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

Abstract

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.

Keywords

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

Farklı Stabilizasyon Sistemlerinden Elde Edilen Susuzlaştırılmış Çamurların Çilek Bitkisinin Gelişimine Etkisi

Abstract

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.

Keywords

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

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