INTRODUCTION
Fly ash is the remaining fine particles from coal combustion at power plants. Burning coal can produce 5% ash consisting of 80-90% fly ash and 10- 20% bottom ash (Hower et al., 2017). Fly ash is the most significant part of the combustion residue that has potency in agriculture because it can be used as an ameliorant and can reclaim ex-mining land (Ram
& Masto, 2010); (Jarosz-Krzemińska et al., 2020).
Based on its physical and chemical properties, fly ash has low density, high holding capacity, and essential nutrients. It can increase pH to be used as an ameliorant in soil (Pandey & Singh, 2010). Fly ash also contains macronutrients such as K, P, Mg, Ca, S, and micronutrients Cu, Fe, Mn, and Zn (Jarosz- Krzemińska & Poluszyńska, 2020).
Although it can potentially be used as an ameliorant, fly ash is limited by government regulations that classify hazardous and toxic materials. This regulation allows using fly ash only in the construction sector. The utilization of fly ash must be permitted through the harmful characteristics leaching procedures test. On the other hand, besides fly ash being used in the construction sector, fly ash is also widely used in agriculture as a soil amendment
(Sahu et al., 2017); (Jambhulkar et al., 2018); and to provide plant nutrients (He et al., 2017); and to increase soil pH, available P and boron (Tsadilas et al., 2018). However, there is little information regarding the use of fly ash on marginal soils such as Ultisols.
Ultisols are soils with intensive leaching, low nutrient content and soil pH (USDA, 2014). Therefore, efforts are needed to improve the characteristic of the Ultisol properties. Several methods have been carried out to improve Ultisol, including ameliorant materials such as fly ash (Kotelnikova et al., 2022); (Bamdad et al., 2022), organic matter (Zhao et al., 2020), liming (Litvinovich et al., 2019), vermicompost (Muktamar &
Lifia, 2020), biochar (Wang et al., 2020), also used to cover crops (Ye et al., 2019). Currently, these efforts have not significantly increased productivity in Ultisols. Some inputs are still needed to use ameliorant materials to achieve optimal productivity.
Sun et al. (2022) found that the total nitrogen content of water spinach remained unaffected by the application of hydro char amendment. However, the full recovery of nitrogen increased only when 2.0 wt % hydro char was combined with 120 kg N ha-
1. In addition, when combined with nitrogen fertilizer, organic fertilizer proved to be effective in enhancing the yield of crops (Ye et al., 2020).
ARTICLE INFO Keywords:
Ameliorant Cow Manure Fly Ash Heavy Metals Ultisol
Article History:
Received: June 9, 2021 Accepted: March 14, 2023
*) Corresponding author:
E-mail: [email protected]
ABSTRACT
Fly ash is the residue of coal combustion that can potentially be an ameliorant. Unfortunately, its use is limited by government regulations that are classified as hazardous and toxic materials. This study examines the effectiveness of fly ash and cow manure as an ameliorant for Ultisols. The experiment was carried out by two factors, i.e., the dose of fly ash, namely 0, 50, 100, and 150 t/ha, and the quantity of cow manure, i.e., 10, 20, and 30 t/ha. The results show that fly ash and cow manure could be ameliorants for low-pH soils such as Ultisols. The suitable dose of fly ash and cow manure as ameliorants in this study are 50 t/ha and 20 t/ha, respectively. Increasing the amount of fly ash caused a decrease in the growth of water spinach, plant height, number of leaves, fresh plant weight, root length, and dry weight of the root. In addition, fly ash increased pH 6.66-7.30, total P 31.74-52.21 mg/100 g, and total K 16.19-25.75 mg/100 g.
ISSN: 0126-0537Accredited First Grade by Ministry of Research, Technology and Higher Education of The Republic ofIndonesia, Decree No: 30/E/KPT/2018
Cite this as: Priyadi., Taisa, R., & Kurniawati, N. (2023). The effects of fly ash and cow manure on water spinach grown on an Ultisol of Lampung, Indonesia. AGRIVITA Journal of Agricultural Science, 45(2), 209–219 http://doi.org/10.17503/
agrivita.v45i2.3023
The Effects of Fly Ash and Cow Manure on Water Spinach Grown on An Ultisol of Lampung, Indonesia
Priyadi1*), Rianida Taisa1) and Nurleni Kurniawati2)
1) Politeknik Negeri Lampung, Lampung, Indonesia
2) STIPER Dharma Wacana, Lampung, Indonesia
The extent of the effects of heavy metals in fly ash on the soil and the plants can be evaluated by several methods. Phytoremediation is a technology that uses plants to clean contaminants from soil, sediment, and water (Tangahu et al., 2011);
(Handayanto et al., 2017). This is an alternative technology that is innovative, efficient, and cost- effective, as well as an environmentally friendly remediation strategy compared to other methods of dealing with hazardous waste (Ashraf et al., 2019);
(Moosavi & Seghatoleslami, 2013); (Wan & Lei, 2016). One type of plant used for phytoremediation is water spinach. Water spinach is a hyperaccumulator plant widely used in the phytoremediation of polluted planting media. Water spinach can absorb heavy metals through phytoextraction, phyto-stabilization, rhizo-filtration, and phytovolatilization (Zhang et al., 2010).
