The Effect of Dewatered Sludges Obtained from Different Stabilization Systems on the Development of Strawberry Plant

Öz

This study investigates the comparative efficacy of dewatered wastewater sludges derived from conventional treatment system followed by anaerobic digestion and extended aeration processes as organic fertilizers for strawberry (Fragaria × ananassa) cultivation. Conducted over a six-week duration in a controlled greenhouse environment, the research evaluated the vegetative and morphological development of 'Quinault' strawberry seedlings grown in sandy loam soil. The experimental design utilized a blank control group alongside five distinct mass-by-mass application rates: 1/5, 1/10, 1/20, 1/25, and 1/50. Initial results identified a clear phytotoxic threshold, as high-dosage treatments (1/5, 1/10, and 1/20) resulted in plant mortality. Conversely, optimized lower ratios significantly enhanced plant vigor. The most substantial development was recorded in the 1/50 ratio group utilizing anaerobically digested sludge, which exhibited a 244.4% increase in plant body length and a 162% increase in root length compared to initial measurements. Statistical analysis confirmed significant correlations (p<0.05) between stabilized biosolid application and improved morphological indicators. Elemental analysis revealed that anaerobic residuals possessed superior organic matter and nitrogen profiles, providing a more stable nutrient flux than the extended aeration system. The findings conclude that stabilized urban sludge is a high-efficiency organic fertilizer when applied at optimized ratios. This approach supports circular economy goals by converting wastewater residuals into valuable agricultural resources while prioritizing food safety and environmental health. However, it is emphasized that these fertilizers cannot be safely utilized without rigorous verification that they are free of heavy metal contamination.

Anahtar Kelimeler

• Strawberry
• Stable sludge
• Fertilizer
• Dewatered sludge
• Optimized sludge ratio

Farklı Stabilizasyon Sistemlerinden Elde Edilen Susuzlaştırılmış Çamurların Çilek Bitkisinin Gelişimine Etkisi

Öz

Bu çalışma, geleneksel arıtma sistemini takiben anaerobik çürütme ve uzun havalandırmalı aktif çamur proseslerinden elde edilen susuzlaştırılmış atıksu çamurlarının, çilek (Fragaria × ananassa) yetiştiriciliğinde organik gübre olarak kullanımındaki etkinliğini karşılaştırarak incelemektedir. Kontrollü bir sera ortamında altı haftalık bir süre boyunca yürütülen araştırma, kumlu tınlı toprakta yetiştirilen 'Quinault' çilek fidelerinin vejetatif ve morfolojik gelişimini değerlendirmiştir. Deneysel tasarımda, bir kontrol grubunun yanı sıra kütlece beş farklı uygulama oranı (1/5, 1/10, 1/20, 1/25 ve 1/50) kullanılmıştır. İlk sonuçlar net bir fitotoksik eşik belirlemiştir; yüksek dozlu uygulamalar (1/5, 1/10 ve 1/20) bitki ölümleriyle sonuçlanmıştır. Buna karşılık, optimize edilmiş daha düşük oranlar bitki canlılığını önemli ölçüde artırmıştır. En belirgin gelişim, başlangıç ölçümlerine kıyasla bitki boyunda %244,4 ve kök uzunluğunda %162 artış gösteren, anaerobik olarak çürütülmüş çamurun kullanıldığı 1/50 oranındaki grupta kaydedilmiştir. İstatistiksel analizler, stabilize edilmiş biyolojik çamur uygulaması ile iyileşen morfolojik göstergeler arasında anlamlı korelasyonlar (p<0.05) olduğunu doğrulamıştır. Elementel analizler, anaerobik kalıntıların üstün organik madde ve azot profillerine sahip olduğunu ve uzun havalandırmalı sisteme göre daha stabil bir besin akışı sağladığını ortaya koymuştur. Bulgular, stabilize kentsel çamurun optimize edilmiş oranlarda uygulandığında yüksek verimli bir organik gübre olduğu sonucuna varmaktadır. Bu yaklaşım, atıksu kaynaklı stabil çamurları değerli tarımsal kaynaklara dönüştürerek gıda güvenliğini ve çevre sağlığını önceliklendirirken döngüsel ekonomi hedeflerini desteklemektedir. Ancak, bu gübrelerin ağır metal kontaminasyonu içermediğine dair titiz bir doğrulama yapılmadan güvenli bir şekilde kullanılamayacağı da vurgulanmaktadır.

