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Plant Science Today (PST)

Research Articles

Vol. 13 No. 3 (2026)

Enhancing barren agricultural soil, autumn-grown okra (Abelmoschus esculentus (L.) Moench) yield and mineral content using rice husk biochar and organic fertilisers

DOI
https://doi.org/10.14719/pst.14636
Submitted
22 March 2026
Published
24-08-2026 — Updated on 31-08-2026
Versions

Abstract

Contemporary agricultural systems are increasingly embracing organic inputs as a sustainable and effective alternative. These inputs contribute significantly to agroecosystem health, enhance ecological resilience and support sustained crop productivity. However, limited studies exist regarding the effects of biochar (B) and organic fertilisers (F) on fruit crops when cultivated in the acidic soils of Pingtung, Taiwan. To address this gap, a study was conducted during 2024–25 to evaluate the impact of rice husk B and F on soil properties, yield and mineral content of okra. Seven treatments with three replicates were arranged in a completely randomised design (CRD) under greenhouse pot conditions. Treatments consisted of varying combinations in grams of B and F, produced from a mixture of pig, cow and chicken manure: B50 + F0, B0 + F75, B25 + F25, B50 + F25, B50 + F50 and B50 + F75, alongside an unamended control (CK) that received 0 g of either B or F. Following 90 days of amendment, the B50 + F75 treatment significantly elevated soil pH to 5.93 relative to the CK treatment, whereas B0   + F75 recorded the highest soil organic matter content of 3.95 %. B25 + F25, B0 + F75 and B50 + F25 significantly increased soil-available phosphorus (P) (253.82 mg/kg), calcium (Ca) (1047.48 mg/kg) and magnesium (Mg) (97.96 mg/kg) compared with the CK respectively. Microbial activity was also enhanced, with bacterial populations peaking at 9.39 log CFU/g in B50+F25 and fungal populations reaching 8.10 log CFU/g in B50  + F50. Interestingly, the B50   + F75 treatment significantly increased potassium (K) levels in both the soil and okra fruits compared with the CK. In contrast, fruits from the control exhibited higher iron (Fe) content (12.47 mg/100 g). The heaviest fruits (156.13 g plant-1) were harvested under B50 + F50, while fruit number peaked at 9 per plant in B50 + F25. Overall, the combined use of B and F enhanced soil health and boosted okra productivity, demonstrating their strong potential for restoring infertile soils.

References

  1. 1. Uwiringiyimana T, Habimana S, Umuhozariho MG, Bigirimana VP, Uwamahoro F, Ndereyimana A, et al. Review on okra (Abelmoschus esculentus (L.) Moench) production, nutrition and health benefits. RJAS. 2024;3(1):71–87.
  2. 2. Woumbo CY, Kuate D, Metue Tamo DG, Womeni HM. Antioxidant and antidiabetic activities of a polyphenol-rich extract obtained from Abelmoschus esculentus (okra) seeds using optimized conditions in microwave-assisted extraction (MAE). Front Nutr. 2022; 9:1030385. https://doi.org/10.3389/fnut.2022.1030385
  3. 3. Smith P, Poch RM, Lobb DA, Bhattacharyya R, Alloush G, Eudoxie GD, et al. Status of the world's soils. Annu Rev Environ Resour. 2024;49(1):73–104. https://doi.org/10.1146/annurev-environ-030323-075629
  4. 4. Pavlů L, Borůvka L, Drábek O, Nikodem A. Effect of natural and anthropogenic acidification on aluminium distribution in forest soils of two regions in the Czech Republic. J For Res. 2021;32(1):363–70. https://doi.org/10.1007/s11676-019-01061-1