Besides fly ash, another type of ameliorant used is organic matter. In addition, organic matter can reduce the level of heavy metal pollution through the chelating mechanism. Organic matter can improve soil’s physical, chemical, and biological properties. Organic matter contains macronutrients (N, P, K, Mg, Ca, and S) and micronutrients (Cu, Zn, Mo, B, Co, Fe, and Mn) to improve marginal soils (Wood & Baudron, 2018). Moreover, organic materials contain important distinctive compounds in the form of functional groups, including carboxyl (-COOH), hydroxyl (-OH), carbonite (= C = O), methoxyl (-OCH3), and amino (-NH2). These compounds play an essential role in cation exchange as the stabilization of soil structure, the supply of N elements, C metabolism, and metal complexing.
Cow manure is an organic material that can be used as a soil ameliorant (Epelde et al., 2018); (Adhikari et al., 2022). The use of cow manure not only can increase plant growth and significantly improve the physicochemical properties of soil pH, total carbon, available P, and cation exchange capacity (Uzoma et al., 2011). Accordingly, the objective of this study was to examine the effectiveness of fly ash and cow manure as ameliorants for Ultisols.
MATERIALS AND METHODS Experimental Design
The experiment was conducted in Metro City, Lampung from November 2020 to April 2021. This research used the Hapsari variety of water spinach (Ipomea reptans). The pot experiment was carried out in a greenhouse by factorial in a randomized
complete block design of two factors. The first factor was the application rates of fly ash (0, 50, 100, and 150 t/ha). The second factor was the application rates of cow manure (10, 20, and 30 t/ha). Each treatment was replicated three times to obtain 36 experiment units. Planting media was prepared in plastic pots containing 5 kg of Ultisol. Sifted Ultisol was evenly mixed with fly ash according to treatment dosages 125 g, 250 g, and 750 g, respectively. While the second treatment was cow manure added 25, 50, and 75 g, respectively. This study avoided using basic fertilizers like NPK to ensure that any effects observed were solely attributable to the treatments.
Table 1. Soil chemical and physical characteristics of Ultisols Lampung
Soil Properties Values
Water content (%) 14.83
pH (H2O) 5.02
pH (KCl) 4.55
Organic C (%) 1.32
Total N (%) 0.186
N-NH4 (%) 0.012
N-NO3 (%) 0.002
P (mg/kg) 98.43
K (mg/kg) 47.67
Ca (mg/kg) 98.10
Mg (mg/kg) 81.79
Na (mg/kg) 13.39
Fe (mg/kg) 11.11
Zn (mg/kg) 0.63
Mn (mg/kg) 8.67
Cu (mg/kg) 0.27
Exchangeable Al (cmol/kg) 0.06
Exchangeable H (cmol/kg) 0.04
Total CEC (cmol/kg) 8.90
CECEff (cmol/kg) 5.87
Sand (%) 34.18
Silt (%) 10.98
Soil, Fly Ash, and Cow Manure Properties
Samples of Ultisol were collected from Metro City, Lampung 5°09’39.6”S - 105°18’21.4”E. The Ultisols analysis showed that the soil was classified as low infertility, as indicated by the soil pH, organic C, CEC, and some nutrient content such as N, P,
and K (Table 1). The ameliorant material used in this study was coal fly ash collected from the Great Giant Pineapple Company. The fly ash contained macro, micronutrients, and heavy metals (Table 2). Then the second was ameliorant organic matter from cow manure (Table 2).
Crop Measurement and Heavy Metals Content Plant maintenance involves various activities such as watering, replacing plants as needed, weeding, and managing pests and diseases through organic pesticides. Vegetative measurements of water spinach were determined by plant height and the number of leaves ranging from 0 to 28 days after planting (DAP). The fresh weight of the plant, root length, and dry weight of the root was determined based on destructive samples in the harvest. The sample was weighed and then put in an oven overnight at 60oC to obtain a constant weight—
measurement of heavy metals in soil and plants, including Cu, Pb, and Cd. Soil samples were dried at 110ºC for 2 hours and homogenized after cooling.
Approximately 0.4 g of the sample was weighed and transferred to the digestion vessel, then 15 ml of aqua regia was added. The beaker was covered with glass and heated at 95ºC without boiling. The obtained solutions were filtered, collected in 50 ml flasks, and diluted with distilled water (Ilieva et al., 2018). ICP-OES determined Cu, Pb, and Cd (Varian 715-ES inductively coupled plasma optical emission spectrometry Varian Associates, Walnut Creek, California, now Agilent Technologies, Santa Clara, California).
Statistical Analysis
The effect of fly ash application combined with cow manure as soil ameliorants for the growth of water spinach and heavy metals uptake in soil were analyzed by two-way ANOVA followed by a least significant difference (LSD) at P<0.05 to determine statistical differences (Hoaglin et al., 2009).
RESULTS AND DISCUSSION
Effect of Fly Ash and Cow Manure Applications on Soil Chemical Properties
There were some changes in the soil’s chemical properties after fly ash and cow manure applications. The results showed that adding fly ash and cow manure increased soil pH (H2O and KCl), total K, and total P (Table 3). Increases in soil pH, total K, and total P occurred with the addition of fly ash doses. Adding fly ash and cow manure increased soil pH, both H2O and KCl. The increase in pH of H2O after applying fly ash and cow manure was 0.64, while the pH of KCl was 0.63. This research indicated the highest pH values at 100 and 150 t/ha.
