Reuse of phosphorus (P) from waste streams used for bioenergy conversion is desirable to reduce dependence on nonrenewable P resources. Two different ash materials from low‐temperature biomass gasification of wheat straw and sewage sludge, respectively, were investigated with regard to their P bioavailability. A set of pot experiments with spring barley was carried out to compare the ash P fertiliser value with mineral P fertiliser and the sewage sludge feedstock. An indirect radioactive labelling approach with 33P was used to determine the amount of P taken up from the fertiliser materials. Depending on the application rate, straw gasification ash produced a fertiliser response comparable to mineral P. However, P uptake from the ash was generally less than uptake from equivalent amounts of mineral P, and the calculated relative effectiveness was 44% after 6 weeks of plant growth. In contrast, the P fertiliser value of Fe‐rich sewage sludge after low‐temperature gasification was practically zero. These results suggest that ash from low‐temperature gasification could be developed into alternative P fertilisers; however, as the P bioavailability depends greatly on the feedstock used, a greater emphasis on feedstock composition is required.
|Translated title of the contribution||Phosphorus bioavailability in straw and sewage sludge ashes from low-temperature biomass gasification|
|Journal||Soil Use and Management|
|Publication status||Published - 2018|
- Sewage sludge