Effects Of Wood Ash Research Articles

Ash Treatment Promotes the Revegetation of Abandoned Extracted Peatlands

Treating peat with nutrient-rich ash significantly increases the content of different nutrients in the substrate. Such ash treatment promotes the revegetation of abandoned extracted peatlands. The aim of this study is to analyze the effect of wood ash (WA15 = 15 t ha−1 and WA10 = 10 t ha−1), oil shale ash (OSA8 = 8 t ha−1), and a mixture of wood ash and oil shale ash (WA10 + OSA8) on the revegetation (vascular plants and bryophytes) of the Puhatu abandoned extracted peatland in NE Estonia. The following results were obtained: (1) The MRPP tests indicate that there are compositional differences between the treatments. (2) Altogether, 23 vascular plant and 3 bryophyte species were recorded in the treatment areas. (3) Nine years after these ash treatments, the highest mean vascular plant species richness was recorded for WA15 (3.8 ± 0.3) and the lowest for OSA8 (2.0 ± 0.3). (4) A greater number of vascular plant species was observed in the WA15 area. (5) Mixed ash and wood ash had a significant effect on the amount of biomass in vascular plants. Treating with either wood ash or a mixture of ash ensured the rapid formation of vascular plants and bryophyte layers, contributing to the restoration of the abandoned peatland ecosystem.

Functional Effect of Wood Ash on Soil Quality

Functional Effect of Wood Ash on Soil Quality

Paper mill wastes and biochar improve physiochemical properties and reduce heavy metals leaching risks in podzolic soils

Background: The incorporation of industrial wastes, such as wood ash and paper sludge, as soil amendments is vital for both environmental sustainability and agroecosystem productivity. Herein, we evaluated the effects of wood ash and paper sludge alone and in combination with biochar on the physicochemical properties and heavy metal leaching risks in podzolic soils. Methods: The treatments included limestone (control), wood ash, paper sludge, wood ash+paper sludge, limestone+biochar, wood ash+biochar, paper sludge+biochar and wood ash+paper sludge+biochar, arranged in a 4 × 2 factorial design with three replicates. The Hydrus-1D model was employed to simulate the water movement under these soil amendments using leaching colums. Results: Overall, wood ash, paper sludge and biochar application significantly increased the pH of amended soil compared to control. Paper sludge amended treatments alone or in combination with biochar significantly decreased bulk density (8%–17%) and increased the total porosity (14%–25%). While biochar addition to wood ash and paper sludge significantly reduced the concentrations of Cd (by 6.42%), Co (by 10.95%), Cu (by 11.76%), Pb (by 30%) and Ni (by 3.75%) in the collected leachates. The treatment paper sludge + biochar was found to be the most effective treatment to retain the heavy metals, with maximum plant available water (0.28 cm3 cm−3) and field capacity (0.36 cm3 cm−3) compared to control treatment. The predictions from Hydrus-1D showed that paper mill wastes with biochar has a significant potential to increase the volumetric moisture contents of amended podzolic soil, with the simulated leaching times and saturation levels closely aligning with the measured values. Conclusion: paper sludge + biochar treatment showed improved soil physicochemical properties and displayed lower heavy metals than allowed limits to be used in soil. Further, experiments are needed to assess the effects of papermill waste products on podzolic soil properties under variable field conditions.

Wood Ash Effect on Cement Based Self-Compacting Mortars

In this experimental study, the effect of wood ash (WA) substituted into Portland cement (PC) at variable proportions by volume on the fresh state, hardened state, and microstructure of self-compacting mortars (SCMs) was investigated. In the designed SCMs, WA was substituted into PC at 5% increasing ratios in the 0%-30% band. A total of 84 40*40*160 mm prism specimens and 42 50*50*50 mm cube specimens were produced for 7 different SCM designs. V-funnel and slup flow test were done according to EFNARC kriteria. Hardened state tests were carried out at 7, 28, 56 and 90 days with oven dry unit volume weight, porosity, capillary water absorption, flexural tensile, compression and splitting tensile tests. In addition, WA used in the mixture and after 28 days of water curing, samples containing WA 0%, 15%, 30% were evaluated after microstructure analysis. According to the results of the study, increasing WA substitution rate has a determining effect on the fresh state properties. Increasing WA substitution has a negative effect on flexural tensile strength and compressive strength and a variable effect on splitting tensile strength. Increasing the amount of WA increases the unit volume weight and decreases the porosity at 5% substitution. For the other substitution cases, the unit volume weight decreases and porosity increases. Except for the control mixture, Magnesium calcite and Aluminum-based compounds were detected in microstructure examinations of SCMs.