  5. 5. Sopandie D, Wirnas D. Phosphorus deficiency tolerance in sorghum. Indones J Agron. 2023;51(1):121–33. https://doi.org/10.24831/ija.v51i1.46535
  6. 6. Ngui ME, Lin YH, Blanco SD. Synergy of biochar and organic fertilizer improves soybean (Glycine max L.) growth by alleviation nutrient stress in strongly acidic Taiwanese soil. Arch Agric Environ Sci. 2025;10(1):59–66. https://doi.org/10.26832/24566632.2025.100109
  7. 7. Lestari PG, Sinaga AOY, Marpaung DSS, Nurhayu W, Oktaviani I. Application of organic fertilizer for improving soybean production under acidic stress. Oil Crop Sci. 2024;9(1):46–52. https://doi.org/10.1016/j.ocsci.2024.02.001
  8. 8. Chauhan DK, Yadav V, Vaculik M, Gassmann W, Pike S, Arif N, et al. Aluminum toxicity and aluminum stress-induced physiological tolerance responses in higher plants. Crit Rev Biotechnol. 2021;41(5):715–30. https://doi.org/10.1080/07388551.2021.1874282
  9. 9. Lin YH, Chen JH. Effects of aluminum on the cell morphology in the root apices of two pineapples with different Al-resistance characteristics. Soil Sci Plant Nutr. 2019;65(4):353–7. https://doi.org/10.1080/00380768.2019.1625286
  10. 10. Binte BI, Akter M, Khanam M, Alam MA, Kabir MP, Kamal MZU. Effect of integrated nutrient management on okra production in acid soil. EJFOOD. 2021;3(6):55–60. https://doi.org/10.24018/ejfood.2021.3.6.406
  11. 11. Cheng X, Fang T, Zhao E, Zheng B, Huang B, An Y, et al. Protective roles of salicylic acid in maintaining integrity and functions of photosynthetic photosystems for alfalfa (Medicago sativa L.) tolerance to aluminum toxicity. Plant Physiol Biochem. 2020; 155:570–8. https://doi.org/10.1016/j.plaphy.2020.08.028
  12. 12. Guo P, Qi YP, Cai YT, Yang TY, Yang LT, Huang ZR, et al. Aluminum effects on photosynthesis, reactive oxygen species and methylglyoxal detoxification in two Citrus species differing in aluminum tolerance. Tree Physiol. 2018;38(10):1548–65. https://doi.org/10.1093/treephys/tpy035
  13. 13. Ofoe R, Thomas RH, Asiedu SK, Wang-Pruski G, Fofana B, Abbey L. Aluminum in plant: Benefits, toxicity and tolerance mechanisms. Front Plant Sci. 2023; 13:1085998. https://doi.org/10.3389/fpls.2022.1085998
  14. 14. Zhang J, Wei J, Li D, Kong X, Rengel Z, Chen L, et al. The role of the plasma membrane H+-ATPase in plant responses to aluminum toxicity. Front Plant Sci. 2017; 8:1757. https://doi.org/10.3389/fpls.2017.01757
  15. 15. Jing T, Li J, He Y, Shankar A, Saxena A, Tiwari A, et al. Role of calcium nutrition in plant physiology: Advances in research and insights into acidic soil conditions—a comprehensive review. Plant Physiol Biochem. 2024; 210:108602. https://doi.org/10.1016/j.plaphy.2024.108602
  16. 16. Liu Y, Lan X, Hou H, Ji J, Liu X, Lv Z. Multifaceted ability of organic fertilizers to improve crop productivity and abiotic stress tolerance: Review and perspectives. Agronomy. 2024; 14:1141. https://doi.org/10.3390/agronomy14061141
  17. 17. Fathi A. Role of nitrogen (N) in plant growth, photosynthesis pigments and N use efficiency: A review. Agrisost. 2022; 28:1–8. https://doi.org/10.5281/zenodo.7143588
  18. 18. Khan F, Siddique AB, Shabala S, Zhou M, Zhao C. Phosphorus plays key roles in regulating plants' physiological responses to abiotic stresses. Plants. 2023;12(15):2861. https://doi.org/10.3390/plants12152861
