Optimized rice seed coating with zeolite for enhanced germination and initial growth in water direct seeding

Korean rice farming faces increasing challenges due to labor shortages and rising costs, necessitating more efficient cultivation methods. Water direct seeding offers a promising solution, but issues such as seed flotation and low seedling establishment hinder its adoption. This study aimed to enhance the efficiency of rice direct seeding in flooded paddy fields by optimizing seed coating technology. Using the Shindongjin rice variety, various filler materials and binder concentrations were evaluated for their impact on coating quality, germination, and early seedling growth under submerged conditions. Zeolite emerged as the most effective filler, demonstrating superior adhesion, germination performance, and seedling stability, attributed to its slow decomposition rate and reduced seed flotation. Diatomite and SiO₂ showed promising results, particularly in promoting root elongation and seedling growth, but exhibited limitations at higher application rates due to seed flotation issues. Conversely, clay and bentonite exhibited inconsistent performance, highlighting the importance of selecting suitable materials for stable seed establishment. The study identified an optimal PVA500 binder concentration of 1% for most fillers, ensuring uniform coatings and enhanced processability. These findings underscore the potential of zeolite-coated rice seeds as a practical solution for water direct seeding systems.