Randomized trial evaluates bioacidification and fertilizer placement on phosphorus supply in maize, suggesting improved agronomic value of biowaste.
Key Points
To assess the effectiveness of bioacidification and fertilizer placement on phosphorus supply and maize growth.
Produced sulfuric acid-acidified and bioacidified fertilizers from biogas digestate solid fraction, biochar, and bone meal.
Grew maize for 42 days in a climate chamber with fertilizers applied at 60 mg P kg⁻1 soil.
Compared the effects of mixed versus placed fertilizer applications on maize growth and phosphorus uptake.
Bioacidification increased water-extractable phosphorus by 11% to 36%, compared to untreated feedstocks, lower than sulfuric acid treatment (up to 56%).
Placed sulfuric acid biogas digestate solid fraction produced 8.68 g pot−1 biomass and 10.8 mg pot−1 phosphorus uptake, superior to triple superphosphate (6.38 g and 7.54 mg per pot respectively).
Bioacidified products exhibited lower fertilizer value for maize potentially due to inhibitory by-products.