Indonesian Journal of Innovation and Applied Sciences (IJIAS), 1 (3), 200-207 200 Volume 1 Issue 3 October (2021) DOI: 10.47540/ijias.v1i3.288 Page: 200 – 207 Effects of Poultry Biochar on Electrochemical Properties of an Alfisol and Vertisol of Northern Nigeria Onokebhagbe Victor Odiamehi1, Uzoma Kingsley Chinyere2, Lawal Mubarak3, Auwalu Abubakar4, Habib Dahiru Wakili5 1,3,4,5Department of Soil Science, Faculty of Agriculture, Federal University Dutse, Jigawa State, Nigeria 2Department of Soil Science and Meteorology, College of Crop and Soil Sciences, Michael Okpara, Nigeria Corresponding Author: Onokebhagbe Victor Odiamehi; Email: victor.o@fud.edu.ng A R T I C L E I N F O A B S T R A C T Keywords: Biochar, Cation Exchange Capacity, Electrical Charge, Point Zero Charge, Surface Potentials. Received : 04 July 2021 Revised : 13 October 2021 Accepted : 15 October 2021 This study was aimed to know the effects of biochar on charge properties of an Alfisol and Vertisol of semi-arid soils of Northern Nigeria. A laboratory experiment was conducted to determine the effects of biochar on point zero charge of soils. An experiment was laid out in a complete randomized design and consisted of two factors; 2 soil types and biochar at 4 levels giving a total of 8 treatment combinations with 3 replications each. The results obtained from the study showed that the pH in KCl of the incubated soils ranged from 7.3 to 7.4 and 7.6 to 7.9 for the Alfisol and Vertisol; 7.5 to 7.7 and 7.9 to 8.3 pH in H2O, was obtained for the Alfisol and Vertisol respectively. Electrical conductivity obtained ranged from 3.22 to 4.72 and 2.88 to 4.21 dS m-1 for Alfisol and Vertisol respectively. Electrical potentials ranged from -19.70 to -35 and -31.45 to -63.04 for the Alfisol and Vertisol respectively. The Point Zero Charge of soils correlated positively with the properties of the soils and the biochar rates. The addition of biochar to soils modified the PZC, increased the pH, electrical conductivity (ECe), and cation exchange capacity (CEC) of the soils. INTRODUCTION Retention and availability of plant nutrients are some major problems in agricultural soils of the semi-arid regions of northern Nigeria, due to high temperature, leaching, loss of surface soil due to erosion, wide range of pH variations, and low organic matter content. This inadvertently affects the nature and composition of the soil colloids (Ibrahim et al., 2014). The surfaces of soil colloids are largely dominated by negative charges which aid in the attraction and retention of cations in the soils. The predominance of these charges largely influences the cation exchange capacity of soils. These charges are generated by the adsorption and desorption potential of the ions, particularly H+ and OH- hence the colloids are called per charge pH- dependent (Zhang et al., 1991). The study of the electrical charges of colloidal particles (organic and inorganic) is necessary for the understanding of different physical and chemical reactions that occur in the soil because most electrochemical reactions influence fertility and plant nutrition (Fontes et al., 2001; Kononova, 2006). Point of Zero Charge (PZC) is an electrochemical characteristic of great importance in soils with a predominance of pH-dependent charges, affecting soil properties such as flocculation, dispersion, cation exchange, and nutrient availability, among others (Fontes et al., 2001; Appel et al., 2003; Fontes and Alleoni, 2006). “The point of Zero Charge (PZC) is corresponding to the soil pH value in which the balance between the positive and negative charges is zero. i.e., if it is negative, pH>PZC, and positive, if pH 12 (high). Exchangeable bases Ca2+ was 1.82 and 4.01C mol (+) kg -1); Mg2+ 0.92 and 1.44 C mol (+) kg - 1; K+, 0.18 and 0.42 C mol (+) kg -1 and Na+, 0.58 and 0.60 C mol (+) kg -1 for Dutse and Jama’are soils, respectively. Table 1. Physical and Chemical Properties of the Study Soils Soil Properties Alfisol Vertisol Particle Size Distribution Clay (%) 22 32 Silt (%) 14 30 Sand (%) 64 38 Textural Class Sandy clay loam Clay loam pH(H2O) 5 4.8 pH(kcl2) 4.9 4.4 EC (dSm-1 ) 1.06 1.08 Organic Carbon (g kg-1 ) 4.9 5.95 Organic Matter (g kg-1 ) 1.03 2.68 Total Nitrogen (g kg-1 ) 0.6 0.8 Available P (mg kg-1 ) 11.02 27.9 Exchangeable Ca (C mol (+) kg -1) 1.82 4.01 Exchangeable Mg (C mol (+) kg -1) 0.92 1.44 Exchangeable K (C mol (+) kg -1) 0.18 0.42 Exchangeable Na (C mol (+) kg -1) 0.58 0.60 SEB (Cmol (+) kg -1 ) 3.53 6.47 SEB: Sum of Exchangeable Bases Chemical Properties of Biochar The chemical properties of the biochars are presented in Table 2. The pH of the biochar was slightly alkaline (pH= 8). Mineral analysis showed that the biochar has various amounts of inorganic elements. The amounts of the mineral elements contained in the biochar (Table 2) were higher than the amounts of elements contained in the soil samples (Table 1) used for the laboratory study thereby signifying their potential as alternative sources to fertilizers. Indonesian Journal of Innovation and Applied Sciences (IJIAS), 1 (3), 200-207 203 Table 2. Chemical Properties of Poultry Biochar Parameters Values pH 8 Total Nitrogen (g kg-1 ) 31.1 Total P (g kg-1 ) 52.02 Exchangeable bases (cmol kg-1) K 25.46 Ca 59.75 Na 14.07 Mg 38.4 The nitrogen content of the biochar was 31.01 g kg-1. Total P was 52.02 g kg-1 respectively for poultry biochar. The P content obtained from the biochar was high when compared to soil P. Lower K value of 25.46 cmol (+) kg -1 was reported for the biochar. Calcium (59.75 cmol (+) kg -1) in the biochar was higher than the Ca in soils as shown in Table 1. Effect of Poultry Biochar on Properties of Dutse and Jama’are Soils Table 3 shows the effect of biochar on charge properties of the soils. . Electrical conductivities of the soils increased with increasing rates of biochar. Significant (p<0.05) differences were observed among the ECe means obtained from the soils. The ECe values of the biochar infused soil samples as shown in Table 3 were significantly (p<0.05) different. Treatments with 80 g infused biochar from both soils had the highest EC values of 4.21 and 4.72. Wide variation in ECe was also observed as the values vary from 0.39 - 4.18 dSm-1. Table 3. Effect of Poultry Biochar on Electrical Properties of Alfisol and Vertisol Treatment pH KCl pHH20 ECe (dSm -1) ∆pH PZC Ψ0 (mV) Alfisol AlfBC50 7.3 7.5 3.22 b -0.13 7.1 -23.64 AlfBC60 7.3 7.6 3.92 ab -0.30 7.0 -35.40 AlfBC70 7.4 7.5 4.16 ab -0.17 7.2 -19.70 AlfBC80 7.4 7.7 4.72 a -0.27 7.1 -31.46 Vertisol VerBC50 7.7 ab 7.9 2.88bc -0.33abc 7.3 -35.46 VerBC60 7.6 b 8.2 2.70c -0.53c 7.1 -63.04 VerBC70 7.6 b 8.0 3.51ab -0.47bc 7.1 -55.16 VerBC80 7.9 a 8.3 4.21a -0.43abc 7.4 -51.22 Means with the same letters were not significantly different at p<0.05. Table 4. Pearson Correlation Coefficients (r) and Significance of Linear Relationship Between PZC and Electrochemical Properties of Biochar Incubated Soils. Factors Alfisol Vertisol r Significance level r Significance level ECe -0.13 NS 0.62 * pH 0.91 *** 0.84 *** Ψ0 0.91 *** 0.81 ** *, **, *** are significance level of < 0.05, < 0.01 and < 0.001, respectively; NS: not statistically significant. Indonesian Journal of Innovation and Applied Sciences (IJIAS), 1 (3), 200-207 204 Correlation Coefficient between PZC and Some Selected Properties of Biochar Incubated Soils The result of the estimated relationship between PZC and electrochemical properties of the soils are shown in Table 4. The result showed that the pH and Ψ0 had a strong correlation with the PZC of the Alfisol and Vertisol under the experimental conditions. The r value of 0.91 showed that 91% change in PZC in the Alfisol was influenced by ΔpH and Ψ0. For the Vertisol, Pearson r value of 0.62, 0.84 and 0.81 revealed that PZC strongly correlated with ECe, pH and Ψ0. This showed that variations in the PZC of the Vertisol were highly influenced by the three parameters mentioned above. Electrical conductivity (ECe) had no effects on the PZC of the Alfisol as shown in Table 4. This was contrary to the results obtained from