Comparative study on Organic Composts in Blueberry: Insights into Soil Physicochemical Properties and Heavy Metal Control

Organic fertilization is an essential method for sustainable agricultural development. Composts of edible fungal substrates (CEFS) and Chinese herbal residues (CCHR) are potential ecological organic fertilizers, but rarely used in blueberry cultivation. The purport is to compare different fertilizations on the integrated soil fertility (ISF), nutrients availability, and the heavy metals (HMs) risks in the blueberry soil and fruit; simultaneously to clarify the relationships between nutrients input and HMs risks for the blueberry. In this study, we conducted a field trial using CEFS and CCHR in blueberry, comparing to the special fruit organic fertilizer in the market (SFOF) and potassium sulfate compound fertilizers (PSCF). Results showed that the ISF of blueberry was mostly affected by the input of nitrogenous and organic matters, and restricted by HMs. CEFS and CCHR demonstrated a better fertility and heavy-metal prevention efficiency comparing to SFOF and PSCF. But excess organic matters in soil would affect blueberry's absorption of potassium, it is necessary to replenish potassium fertilizer in time for blueberry. Our results would provide a theoretical basis for the application of CEFS and CCHR in the safety production of blueberry.