Ash Amendment Research Articles

Wood ash effects on growth and cadmium uptake in Deschampsia flexuosa (Wavy hair-grass)

Wood ash recycling to forests is beneficial because it regains nutrients and prevents acidification, but wood ash application is restricted due to its cadmium (Cd) content. We question if Cd in wood ash represents a problem, since decreases in Cd bioavailability due to ash-induced pH changes may counteract increased total Cd concentration. We studied effects of wood ash (0, 3, 9 and 30 t ha−1) and lime (pH increase equivalent to the wood ash treatments) on growth and Cd uptake in Deschampsia flexuosa. After four months, we measured plant biomass and Cd accumulation, and extracted Cd from the soil using three different methods; HNO3 (total), EDTA (chelator-based) and NH4NO3 (salt-based). Wood ash and lime strongly stimulated plant growth. Cd concentration in the plant tissue decreased with wood ash and lime addition, and correlated positively with the NH4NO3 extractable fraction of Cd in the soil. In contrast, HNO3 and EDTA extracted more Cd with increased wood ash application. We conclude that wood ash amendment increases soil pH, total Cd concentration, nutrient levels and stimulates plant growth. However, it does not increase Cd accumulation in D. flexuosa, as pH-driven decreases in Cd bioavailability leads to reduced plant Cd uptake. Finally, soil bioavailable Cd is best determined using NH4NO3-extraction.

The impacts of raw, apatite-synthesized and organic-treated coal fly ash amendment on soil/sand water retention capacity

The impacts of raw, apatite-synthesized and organic-treated coal fly ash amendment on soil/sand water retention capacity

The impacts of raw and apatite-synthesized coal fly ash amendment on water retention capacity focusing on fly ash treatment, water repellency and surface area

The impacts of raw and apatite-synthesized coal fly ash amendment on water retention capacity focusing on fly ash treatment, water repellency and surface area

Strength benefit of sawdust/wood ash amendment in cement stabilization of an expansive soil

The investigation evaluated the strength benefits obtained by amending cement stabilization of an expansive soil by using saw dust ash (SDA), a waste generated in wood milling industries due to burning. The experimental program involved the preparation of cylindrical specimens of size 38 mm x 76mm for evaluating the unconfined compression strength (UCS) of the cement stabilized and amended samples cured for varying periods of 2 hours, 7, 14 and 28 days. Two cement contents of 2% and 6% by weight of soil were adopted to stabilize the soil. The SDA amended cement stabilized samples adopted SDA contents of 5%, 10% and 20% by weight of soil. Strength gain trends for the amended samples were also fitted based on the results of the UCS tests. In order to analyse benefits in pavement design and thickness reduction, the UCS values were used to predict the CBR value of the specimens based on which the reduction in pavement thickness was calculated for different traffic densities. The investigation revealed that 5% SDA amendment of cement stabilization can result in up to 26% increase in early strength and 20% increase in delayed strength. Based on the predicted CBR values, pavement thickness can be reduced up to 8.3%.

Fertilising effect of sewage sludge ash inoculated with the phosphate-solubilising fungus Penicillium bilaiae under semi-field conditions

Sewage sludge ashes provide interesting possibilities to recycle phosphorus (P) to soil, although the immediate plant availability is often low. The objective of this work was to increase the P-fertilising effect of sewage sludge ash through inoculation with the phosphate-solubilising fungus Penicillium bilaiae. In a soil incubation study, ash amendment enhanced the content of water-extractable P, but in contrast to previous in vitro experiments, inoculation with P. bilaiae did not further increase P availability, probably due to limited competitiveness of the fungus in soil. In a micro-plot field trial, a moderate P fertiliser effect of the ash was found without any additional effect of P. bilaiae ash inoculation on plant biomass and P-uptake. However, soil microbial functions determined by the MicroResp™ method were not negatively affected by the ash amendment. In conclusion, inoculation with P. bilaiae did not prove to be a suitable strategy to enhance P availability from sewage sludge ash. A better insight into the fungus’ ecology and colonisation ability in soil and rhizosphere as well as into its interactions with ash P is needed to further develop such alternative P-fertilising approaches.