The content of alkaline elements such as Na, Ca, and Mg in fly ash increases the pH value. Research conducted by (Kishor et al., 2010) explained that fly ash contains K, Ca, Zn, Na, Mg, and Fe that caimprove soil health and increase plant production.
Analysis of C and N content in the soil did not show a significant increase in fly ash applications. The C and N content from coal has been lost during the combustion process at the power plant. The carbon content in coal fly ash varies widely and depends on the conditions during combustion.
Table 2. The properties of coal fly ash and cow manure
Cow Manure Properties Values Fly Ash Properties Values
Water content (%) 39.91 Na (%) 0.56
Organic C (%) 21.04 Mg (%) 0.67
Total N (%) 1.25 Al (%) 4.72
C/N Rasio 16 Ca (%) 7.39
Total P2O5 (%) 0.73 Ni (mg/kg) 10.26
Total K2O (%) 0.77 Cu (mg/kg) 167.21
Total Pb (mg/kg) 25 Pb (mg/kg) 2.54
Total Cd (mg/kg) * Cd (mg/kg) 7.21
Total As (mg/kg) * Cr (mg/kg) 3.00
Total Hg (mg/kg) * Co (mg/kg) *
CEC (cmol/kg) 27.09 pH (H2O) 10.21
Humic Acid (%) 8.97 pH (KCl) 9.46
Remarks: * = not detected
The highest P and K content showed at the dose of fly ash 150 t/ha. In addition to increasing the soil pH, fly ash also plays a role as the source of P and K nutrients. In line with (Mittra et al., 2003), applications of fly ash combined with organic matter can increase the availability of nutrients N, P, and K. Increased nutrient availability indirectly also causes an increase in the efficiency of N, P, and K fertilization. It explains that the alkaline content in fly ash will indirectly increase the phosphate- solubilizing bacteria (PSB) population due to an increase in pH value. Furthermore (Mittra et al., 2003) explained that applying fly ash at a dose of 40 t/ha combined with phosphate-solubilizing bacteria P. striata increased the yield and uptake of P in legumes. It also did not show the loss effects of P. striata population in the soil.
Analysis of the variance of the application of fly ash and cow manure to heavy metals in the soil and water spinach is presented in Table 4. The application was not significantly different in heavy metals observations except for soil Pb in cow manure. Also, there was no interaction between fly ash dosage treatment and cow manure on all observed variables. The fly ash application did not give any difference in the concentration of heavy metals in both soil and plants. The highest heavy metal content was found in the soil, namely Pb (31.87 - 37.47 mg/kg), followed by Cu (7.88 - 9.04
mg/kg) and Cd (0.80 - 2.08 mg/kg) (Table 5). The highest heavy metal content in plants was Cu (3.21 - 4.92 mg kg-1), Pb (0.72 - 1.65 mg/kg), and Cd (0.25 - 0.91 mg/kg). Cow manure treatment did not give significant differences in the content of heavy metals in soil and plants, except for soil Pb. Applying 20 t cow manure per ha showed the highest Pb concentration in the soil compared to treatments of 10 t/ha and 30 t/ha.
In general, the highest concentrations of heavy metals in the soil due to the application of fly ash and cow manure were in the order of Pb >
Cu > Cd. Meanwhile, the highest concentrations of heavy metals in plants were in the order Cu >
Pb > Cd. The heavy metal content in the soil might have come from the content in fly ash and cow manure, namely Cu 167.21 mg/kg, Ni 10.26 mg/
kg, and Cd 7.21 mg/kg (Table 2). Moreover, the soil also contains several heavy metals that affect the increase of heavy metal concentrations. The heavy metals analysis results showed that water spinach could absorb high Cu. Water spinach is a phytoremediation plant that can absorb Cu, Pb, and Cd. Water spinach is a hyperaccumulator plant used as a phytoremediator (Mohotti et al., 2016). (Effendi et al., 2015) stated that water spinach, as a phyto bioremediation of metals in the soil, effectively reduced the Cd concentration by 66.31%.
Table 3. Soil chemical properties after application of fly ash and cow manure as an ameliorant Fly ash dose
(t/ha) pH
(H2O) pH
(KCl) Organic C
(%) Total N
(%) Total P
(mg/100 g) Total K (mg/100 g)
0 6.66 a 6.13 a 0.94 a 0.07 a 31.74 a 16.19 a
50 6.87 a 6.30 a 1.01 a 0.08 a 37.03 a 21.76 a
100 7.31 b 6.68 b 0.95 a 0.07 a 44.51 b 19.73 a
150 7.30 b 6.77 b 1.09 a 0.07 a 52.21 b 25.75 b
LSD 0.15 0.16 0.12 0.01 2.95 2.73
Remarks: The mean followed by the same letter indicates no significant difference in the same row (P =0.05) by the LSD test at P<0.05.
Table 4. Analysis of variance of the effects of fly ash and cow manure applications on heavy metals on soil and plants
Treatment ---Soil--- ---Plants---
Cu Pb Cd Cu Pb Cd
Fly ash 1.00 ns 1.50 ns 1.17 ns 1.98 ns 0.83 ns 2.39 ns
Cow Manure 1.63 ns 8.88 * 0.40 ns 1.44 ns 0.20 ns 0.23 ns
Interaction 1.19 ns 1.50 ns 2.47 ns 0.23 ns 1.60 ns 0.48 ns Remarks: ns = not significant; * = significant at P<0.05.
