Work

Thermochemically Treated Sewage Sludge Ash From Pilot‐Scale Production as P‐Fertilizer for Spring Wheat and Maize in Different Soil Conditions

Year: 2025

Type: article

Abstract: ABSTRACT Background P‐fertilizers made from sewage sludge ash (SSA) may be suitable substitutes for rock phosphate (RP)‐based fertilizers and contribute to sustainable use of waste. In this context, the thermochemical AshDec treatment of SSA (TC‐SSA) has been continuously improved and has emerged as a possible method to produce plant‐available and low‐pollutant P‐fertilizers. Aim Evaluation of the P‐fertilizer efficacy of TC‐SSA produced in pilot trials in vegetation experiments with different plants, soils, and fertilizer doses. Methods TC‐SSA was tested in pot experiments for spring wheat and maize on different soils and at two doses (0.2 and 0.4 g fertilizer P pot −1 ) and is compared to untreated SSA (USSA), RP, Struvite, triple superphosphate (TSP), and a control without P‐fertilization (Zero P). Pot experiments are complemented by an analysis of fertilizer P‐solubility. Results P‐solubility of SSA with different extraction methods increased due to the thermochemical treatment, whereas the water‐insoluble property remained. In contrast to RP or USSA, TC‐SSA enriched calcium–acetate–lactate extractable soil P to the same extent as TSP. Plant biomass and P‐uptake increased with TC‐SSA compared to Zero P, RP, and USSA and were in most cases equal to TSP fertilization under different soil conditions. In contrast, the effects of RP and USSA varied among soils but, mostly, did not exceed plant biomass and P‐uptake of the unfertilized control. Conclusion TC‐SSA has an increased fertilizer efficacy compared to USSA and is an effective P‐fertilizer for spring wheat and maize in different soil conditions.

Source: Journal of Plant Nutrition and Soil Science

DOI: 10.1002/jpln.70035

Authors: Kai Leers, Ute Arnold, Hannes Herzel, Christian Adam, Jürgen Burkhardt

Institutions: University of Bonn, Federal Institute For Materials Research and Testing

Language: English

Topic: Phosphorus and nutrient management

Subfield: Waste Management and Disposal

Field: Environmental Science

Domain: Physical Sciences

SDGs: Responsible consumption and production, Zero hunger

Open Access status: hybrid

Estimated APC paid: $4,030