Effect of coal and wood ash on phosphorus immobilization in different textured soils

Decreased phosphorus (P) losses and improved environmental quality are crucial to consider while recycling farm wastes and adding various soil amendments. This study investigated the impact of coal and wood ash on the extractability of P from soils (sandy loam and loamy sand) amended with organic and inorganic phosphorus fertilizers. These soils were further amended coal and wood ash, and analyses were carried out to quantify the water-, Olsen-, and Mehlich 1-extractable P. Ratio of the ashes applied to soils were 5% to sandy loam soil while 10% to loamy sand soil. Water-extractable P was observed to be mainly dependent on the ash type as well as the extraction method. Ash amendment reduced the solubilization of P across soils up to 9% and 23% and 7% to 17% upon 5% and 10% ash amendment in loamy sand and sandy loam soils, respectively. However, the water-extractable P was found to be low in wood ash-amended soil as compared to coal ash. Interestingly, this extractability was greater in soils treated with inorganic P. Phosphorus extraction from soil followed the trend as Mehlich 1 > Olsen > water. P leachability was found to be mainly dependent on ash amendment but values were high for the soil treated with inorganic P. The study inferred that using ash materials such as coal ash and wood ash can be a practical measure for moderating P losses from soils important for economic and environmental perspectives.

Nutrients uptake and utilization efficiency of wheat (Triticum Turgidum L. Var) as affected by filter cake and bagasse ash amendment in nitisol

ABSTRACTA greenhouse experiment was conducted to evaluate the effect of six rates of filter cake and bagasse ash each separately (0, 20, 40, 60, 80, and 100 ton ha−1) on nutrients uptake and utilization efficiency of wheat in nitisol. Filter cake application was found to better increase in nitrogen (N), sodium (Na), calcium (Ca), potassium (K), and magnesium (Mg) uptake and utilization efficiency while bagasse ash influenced zinc (Zn) and copper (Cu) uptake. Bagasse ash application also reduced the uptake of iron (Fe) and manganese (Mn) by wheat. Multiple regression analysis showed that the soil properties explained selected macronutrients and micronutrients uptake. Exchangeable acidity negatively explained some of the nutrient uptakes. In general, filter cake and bagasse ash were found effective in enhancing the nutrient uptake and utilization efficiency by wheat cultivated in acidic soils such as nitisol.

Improvement of Growth, Photosynthesis and Antioxidant Defense in Rice (Oryza sativa L.) Grown in Fly Ash-Amended Soil

Due to the hostile conditions created by fly ash, its utilization in vegetation is restricted. Therefore, fly ash with soil amendment may offer a suitable combination to support plant growth, with reduced risk of metal toxicity. The present study evaluated different concentrations of fly ash with soil amendments on growth, photosynthesis, photosystem (PS) II activity and antioxidant defense in rice (Oryza sativa L.) seedlings to find out the optimum use of fly ash in rice cultivation. Low levels of fly ash (25%) amended soil improve the seedling growth parameters, CO2 photosynthetic rate and stomatal conductance in rice seedlings. Whereas leaf pigments and PS II activity remain unchanged under 25% fly ash treatment as compared to the plants grown in garden soil; however, these parameters declined under the treatments with higher levels of fly ash. Furthermore, the activities of some antioxidant enzymes and protein increased over control under low level of fly ash. The results showed maintenance of photosynthesis and PS II activity of rice seedlings under low levels of fly ash amendment, due to better antioxidative protection from oxidative damage. Taken together, soil amended at 25% fly ash improved the growth of rice seedlings; making fly ash a suitable component of plant growth substance. It can be concluded that a low level of fly ash can be used in amending rice soil for a short period of time but continuous use of fly ash can cause permanent soil contamination by increasing the load of toxic metals.