the Vertisol, which showed a significant correlation between the ECe and the Vertisol. Effects of Biochar on Electrochemical Properties of Soils The application of poultry biochar to the soils increased the PZC of the soils. The PZC of both soils was within the same range. Higher pH values were obtained from the biochar treated soils concerning the native pH values of the soils though there was no corresponding increase in pH values with increase biochar rates. The high pH values obtained from the biochar were similar to the range of pH values of biochars obtained by Chan and Xu (2009). This tends to be in contrast with the result obtained by Lehmann (2007) which stated that the pH of soils increased with an increase in biochar rates and Chaves et al. (2016) who also obtained a similar linear increase in pH with an increase in biochar rates in Ultisol, Oxisol, Entisols. The increase in pH values of the biochar- incubated soils could be linked to the dissociation reactions of functional groups containing oxygen on the surfaces of the biochar and these are consistent with the findings by Marta et al., (2019). Also, the liming effects of biochar could have played a role in an increase in soil pH, which could reduce cationic attraction and mobility due to reduced competition between the H+/metal cations for the exchange sites on the biochar and soil surfaces (Beesley et al., 2011). Similarly, negative electric potential (Ψ0) values as shown in this study were due to the increase in pH of the biochar incubated soils as well as the low PZC values (Table 3). Higher negative charges were obtained from the Vertisol after incubation. The number of surface charges could be directly linked to the clay mineral contents of the soils. Charges have been known to vary from positive under acidic conditions to negative under strongly alkaline conditions. With the effects of the biochar on the pH of the soils as observed from the study, it is logical to assume that the negative potential values obtained from the study were directly influenced by the modification of the soils’ pH by the biochar. This corresponds with the observation made by Chaves et al. (2006) who stated that “this negative sign and magnitude of Ψ0 were directly influenced by the related magnitude of the ΔpH”. The increase in negative charges could be directly linked to the aging of the biochar as well as the dissociation of functional groups and activity of PDI (potential determining ions, e.g., H+ and OH) during the incubation period. This is similar to the findings of Cheng et al. (2006) that over time with aging, biochar in the soil and the occurrence of abiotic oxidation reaction on its surface, especially for the formation of carboxyl groups tend to increase the negative charge consequently leading to an increase in the CEC. The negative ΔpH values indicated a predominance of negative charges in the two soils samples. In this case, the cation exchange capacity (CEC) of these soils exceeded the anion exchange capacity (AEC) of the incubated soils in the modified pH conditions. However, the magnitude of ΔpH decreased with increasing biochar rates and as well, showed a reduction of CEC. The cation exchange capacity increase is primarily attributed to the negative charge on the outer surface of the bio- char, which arises from the dissociation of functional groups (Cheng et al. 2006). Anegbe et al. (2015) also demonstrated that cation exchange capacity increased with the increased doses of biochar and lapse of time from the application of material into the soil. On the other hand, Kuzyakov et al. (2009) reported that biochar introduced into the soil undergoes an aging process in the presence of air, water, and microorganism activity, which in turn leads to the formation of stable complexes of trace element and biochar. Indonesian Journal of Innovation and Applied Sciences (IJIAS), 1 (3), 200-207 205 Strong positive correlations were identified for the ECe (Vertisol), pH and Ψ0. This indicated that increased variations in PZC were