Biofilm-Based Microalgal-Bacterial Fertilizer Maintains Tomato Growth Under Reduced Chemical Fertilization in Acidic and Alkaline Soils
JOURNAL OF SOIL SCIENCE AND PLANT NUTRITION, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Basım Tarihi: 2026
- Doi Numarası: 10.1007/s42729-026-03536-7
- Dergi Adı: JOURNAL OF SOIL SCIENCE AND PLANT NUTRITION
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Natural Science Collection (ProQuest), Biological Science Database (ProQuest)
- Orta Doğu Teknik Üniversitesi Adresli: Evet
Özet
Soil pH is a key determinant of nutrient availability and microbial fertilizer performance. This study evaluated whether an algal biofilm fertilizer (ABF) could sustain tomato growth and nutrient acquisition under reduced mineral fertilization in soils with contrasting acidity and alkalinity. A Chlorella-derived biofilm matrix was produced in a biofilm reactor and inoculated with plant growth-promoting bacteria (Lactococcus lactis, Bacillus methylotrophicus, and Azotobacter vinelandii). A greenhouse experiment was conducted using an acidic soil (Leptosol, pH 6.11) and an alkaline soil (Regosol, pH 7.36) under full fertilization, 50% reduced fertilization, ABF-only, and combined ABF-reduced fertilization treatments. Soil chemical properties, plant growth parameters, and nutrient composition were analyzed, and treatment patterns were evaluated using principal component analysis. ABF alone did not consistently match plant biomass obtained under full fertilization. However, ABF, combined with a 50% reduction in fertilization, maintained biomass and nutrient uptake at statistically comparable levels (p < 0.05). In alkaline soils, ABF treatments were associated with increased soil organic matter and potassium availability relative to the control. Multivariate analysis revealed more structured treatment responses under alkaline conditions, with PC1 and PC2 accounting for 45.13% and 17.60% of the total variance, respectively, compared with 33.95% and 21.13% in acidic soils. Biofilm-based microbial fertilization primarily enhanced nutrient-use efficiency rather than acting as a direct nutrient source. The stronger responses observed in alkaline soils suggest that biofilm-mediated microbial stability may enhance fertilizer efficiency under nutrient-limitation conditions. These findings indicate that biofilm-based microbial formulations can serve as complementary inputs in reduced fertilization strategies.