientific basis for estimating the geotechnical parameters.

Modeling the influence of lime on the unconfined compressive strength of reconstituted graded soil using advanced machine learning approaches for subgrade and liner applications.

In the field of soil mechanics, especially in transportation and environmental geotechnics, the use of machine learning (ML) techniques has emerged as a powerful tool for predicting and understanding the compressive strength behavior of soils especially graded ones. This is to overcome the sophisticated equipment, laboratory space and cost needs utilized in multiple experiments on the treatment of soils for environmental geotechnics systems. This present study explores the application of machine learning (ML) techniques, namely Genetic Programming (GP), Artificial Neural Networks (ANN), Evolutionary Polynomial Regression (EPR), and the Response Surface Methodology in predicting the unconfined compressive strength (UCS) of soil-lime mixtures. This was for purposes of subgrade and landfill liner design and construction. By utilizing input variables such as Gravel, Sand, Silt, Clay, and Lime contents (G, S, M, C, L), the models forecasted the strength values after 7 and 28 days of curing. The accuracy of the developed models was compared, revealing that both ANN and EPR achieved a similar level of accuracy for UCS after 7 days, while the GP model performed slightly lower. The complexity of the formula required for predicting UCS after 28 days resulted in decreased accuracy. The ANN and EPR models achieved accuracies of 85% and 82%, with R2 of 0.947 and 0.923, and average error of 0.15 and 0.18, respectively, while the GP model exhibited a lower accuracy of 66.0%. Conversely, the RSM produced models for the UCS with predicted R2 of more than 98% and 99%, for the 7- and 28- day curing regimes, respectively. The RSM also produced adequate precision in modelling UCS of more than 14% against the standard 7%. All input factors were found to have almost equal importance, except for the lime content (L), which had an average influence. This shows the importance of soil gradation in the design and construction of subgrade and landfill liners. This research further demonstrates the potential of ML techniques for predicting the strength of lime reconstituted G-S-M-C graded soils and provides valuable insights for engineering applications in exact and sustainable subgrade and liner designs, construction and performance monitoring and rehabilitation of the constructed civil engineering infrastructure.

Investigation of phosphogypsum-based cementitious materials: The effect of lime modification

Phosphogypsum-based cementitious material (PBC) is acknowledged as a low-carbon green composite material. The addition of lime to modify PBC has been found to significantly enhance PBC utilization rate. This study investigates the effects of varying lime contents in PBC on mechanical properties, volume expansion, hydration products, micromorphology, and pore structure of modified Phosphogypsum (PS). The results demonstrate that lime effectively counteracts the retarding effect of water-soluble impurities in PS, thereby reducing setting time. Additionally, the 7 days and 28 days strength of PBC initially increases and then decreases with increasing lime content, with the 28 days compressive strength of B0 (0.5%) reaching 48 MPa. A 0.5% lime-modified PS proves beneficial in promoting PBC hydration, reducing pore size, densifying the microstructure, and enhancing mechanical properties. Moreover, the volume expansion results highlight the significant influence of the alkaline environment on both the generation and distribution of ettringite, consequently impacting PBC expansion.

Effects of lime content on properties of autoclaved aerated concrete made from circulating fluidized bed ash

In order to reduce the cement consumption during the production of autoclaved aerated concrete (AAC) made from circulating fluidized bed ash (CFBA), this paper investigated the effects of lime replacements for cement on gas-forming volume, bulk density, water absorption and compressive strength of AAC. The results show that the volume of gas formed in AAC during the pre-curing stage decreased as the lime content increased from 3 wt% to 22 wt%. After autoclaving cured for 7 h, the bulk density and water absorption of AAC increased with increasing the lime content. The compressive strength of AAC gradually increased from 3.0 MPa to 3.6 MPa as the lime content increased to 16 wt%. More defined tobermorite crystals formed as the lime content increases to 19 wt%, contributing much to the strength enhancement of AAC, whereas the lime content beyond 16 wt% adversely affected the microstructure of AAC.

Fertility and heavy metal pollution in silage maize soil irrigated with different levels of recycled wastewater under conventional and no-tillage practices