Wood ash application for crop production, amelioration of soil acidity and contaminated environments

Agriculture is vital to human life and economic development even though it may have a detrimental influence on soil quality. Agricultural activities can deteriorate the soil quality, endangers the ecosystem health and functioning, food safety, and human health. To resolve the problem of soil degradation, alternative soil conditioners such as wood ash are being explored for their potential to improve soil-plant systems. This study provides an overview of the production, properties, and effects of wood ash on soil properties, crop productivity, and environmental remediation. A comprehensive search of relevant databases was conducted in order to locate and assess original research publications on the use of wood ash in agricultural and environmental management. According to the findings, wood ash, a byproduct of burning wood, may improve the structure, water-holding capacity, nutrient availability, and buffering capacity of soil as well as other physico-chemical, and biological attributes of soil. Wood ash has also been shown to increase agricultural crop yields and help with the remediation of polluted regions. Wood ash treatment, however, has been linked to several adverse effects, such as increased trace element concentrations and altered microbial activity. The examination found that wood ash could be a promising material to be used as soil conditioner and an alternative supply of nutrients for agricultural soils, while, wood ash contributes to soil improvement and environmental remediation, highlighting its potential as a sustainable solution for addressing soil degradation and promoting environmental sustainability in agricultural systems.

Effectiveness of wood ash and paper sludge as liming and nutrient sources for annual ryegrass grown in podzolic soils of Newfoundland

AbstractThe acidic soils of western Newfoundland require liming for successful production of most crops. Locally sourced paper mill waste wood ash (WA) and paper sludge (SL) have potential as cheaper alternatives to limestone (LIME). Two greenhouse experiments evaluated WA and SL as liming and soil conditioning amendments for annual ryegrass (Lolium multiflorum) production. At 55 days after seeding, soil pH in WA (6.2 and 6.3) and wood ash and paper sludge (WASL) (6.0 and 6.3) were not different from that in LIME (6.0 and 6.5) for Experiments 1 and 2, respectively. However, pH in SL was 0.4 and 0.3 points lower than in LIME. Compared to LIME, WA, SL, and WASL produced 31%–52% and 57%–74% greater biomass yield in Experiments 1 and 2, respectively. N uptake was greater in WA (60 and 129 kg N ha−1) and WASL (51 and 97 kg N ha−1) compared to LIME (40 and 85 kg N ha−1), in Experiments 1 and 2, respectively. SL did not differ from LIME in Experiment 1, but reduced N uptake by 57% in Experiment 2. The results show significant potential of WA as an alternative amendment for liming and yield improvement of annual ryegrass grown in NL podzolic soils. However, SL has limited potential due to the risk of increasing N immobilization and residual soil mineral N when growing conditions are limiting. Combining SL with WA or biochar seemed to alleviate these risks. Overall, the adoption of these amendments for field production systems warrants serious consideration, following supplemental field studies to determine optimal application rates and timing.

Angle of repose of granulated ice: effect of wood ash

Abstract New experiments have revealed that the addition of a small amount of wood ash doubles the angle of repose of granulated ice at −10°C, but has little effect at −30°C. It is hypothesized that this behavior may be explained in terms of the freezing of water that is formed at the higher temperature through the reaction of salt within the ash.

Long-Term Effect of Wood Ash and Wastewater Sludge Fertilization on Tree Growth in Short-Rotation Forest Plantations on Abandoned Agricultural Land: A Case Study

Short-rotation forest plantations on former agricultural land capture CO2, provide bioeconomic materials, and mitigate climate change. This study aimed to enhance our understanding of the long-term effects of wood ash and wastewater sludge fertilization on various tree species (birch, hybrid aspen, grey alder, black alder, and hybrid alder) in short-rotation forestry plantations on abandoned agricultural land where tree growth measurements were taken over an 11-year period. After 11 years, the highest aboveground biomass (AGB) was observed for hybrid aspen clone No. 4 under wastewater sludge treatment (109.0 t ha−1), birch under wood ash treatment (34.3 t ha−1), black alder under wastewater sludge treatment (33.6 t ha−1), grey alder under wastewater sludge treatment (40.9 t ha−1), hybrid alder under control conditions (36.2 t ha−1), and hybrid aspen clone No. 28 under wood ash treatment (37.2 t ha−1). The average survival rate was 73% in control plots, 81% under wastewater sludge treatment, and 78% under wood ash treatment. Short-term positive impacts on tree growth were observed, effects that were not consistent over the long term. The impact of these treatments on tree growth varied between species, and the effects tended to diminish over time, which must be considered before fertilization.