  19. 19. Tränkner M, Tavakol E, Jákli B. Functioning of potassium and magnesium in photosynthesis, photosynthate translocation and photoprotection. Physiol Plant. 2018;163(3):414–31. https://doi.org/10.1111/ppl.12747
  20. 20. Andrés Z, Perez-Hormaeche J, Leidi EO, Schlücking K, Steinhorst L, McLachlan DH, et al. Control of vacuolar dynamics and regulation of stomatal aperture by tonoplast potassium uptake. Proc Natl Acad Sci U S A. 2014;111(17): E1806–14. https://doi.org/10.1073/pnas.1320421111
  21. 21. Šustr M, Konrádová H, Martinčová M, Soukup A, Tylová E. Potassium transporter KUP9 regulates plant response to K+ deficiency and affects carbohydrate allocation in A. thaliana. J Plant Physiol. 2024; 292:154147. https://doi.org/10.1016/j.jplph.2023.154147
  22. 22. Wdowiak A, Podgórska A, Szal B. Calcium in plants: An important element of cell physiology and structure, signaling and stress responses. Acta Physiol Plant. 2024;46(12):108. https://doi.org/10.1007/s11738-024-03733-w
  23. 23. Shao Y, Li S, Gao L, Sun C, Hu J, Ullah A, et al. Magnesium application promotes Rubisco activation and contributes to high-temperature stress alleviation in wheat during the grain filling. Front Plant Sci. 2021;12:675582. https://doi.org/10.3389/fpls.2021.675582
  24. 24. Nam K, Thodika AR, Tischlik S, Phoeurk C, Nagy TM, Schierholz L, et al. Magnesium-induced structural reorganization in the active site of adenylate kinase. Sci Adv. 2024;10(32):eado5504. https://doi.org/10.1126/sciadv.ado5504
  25. 25. Ishfaq M, Wang Y, Yan M, Wang Z, Wu L, Li C, et al. Physiological essence of magnesium in plants and its widespread deficiency in the farming system of China. Front Plant Sci. 2022;13:802274. https://doi.org/10.3389/fpls.2022.802274
  26. 26. Chen G, Li J, Han H, Du R, Wang X. Physiological and molecular mechanisms of plant responses to copper stress. Int J Mol Sci. 2022;23(21):12950. https://doi.org/10.3390/ijms232112950
  27. 27. Gupta N, Ram H, Kumar B. Mechanism of zinc absorption in plants: Uptake, transport, translocation and accumulation. Rev Environ Sci Biotechnol. 2016;15(1):89–109. https://doi.org/10.1007/s11157-016-9390-1
  28. 28. Alejandro S, Höller S, Meier B, Peiter E. Manganese in plants: From acquisition to subcellular allocation. Front Plant Sci. 2020;11:300. https://doi.org/10.3389/fpls.2020.00300
  29. 29. Rout GR, Sahoo S. Role of iron in plant growth and metabolism. Rev Agric Sci. 2015;3:1–24. https://doi.org/10.7831/ras.3.1
  30. 30. Schmidt W, Thomine S, Buckhout TJ. Iron nutrition and interactions in plants. Front Plant Sci. 2020;10:1670. https://doi.org/10.3389/fpls.2019.01670
  31. 31. Brempong MB, Addo-Danso A. Improving soil fertility with organic fertilizers. In: New Generation of Organic Fertilizers. 2022. p. 1–15. https://doi.org/10.5772/intechopen.95683
  32. 32. Bocean CG. The role of organic farming in reducing greenhouse gas emissions from agriculture in the European Union. Agronomy. 2025;15(1):198. https://doi.org/10.3390/agronomy15010198
  33. 33. Gerke J. The central role of soil organic matter in soil fertility and carbon storage. Soil Syst. 2022;6(2):33. https://doi.org/10.3390/soilsystems6020033
  34. 34. Sarkar S, Singh S, Singh R. The effect of organic and inorganic fertilizers on soil physical condition and the productivity of a rice–lentil cropping sequence in India. J Agric Sci. 2003;140(4):419–25. https://doi.org/10.1017/S0021859603003186