Furthermore, water spinach was able to accumulate metals in soil contaminated with Pb in three harvest periods, with total biomass reaching 308.13 mg, 392.07 mg, and 482.21 mg Pb from 328.24 ± 2.33 mg/kg, 433.03 ± 0.59 mg/kg and 537.25 ± 0.92 mg/kg Pb (Okoro et al., 2018). It is also promising plant species for the remediation of Pb and Cd-contaminated wastewater (Bindu et al., 2010).
The results showed that water spinach absorbed Cu in high concentrations compared to Pb and Cd metals.
It shows that the increase in pH in the soil due to the application of fly ash causes several metal elements in the soil solution to settle and are unavailable to plants.(Soares et al., 2015) stated that the increase of pH due to liming in acidic soils reduces the mobility of metals in the form of Cd and Zn.
Increasing pH is a strategy to precipitate dissolved metal mobilization in the planting root zone (Shaheen et al., 2017). Low soil pH conditions will directly affect the availability of metals because the soil’s acidity determines the solubility and movement of metals in the soil (Elekes, 2014).
Meanwhile, in neutral or alkaline pH conditions, most of the metals in the soil become unavailable because they are deposited or immobile (Laghlimi et al., 2015). According to (Chaney & Oliver, 1996), the solubility of heavy metals decreases with increasing soil pH in the order Pb > Cu > Mn > Zn > Ni > Cd.
Effect of Fly Ash and Cow Manure Applications on Plant Yield
The analysis of variance of fly ash applications significantly differed on plant height, number of
leaves, fresh weight plant, root length, and root dry weight (Table 6). At the same time, the application of cow manure was not significantly different from all parameters except for the fresh weight of the plant.
Also, all parameters have no interaction between fly ash and cow manure applications.
Phytoremediation is a method that uses plants to remove metal content from the soil. This technique is suitable for eliminating pollution over large areas and when contaminants are in the root zone (Wang et al., 2017); (Rostami & Azhdarpoor, 2019). In this research, water spinach used as a hyperaccumulator plant generally has the following criteria; The ability to transport metal content from root to shoot and the existence of high tolerance ability (Marques et al., 2009), the total metal concentration in the root should be higher than 0.1% for Al Cu, Cr, Co, Ni, Se;
higher than 0.5% for Cu, Zn, Pb, Cd, Ni (Rezapour et al., 2019). Phytoremediation in this study is the phytoextraction mechanism with characteristics; high biomass, extensive root system, fast growth rate, and ability to tolerate high amounts of heavy metals.
Several studies have stated that water spinach was effective as a plant that could absorb heavy metals.
Although this research still requires some supporting data, such as bioconcentration factor (BCF) in plant biomass by heavy metals in fly ash (Maiti et al., 2022).
Generally, the ability of water spinach plants to tolerate heavy metals in fly ash was up to 50 t/hadose, so it was considered one of the phytoextraction plants.
In-line research (Ogungbile et al., 2021) revealed that kale plants have ecological risk quotient, and bioaccumulation effectively binds heavy metals.
Table 5. The effects of heavy metals on soil and plants
Treatment ---Soil (mg/kg)--- ---Plants (mg/kg)---
Cu Pb Cd Cu Pb Cd
Fly Ash 0 t/ha 7.88 31.87 0.99 3.21 0.83 0.25
Fly Ash 50 t/ha 8.73 37.13 0.80 4.54 0.72 0.91
Fly Ash 100 t/ha 9.04 34.13 1.84 4.85 0.87 0.28
Fly Ash 150 t/ha 8.99 37.47 2.08 4.92 1.65 0.55
Manure 10 t/ha 8.80 28.87 a 1.77 5.05 1.11 0.44
Manure 20 t/ha 9.18 39.55 b 1.15 3.94 1.14 0.59
Manure 30 t/ha 8.01 37.03 a 1.35 4.15 0.81 0.46
LSD Fly Ash 1.36 5.50 1.47 1.44 1.18 0.50
LSD Manure 1.58 6.35 1.70 1.67 1.37 0.58
LSD Fly Ash x Manure 2.73 11.00 2.95 2.89 2.37 1.01
Remarks: The mean followed by the same letter indicates no significant difference in the same row (P =0.05) by the LSD test at P<0.05.
The effect of fly ash and cow manure application on the growth of water spinach is shown in Table 7. Applying fly ash with a dose of 0 t/ha gave the highest yield on the number of leaves and fresh weight plant. While the parameters of plant height, root length, and dry weight showed the highest in the treatment of fly ash doses of 0 t/ha and 50 t/ha. The higher the amount of fly ash applied, the less the growth of water spinach. Water spinach can grow well on fly ash applications up to a dose of 50 t/ha. Meanwhile, applying fly ash at doses of 100 t/ha to 150 t/ha will cause a decrease in plant growth. The results of the study state that a plant’s response to fly ash with a content of 21 elements, macro, micro, and metal, causes a decrease in plant biomass by up to 15.2% (Yu et al., 2019). The analysis showed that the fly ash dose increase would decrease plant growth but not significantly.
LSD test results on fresh plant weight showed that the significant difference in water spinach was due to fly ash and cow manure application. Water spinach without the provision of coal fly ash produced higher plant fresh weights of 7.05%, 10.99%, and 16.11% compared to the doses of coal fly ash 50 t/ha, 100 t/ha, and 150 t/
ha. In comparison, the application of cow manure with a dose of 30 t/ha showed a higher yield of 2.85% and 9.07% compared to the amount of cow manure of 10 t/ha. Applying fly ash with a dose of
0 t/ha affected the increase in root length and root dry weight of water spinach but did not differ by 50 t/ha. The root length of water spinach decreased along with the increasing number of fly ash doses.