The Effect of Wood Ash and Soil Applications on the Behavior and Survival of Spodoptera frugiperda (Lepidoptera: Noctuidae) Larvae on Maize.

Cryptic feeding inside maize whorls makes it difficult to control fall armyworm (FAW). Smallholder farmers use alternative methods of control, of which the efficacy is uncertain. We determined the efficacy of wood ash and soil for the control of FAW and recorded its effect on larval preference and ballooning. Maize plants were artificially infested with larvae of different instars and treatments were either soil, wet ash, or dry ash, applied as single preventative or curative applications. Larvae exhibited non-preference for treated leaves in choice tests. The efficacy of treatments varied largely between experiments. Under laboratory conditions, ash treatments resulted in significant mortality of 1st and 5th instars. Dry and wet ash as curative applications for 1st instars resulted in 67 and 66% mortality, respectively, compared to mortality recorded in the control (22%). Under field conditions, survival of 3rd instars on treated plants was low (21-34%), compared to 70% on untreated plants. Due to the high variability in efficacy, the use of these alternative methods does not guarantee effective control. They do, however, have a place in IPM systems if applied as soon as infestations are observed and when larvae as still small. Recommendations on the use of ash and soil as spot treatments against FAW are provided.

Effect of Wood Ash on salt Crystallization and Rapid Chloride Permeability Test (RPCT) in Mortar

Abstract: Ash by-products obtained from combustion of wood biomass are generally used in land filling for embankments, road/highway construction. It can be used as soil supplementing material to reduce the alkalinity of soil in agricultural lands. And it can also be used as raw material in the manufacturing of cement in cement industries. Many researches had been carried out to incorporate wood waste ash as a cement replacement material in the production of greener construction material (concrete/mortar) and also as a sustainable means of disposal for wood waste ash. Results of these researches indicated that wood waste ash can be effectively used as a cement replacement material for the production of structural concrete/mortar of acceptable strength and durability parameters. In the present study salt crystallization, rapid chloride permeability test are performed. The results shows As wood ash contains more amount of calcium oxides which are soluble in water and leached out and further react with sodium sulphate. That is why, on increasing the percentage of wood ash, loss in weight as well as loss in compressive strength and chloride ion permeability is high in all the cases but as we increase the percentage of wood ash, chloride ion permeability decreases

Effects of wood ash on the soil properties and fungal community structure in a beech forest in Poland

The aim of this study was to determine how wood-ash fertilization affects the basic properties of soil, including the pH and the carbon (C), nitrogen (N) and phosphorus stoichiometric, and, consequently, the microbial activity, including the abundance and composition of the soil fungi. The studied plots were amended using 3, 4.5 and 6 t of wood ash per hectare, with control plots with no added wood ash also being designated. Analyses of the main physicochemical properties of the soils, enzymatic activity and microbial biomass of C and N were performed two years after the addition of the wood ash. The fungal communities were investigated using next-generation sequencing technology. We found that the use of wood ash increased the soil pH over a short time, with the highest dose having the strongest effect, and increased the abundance of nutrients, which in turn increased the microbiological activity. The addition of wood ash to the soil was also important in shaping the composition of the fungi.

Soil change and broadleaf tree growth 10 years after wood ash and brash co-application to a clearfelled lowland conifer site in Britain

