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Plant Science Today (PST)

Research Articles

Early Access

Optimising digestate fertilisation for onion (Allium cepa L.) production under semi-arid conditions: Effects on soil fertility, crop performance and yield

DOI
https://doi.org/10.14719/pst.12843
Submitted
20 November 2025
Published
20-04-2026

Abstract

Onion (Allium cepa L.) farming in the Fez–Meknes region is heavily dependent on mineral fertilisers, yet prolonged use has weakened soil quality and nutrient efficiency. This study assessed whether anaerobic digestate (AD) could provide a viable alternative in semi-arid conditions and regions. The experiment took place in the field during the 2023–2024 season in a randomised complete block design, comparing six treatments: an unfertilized control, local recommended mineral fertilisation (10:30:10) and digestate applied at (10, 20, 30 and 40 dry weight (DW) t/ha). Soil characteristics, plant growth traits, biomass and yield were recorded at 30, 60 and 90 days after planting and at harvest. Differences among treatments were statistically significant according to ANOVA (P < 0.05). Digestate doses shifted soil fertility indicators. Organic matter rose by +21.1 %, available phosphorus by +64.1 % and mineral nitrogen by +483 %, while electrical conductivity increased with higher application rates. Onion plants also responded strongly. At 60 days after planting, the (40 DW t/ha) dose raised plant height by +38.8 % and by 90 days after planting, the same treatment sharply increased the leaf number (+94.5 %). Biomass patterns followed a similar trend, with bulb fresh weight at 60 days after planting climbing by +140.8 % under (40 DW t/ha). Yield gains were clear across all digestate levels: the control treatment produced 54.64 t/ha, the recommended mineral fertilization reached (73.69 t/ha) and the highest value appeared at (30 DW t/ha) with 75.25 t/ha (+37.8 % above the control treatment), slightly exceeding both the recommended mineral fertilization and the (40 DW t/ha) treatment.