The heavy metal content in fly ash causes stunted root growth, so it cannot take nutrients and grow well. Research conducted by (Ahmad et al., 2012), (Yourtchi & Bayat, 2013) explained that the heavy metal content of Cd would decrease the germination ability of wheat.
Furthermore, the heavy metal content of Cd was also able to reduce chlorophyll content, root biomass, and root growth of Brassica napus (Benakova et al., 2017) and inhibit root growth in maize (Figlioli et al., 2018). In general, water spinach can grow normally with different fly ash doses (Fig. 1), although there are decreases in some parameters. The decline in the growth of water spinach is still at normal limits because it does not cause death in plants.
Water spinach experienced a decrease in the dry weight of root and root length with an increase in the dose of fly ash, but water spinach could still grow normally (Fig. 2). It is assumed that water spinach can adapt to heavy metals and be affected by fly ash and cow manure. Cocozza et al., (2008) found that Cd metal treatment was not strongly affected by primary and secondary roots, although the metal was found in most of the root tissues.
Table 6. The analysis of variance of the effects of fly ash and cow manure applications on the growth of water spinach
Treatment Plant height Number of leaves Fresh weight plant Root length Dry weight of root
Fly Ash 4.06* 4.25* 10.65* 10.16* 5.31*
Cow Manure 2.98ns 1.31 ns 3.71* 2.30 ns 0.48 ns
Interaction 1.32 ns 0.26 ns 1.32 ns 0.49 ns 0.53 ns
Remarks: ns = not significant; * = significant at P<0.05.
Table 7. The effect of water spinach growth on fly ash and cow manure applications Fly ash dose
(t/ha) Plant height
(cm) Number of leaves Fresh weight plant
(g) Root length
(cm) Dry weight of root (g)
0 27.24 a 12.20 a 36.41 a 36.11 a 0.79 a
50 26.78 ab 11.31 b 28.76 b 35.20 a 0.65 ab
100 24.64 bc 11.16 b 24.48 bc 31.41 b 0.53 bc
150 24.02 c 10.84 b 18.92 c 27.44 c 0.41 c
LSD 5 % 2.30 0.83 6.63 3.49 0.21
Remarks: The means followed by the same letter indicates no significant difference in the same row (P=0.05) by the LSD test at P<0.05.
Cow manure is one of the organic materials that can increase plant growth and significantly increase the physical-chemical properties of soil in the form of pH, total carbon, available P, and cation exchange capacity (Uzoma et al., 2011). Besides, cow manure can reduce heavy metal pollution
because it contains humus. Humus will form complex compounds and chelates, so heavy metals are unavailable in soil solution (Chu et al., 2022).
Chen et al. (2019) revealed that biochar from cow manure could be a potential sorbent because it has a high retention capacity for Pb and Cd.
Fig. 1. Growth of water spinach on the application of fly ash and cow manure 25 day after plant (DAP)
Fig. 2. Water spinach in fly ash dose applications at 25 day after plant (DAP): (A) root length; and (B) dry weight
CONCLUSION AND SUGGESTION
The fly ash application combined with cow manure at different doses did not significantly affect the growth of water spinach plants on Ultisol. Fly ash and cow manure applied to the soil increased soil pH, total P, and K. The suitable dose of fly ash and cow manure as ameliorants in this study were 50 t/ha and 20 t/ha, respectively. In this case, fly ash can be used as an ameliorant in soil combined with organic matter to reduce heavy metal content.
ACKNOWLEDGEMENTS
This research was supported by the Ministry of Research and Technology/ National Research and Innovation Agency through PDP grant program number 078/SPH2/LT/DPRM/2020.
REFERENCES
Adhikari, S., Timms, W., & Mahmud, M. A. P.
(2022). Optimising water holding capacity and hydrophobicity of biochar for soil amendment–A review. Science of The Total Environment, 158043. https://doi.org/10.1016/j.
scitotenv.2022.158043.
Ahmad, I., Jamil, A., & Zahir, Z. A. (2012). Effect of cadmium on seed germination and seedling growth of four wheat (Triticum aestivum L.) cultivars. Pakistan Journal of Botany, 44(5), 1569–1574.
Ashraf, S., Ali, Q., Ahmad, Z., Ashraf, S., & Naeem, H.
(2019). Phytoremediation: Environmentally sustainable way for reclamation of heavy metal polluted soils. Ecotoxicology and Environmental Safety, 174, 714–727. https://doi.org/10.1016/j.
ecoenv.2019.02.068.
Bamdad, H., Papari, S., Lazarovits, G., & Berruti, F.
(2022). Soil amendments for sustainable agriculture: Microbial organic fertilizers. Soil Use and Management, 38(1), 94–120. https://doi.
org/10.1111/sum.12762.
Benakova, M., Ahmadi, H., Du, Z., Tylova, E., & Clemens, S. (2017). Effects of Cd and Zn on physiological and anatomical properties of hydroponically grown Brassica napus plants. Environmental Science and Pollution Researsch, 24, 20705–
20716. https://doi.org/10.1007/s11356-017- 9697-7.
