Objective To study the effect of adhesive in the forming process of seedling tray and explore the effect of different amounts of glue on the physical and chemical properties of rice seedling tray.

Method straw and cow manure were fermented in a certain proportion, and the products were used as biodegradable substrates. The self-synthesized modified starch adhesive, characterized by its weak acidity, high bond strength, and excellent water resistance, was incorporated into the formulation. Concurrently, nutritional elements were introduced and thoroughly mixed. Then, the rice seedling tray was fabricated through low-pressure molding at a pressure of 2~3 MPa, followed by drying after maintaining the pressure for 5-7 min. Single factor analysis of variance was used to analyze the effects of different amounts of glue on the biodegradation rate, volume expansion rate, moisture content and shear strength of seedling tray.

Result The optimal glue amount was 21% of the total weight of the seedling tray, and the resulting seedling tray had biodegradation rate of 82%, shear strength of 0.07 MPa, moisture content of 12.5% and volume expansion rate of 46%.

Conclusion Compared to commercially available seedling trays, the prepared rice seedling trays have reduced the amount of glue used, improved water resistance, and have a higher biodegradation rate, meeting the requirements for rice seedling trays. This provides technical support for the industrial production of seedling trays, offers a new avenue for the high-value utilization of straw and cow dung, promots the quality production of seedlings.