strongly influenced by change in ECe, pH (ΔpH) and surface electrical potential (Ψ0). A high pH in biochar can be linked to the high content of alkaline minerals contained in the biochar. The charge development in the soils could as well be linked to the dissociation of the functional groups contained in the biochar. This also largely depends on the pH of the biochar, as dissociation of different functional groups varies with the pH of the biochar material. CONCLUSION This study showed that the properties of the semi-arid soils were influenced by the addition of the biochar. The chemical properties of Alfisol and Vertisol obtained from Dutse and Jama’are were enhanced by the application of poultry waste biochar. The addition of biochar to the soils modified and decreased the values of the ∆pH, Ψ0, CEC but raised the PZC of the soils. This study has also revealed the importance of the role played by biochar due to the increase in negative charges that will help in plant nutrients (cations) adsorption and retention thereby increasing the fertility status of the soil. Therefore the addition of biochar to soils will lead to positive responses by plants due to improved fertility of the soils. Hence knowledge of the effects of biochar on pH and electric charges of soils will contribute immensely to understanding its impact on soil fertility and plant nutrient retentions in soils, especially when used as soil amendments. It is therefore recommended that biochar amendments applied to the soil should be allowed to decay over some time before cultivating such soil as this helps to lower the PZC of the soil thereby improving soil fertility. REFERENCES 1. Abdu, N. & Etiene, U. A. (2015). Fifteen-year fallow altered the dynamics of soil phosphorus and cationic balance of a savannah Alfisol. Archives of Agronomy and Soil Science, 61: 645- 656. 2. Agbenin, J. O. (1995). Laboratory manual for Soil and Plant Analysis (Selected Methods and Data Analysis). Institute for Agricultural Research, Zaria, Nigeria. 3. Anderson, J. M. & Ingram, J. S. I. (1993). In Tropical soil biology and fertility: A handbook of methods. CAB International, Wallingford, U. K. Pp 68-71. 4. Anegbe, B., Okuo, J. M., Ewekay, E. O. & Ogbeifun D. E. (2015). Fractionation of lead- acid battery soil amended with biochar. Bayero Journal of Pure and Applied Sciences, 7(2): 36- 43. 5. Appel C., Ma L. Q., Rhue, R. D. & Kennelley, E. (2003). Point of zero charge determination in soils and minerals via traditional methods and detection of electroacoustic mobility. Geoderma, 113:77-93. 6. Asai, H., Samson, B. K., Stephan, H. M., Songyikhangsuthor, K., Homma, K., Kiyono, Y., Inoue, Y., Shiraiwa, T. & Horie, T. (2009). Biochar amendment techniques for upland rice production in Northern Laos: 1. Soil physical properties, leaf SPAD and grain yield. Field Crops Research, 111: 81–84. 7. Beesley, L., Moreno-Jimenez, E., Gomez- Eyles, J., Harris, E., Robinson, B. & Sizmur, T. (2011). A review of biochars’ potential role in the remediation, revegetation and restoration of contaminated soils. Environmental Pollution, xxx: 1-14. 8. Brady, N. C. & Weil, R. C. (2013). The nature and properties of soils. (14th revised ed.). Noida, India: Dorling Kindersley Pvt. Ltd. 350p. 9. Bremner, J. M. (1996). Nitrogen-Total. In A. Miller, & D. Keeny, Methods of soil analysis (pp. 595-624). Madison, USA: American Society of Agronomy. 10. Chan, K. Y., Van Zwieten, L., Meszaros, I., Downie, A. & Joseph, S. (2007). Agronomic values of greenwaste biochar as a soil amendment. Australian Journal of Soil Research. 45: 629–634. 11. Chaves, L. H. G., Mendes, J. S. & Iede de Brito Chaves. (2016). Effects of poultry biochar on electrochemical properties of electronegative Indonesian Journal of Innovation and Applied Sciences (IJIAS), 1 (3), 200-207 206 soils. International Journal of Current Research, 8 (11): 40834-40837. 12. Cheng, C. H., Lehmann, J., Thies, J. E., Burton, S. D., & Engelhard, M. H. (2006). Oxidation of black carbon by biotic and abiotic processes. Organic Geochemistry. 