Bindu, T., Sumi, M. M., & Ramasamy, E. V. (2010).
Decontamination of water polluted by heavy metals with Taro (Colocasia esculenta) cultured in a hydroponic NFT system. Environmentalist,
30(1), 35–44. https://doi.org/10.1007/s10669- 009-9240-6.
Chaney, R. L., & Oliver, D. P. (1996). Sources , potential adverse effects and remediation of agri- cultural soil contaminants. In R. Naidu, R. S. Kookana, D. P. Oliver, S. Rogers, & M. J. McLaughlin (Eds.), Contaminants and the Soil Environment in the Australasia-Pacific Region (pp. 323–359).
Springer. https://doi.org/10.1007/978-94-009- 1626-5_11.
Chen, Z. L., Zhang, J. Q., Huang, L., Yuan, Z. H., Li, Z.
J., & Liu, M. C. (2019). Removal of Cd and Pb with biochar made from dairy manure at low temperature. Journal of Integrative Agriculture, 18(1), 201–210. https://doi.org/10.1016/S2095- 3119(18)61987-2.
Chu, S., Feng, X., Liu, C., Wu, H., & Liu, X. (2022).
Advances in Chelating Resins for Adsorption of Heavy Metal Ions. Industrial & Engineering Chemistry Research, 61(31), 11309–11328.
https://doi.org/10.1021/acs.iecr.2c01353
Cocozza, C., Minnocci, A., & Tognetti, R. (2008).
Distribution and concentration of cadmium in root tissue of Populus alba determined by scanning electron microscopy and energy- dispersive x-ray microanalysis. IForest-Biogeosciences and Forestry, 1(2), 96–103. https://doi.org/10.3832/
ifor0458-0010096.
Effendi, H., Utomo, B. A., Darmawangsa, G, M., & Sulaeman, N. (2015). Combination of water spinach (Ipomea aquatica) and bacteria for freshwater cryfish red claw (Cherax quadricarinatus) culture wastewater treatment in aquaponic system.
Journal of Advances in Biology, 6(3), 1072–
1078. https://agris.fao.org/agris-search/search.
do?recordID=ID2021108951.
Elekes, C. C. (2014). Eco-Technological Solutions for the Remediation of Polluted Soil and Heavy Metal Recovery. In Environmental Risk Assessment of Soil Contamination (pp. 309–335). INTECH.
https://books.google.co.id/
Epelde, L., Jauregi, L., Urra, J., Ibarretxe, L., Romo, J., Goikoetxea, I., & Garbisu, C. (2018).
Characterization of Composted Organic Amendments for Agricultural Use. Front.
Sustainable Food Syst., 2(44), 1–12. https://doi.
org/10.3389/fsufs.2018.00044.
Figlioli, F., Sorrentino, M. C., Memoli, V., Arena, C., Maisto, G., Giordano, S., Capozzi, F., &
Spagnuolo, V. (2018). Overall plant responses to Cd and Pb metal stress in maize: Growth pattern , ultrastructure , and photosynthetic activity.
Environmental Science and Pollution Research , 26, 1781–1790. https://doi.org/10.1007/s11356- 018-3743-y.
Handayanto, E., Nuraini, Y., Muddarisna, N., Syam, N., &
Fiqri, A. (2017). Fitoremediasi dan phytomining logam berat pencemar tanah. Universitas Brawijaya Press. https://opac.perpusnas.go.id/
DetailOpac.aspx?id=1141238.
He, H., Dong, Z., Peng, Q., Wang, X., & Fan, C. (2017).
Impacts of coal fly ash on plant growth and accumulation of essential nutrients and trace elements by alfalfa (Medicago sativa) grown in a loessial soil. Journal of Environmental Management, 197, 428–439. https://doi.
org/10.1016/j.jenvman.2017.04.028.
Hoaglin, D. C., Mosteller, F., & Tukey, J. W. (2009).
Fundamentals of Exploratory Analysis of Variance Books. John Wiley & Sons. https://
books.google.co.id/
Hower, J. C., Henke, K. R., Dai, S., Ward, C. R., French, D., Liu, S., & Graham, U. M. (2017). Generation and nature of coal fly ash and bottom ash. In Coal Combustion Products (CCP’s). Elsevier Ltd. https://doi.org/10.1016/B978-0-08-100945- 1.00002-2
Ilieva, D., Surleva, A., Murariu, M., Drochioiu, G., &
Abdullah, M. M. A. B. A. (2018). Evaluation of ICP-OES Method for Heavy Metal and Metalloids Determination in Sterile Dump Material. Solid State Phenomena, 273, 159–166. https://doi.
org/10.4028/www.scientific.net/SSP.273.159 Jambhulkar, H. P., Shaikh, S. M. S., & Kumar, M. S. (2018).
Fly ash toxicity , emerging issues and possible implications for its exploitation in agriculture ; Indian scenario: A review. Chemosphere, 213, 333–344. https://doi.org/10.1016/j.
chemosphere.2018.09.045
Jarosz-Krzemińska, E., & Poluszyńska, P. (2020).
Repurposing Fly Ash Derived from Biomass Combustion in Fluidized Bed Boilers in Large Energy Power Plants as a Mineral Soil Amendment. Energies, 13(18), 4805. https://doi.
org/10.3390/en13184805.