Abstract Wood ash use, to raise pH and replace nutrients lost through forest harvesting, is well regulated in Scandinavia and Canada, but not yet in the UK. This experiment applied granulated wood ash from mixed tree thinnings to a lowland clay mineral soil at ~2.3 t ha−1 dose rate, after clearfell of western hemlock (Tsuga heterophylla (Raf.) Sarg.). With brash (~56 t ha−1 dry weight) as N resource, a 4 × 4 matrix of ash only, ash + brash, brash only and control treatments were planted with oak seedlings (Quercus robur L.). Soil survey was undertaken before ash application and followed over 10 years. By year 2, self-sown grass was dominant in the control and ash plots, and birch (Betula pendula, Roth.) was present across all treatments by year 4. In year 10, oak height was 25–29 per cent greater in brash and ash + brash plots, with DBH increased >20 per cent over the controls. Birch DBH was greater by 30 per cent in brash plots but was over 50 per cent in the ash + brash plots. Foliar concentrations of Ca, K and P significantly increased with ash addition in both oak and birch, as Al, Mn, Fe and Cr decreased. Soil pH (CaCl2) was reduced in all treatments in year 2 likely due to nitrification, during organic matter and needle breakdown, but recovered 8 years later to be significantly highest in ash and ash + brash plots. Mg, K, Ca, Na, Ba and S concentrations were higher in ash plot soils, but soil organic matter, total carbon and total nitrogen declined due to mineralization and uptake by grass and trees. Wood ash addition did not significantly increase heavy metal concentrations in either soil or foliage. In the long term, wood ash aided soil recovery and promoted tree growth in combination with the brash – it could be beneficial for tree growth after thinning/coppicing on heavy mineral soils, with the prerequisite of an existing ground cover. Aim To quantify the effects of wood ash and brash addition over time to soils and tree growth after conifer clearfelling on a lowland clay soil site.

Wood Ash as Sustainable Alternative Raw Material for the Production of Concrete—A Review

Different ecological binders have been used to minimize the negative effects of cement production and use on the environment. Wood ash is one of these alternative binders, and there has been increasing research related to this topic recently. The wood ash utilized in the literature primarily originates from power plants and local bakeries, and predominantly wood fly ash is used. This review paper examines the use of wood ash as an ecological binder in two different applications: as a cement replacement and as an alkali-activated material. Studies have shown that while increased wood ash content in concrete and mortars can have negative effects on strength and durability, it is still a promising and developable material. Depending on the chemical composition of the wood ash, the strength and durability properties of concrete might be slightly improved by utilizing wood ash as a replacement for cement, with an optimal replacement level of 10-20%. However, there is a need for more research regarding the effects of wood ash on the durability of cement-based materials and its use in alkali-activated materials. Overall, this review provides a comprehensive overview of the properties of wood ash and its potential applications in conventional concrete and mortars, as well as in alkali-activated materials.

Propriedades físico-hídricas de Oxisol e Quartzipsamment associadas a aplicação de cinzas de madeira

ABSTRACT The addition of wood ash to soil is an alternative to disposing of this residue. However, the effects of wood ash on soil physical-hydric properties remain divergent. In this study, the effects of added wood ash on the soil water characteristic curve, gravitational water, field capacity, total available water, and saturated hydraulic conductivity were evaluated in Oxisol (40% clay and clay texture) and Quartzipsamment (6% clay and sand texture). The experimental design was completely randomized in a 2 × 4 factorial scheme, where the factors were two soils and four doses of wood ash, with three replicates. The wood ash came from an agribusiness and was the result of burning eucalyptus wood. The wood ash doses were 0, 16, 32, and 64 g dm-3. The gravitational water, field capacity, and total available water were fitted to a quadratic model as a function of the wood ash dose. The saturated hydraulic conductivity decreased linearly with an increase in wood ash dose for both soil classes. The soil water characteristic curve only increased significantly (p ≤ 0.05) with a wood ash dose of 64 g dm-3. The increase in total available water was more evident in Oxisol than that in Quartzipsamment, with increments of 64 and 31%, respectively, at a maximum dose of 64 g dm-3 of wood ash.

Effect of Wood Ash in the Preparation of “Soumbala” from Parkia biglobosa Seeds

Aims: Evaluation of the biochemical and microbiological characterization of Parkia biglobosa seeds added with wood ash during the fermentation for the preparation of "soumbala" (traditional condiment used across West Africa).
 Study Design: Food safety
 Methodology: 32 soumbala samples due to eight samples per commune were collected in the markets of Dimbokro (city in the center of Côte d'Ivoire) and three communes from Abidjan district, namely Adjamé, Abobo and Cocody. Also, 5 kg of Parkia biglobosa seeds divided into 14 samples were collected on Adjamé’s market. The loads of microorganisms (mesophilic aerobic germs, lactic acid bacteria, Bacillus, yeasts and moulds) were determined by counting after culture in agar medium. The physico-chemical composition (pH, titratable acidity and soluble sugars) of Soumbala and Parkia bigloboda seeds has been determined according to standard methods.
 Results: The results of physico-chemical analyses showed that the pH varied from 5.53 to 7.95 for the control and from 8.2 to 8.6 for the "soumbala" produced in the presence of ash during 72 hours of fermentation, while that of the commercial "soumbala" was between 6.4 and 7.7. The protein, reducing sugar and fat contents increase while the dry matter and total carbohydrate contents of the seeds decrease during the fermentation process. Microbiological analyzes showed that the Bacillus loads varied from 5.2 to 9.9 log (CFU/g) for the control and 4.2 to 10.9 log (CFU/g) with the addition of wood ash with a respective optimum of 60 hours, those of lactic acid bacteria varied respectively by 2.3 log (UFC/g) and 3.1 log (UFC/g) in the control and supplemented with wood ash to reach an optimal load similar of 5.5 log (CFU/g). Yeast and mold loads varied from 2 to 5.2 log (CFU/g) for the control and from 3 to 4.5 and 5.6 log (CFU/g) respectively with the addition of wood ash. Bacillus was the only microorganism with the highest load both in commercial soumbala [10.2 log (CFU/g)] and in laboratory-produced soumbala [9.7 log (CFU/g)].
 Conclusion: Wood ash had a enhancing effect on the fermentation of Parkia biglobosa seeds where Bacillus are in the majority. "Soumbala" produced in the laboratory were free of lactic acid bacteria and fungi at the end of fermentation.