AbstractIrrigation with recycled domestic wastewater has been known to obtain positive effects on improving soil fertility, but it may also become a risk factor in case of causing an increase in soil salinity and/or heavy metal concentration of soil. No-tillage can retain soil moisture, helping to reduce irrigation water necessity, and thus lower amounts of heavy metals and salts are added to soil under wastewater irrigation conditions. The objective of this study was to analyze the effects of wastewater irrigation at different levels of on silage maize cultivation under conventional tillage and no-tillage conditions by comparing to full irrigation with fresh water. The two-year experiment was planned according to the split-plots design in the random blocks with three replications. The results indicated that full irrigation with wastewater increased soil salinity, organic matter content, total nitrogen, plant available phosphous, exchangeable cations, exchangeable sodium percentage and soil essential and non-essential heavy metal contents, but decreased soil pH and lime content. Increasing rates in organic matter content, total nitrogen, plant available phosphorus and exchangeable potassium were higher, but in electrical conductivity, and heavy metal accumulation were lower in soil under no-tillage as compared to conventional tillage. Contamination and enrichment factors and geographic accumulation index showed that non-essential heavy metal contamination due to cadmium and nickel, increased in full irrigation with wastewater. Irrigation with wastewater also increased heavy metal accumulation in silage maize. No-tillage can be a recommendable water management practice considering that the risks of soil salinity and heavy metal accumulation can be reduced and that soil fertility can be increased. Also, in reducing the risk of accumulation of cadmium and nickel in soil, 33% deficit irrigation with wastewater can make no-tillage more available.

An experimental study to investigate the mechanical behaviour of low plasticity fine-grained soil stabilized with different contents of lime and fly ash

ABSTRACT Shear strength, small and large strain stiffness moduli, and cyclic stiffness degradation of fine-grained soil with low plasticity (CL-ML) stabilized with different contents of lime and fly ash were investigated in this work. The results of static triaxial tests showed that adding fly ash to the soil-lime mixture increases significantly the compressive strength of the samples due to an increase in pozzolanic reactions. By varying fly ash up to 15% and lime up to 7%, an optimal composition with 5% lime and 15% fly ash was achieved, in which the shear strength was maximum. The results of the bender element tests also showed that the mixture of 5% lime and 15% fly ash has the highest maximum shear modulus. The results of the cyclic triaxial tests on the samples with the optimal composition; showed cyclic degradation of the stiffness due to the failure of cement bonds.

The Performance of Portland Cement Pastes (OPC) Incorporated with Ceramic Sanitary Ware Powder Waste (CSPW) at Ambient Temperature

The physical and mechanical performance of Portland cement pastes (OPC) incorporated waste ceramic sanitary ware powder waste (CSPW) at ambient temperature has been investigated. Cement mixes were prepared by replacing the cement with CSPW at proportions of 0, 4, 8, 12, 16 and 20 wt. %. The results showed that the water of consistency and setting times (initial and final) were increased with the gradual addition of CSP, whereas the water absorption and total porosity were decreased, while the bulk density slightly was enhanced but only up till 16 wt. % CSPW. The same trend was displayed with mechanical properties, where the flexural (FS) and compressive strengths (CS) of the cement specimens were also improved and enhanced till 16 wt. %, but then all were decreased with further addition of CSPW. The experimental results indicated that the CSPW has a potential to be successfully recycled in the OPC pastes as a partial replacement merely up to 16 wt. % which had a better performance than the blank at ambient temperature. The FT-IR spectra illustrated that the amount of CSHs was increased, while that of free lime content decreased. This was conformed by SEM microscopy. Moreover, the recovery of CSPW contributes to both reducing environmental pollution and CO2 emissions.

Effect of zeolite replacement and tyre fibre inclusions on geotechnical properties of cement- or lime-stabilised sand

ABSTRACT In the current study, the effects of cement or lime content, fibre content, partial cement or lime replacement with zeolite and curing time on the Unconfined Compressive Strength (UCS) of sand have been investigated. The results reveal that increasing cement or lime content increases Maximum Dry Density (MDD) and Optimum Water Content (OMC). However, increasing zeolite replacement percentage decreases MDD and OMC. Increasing the fibre content from 0 to 4% reduces the MDD and increases OMC. The optimum combination of the stabiliser and fibre has been derived from an array of tests. Results comparison shows the 0.5% fibre content and 8% stabiliser results in maximum effect. Also, the optimum percentage of 80% replacement of lime and 30% and 40% replacement of the cement with zeolite leads to the maximum UCS. Observing failure patterns demonstrates the influential performance of fibre content such as controlling the crack length and brittle behaviour. Moreover, SEM analysis was conducted to compare the microscale behaviour.

Environmental impact of concrete containing high volume fly ash and ground granulated blast furnace slag

Concrete production is energy-intensive and has an adverse impact on the environment due to the raw materials involved. Currently, India has abundant reserves of fly ash and ground granulated blast furnace slag (GGBS). Despite various applications, fly ash often ends up in landfills. Given its abundance, there is a growing interest in utilising substantial quantities of fly ash in concrete production. In the current study, M30-grade concrete is designed with very high levels of fly ash and GGBS. Additionally, quick lime (QL) is incorporated as a supplementary agent to augment lime content. A total of twenty concrete mixes have been developed with different combinations of fly ash, GGBS, and QL. Results illustrate that the addition of QL does not show overall strength improvement to the GGBS-based mixes, but it impacts on fly ash-based mixes. The targeted design strength is achieved with 70% cement replacement with fly ash and QL. The strength development depends on the pozzolanic reaction initiated and the formation of hydration products in the system. The environmental impact of concrete is assessed by analysing its life cycle assessment using a cradle-to-gate approach. The energy requirement and kg-CO2 eq. emissions depend on the level of cement replacement. The fly ash-based concrete emits less kg-CO2 eq. and requires less energy than the GGBS-based mixes. Overall, the designed strength is achieved with 65% fly ash, requiring 59% less energy, reducing 54% CO2 footprint, 56% GWP100, 80% HTPinf, 46% ODPinf, and cost by 34% compared to OPC-based concrete.