Kishor, P., A.K, Ghosh., & Kumar, D. (2010). Use of Flyash in Agriculture : A Way to Improve Soil Fertility and its Productivity. Asian Journal of Agricultural Research, 4(1), 1–14. https://doi.org/10.3923/
ajar.2010.1.14
Kotelnikova, A. D., Rogova, O. B., Karpukhina, E.
A., Solopov, A. B., Levin, I. S., Levkina, V.
v, Proskurnin, M. A., & Volkov, D. S. (2022).
Assessment of the structure, composition, and
agrochemical properties of fly ash and ash- and-slug waste from coal-fired power plants for their possible use as soil ameliorants. Journal of Cleaner Production, 333, 130088. https://doi.org/
https://doi.org/10.1016/j.jclepro.2021.130088 Laghlimi, M., Baghdad, B., & El Hadi, H. (2015).
Phytoremediation Mechanisms of Heavy Metal Contaminated Soils : A Review. Open Journal of Ecology, 5(8), 375–388. https://doi.org/10.4236/
oje.2015.58031.
Litvinovich, A., Salaev, I., Pavlova, O., Lavrishchev, A., Bure, V., & Saljnikov, E. (2019). Utilization of Large-Sized Dolomite By-Product Particles and Losses of Cations from Acidic Soil.
Communications in Soil Science and Plant Analysis, 50(7), 869–877. https://doi.org/10.108 0/00103624.2019.1589490
Maiti, S. K., Ghosh, D., & Raj, D. (2022). Phytoremediation of fly ash: bioaccumulation and translocation of metals in natural colonizing vegetation on fly ash lagoons. In K. K. Kar (Ed.), Handbook of Fly Ash (pp. 501–523). Butterworth-Heinemann.
https://doi.org/https://doi.org/10.1016/B978-0- 12-817686-3.00011-6
Marques, A. P. G. C., Rangel, A. O. S. S., & Castro, P. M. L. (2009). Remediation of Heavy Metal Contaminated Soils : Remediation of Heavy Metal Contaminated Soils : Phytoremediation as a Potentially Promising Clean-Up Technology. Environmental Science and Technology, 39, 622–654. https://doi.
org/10.1080/10643380701798272
Mittra, B. N., Karmakar, S., Swain, D. K., & Ghosh, B.
C. (2003). Fly Ash – a Potential Source of Soil Amendment and a Component of Integrated Plant Nutrient Supply System. International Ash Utilization Symposium, 5, 28–35. https://doi.
org/10.1016/j.fuel.2004.10.019
Mohotti, A. J., Geeganage, K. T., Mohotti, K. M., Karunaratne, C. L. S. M., & Chandrajith, R. (2016).
Phytoremedial potential of ipomoea aquatica and colocasia esculenta in soil contaminated with heavy metals through automobile painting, repairing service centres. Sri Lankan Journal of Biology, 1(1), 27–37.
Moosavi, S. G., & Seghatoleslami, M. J. (2013).
Phytoremediation - A Review. Advance in Agriculture and Biology, 1(1), 5–11.
Muktamar, Z., & Lifia, T. A. (2020). Phosphorus availability as affected by the application of organic amendments in Ultisols. Sains Tanah, 17(1), 16–
22. https://doi.org/10.20961/stjssa.v17i1.41284
Ogungbile, P., Ayeku, P., & Ajibare, A. (2021). Comparative biotolerance of water spinach, Ipomoea aquatica , to heavy metal pollution in the Agodi Reservoir and the Ogunpa River, Oyo State, Nigeria.
African Journal of Aquatic Science, 46, 1–7.
https://doi.org/10.2989/16085914.2021.1911780 Okoro, J. C., Saidu, Y., & Anka, S. A. (2018).
Phytoremediation potential of Ipomoea asarifolia on lead poluted soils. Bayero Jounal of Pure and Aplied Science, 11(1), 301–307. https://doi.
org/10.4314/bajopas.v11i1.49S.
Pandey, V. C., & Singh, N. (2010). Impact of fly ash incorporation in soil systems. Agriculture, Ecosystems and Environment, 136(1–2), 16–27.
https://doi.org/10.1016/j.agee.2009.11.013.
Ram, L. C., & Masto, R. E. (2010). An appraisal of the potential use of fly ash for reclaiming coal mine spoil. J. Environ. Manage., 91(3), 603–617.
https://doi.org/10.1016/j.jenvman.2009.10.004.
Rezapour, S., Atashpaz, B., Moghaddam, S. S.,
& Damalas, C. A. (2019). Heavy metal bioavailability and accumulation in winter wheat (Triticum aestivum L.) irrigated with treated wastewater in calcareous soils. Science of the Total Environment, 656, 261–269. https://doi.
org/10.1016/j.scitotenv.2018.11.288.
Rostami, S., & Azhdarpoor, A. (2019). Chemosphere The application of plant growth regulators to improve phytoremediation of contaminated soils:
A review. Chemosphere, 220, 818–827. https://
doi.org/10.1016/j.chemosphere.2018.12.203.
Sahu, G., Bag, A. G., Chatterjee, N., & Mukherjee, A. K.
(2017). Potential use of flyash in agriculture: A way to improve soil health Potential use of flyash in agriculture: A way to improve soil health.