37, 1477–1488. 13. FAO. (1974). The Euphrates Pilot Irrigation Project. Methods of soil analysis, Gadeb Soil Laboratory (A laboratory manual). Food and Agriculture Organization, Rome, Italy. 14. Fontes, M. P. F. Camargo, O. A. & Sposito, G. (2001). Eletroquímica das partículas coloidais e sua relação com a mineralogia de solos altamente intemperizados. Sci. Agric. 58 (3): 627-646. 15. Fontes, M. P. F. & Alleoni, L. R. F. (2006). Electrochemical attributes and availability of nutrients, toxic elements, and heavy metals in tropical soils. Sci. Agric, 63 (6): 589-608. 16. Gaskin, J. W., Steiner, C., Harris, K., Das, K. C., & Bibens, B. (2008). Effect of low temperature pyrolysis conditions on biochars for agricultural use. Transitional ASABE 51: 2061–2069. 17. Gee, G. W. & Bauder, J. W. (1986). Particle size analysis. In A. a. SSSA, In Methods of soil analysis, Part 1, 2nd ed (pp. 383-411). Madison, WI: Agronomy Monogram, 9. 18. Glaser, B., Lehmann, J. & Zech, W. (2002). Ameliorating physical and chemical properties of highly weathered soils in the tropics with charcoal: A review Biology and Fertility of Soils 35: 219-230. 19. Gomez, K. A. & Gomez, A. A. (1984). Statistical procedure for agricultural research. (2ed.). John Wiley and Sons, New York, U.S.A. pp.: 680. 20. Ibrahim, Y. E., Nuradeen, A. M. & R. A. Abubakar. (2014). Factors affecting soil quality maintenance in Northern Katsina State, Nigeria. Science World Journal, 9 (4): 39-45. 21. Jackson, M. L. (1962). Soil Chemical Analysis. Prentice-Hall, Englewood Cliffs, NJ, USA. 22. Jaiswal, P. C., (2003). Soil, Plant and Water Analysis. Kalyani Publishers, New Delhi. 23. Keng, J. C. W. & Uehara, G. (1974). Chemistry, mineralogy and taxonomy of Oxisols and Ultisols. Soil and Crop Science Society of Florida Proceedings, 33:119-26. 24. Kononova, M. M. (2006). Organic matter and soil fertility. Soviet Soil Science, 16:71-86. 25. Kuzyakov, Y., Subbotina, I. & Chen, H., Bogomolova, I., Xu, X., (2009). Black carbon decomposition and incorporation into soil microbial biomass estimated by 14C labeling. Soil Biology and Biochemistry, 41: 210-219. 26. Lehmann J, Gaunt, J. & Rondon, M. (2006). Bio-char sequestration in terrestrial ecosystems - A review. Mitigation and Adaptation Strategies for Global Change, 11:403-27. 27. Lehmann, J. (2007). Bio-energy in the black. Fronted Ecological Environment. 5, 381–387. 28. Malgwi, W. B., Ojanuga, A. G., Chude, V. O., Kparmwang, T. & Raji, B. A.. (2000). Morphological and physical properties of some soils at Samaru, Zaria, Nigeria. Nigerian Journal of Soil Research, 1: 58-64. 29. Marta, C., Zofia, S. & Boguta, P. (2019). Impact of biochar on physicochemical properties haplic luvisol soil under different land use: A plot experiment. Agronomy, 9 (531): 1-16. 30. Onokebhagbe, O. V., Abdu, N. & Santuraki, H. A. (2018). Residual effects of biochar on dry matter yield of grain amaranths (Amaranthus cruentus L.) grown on Alfisols of Nigerian Northern Guinea and Sudan savanna agro- ecologies. Dutse Journal of Agriculture and Food Security, 5 (1): 97-108. 31. Reeuwijk, V. (1993). Procedures for soil analysis; Technical paper No.9. Fourth Edition. International soil reference and information centre (ISRIC). 32. Voncir, N., Mustapha, S., Tenebe, V. A., Kumo, A. L. & Kushwaha, S. (2008). Content and profile distribution of extract Zinc (Zn) and some physiological properties of soil along a toposequence at Bauchi, Northern Guinea Savannah of Nigeria International Journal of soil science 3:62-68. Indonesian Journal of Innovation and Applied Sciences (IJIAS), 1 (3), 200-207 207 33. Yamato, M., Okimori, Y., Wibowo, I. F., Anshori, S. & Ogawa, M. (2006), Effects of the application of charred bark of Acacia mangium on the yield of maize, cowpea and peanut, and soil chemical properties in South Sumatra, Indonesia. Soil Science and Plant Nutrition, 52 (6): 489-495. 34. Zhang, F. S., Zhang, X. N. & Yu, T. R. (1991). Reactions of hydrogen ions with variable charge soils: Ion mechanisms of reaction. Soil Science, 151:436-43.