Extra CO2 sequestration following reutilization of biomass ash

Although combustion ashes are usually used in soils, little attention is paid to the CO2 sequestration potential of this practice. The present study aims to quantify carbon sequestration as carbonate compounds in a tailored synthetic calcareous soil treated with biomass ash from a gasification power plant that uses olive cake. It is estimated that after ash amendment, 14.5g CO2 remained fixed per kg of fly biomass ash, 16.5g CO2 per kg of bottom biomass ash with plant cultivation and 19.7g CO2 per kg of bottom biomass ash without plant cultivation. This inorganic C fixation plus the organic (black) C contained in the ashes made the reutilization of ashes as K fertilizer a relevant practice due to its C resilience and rate, with a yearly C sequestering potential of ca. 8% of ‘Soil carbon 4 per mille’ goal, an initiative launched at the COP21.

COMPARATIVE EFFECT OF POULTRY MANURE, ASH AND NPK FERTILIZER ON SOIL CHEMICAL PROPERTIES AND TRIFOLIATE YAM (Dioscorea dumentorum) PERFORMANCE IN AN ALFISOL OF SOUTHWESTERN NIGERIA

The decline in soil fertility is a fundamental impediment to agricultural growth and food production. This has necessitated the growing search for efficient soil fertility improvement practices. The field experiment was conducted in Akure during the major cropping seasons of 2013 and 2014 to assess the effect of different amendments on the chemical properties of an Alfisol using trifoliate yam (Dioscorea dumetorum) as a test crop. The experiment was laid out in a randomized complete block design with three replications. The treatments were Poultry Manure (PM) at 20tha-1, Wood Ash (WA) at 20tha-1, NPK 15:15:15 at 400kgha- 1 and a Control (CTRL) (no soil amendment). Data collected on soil chemical properties and crop growth and yield performance were subjected to analysis of variance (ANOVA) with the means separated using Duncan Multiple Range Test (DMRT). Results of this study indicated that WA increased the number of leaves, vine length, tuber length and tuber weight of yam and also improved soil pH, OC, N, P, K, Ca and Mg compared with the CTRL (control). NPK did not increase the yield of trifoliate yam but improved the soil nutrient concentrations compared with the CTRL (control). Relative to the control, WA increased the tuber weight by 14% in 2013 and 34% in 2014 respectively. Compared with NPK fertilizer, WA improved tuber yield of trifoliate by 17% in 2013 and 31% in 2014 respectively. Wood Ash amendment applied at 20 t/ha gave the highest yam tuber yield compared with other treatments and therefore recommended for yam production on an Alfisol for improving soil fertility conditions and sustained productivity.

Biofuel ash addition increases ectomycorrhizal fungal exudation in pure culture

Environmental contextSpreading recycled wood ash in forests may counteract acidification and nutrient losses, but the process may also affect symbiotic fungi in these eco-systems. We show how fungal species react when exposed to ash solutions; for example, by an increased release of organic acids and other compounds. These effects can influence pH and metal availability in forest soils treated with ash. AbstractRecycling of wood ash may counteract acidification and losses of base cations resulting from whole-tree harvesting in boreal forest ecosystems. The effects of ash treatment on growth and exudation of eight ectomycorrhizal fungal species were investigated in this study. Six basidiomycetes and two ascomycetes were grown in liquid pure culture with different levels of ash amendments. Biomass production, pH and the exudation of 17 low-molecular-mass organic acids (LMMOAs), 23 amino acids (AAs) and 9 hydroxamate siderophores (HSs) were recorded after 1, 2 and 4 weeks of incubation. Ash did not affect fungal growth, but resulted in higher exudation of the investigated compounds, in particular LMMOAs. Ash also influenced the composition of the exudates. We measured exudation of LMMOAs and AAs up to millimolar and micromolar concentrations respectively. For example, Rhizopogon roseolus mainly produced oxalic acid, whereas Lactarius rufus and Tomentellopsis submollis produced the highest concentrations of AAs. Ferricrocin, the only HS detected, was exuded at the nanomolar level. Exudation responses were also highly species-dependent, e.g. the ascomycetous isolates that produced the largest biomass released low amounts of exudates compared with the basidiomycetes, and were the only ones producing siderophores. This growth–exudation response to ash is likely a trade-off in carbon allocation whereby the mycorrhizal fungal species invest carbon in either higher biomass production or higher exudation.