Prediction of unconfined compressive strength of lime treated soils

ABSTRACT Robust models based on Artificial Neural Network and simplified linear regression were proposed to predict the Unconfined Compressive Strength (UCS) of Lime Treated Soils (LTS). In total, an experimental database using 1120 test specimens was created. Critical examination of the collected experimental data suggested that there are eight key parameters that govern the attained strength gain. These input parameters are liquid limit, plastic limit, dry unit weight, water content, fine content, lime content, curing temperature and curing time whereas the only output dependent parameter is the UCS. The parameters of the proposed model including weights, biases and transfer functions were successfully converted to an explicit mathematical model relating the UCS with the key input parameters. Based on the results of the statistical evaluation, it was shown that a three-layered Artificial-Neural-Network model with 19 hidden neurons was capable to predict the UCS of (LTS) with a high degree of accuracy that was better than that achieved by the developed regression model. A coupling effect of the input parameters and weights analysis were conducted for the developed Artificial-Neural-Network-model to assess the importance of the key parameters. Analysis of weights of the model showed that curing time was the most significant factor affecting strength gain.

Study on the Mechanical Properties of Two General-Purpose Cement-Lime Mortars Prepared Based on Air Lime.

It is believed that the use of mortars based on air lime in the construction and renovation of brick buildings has a number of advantages, especially those closely related to the durability and strength of the structure. However, there is still a noticeable difference in the mechanical properties of these materials. This research investigated the mechanical characteristics of a mixed cement-lime mortar with the two most popular proportions of an air lime, cement, and sand mix: 1:1:6 and 1:2:9 (by volume). Mechanical tests were performed on standard and non-standard samples to assess compressive strength, tensile strength, flexural strength, and fracture energy. The obtained results indicate the possibility of using these mixtures in modern masonry construction, as well as in the aspect of sustainable development. Additionally, lime mortar with a higher lime content can be used in non-load-bearing walls and in renovation and repair works.

Building MLR, ANN and FL models to predict the strength of problematic clayey soil stabilized with a combination of nano lime and nano pozzolan of natural sources for pavement construction

The current study aims at predicting the strength of the problematic clayey soils treated with combinations of pozzolan of natural sources and lime powder when added as soil additives at a nano scale. Multiple linear regression (MLR), artificial neural networks (ANN) and fuzzy logic (FL) tools were employed in the analytical study. The variables of the present study include the following: nano pozzoaln of natural source (NNP) content, nano lime content (NL), median particle size of NNP, active silica content of NNP (SiO2active), Initial liquid limit (ILL) and initial plastic limit (IPL) of the investigated soils. NNP was added at five percentages, i.e. 0%, 0.5%, 1%, 1.5% and 2%, while NL was added at five percentages, i.e. 0%, 0.3%, 0.6%, 0.9% and 1.2%. Three median particle sizes namely 50, 100 and 500 nm size were studied. Based on the different investigated soils and combinations, 120 soil mixtures were prepared and tested. California bearing ratio (CBR) and plasticity index (PI) were particularly examined. CBR tests were conducted at a soaked condition on specimens compacted to a maximum dry density (MDD) at the optimum moisture content (OMC). PI values were obtained following the Atterberg limits test. Based on the results of the performance criteria of the developed predictive models, it can be concluded that the CBR and PI of the expansive clayey soils can be effectively predicted using ANN and FL techniques. The results obtained by MLR were far from those obtained by both ANN & FL. In addition, ANN tool was slightly more accurate than FL as far as prediction of CBR and PI is concerned. The higher capability of ANN & FL models in predicting CBR & PI values, which generally obtained through time-consuming and expensive tests, could be useful for geotechnical engineers to assess or design a new pavement project. Further, it is recommended to do a re-evaluation of the current study in future, particularly when more data is available in the literature.