  35. 35. Bai J, Moreira BRDA, Bai Y, Nadar CG, Feng Y, Yadav S. Assessing biochar's impact on greenhouse gas emissions, microbial biomass and enzyme activities in agricultural soils through meta-analysis and machine learning. Sci Total Environ. 2025;963:178541. https://doi.org/10.1016/j.scitotenv.2025.178541
  36. 36. Wantaneeyakul N, Kositkanawuth K, Turn SQ, Fu J. Investigation of biochar production from copyrolysis of rice husk and plastic. ACS Omega. 2021;6(43):28890–902. https://doi.org/10.1021/acsomega.1c03874
  37. 37. Khater ES, Bahnasawy A, Hamouda R, Sabahy A, Abbas W, Morsy OM. Biochar production under different pyrolysis temperatures with different types of agricultural wastes. Sci Rep. 2024;14(1):2625. https://doi.org/10.1038/s41598-024-52336-5
  38. 38. Khitab A, Ahmad S, Khan RA, Arshad MT, Anwar W, Tariq J, et al. Production of biochar and its potential application in cementitious composites. Crystals. 2021;11(5):527. https://doi.org/10.3390/cryst11050527
  39. 39. Sopandie D. Integrated strategies to overcome aluminum toxicity in tropical acid soils. J Agron Indones. 2025;53(3):304–19. https://doi.org/10.24831/jai.v53i3.69190
  40. 40. Shrestha A, Sai R, Devkota M. Potential of biochar-based fertilizers for increasing the productivity of okra in Gajuri, Dhading. Turk J Agric Food Sci Technol. 2024;12(S1):2021–31. https://doi.org/10.24925/turjaf.v12is1.2021-2031.6946
  41. 41. Patil L, Valvi V, Patil D, Nimbalkar S, Kauthale V. Influence of microbial-enriched biochar as soil amendment on growth, yield and economics of okra (Abelmoschus esculentus) and soil fertility. Int J Adv Biochem Res. 2024;8(12):1089–93. https://doi.org/10.33545/26174693.2024.v8.i12n.3370
  42. 42. Bouyoucos GJ. Hydrometer method improved for making particle size analyses of soils. Agron J. 1962;54:464–5. https://doi.org/10.2134/agronj1962.00021962005400050028x
  43. 43. McLean EO. Soil pH and lime requirement. In: Page AL, editor. Methods of Soil Analysis. Part 2. 2nd ed. Agron Monogr 9. Madison (WI): ASA and SSSA; 1982. p. 199–224. https://doi.org/10.2134/agronmonogr9.2.2ed.c12
  44. 44. Nelson DW, Sommers LE. Total carbon, organic carbon and organic matter. In: Page AL, editor. Methods of Soil Analysis. Part 2. 2nd ed. Agron Monogr 9. Madison (WI): ASA and SSSA; 1982. p. 539–79. https://doi.org/10.2134/agronmonogr9.2.2ed.c29
  45. 45. Mehlich A. Mehlich 3 soil test extractant: A modification of Mehlich 2 extractant. Commun Soil Sci Plant Anal. 1984;15(12):1409–16. https://doi.org/10.1080/00103628409367568
  46. 46. Piash MI, Iwabuchi K, Itoh T, Uemura K. Release of essential plant nutrients from manure- and wood-based biochars. Geoderma. 2021;397:115100. https://doi.org/10.1016/j.geoderma.2021.115100
  47. 47. Ameh A, Kawo A. Enumeration, isolation and identification of bacteria and fungi from soil contaminated with petroleum products using layer chicken droppings as an amendment. BAJOPAS. 2017;10(1):219–25. https://doi.org/10.4314/bajopas.v10i1.44S
  48. 48. Gairhe JJ, Bhattarai P, Gyanwali P, Khanal R, Mainali R, Poudel S, et al. Effect of various biochar on selected soil properties and agronomical parameters of okra (Abelmoschus esculentus L.) at Rupandehi, Nepal. Arch Agric Environ Sci. 2024;9(1):134–42. https://doi.org/10.26832/24566632.2024.0901019
  49. 49. dos Santos Farias DB, de Freitas MI, Lucas AA, Gonzaga MI. Biochar and its impact on soil properties and on the growth of okra plants. Colloq Agrariae. 2020;16(2):29–39.