Anahtar Kelimeler

• Çilek
• Stabil çamur
• Gübre
• Optimize edilmiş çamur oranı

Kaynakça

1. [1] Turkish Statistical Institute [TURKSTAT]. (2025). Waste statistics, 2024 (Press Release No. 54134).
2. [2] Topçuoğlu, B. (2016). Kentsel arıtma çamurunun tarımsal kullanımı. Derim, 18(3), 132-142. https://izlik.org/JA22SJ63UM. [in Turkish]
3. [3] Kelessidis, A., & Stasinakis, A. S. (2012). Comparative study of the methods used for treatment and final disposal of sewage sludge in European countries. Waste Management, 32(6), 1186–1195. https://doi.org/10.1016/j.wasman.2012.01.012
4. [4] Warman, P. R., & Termeer, W. C. (2005). Evaluation of sewage sludge, septic waste and sludge compost applications to corn and forage: Yields and N, P, and K content of crops and soils. Bioresource Technology, 96(8), 955–961.
5. [5] Haktanır, K., & Arcak, S. (1998). Toprak kirliliği. Ankara Üniversitesi Ziraat Fakültesi Yayınları. Ankara, Türkiye. [in Turkish]
6. [6] Judd, S. (2022). Sludge dewatering. Sludge Processing. https://www.sludgeprocessing.com/sludge-dewatering/ [January, 2026]
7. [7] Republic of Türkiye Ministry of Environment, Urbanization and Climate Change. (2022). Atıksu arıtma tesisleri teknik usuller tebliği. T.C. Resmî Gazete (Sayı: 31711). Ankara, Türkiye. [in Turkish]
8. [8] Amuda, O. S., Deng, A., Alade, A. O., & Hung, Y. T. (2008). Conversion of sewage sludge to biosolids. In L. K. Wang, N. K. Shammas, & Y. T. Hung (Eds.), Biosolids Engineering and Management (Vol. 7, pp. 41–105). Humana Press.