Effects of fly ash amendments, Ralstonia solanacearum, Meloidogyne incognita and Phomopsis vexans on the growth of Solanum melongena

Effects of fly ash amendments in soil (0%, 25% and 50% vol/vol), Ralstonia solanacearum, Meloidogyne incognita and Phomopsis vexans were observed on the growth, chlorophyll and carotenoid contents of eggplant. Addition of 25% fly ash in soil caused a significant increase in plant growth, chlorophyll and carotenoid contents over plants grown without fly ash. However, amendments of 50% fly ash in soil had an adverse effect on the growth, chlorophyll and carotenoid contents of eggplant. Inoculation of the pathogens caused a significant reduction in growth, chlorophyll and carotenoid contents. Inoculation of R. solanacearum caused the greatest reduction followed by P. vexans and M. incognita. Root galling and nematode multiplication was reduced with the increase in fly ash. Wilting and blight indices were 3 in plants grown in 0% and 25% fly ash amended soil while 4 in 50% fly ash amended soil.

Cadmium and Lead Sorption/Desorption on Non-Amended and By-Product-Amended Soil Samples and Pyritic Material

Batch-type experiments were used to study cadmium (Cd) and lead (Pb) sorption/desorption on forest soil, vineyard soil and pyritic material samples, on the by-products mussel shell, oak ash, pine bark and hemp waste, and on forest soil, vineyard soil and pyritic material amended with 48 t ha−1 of oak ash, mussel shell, and hemp waste. The main results were that the forest soil showed higher Cd and Pb retention than the vineyard soil and the pyritic material. Regarding the byproducts, sorption was in the following order: oak ash > mussel shell > hemp waste > pine bark, with desorption following an inverse sequence. The pH was the parameter that most influenced Cd and Pb sorption. Cd and Pb sorption curves showed better fitting to the Freundlich than to the Langmuir model, indicating the dominance of multilayer interactions. Oak ash and mussel shell were the amendments causing higher increase in Cd and Pb sorption on both soils and the pyritic material (close to 100% with the oak ash amendment), as well as more a pronounced decrease in desorption. These results could be used to favor an effective management of the by-products studied, which could retain Cd and Pb in soils and degraded areas, preventing water pollution.

Phosphorus Retention by Fly Ash Amended Filter Media in Aged Bioretention Cells

Bioretention cells (BRCs) have shown potential for storm water quantity and quality control. However, the phosphorus (P) removal in BRC has been variable due to differences of soil properties in filter media. The objectives of this research were to identify and evaluate P accumulation in filter media and to quantify effluent P reduction in BRC. Each cell has a sand and fly ash media designed to remove phosphorous. Filter media were collected in 2014 across the cell surface and to a depth of 0.6 m to quantify the P accumulation. The mean total P (T-P) concentration increased over the seven years of operation, but the changes were not statistically significant. The average Mehlich-3 P (M3-P) and water-soluble P (WS-P) concentrations in the media profiles showed higher P accumulation in the top 0.15 m. The average M3-P and WS-P concentrations between 0.15 m to 0.30 m, and 0.30 m to 0.60 m were variable on all four BRCs media. The media with 5% fly ash significantly retained M3-P and WS-P over the top 0.15 m. Stormwater influent and effluent samples from three of the BRCs monitored over one year showed reductions in both P concentration (68% to 75%) and P mass (76% to 93%).

How Rice (Oryza sativa L.) Responds to Elevated As under Different Si-Rich Soil Amendments.

