Abstract: [Objective] To assess the effects of various disinfection durations, straw substrates, and layout methods on substrates mildewing as well as germination and seedling growth of wheat and corn grains, aiming to optimize the use of straw as a substrate material for fresh grass production and to lower the cost of large-scale fresh grass production. [Method] Using wheat and corn grains as experimental materials, the mildewing status of substrate materials after different durations of disinfection by boiling was observed, and the germination rate, germination potential, and germination index of wheat and corn grains in different substrate materials were investigated. Furthermore, the impacts of various layout methods, particle sizes, and material ratios on seedling growth height were evaluated. [Result] As substrate materials, Artemisia and reed straws required a disinfection for 30 minutes and 60 minutes, respectively, and maize, millet, soybean, and Caragana straws required a disinfection for 120 minutes. Compared with the filter paper, the straw substrates of maize, millet, soybean and reed had no significant （P>0.05） changed germination rate, germination potential, and germination index of wheat and corn grains. The inside-substrate layout method had higher height of wheat and maize seedlings than the other layout methods. There was no significant （P>0.05） difference in height of wheat and maize seedlings treated with coarse flour or fine flour substrate materials on 10^th day of growth. On 3^rd, 7^th, and 10^th day of growth, no significant （P>0.05）difference in wheat seedling height was observed under different material ratios. There was no significant （P>0.05） change in maize seedling height under different material ratios during the whole experiment. [Conclusion] In industrialized fresh grass production, it is preferable to use maize, millet, soybean, and reed straw as substrate materials. Prior to production, the substrate materials must be boiled for disinfection for at least 120 minutes. Fresh grass production may achieve a better performance with the inside-substrate layout method, straw particle length of roughly 2 cm, a material ratio of 3∶1 for wheat, and a material ratio of 4∶1 for maize.

Key words: fresh grass production, straw utilization, substrate material, seedling growth