Laboratory Evaluation of the Hydraulic Conductivity as a Function of Changes in the Particle Size of a Cubitermes Sp Termite Mound Soil Treated with Lime

This work characterizes the geotechnical properties and microstructure that served as a fundamental and more practical basis for describing the hydraulic conductivity of the lime-treated cubitermes sp termite mound soil. The results show that changes in particle size lead to a decrease in dry density and linear swelling. Permeability is strongly correlated with particle size distribution and compaction. Permeability increases up to the lime fixation point obtained at 6% of the lime content. Compaction for micropore reduction in treated soil is higher than in raw soil. The treated soil has a denser internal structure with agglomerations of dispersed clay particles. The increase in compaction energy reduces macropores and permeability, and the soil microstructure becomes homogeneous. Natural soil is highly impermeable, and soil-lime mixes are among the least draining materials. Higher values of hydraulic conductivity were obtained as a function of time. Soil and mixtures can be used in civil engineering works (earthworks). Correlations between hydraulic conductivity and particle size fractions are polylinear fits with R2 (0.962-0.993) and the Slogistic1 model with χ²(2.06E-15) for the mean silt fraction. This study is decisive for predicting hydraulic conductivity from the geotechnical properties of the soil, by solving the mathematical expressions of the models used.

Influence of Cow Bone Powder on Selected Engineering Properties of Lime-Stabilized Soil

This study investigates the influence of cow bone powder (CBP) on consistency and compaction characteristics of lime-stabilized soil. Twelve soil samples were collected from four routes connecting Ado-Ekiti. Index and compaction tests were performed on the natural and stabilized samples. The soil samples were classified according to AASHTO groups and eventually restructured into four (4) groups: A-6, A-7-6, A-4, and A-7-5. They were named samples A, B, C, and D respectively. The oxide compositions of the samples were determined. Lime was blended with soils at proportions of 0, 2, 4, 6, 8,10 %, and the optimal lime content (LimeOpt) was obtained. The LimeOpt + soil mixture was mixed with 2, 4, 6, 8,10 % of CBP. The Soil + LimeOpt + CBP mixtures were subjected to consistency limits and compaction tests. Plasticity index (PI) of soils A, B, C, and D was 14.19, 21.06, 11.64, and 14.19 % respectively, while the MDD was 1640, 1730, 1630, and 1631 kg/m3. Soil A, B, C, and D + LimeOpt all had reduced PIs of 7.68, 16.40, 5.04, and 12.05%, respectively. For the MDD of soil + LimeOpt mixtures, 1789, 1920, 1906, and 1898 kg/m3 were also found for Samples A, B, C, and D. Soil + LimeOpt + CBP showed that both the PI (from 0.6 to 81.7%) and MDD (from 0.1 to 14.6%) improved. On the other hand, the addition of lime to soils A, B, C, and D showed that 8% lime content offered the optimal CBR performance. Further addition of CBP to the soil + LimeOpt mixtures equally improved both the soaked and unsoaked CBR of soils A, B, C, and D predominantly with 6% CBP addition offering the peak performance. This suggests that CBP is viable and can save cost, mitigate environmental hazards, and complement lime. Strength and durability evaluation of the ternary mixture is however recommended.

İzmir Yöresi Zeytin Bahçe Topraklarının Karbon ve Azot Stokları

Soil organic carbon (SOC) and total nitrogen (TN) have a very important role in sustainable soil quality, crop production, and environmental impacts, and determining of carbon nitrogen ratio (C: N ratio) is very important for creating data banks in terms of ecosystem functions. Plants influence the interaction of SOC and TN, as well as ecosystem yield and the continental carbon cycle. Climate, atmosphere, and land-use change are all included in numerical models of the carbon (C) and nitrogen (N) cycles. This study was conducted to determine the SOC and TN stocks, the C: N ratio and their relationships with the soil properties of olive orchards in Aliaga, Bayindir, Bergama, Dikili, Foca, Karaburun, Kemalpasa, Menderes, Menemen, Odemis, Seferihisar, Selcuk, Tire, Torbali and Urla provinces of Izmir in Turkey. For this purpose, 129 soil samples were taken from 0-30 cm depth. The texture, pH, EC, lime, OM, SOC and TN content and stocks, Bulk density (Db) was determined. Db and C: N ratio varied between 0.84-1.31 g cm-3, 5.17-80.50, and SOC density and stocks changed between 4.00-53.00 mg cm-3, 1.25-1.59 kg m-2, N density and stocks between 0.09-2.66 mg cm-3, 0.03-0.80 kg m-2, respectively. The highest BD was obtained from Tire, the highest SOC stocks from Karaburun, the highest TN from Seferihisar and Karaburun. The very small bulk density which is negatively associated with OM and clay is an important feature. The SOC contents were higher in relatively heavy rainfall regions. SOC and soil texture have a strong relationship. As a result, texture, precipitation, temperature, soil depths, and regeneration of soil affect the SOC and TN stocks. The results may be effective in terms of sustainable soil quality and ecosystem functions for olive cultivation.