Several strategies exist to mitigate As impacts on rice and each has its set of trade-offs with respect to yield, inorganic As content in grain, and CH4 emissions. The addition of Si to paddy soil can decrease As uptake by rice but how rice will respond to elevated As when soil is amended with Si-rich materials is unresolved. Here, we evaluated yield impacts and grain As content and speciation in rice exposed to elevated As in response to different Si-rich soil amendments including rice husk, rice husk ash, and CaSiO3 in a pot study. We found that As-induced yield losses were alleviated by Husk amendment, partially alleviated by Ash amendment, and not affected by CaSiO3 amendment. Furthermore, Husk was the only tested Si-amendment to significantly decrease grain As concentrations. Husk amendment was likely effective at decreasing grain As and improving yield because it provided more plant-available Si, particularly during the reproductive and ripening phases. Both Husk and Ash provided K, which also played a role in yield improvement. This study demonstrates that while Si-rich amendments can affect rice uptake of As, the kinetics of Si dissolution and nutrient availability can also affect As uptake and toxicity in rice.

Compression Behavior of Mine Tailings Amended with Cementitious Binders

The objective of this study was to evaluate the effect of fly ash amendment on the compression behavior of mine tailings. Natural and synthetic (i.e., laboratory prepared) mine tailings were used to assess the effects of tailings composition and tailings solids content on compressibility. Three types of off-specification fly ashes and Type I–II Portland cement were used as cementitious binders. Tailings-fly ash mixtures were prepared at solids content of 60–75% (water content = 33–67%), water-to-binder ratios of 2.5 and 5, and were cured for 0.1 days (2 h), 7, and 28 days. Bi-linear compression curves on semi-log plots were observed in most of the binder-amended tailings specimens. The break in slope on the compression curve was identified as the breaking stress, whereupon cementitious bonds were broken. The breaking stress increased with an increase in fly ash content, which was attributed to a lower water-to-binder ratio and void volume-to-binder volume ratio that produced more effective particle bonding. Breaking stress also increased with an increase in CaO content and CaO-to-SiO2 ratio of fly ash, which resulted in more effective bonding between particles. The effect of curing time on the breaking stress of fly ash amended specimens was characterized by (1) an increase in breaking stress via increase in curing time and cementitious bond formation or (2) a constant breaking stress with curing time due to competing mechanisms during loading. Specimens cured under a vertical stress showed an increase in breakings stress with applied load water removal prior to cementitious bond formation that reduced the water-to-binder ratio and led to more effective cementation.

English

The effect of tillage methods and rates of wood ash on soil chemical properties and castor bean plant performance was studied in field trial at Abakaliki in three planting seasons. The experiment was a split plot in randomized complete block design with three tillage methods (mound, ridge, flat) and four rates of wood ash (0, 2t, 4 and 6 tha-1) replicated three times. Crop start version 7.2 was used to analyze data collected and mean separation was done using least significant difference (LSD) at 5% alpha level. The results of soil pH and available P showed that tillage method (TM) increased the values of the nutrients in 2nd year, but decreased in the 3rd year planting. The values of these parameters observed in Ridge method was found to be higher when compared to the values of Mound and Flat except for the result of available P in 1st  and 3rd year planting periods. The wood ash (WA) amendment was found to change the soil from slightly acidic in 1st year to alkaline in 2nd year to slightly acidic in 3rd year. The control soil remained acidic throughout the three years of study. The available P obtained from Rd6 consistently gave the highest values among the TM and rates of WA. Tillage methods had no effect on leaf area index (LAI) at 50 days after planting (DAP) and 100 DAP in 1st and 2nd year planting periods, but had significant effect on the parameters in 3rd year planting season. Flat showed highest plant height in 1st and 2nd years but decreased in the 3rd year. While the least value in plant height for the 3 years’ of study was recorded in Mound. The findings from this study has clearly shown that soil application of wood ash and tillage practices has the potential to cause positive and useful changes in the fertility and productivity status of the soil by improving the soil properties and yield component of castor.   Key words:  Ash, available P, castor plant, leaf area, plant height, soil reaction, tillage.