9. [9] Akat, H., & Altunlu, H. (2019). The effects of sewage sludge applications on growth, yield and flower quality of Limonium sinuatum (Statice) under salinity conditions. Ege Üniversitesi Ziraat Fakültesi Dergisi, 56(1), 103–108. https://doi.org/10.20289/zfdergi.423273
10. [10] Çakır, H. N., & Çimrin, K. M. (2020). The effect of sewage sludge applications on the growth of maize (Zea mays L.) and some soil properties. KSU Journal of Agriculture and Nature, 23(2), 321–327.
11. [11] Johansen, J. L., Dam, M., Kudjordjie, E. N., Santos, S. S., Palmqvist, A., Magid, J., & Vestergård, M. (2023). Effects of long-term fertilization with contemporary Danish human urine, composted household waste and sewage sludge on soil nematode abundance and community structure. Science of The Total Environment, 860, 160485. https://doi.org/10.1016/j.scitotenv.2022.160485
12. [12] Metcalf & Eddy, Inc., Abu-Orf, M., Bowden, G., Burton, F. L., Pfrang, W., Stensel, H. D., Tsuchihashi, R., & Tchobanoglous, G. (2014). Wastewater engineering: Treatment and resource recovery (5th ed.). McGraw-Hill Education.
13. [13] Möller, K., & Müller, T. (2012). Effects of anaerobic digestion on digestate nutrient availability and crop growth: A review. Advances in Agronomy, 117, 145–220. https://doi.org/10.1016/B978-0-12-394278-4.00004-8
14. [14] Tambone, F., Scaglia, B., D’Imporzano, G., Schievano, A., Orzi, V., Salati, S., & Adani, F. (2010). Assessing amendment and fertilizing properties of digestates from anaerobic digestion through a comparative study with settled sewage sludge and compost. Chemosphere, 81(5), 577–583. https://doi.org/10.1016/j.chemosphere.2010.08.034
15. [15] Latare, A. M., Kumar, O., Singh, S. K., & Gupta, R. K. (2014). Direct and residual effect of sewage sludge on yield, heavy metals content and soil fertility under rice–wheat system. Ecological Engineering, 69, 17–24. https://doi.org/10.1016/j.ecoleng.2014.03.066
16. [16] Eid, E. M., Shaltout, K. H., El-Bana, M. J., Al-Askar, A. A., & Galal, T. M. (2017). Potential use of sewage sludge as a fertilizer for Eruca sativa L.: Growth, heavy metal accumulation and health risk assessment. International Journal of Phytoremediation, 19(3), 273–282. https://doi.org/10.1080/15226514.2016.1225286
17. [17] Cucina, M., De Nisi, P., Sordi, S., & Adani, F. (2021). Sewage sludge as N-fertilizers for crop production enabling the circular bioeconomy in agriculture: A challenge for the new EU regulation 1009/2019. Sustainability, 13(23), 13165. https://doi.org/10.3390/su132313165
18. [18] Lazcano, C., Arnold, J., Tato, A., Zaller, J. G., & Domínguez, J. (2009). Compost and vermicompost as nursery pot components: effects on tomato plant growth and morphology. Spanish Journal of Agricultural Research, 7(4), 944–951. https://doi.org/10.5424/sjar/2009074-1107
19. [19] Tzortzakis, N., Gouma, S., Paterakis, C., & Manios, T. (2012). Deployment of municipal solid wastes as a substitute growing medium component in marigold and basil seedlings production. The Scientific World Journal, 2012, 285874. https://doi.org/10.1100/2012/285874
20. [20] Jatav, S. S., Singh, S. K., Parihar, M., Alsuhaibani, A. M., Gaber, A., & Hossain, A. (2022). Application of sewage sludge in a rice (Oryza sativa L.)-wheat (Triticum aestivum L.) system influences the growth, yield, quality and heavy metals accumulation of rice and wheat. Life, 12(4), 484. https://doi.org/10.3390/life12040484
21. [21] Martínez Durán, E., et al. (2023). Use of biosolids from wastewater treatment plants and other organic fertilizers in agriculture—A preliminary results of a case study. Frontiers in Water, 5, 1236924. https://doi.org/10.3389/frwa.2023.1236924
22. [22] Ghorbani, M., Konvalina, P., Walkiewicz, A., Neugschwandtner, R. W., Kopecký, M., Zamanian, K., Chen, W. H., & Bucur, D. (2022). Feasibility of biochar derived from sewage sludge to promote sustainable agriculture and mitigate GHG emissions—A review. International Journal of Environmental Research and Public Health, 19(19), 12983. https://doi.org/10.3390/ijerph191912983
23. [23] Mierzwa-Hersztek, M., Gondek, K., Klimkowicz-Pawlas, A., Baran, A., & Bajda, T. (2018). Sewage sludge biochars management: Ecotoxicity, mobility of heavy metals, and soil microbial biomass. Environmental Toxicology and Chemistry, 37(4), 1197–1207. https://doi.org/10.1002/etc.4045
24. [24] Parkash, V. & Singh, S. (2020). Potential of Biochar Application to Mitigate Salinity Stress in Eggplant. HortScience, 55(12), 1946–1955. https://doi.org/10.21273/HORTSCI15398-20
25. [25] Murtaza, G., Usman, M., Iqbal, J., Tahir, M., Elshikh, M. S., Alkahtani, J., Toleikienė, M., Iqbal, R., Akram, M. W., & Gruda, N. S. (2024). The impact of biochar addition on morpho-physiological characteristics, yield and water use efficiency of tomato plants under drought and salinity stress. BMC Plant Biology, 24(1), 553. https://doi.org/10.1186/s12870-024-05058-9
26. [26] Yang, Y., Wang, H., Dong, W., Li, Q., Han, Q., Li, C., Liu, T., & Zhou, P. (2025). The effects of sewage sludge biochar on rhizosphere microbial community, soil quality, and ryegrass and cosmos growth in pot culture. Plants, 14(5), 641. https://doi.org/10.3390/plants14050641
27. [27] Kumar, V., Chopra, A. K., & Kumar, A. (2017). A review on sewage sludge (biosolids) a resource for sustainable agriculture. Archives of Agriculture and Environmental Science, 2(4), 340–347. https://doi.org/10.26832/24566632.2017.020417
28. [28] Tüzüner, A. (1990). Toprak ve su analizleri (Laboratuvar kılavuzu). Tarım Orman ve Köyişleri Bakanlığı, Köy Hizmetleri Genel Müdürlüğü. [in Turkish]
29. [29] Singh, R. P., & Agrawal, M. (2008). Potential benefits and risks of land application of sewage sludge. Waste Management, 28(2), 347–358. https://doi.org/10.1016/j.wasman.2006.12.010
30. [30] Kamboj, P. (2020). Strawberry: Growth and yield influenced by different organic and inorganic sources – A review. Indian Journal of Pure & Applied Biosciences, 8(1), 32–35. https://doi.org/10.18782/2582-2845.7811
31. [31] Méndez, A., Gómez, A., Paz-Ferreiro, J., & Gascó, G. (2012). Effects of sewage sludge biochar on plant metal availability after application to a Mediterranean soil. Chemosphere, 89(11), 1354–1359. https://doi.org/10.1016/j.chemosphere.2012.05.092
32. [32] Delibacak, S., & Ongun, A. R. (2016). Influence of treated sewage sludge applications on corn and second crop wheat yield and some properties of sandy clay soil. Turkish Journal of Field Crops, 21(1), 1–9.