Co-incorporation of hydrotalcite and starch into biochar-based fertilizers for the synthesis of slow-release fertilizers with improved water retention

Abstract The unsatisfactory nutrient slow-release and water-retention performance of traditional biochar-based compound fertilizers (BCF) severely limit their practical application. Herein, a new type fertilizer with high water retention was fabricated via the incorporation hydrotalcite starch into BCF, named as HS-BCF. releasing prepared HS-BCF related mechanism were investigated. results showed that BCF could increase soil ratio by 5–10% points. accumulated N, P, K leaching amounts in within 30 days 49.4%, 13.3%, 87.4% at most, respectively. Kinetic analysis indicated release nutrients from attributed to coupling diffusion-controlled relaxation-controlled mechanism. Moreover, bind P HS-BCF, contributing enhanced durability Finally, pot experiments N–P–K utilization efficiencies all higher than those due better synchronization between uptake tomato plants. Overall, study may provide promising strategy for simultaneously improving fertilizers. Graphical