References

  1. 1. Rhioui W, Al Figuigui J, Lahlali R, Laasli SE, Boutagayout A, El Jarroudi M, et al. Towards sustainable vegetable farming: Exploring agroecological alternatives to chemical products in the Fez-Meknes region of Morocco. Sustainability. 2023;15(9):7412. https://doi.org/10.3390/su15097412
  2. 2. Pahalvi HN, Rafiya L, Rashid S, Nisar B, Kamili AN. Chemical fertilisers and their impact on soil health. In: Dar GH, Bhat RA, Mehmood MA, Hakeem KR, editors. Microbiota and biofertilisers. Vol 2. Cham: Springer International Publishing; 2021. p. 1–20. https://doi.org/10.1007/978-3-030-61010-4_1
  3. 3. Montoya D, Salguer C. Beyond industrial agriculture: A case for agroecology adoption in Sefrou, Moroccos’ semi arid region. 2024.
  4. 4. Korba J, Šařec P, Novák V, Brož P, Dolan A, Dědina M. Digestate application methods and rates with regard to greenhouse gas emissions and crop conditions. Agronomy. 2024;14(2):336. https://doi.org/10.3390/agronomy14020336
  5. 5. Chojnacka K, Moustakas K. Anaerobic digestate management for carbon neutrality and fertiliser use: A review of current practices and future opportunities. Biomass Bioenergy. 2024;180:106991. https://doi.org/10.1016/j.biombioe.2023.106991
  6. 6. El Bergui O, Abouabdillah A, Bourioug M, Schmitz D, Biel M, Aboudrare A, et al. Innovative solutions for drought: Evaluating hydrogel application on onion cultivation (Allium cepa L.) in Morocco. Water. 2023;15(11):1972. https://doi.org/10.3390/w15111972
  7. 7. Ngetuny J, Hsaine J, Mabrouki A, Rachidi F, El Asli A, Zörner W. Assessment of agricultural residues for small-scale biogas plants and adoption drivers: A case study of the Fès-Meknès region in Morocco. Biomass Convers Biorefin. 2025. https://doi.org/10.1007/s13399-024-06443-y
  8. 8. Tambone F, Scaglia B, D’Imporzano G, Schievano A, Orzi V, Salati S, et al. Assessing amendment and fertilizing properties of digestates from anaerobic digestion through a comparative study with digested sludge and compost. Chemosphere. 2010;81(5):577–83. https://doi.org/10.1016/j.chemosphere.2010.08.034
  9. 9. Jordan-Meille L, Morel C, Salducci X, Michaud J. Valeur agronomique (C, N, P) de digestats de méthanisation d’origine agricole et agro-alimentaire de Dordogne. In: 13 Rencontres de la fertilisation raisonnée et de l’analyse du COMIFER-GEMAS. Nantes, France; 2017.
  10. 10. Zoui O, Baroudi M, Drissi S, Abouabdillah A, Abd-Elkader OH, Plavan G, et al. Utilization of digestate as an organic manure in corn silage culture: An in-depth investigation of its profound influence on soils’ physicochemical properties, crop growth parameters and agronomic performance. Agronomy. 2023;13(7):1715. https://doi.org/10.3390/agronomy13071715
  11. 11. Alburquerque JA, De La Fuente C, Campoy M, Carrasco L, Nájera I, Baixauli C, et al. Agricultural use of digestate for horticultural crop production and improvement of soil properties. Eur J Agron. 2012;43:119–28. https://doi.org/10.1016/j.eja.2012.06.001
  12. 12. Doyeni MO, Stulpinaite U, Baksinskaite A, Suproniene S, Tilvikiene V. The effectiveness of digestate use for fertilization in an agricultural cropping system. Plants. 2021;10(8):1734. https://doi.org/10.3390/plants10081734
  13. 13. Brychkova G, McGrath A, Larkin T, Goff J, McKeown PC, Spillane C. Use of anaerobic digestate to substitute inorganic fertilisers for more sustainable nitrogen cycling. J Clean Prod. 2024;446:141016. https://doi.org/10.1016/j.jclepro.2024.141016
  14. 14. Ragályi P, Szécsy O, Uzinger N, Magyar M, Szabó A, Rékási M. Factors influencing the impact of anaerobic digestates on soil properties. 2025. https://doi.org/10.3390/soilsystems9030078
  15. 15. Decree No. 97-1133. French regulatory limits for concentration of TMs in digestate for agricultural use reference. Department of Information; 1998.
  16. 16. Tan F, Zhu Q, Guo X, He L. Effects of digestate on biomass of a selected energy crop and soil properties. J Sci Food Agric. 2021;101(3):927–36. https://doi.org/10.1002/jsfa.10700
  17. 17. Makádi M, Szegi T, Tomócsik A, Orosz V, Michéli E, Ferenczy A, et al. Impact of digestate application on chemical and microbiological properties of two different textured soils. Commun Soil Sci Plant Anal. 2016;47(2):167–78. https://doi.org/10.1080/00103624.2015.1109652
  18. 18. Barłóg P, Hlisnikovský L, Kunzová E. Effect of digestate on soil organic carbon and plant-available nutrient content compared to cattle slurry and mineral fertilization. Agronomy. 2020;10(3):379. https://doi.org/10.3390/agronomy10030379
  19. 19. Gómez-Brandón M, Juárez MFD, Zangerle M, Insam H. Effects of digestate on soil chemical and microbiological properties: A comparative study with compost and vermicompost. J Hazard Mater. 2016;302:267–74. https://doi.org/10.1016/j.jhazmat.2015.09.067