  50. 50. Zhang S, Zhu Q, de Vries W, Ros GH, Chen X, Muneer MA, et al. Effects of soil amendments on soil acidity and crop yields in acidic soils: A worldwide meta-analysis. J Environ Manage. 2023;345:118531. https://doi.org/10.1016/j.jenvman.2023.118531
  51. 51. Hale SE, Alling V, Martinsen V, Mulder J, Breedveld GD, Cornelissen G. The sorption and desorption of phosphate-P, ammonium-N and nitrate-N in cacao shell and corn cob biochars. Chemosphere. 2013;91(11):1612–9. https://doi.org/10.1016/j.chemosphere.2012.12.057
  52. 52. Haile M, Birhane E, Gebresamuel G, Adaramola MS, Rannestad MM. Application of biochar derived from expansive shrubs and limestone improved acidic soil characteristics. Carbon Manag. 2024;15(1):2364784. https://doi.org/10.1080/17583004.2024.2364784
  53. 53. Ulrich AE, Schnug E. The modern phosphorus sustainability movement: A profiling experiment. Sustainability. 2013;5(11):4523–45. https://doi.org/10.3390/su5114523
  54. 54. Marschner H. Mineral Nutrition of Higher Plants. 3rd ed. London: Academic Press; 2011. https://doi.org/10.1016/B978-0-12-384905-2.00012-2
  55. 55. Ara I, Islam MS, Kashem MA, Osman KT. A comparative study of phosphorus availability in an acidic soil and an alkaline soil amended with organic and inorganic phosphorus sources. J Soil Sci Plant Nutr. 2018;18(2):466–78. https://doi.org/10.4067/S0718-95162018005001402
  56. 56. Jindo K, Audette Y, Higashikawa FS, Silva CA, Akashi K, Mastrolonardo G, et al. Role of biochar in promoting circular economy in the agriculture sector. Part 1: A review of the biochar roles in soil N, P and K cycles. Chem Biol Technol Agric. 2020;7(1):15. https://doi.org/10.1186/s40538-020-00182-8
  57. 57. Fachini J, Figueiredo CC, do Vale AT, da Silva J, Zandonadi DB. Potassium-enriched biochar-based fertilizers for improved uptake in radish plants. Nutr Cycl Agroecosyst. 2024;128(3):415–27. https://doi.org/10.1007/s10705-023-10273-1
  58. 58. Acharya N, Vista SP, Shrestha S, Neupane N, Pandit NR. Potential of biochar-based organic fertilizers on increasing soil fertility, available nutrients and okra productivity in slightly acidic sandy loam soil. Nitrogen. 2023;4(1):1–15. https://doi.org/10.3390/nitrogen4010001
  59. 59. Adekiya AO, Adebiyi OV, Ibaba AL, Aremu C, Ajibade RO. Effects of wood biochar and potassium fertilizer on soil properties, growth and yield of sweet potato (Ipomoea batatas). Heliyon. 2022;8(11):e11728. https://doi.org/10.1016/j.heliyon.2022.e11728
  60. 60. Xia H, Liu B, Riaz M, Li Y, Wang X, Wang J, et al. Thirty-month pot experiment: Biochar alters soil potassium forms, soil properties and soil fungal diversity and composition in acidic soil of Southern China. Plants. 2022;11(24):3442. https://doi.org/10.3390/plants11243442
  61. 61. Kumari S, Dong Y, Safferman SI. Phosphorus adsorption and recovery from waste streams using biochar: Review of mechanisms, modifications and agricultural applications. Appl Water Sci. 2025;15(7):162. https://doi.org/10.1007/s13201-025-02523-0
  62. 62. Hu W, Zhang Y, Rong X, Zhou X, Fei J, Peng J, et al. Biochar and organic fertilizer applications enhance soil functional microbial abundance and agroecosystem multifunctionality. Biochar. 2024;6(1):3. https://doi.org/10.1007/s42773-023-00296-w