Journal of Pharmacognosy and Phytochemistry, 6(6), 873–880. https://www.phytojournal.com/
archives/2017.v6.i6.2172/potential-use-of- flyash-in-agriculture-a-way-to-improve-soil- health
Shaheen, S. M., Shams, M. S., Khalifa, M. R., El- Dali, M. A., & Rinklebe, J. (2017). Various soil amendments and environmental wastes affect the (im)mobilization and phytoavailability of potentially toxic elements in a sewage effluent irrigated sandy soil. Ecotoxicology and Environmental Safety, 142, 375–387. https://doi.
org/10.1016/j.ecoenv.2017.04.02.
Soares, M. A. R., Quina, M. J., & Quinta-Ferreira, R.
M. (2015). Immobilisation of lead and zinc in contaminated soil using compost derived
from industrial eggshell. In International Journal of Environmental Management (Vol.
164, pp. 137–145). https://doi.org/10.1016/j.
jenvman.2015.08.042.
Sun, H., Chen, Y., & Yi, Z. (2022). After-Effects of Hydrochar Amendment on Water Spinach Production, N Leaching, and N2O Emission from a Vegetable Soil under Varying N-Inputs.
Plants, 11(24), 3444. https://doi.org/10.3390/
plants11243444.
Tangahu, B. V., Sheikh Abdullah, S. R., Basri, H., Idris, M., Anuar, N., & Mukhlisin, M. (2011). A review on heavy metals (As, Pb, and Hg) uptake by plants through phytoremediation. International Journal of Chemical Engineering, 1–31. https://
doi.org/10.1155/2011/939161.
Tsadilas, C. D., Hu, Z., Bi, Y., & Nikoli, T. (2018). Utilization of coal fly ash and municipal sewage sludge in agriculture and for reconstruction of soils in disturbed lands: results of case studies from Greece and China. International Journal of Coal Science and Technology, 5(1), 64–69. https://
doi.org/10.1007/s40789-018-0202-9
USDA. (2014). Keys to Soil Taxonomy (12th. Ed). https://
www.nrcs.usda.gov/resources/guides-and- instructions/keys-to-soil-taxonomy.
Uzoma, K. C., Inoue, M., Andry, H., Fujimaki, H., Zahoor, A., & Nishihara, E. (2011). Effect of cow manure biochar on maize productivity under sandy soil condition. Soil Use and Manage., 27(2), 205–212. https://doi.org/10.1111/j.1475- 2743.2011.00340.x.
Wan, X., & Lei, M. (2016). Cost – benefit calculation of phytoremediation technology for heavy- metal- contaminated soil. Science of The Total Environment, 563–564, 796–802. https://doi.
org/10.1016/j.scitotenv.2015.12.080.
Wang, H., Dong, Y., Tong, X., Liu, X., Shao, J., Shi, R., Hong, Z., Xu, R., & Jiang, J. (2020). The amelioration effects of canola straw biochar on Ultisol acidity varied with the soil in which the feedstock crop was cultivated. Journal of Soils and Sediments, 20(3), 1424–1434. https://doi.
org/10.1007/s11368-019-02504-2.
Wang, L., Ji, B., Hu, Y., Liu, R., & Sun, W. (2017). A review on in situ phytoremediation of mine tailings. Chemosphere, 184, 594–600. https://
doi.org/10.1016/j.chemosphere.2017.06.025 Wood, S. A., & Baudron, F. (2018). Soil organic matter
underlies crop nutritional quality and productivity in smallholder agriculture. Agriculture,
Ecosystems and Environment, 266, 100–108.
https://doi.org/10.1016/j.agee.2018.07.025 Ye, L., Camps-Arbestain, M., Shen, Q., Lehmann, J.,
Singh, B., & Sabir, M. (2020). Biochar effects on crop yields with and without fertilizer: A meta- analysis of field studies using separate controls.
Soil Use and Management, 36(1), 2–18. https://
doi.org/10.1111/sum.12546.
Ye, R., Parajuli, B., & Sigua, G. (2019). Subsurface Clay Soil Application Improved Aggregate Stability, Nitrogen Availability, and Organic Carbon Preservation in Degraded Ultisols with Cover Crop Mixtures. Soil Science Society of America Journal, 83(3), 597–604. https://doi.org/10.2136/
sssaj2018.12.0496
Yourtchi, M. S., & Bayat, H. R. (2013). Effect of cadmium toxicity on growth, cadmium accumulation and macronutrient content of durum wheat (Dena CV.). International Journal of Agriculture and Crop Sciences (IJACS), 6(15), 1099–1103.
http://ijagcs.com/.
Yu, C. L., Deng, Q., Jian, S., Li, J., Dzantor, E. K., & Hui, D. (2019). Effects of fly ash application on plant biomass and element accumulations : a meta- analysis. Environmental Pollution, 250, 137–142.
https://doi.org/10.1016/j.envpol.2019.04.013.
Zhang, B. Y., Zheng, J. S., & Sharp, R. G. (2010).
Phytoremediation in engineered wetlands:
Mechanisms and applications. Procedia Environmental Science, 2, 1315–1325. https://
doi.org/10.1016/j.proenv.2010.10.142.
Zhao, W., Li, J., Jiang, J., Lu, H., Hong, Z., Qian, W., Xu, R., Deng, K.-Y., & Guan, P. (2020). The mechanisms underlying the reduction in aluminum toxicity and improvements in the yield of sweet potato (Ipomoea batatas L.) After organic and inorganic amendment of an acidic ultisol. Agriculture, Ecosystems & Environment, 288, 106716. https://doi.org/https://doi.
org/10.1016/j.agee.2019.106716.