  20. 20. Carmo DLD, Lima LBD, Silva CA. Soil fertility and electrical conductivity affected by organic waste rates and nutrient inputs. Rev Bras Cienc Solo. 2016;40:e0150152. https://doi.org/10.1590/18069657rbcs20150152
  21. 21. Vaish B, Srivastava V, Singh UK, Gupta SK, Chauhan PS, Kothari R, et al. Explicating the fertiliser potential of anaerobic digestate: Effect on soil nutrient profile and growth of Solanum melongena L. Environ Technol Innov. 2022;27:102471. https://doi.org/10.1016/j.eti.2022.102471
  22. 22. Messina G, Praticò S, Badagliacca G, Fazio SD, Monti M, Modica G. Monitoring onion crop “Cipolla Rossa di Tropea Calabria IGP” growth and yield response to varying nitrogen fertiliser application rates using UAV imagery. Drones. 2021;5(3):61. https://doi.org/10.3390/drones5030061
  23. 23. Sanwal SK, Kesh H, Kumar A, Dubey BK, Khar A, Rouphael Y, et al. Salt tolerance potential in onion: Confirmation through physiological and biochemical traits. Plants. 2022;11(23):3325. https://doi.org/10.3390/plants11233325
  24. 24. Atav V, Yuksel O, Namli A. Impact of single and cumulative applications of biogas liquid digestate on soil and plant. J Agric Sci Technol. 2025;27(5):1061–77.
  25. 25. Nkoa R. Agricultural benefits and environmental risks of soil fertilization with anaerobic digestates: A review. Agron Sustain Dev. 2014;34(2):473–92. https://doi.org/10.1007/s13593-013-0196-z
  26. 26. Shilpha J, Song J, Jeong BR. Ammonium phytotoxicity and tolerance: An insight into ammonium nutrition to improve crop productivity. Agronomy. 2023;13(6):1487. https://doi.org/10.3390/agronomy13061487
  27. 27. Zhang X, Ni J-Q, Wu S, Cui C, Pang C, Dong R. Leaching and transformation of nitrogen in soil fertilized with digestate: A soil column study. In: 2014 ASABE Annual International Meeting. St Joseph (MI): American Society of Agricultural and Biological Engineers; 2014. p. 1–8. https://doi.org/10.13031/aim.20141913610
  28. 28. Singh RP, Gautam M, Vaish B, Suhani I, Srivastava V. Explicating the fertilizing potential of anaerobic digestate on soil quality, growth and yield responses of Solanum lycopersicum var. Kashi Aman. Int J Environ Res. 2025;19(3):65. https://doi.org/10.1007/s41742-024-00733-z
  29. 29. Solano C, Artola A, Barrena R, Ballardo C, Sánchez A. Effect of the exogenous application of different concentrations of indole-3-acetic acid as a growth regulator on onion (Allium cepa L.) cultivation. Agronomy. 2023;13(9):2204. https://doi.org/10.3390/agronomy13092204
  30. 30. Regessa MD, Gemechis AO, Chala EE. Growth, physiology and yield of onion (Allium cepa L.) under salt stress. Greener J Agric Sci. 2022;12(2):154–67. https://doi.org/10.15580/GJAS.2022.2.053022057
  31. 31. Coaguila P, Bardales R, Zeballos O. Digestates from the production of biogas from cattle slurry in onion production in arid zones. Sci Agropecu. 2019;10(1):119–24. https://doi.org/10.17268/sci.agropecu.2019.01.13
  32. 32. Lee J, Seong D. Replacing conventional nutrient inputs for basal application with anaerobically digested pig slurry for bulb onion production. J Plant Nutr. 2015;38(8):1241–53. https://doi.org/10.1080/01904167.2014.991034
  33. 33. Bouchra H, Brahim B. Profitability analysis of onion production in Morocco. In: Bourekkadi S, Kerkeb ML, El Imrani O, Rafalia N, Zubareva O, Khoulji S, et al., editors. E3S Web Conf. 2023;412:01016. https://doi.org/10.1051/e3sconf/202341201016
  34. 34. Elouattassi Y, Ferioun M, El Ghachtouli N, Derraz K, Rachidi F. Enhancing onion growth and yield through agroecological practices: Organic fertilization and intercropping. Ecol Front. 2024;44(3):547–57. https://doi.org/10.1016/j.chnaes.2023.09.004
  35. 35. El-Sheref G, Abdelhamed H, Fathalla F, Mohamed G. Impact of organic and mineral fertilization on onion yield, quality, storability, some soil properties and its fertility. J Soil Sci Agric Eng. 2023;14(12):407–14. https://doi.org/10.21608/jssae.2023.249223.1200
  36. 36. Andishmand AB, Noori MS. Growth and yield of onion (Allium cepa L.) as influenced by application of organic and inorganic fertilisers. J Sci Agric. 2012;5:55–9. https://doi.org/10.25081/jsa.2021.v5.7270
  37. 37. Messele B. Effects of nitrogen and phosphorus rates on growth, yield and quality of onion (Allium cepa L.) at Menschen Für Menschen demonstration site, Harar, Ethiopia. Agric Res Technol Open Access J. 2016;1(3). https://doi.org/10.19080/ARTOAJ.2016.01.555563
  38. 38. Syed N, Munir M, Ahmad Aliz A, Ghafoor A. Onion yield and yield components as function of the levels of nitrogen and potassium application. Pak J Biol Sci. 2000;3(12):2069–71. https://doi.org/10.3923/pjbs.2000.2069.2071
  39. 39. Maisura M, Nurdin M, Muslina M. Effect of manure and NPK fertilisers on growth and production of onion (Allium cepa L.). J Trop Hortic. 2019;2(1):16. https://doi.org/10.33089/jthort.v2i1.15

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