  63. 63. Duan Y, Zhang J, Petropoulos E, Zhao J, Jia R, Wu F, et al. Soil acidification destabilizes terrestrial ecosystems via decoupling soil microbiome. Glob Change Biol. 2025;31(4):e70174. https://doi.org/10.1111/gcb.70174
  64. 64. Lee JM, Jeong HC, Gwon HS, Lee HS, Park HR, Kim GS, et al. Effects of biochar on methane emissions and crop yields in East Asian paddy fields: A regional-scale meta-analysis. Sustainability. 2023;15(12):9200. https://doi.org/10.3390/su15129200
  65. 65. Philippot L, Chenu C, Kappler A, Rillig MC, Fierer N. The interplay between microbial communities and soil properties. Nat Rev Microbiol. 2024;22:226–39. https://doi.org/10.1038/s41579-023-00980-5
  66. 66. Tan M, Feng T, Wang C, Hao X, Yu H. Effects of microbial agents on soil improvement: A review and bibliometric analysis. Agronomy. 2025;15:1223. https://doi.org/10.3390/agronomy15051223
  67. 67. Yuan Z, Cao Q, Zhang K, Ata-Ul-Karim ST, Tian Y, Zhu Y, et al. Optimal leaf positions for SPAD meter measurement in rice. Front Plant Sci. 2016;7:719. https://doi.org/10.3389/fpls.2016.00719
  68. 68. Mosharrof M, Uddin MK, Mia S, Sulaiman MF, Shamsuzzaman SM, Haque ANA. Influence of rice husk biochar and lime in reducing phosphorus application rate in acid soil: A field trial with maize. Sustainability. 2022;14(12):7418. https://doi.org/10.3390/su14127418
  69. 69. Khandaker MM, Rohani F, Dalorima T, Mat N. Effects of different organic fertilizers on growth, yield and quality of Capsicum annuum L. var. Kulai (Red Chilli Kulai). Biosci Biotechnol Res Asia. 2017;14(1):185–92. https://doi.org/10.13005/bbra/2434
  70. 70. Karim MR, Sattar M, Rouf A, Hossain S, Hoque MM. Effect of different organic and inorganic fertilizers on the growth and yield of okra. IUBAT Rev. 2024;7(2):85–99. https://doi.org/10.3329/iubatr.v7i2.78802
  71. 71. Sangotoye SE, Atere CT, Taiwo LB, Olayinka A. Improving soil chemical properties and okra (Abelmoschus esculentus) yield through complementary applications of biochar and organic and inorganic fertilizers. J Plant Nutr. 2024;47(15):2530–42. https://doi.org/10.1080/01904167.2024.2354193
  72. 72. Prity N, Syed M, Rahman M. Performance and nutrient content of okra (Abelmoschus esculentus L. Moench) fruits as influenced by vermicompost, nitrogen and zinc grown in soil. J Biodivers Conserv Bioresour Manag. 2023;9(1):101–8. https://doi.org/10.3329/jbcbm.v9i1.66635
  73. 73. Akinmutimi A, Akinlade N, Ukpai S. Comparative effects of organic and inorganic fertilizer sources on growth, yield and nutrient content of okra in an Ultisol in southeastern Nigeria. IOSR J Agric Vet Sci. 2021;14:1–11. https://doi.org/10.9790/2380-1403010111
  74. 74. Wieczorek D, Żyszka-Haberecht B, Kafka A, Lipok J. Determination of phosphorus compounds in plant tissues: From colourimetry to advanced instrumental analytical chemistry. Plant Methods. 2022;18(1):22. https://doi.org/10.1186/s13007-022-00854-6
  75. 75. Food and Drug Administration. Food labeling: Revision of the nutrition and supplement facts labels. Final rule. Fed Regist. 2016;81(103):33741–999. PMID: 27236870.
  76. 76. Romdhane MH, Chahdoura H, Barros L, Dias MI, Corrêa RC, Morales P, et al. Chemical composition, nutritional value and biological evaluation of Tunisian okra pods (Abelmoschus esculentus L. Moench). Molecules. 2020;25(20):4739. https://doi.org/10.3390/molecules25204739

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