Nature of fly ash amendments differently influences oxidative stress alleviation in four forest tree species and metal trace element phytostabilization in aged contaminated soil: A long-term field experiment

Aided phytostabilization using coal fly ashes (CFAs) is an interesting technique to clean-up polluted soils and valorizing industrial wastes. In this context, our work aims to study the effect of two CFAs: silico-aluminous (CFA1) and sulfo-calcic (CFA2) ones, 10 years after their addition, on the phytostabilization of a highly Cd (cadmium), Pb (lead) and Zn (zinc) contaminated agricultural soil, with four forest tree species: Robinia pseudoacacia, Alnus glutinosa, Acer pseudoplatanus and Salix alba. To assess the effect of CFAs on trees, leaf fatty acid composition, malondialdehyde (MDA), oxidized and reduced glutathione contents ratio (GSSG: GSH), 8-hydroxy-2′-deoxyguanosine (8-OHdG), Peroxidase (PO) and Superoxide dismutase (SOD) activities were examined. Our results showed that CFA amendments decreased the CaCl2-extractable fraction of Cd and Zn from the soil. However, no significant effect was observed on metal trace element (MTE) concentrations in leaves. Fatty acid percentages were only affected by the addition of sulfo-calcic CFA. The most affected species were A. glutinosa and R. pseudoacacia in which C16:0, C18:0 and C18:2 percentages increased significantly whereas the C18:3 decreased. The addition of sulfo-calcic CFA induced the antioxidant systems response in tree leaves. An increase of SOD and POD activities in leaves of trees planted on the CFA2-amended plot was recorded. Conversely, silico-aluminous CFA generated a reduction of lipid and DNA oxidation associated with the absence or low induction of anti-oxidative processes. Our study evidenced oxidative stress alleviation in tree leaves due to CFA amendments. MTE mobility in contaminated soil and their accumulation in leaves differed with the nature of CFA amendments and the selected tree species.

Biochar and Wood Ash Amendments for Forestry in the Lake States: Field Report and Initial Results

Soil amendments are common in agriculture but are not widely used in Lake States forestry. Our objectives were to test the efficacy of operational-scale application of soil amendments on marginal sites as a management strategy for adaptation to drier conditions. Wood ash and biochar amendments were applied throughout 50 acres of recently harvested scrub oak stands, and red and jack pine seedlings were planted. Short-term results indicate increased water holding capacity and cation exchange capacity in soils amended with biochar and biochar with manure and significant increases in seedling production with wood ash amendment. Here we report on the feasibility of the application methods and their associated financial costs and present initial data on soil properties after amendment with wood ash and biochar.

Radial metal concentration profiles in trees growing on highly contaminated soils

The soil around Metaleurop, a big smelter, is heavily contaminated by Zn, Pb, Cd and Cu. In order to compare the impact of different soil amendments on the metal availability to trees, the polluted soil section was divided in a reference parcel and two others with either sulfo-calcic or silico-aluminous ash amendments. Five different tree species were planted on the parcels and the uptake of heavy metals in these trees was studied. Total and labile metal fractions were assessed in each of the 3 parcels. The mobility and assimilation of the metals was highest in the non-amended, reference soil parcel which had the lowest pH, organic matter and carbonate content. In all soils, pH decreased while organic matter content and mobility of the metals increased over time.Highest bulk concentrations of trace metals were found in white willow trees (Salix alba L.). Laser ablation-ICPMS was used to study changes in metal accumulation over a period of 10 years after planting the trees. The radial metal profiles in the trunk core samples varied between elements and tree species, however, in all willow trees the radial Cd and Zn profiles were significantly correlated.Radial pollutant concentration patterns are discussed in terms of seasonal effects, health status, tree species and metal mobility in the soil. For Cd and Zn, the profiles were influenced by their mobility in the soils. In general, periodical patterns were observed for Pb. Cu concentration profiles were decreasing over time, with the strongest decrease in the initial growth period.