Corrosive Effect of Wood Ash Produced by Biomass Combustion on Refractory Materials in a Binary Al-Si System.

In terms of its chemical composition, biomass is a very complex type of fuel. Its combustion leads to the formation of materials such as alkaline ash and gases, and there is evidence of the corrosive effect this process has on refractory linings, thus shortening the service life of the combustion unit. This frequently encountered process is known as “alkaline oxidative bursting”. Corrosion is very complex, and it has not been completely described yet. Alkaline corrosion is the most common cause of furnace-lining degradation in aggregates that burn biomass. This article deals with an experiment investigating the corrosion resistance of 2 types of refractory materials in the Al2O3-SiO2 binary system, for the following compositions: I. (53 wt.% SiO2/42 wt.% Al2O3) and II. (28 wt.% SiO2/46 wt.% Al2O3/12 wt.% SiC). These were exposed to seven types of ash obtained from one biomass combustion company in the Czech Republic. The chemical composition of the ash is a good indicator of the problematic nature of a type of biomass. The ashes were analyzed by X-ray diffraction and X-ray fluorescence. Analysis confirmed that ash composition varies. The experiment also included the calculation of the so-called “slagging/fouling index” (I/C, TA, Sr, B/A, Fu, etc.), which can be used to estimate the probability of slag formation in combustion units. The corrosive effect on refractory materials was evaluated according to the norm ČSN P CEN/TS 15418, and a static corrosion test was used to investigate sample corrosion.

Effect of Straw and Wood Ash on Soil Carbon Sequestration and Bacterial Community in a Calcareous Soil.

Soil fertility can be improved by effectively utilizing agricultural waste. Straw can supply energy and wood ash adds nutrients to improve soil quality. However, few kinds of research have investigated the effect of wood ash and straw on soil carbon sequestration and the soil bacterial population, particularly in calcareous soils. The main goal of this current study was to quantify the impact of a combination of wood ash and straw on the indicators described above using stable δ13C isotope analyses by applying wheat straw to calcareous soil under a long-term C4 crop rotation. The incubation experiment included four treatments as follows: (i) no amendment (Control); (ii) amendment with wood ash (W); (iii) amendment with straw (S); and (iv) a combined amendment of straw and wood ash (SW). Our results showed that sequestration of soil inorganic carbon (SIC) in the SW and W treatments was higher (an average of 7.78%) than that in the S and Control treatments. The sequestered soil organic carbon (SOC) in the SW treatment was 1.25-fold greater than that in the S treatment, while there was no evident effect on the SOC content compared with straw alone. The microbial biomass carbon increased under SW by 143.33%, S by 102.23%, and W by 13.89% relative to control. The dissolved organic carbon increased under SW by 112.0%, S by 66.61%, and W by 37.33% relative to the control. The pH and electrical conductivity were higher in the SW and W treatments than in the S treatment and the control. The SW was conducive to maintaining soil enzymatic activities and bacterial diversity. Bacteroidetes and Actinobacteriota were dominant in SW, while the Acidobacteria phyla were dominant in the S treatment. The diversity of bacteria in the soil and community composition of the bacteria were predominantly assessed by the levels of water-soluble K, pH, and electrical conductivity. The incorporation of straw and wood ash is probably more effective at improving SIC and SOC sequestration and ameliorates the soil microhabitat.

Effects of wood ash on physicochemical and morphological characteristics of sludge-derived hydrochar pellets relevant to soil and energy applications

Hydrochar is produced through a process called hydrothermal carbonization (HTC) and constitutes a carbon-rich solid material with different remarkable applications. This study investigated the effects of wood ash on the physicochemical and morphological properties of biosludge-derived hydrochar in pelleted form relevant to the use of the pellets as a soil nutritional and liming agent and as a biofuel source. The hydrochar was mechanically compressed into uniformly-sized pellets under applied pressures of 4 and 8 kN after blending with varying percentages of wood ash in the order 0, 20 and 50%. The pure and blended pellets were characterized to determine the impact of wood ash on key properties, correlated to the two applications mentioned above. Results demonstrated a strong relationship between key features of the pellets and ash proportion. The wood ash-blended hydrochar pellets showed good hydrophobicity as a consequence of increased contents of alkali and alkaline earth metals, but were low in aromatic functional groups compared to the pure hydrochar pellet. Furthermore, the heating value of the pure hydrochar pellet was about 4% higher than that of its parent material and indicates that this pellet has the capacity to serve as a source of energy. The study generally reveals that blending hydrochar produced from biosludge under HTC conditions with up to 20%–50% of wood ash and mechanically compressing into homogeneous pellets has promising potential for a nutrient-rich material that can enhance soil fertility.

EFFECTS OF WOOD ASH ON GEOTECHNICAL PROPERTIES OF LATERITIC SOILS

Biochar can be derived from pyrolysis of agricultural waste, wood waste (saw dust), logging residues and other biological waste. Biochar can be use to improve the quality of construction and engineering materials. The study deals with the effect of biochar (wood ash) on geotechnical properties of lateritic soils, and it is to investigate the effect of wood ash on the geotechnical properties of lateritic soils. For these purpose, soil samples that were gotten from borrow pit were made use of and blended with available biochar which is used as a stabilizing agent. This was done at different percentages which include (0%, 3%,5%, 10%,15% and 20%,). The biochar was sieved with 125 micrometer sieve and were after blended with the soil samples. The compaction test, consistency limit test, the unconfined compressive strength test were carried out on the samples. It was discovered that the OMC of the blended samples increases as the percentages of the biochar that was used to blend the samples increases, also the MDD on the contrary decreases. The unconfined compressive strength test were conducted on all the samples (0%,3%,5%,10%,15% and 20%). It was also discovered that the compressive strength of soil samples increases with increase in the addition of biochar of the samples having its peak at 10%. Then reduction in compressive strength was experienced in between 11% to 20% addition of biochar to the soil sample. Conclusively, the results show that biochar can be use as stabilizing material when added to lateritic soil samples. But more addition of it at a particular stage may lead to the reduction in the compressive strength of the sample in which the sample may be weak and brittle. The size of the biochar if not properly crushed and sieved may not yield a desired result.

Pengaruh Penambahan Abu Kayu, Kapur Dan Styrofoam Sebagai Bahan Campuran Pada Tanah Lempung Terhadap Nilai CBR

Building construction is influenced by the existing soil conditions. Clay soil is one of the soils that have deficiencies, both in bearing strength and the nature of the soil itself, so soil stabilization is needed. Soil stabilization is an attempt to improve soil properties. The purpose of this study was to analyze the physical and mechanical properties of the soil and to analyze the effect of wood ash, lime, and styrofoam on the CBR value. The soil samples were located in Tumbang Liting Village, Kasongan Lama Village, Katingan Regency, Central Kalimantan. To overcome this unstable soil, alternative materials were added in this study, the materials used were wood ash, lime, and styrofoam. The mixture of materials mentioned for stabilization is expected to improve soil properties. For the percentage of mixed variations, namely 5%, 7.5%, and 10%. Soil testing is carried out according to ASTM (American Society for Testing and Materials) standards. The results obtained from the test show that the CBR value of clay occurs in each variation of the mixture. For the percentage of the original soil, the CBR value was obtained by 3.05%. Soil yields with a mixture of wood ash, lime, and styrofoam with the highest CBR percentage values ​​occurred at variations of 5%, 7.5%, and 10% increased during the 7-day ripening period of 5.45%; 6.40%; 7.39%. For the highest design CBR value, there was a mixture of soil, wood ash, kapu, and styrofoam 10% 7-day curing of 7.39%, an increase of 142.30% from the original soil CBR, so that the mixture of native soil, wood ash, lime, and styrofoam had an effect on soil stabilization.