Design and Optimizing of Precision Seeder of Pinus sylvestris var. mongolica L. Bud-Seeds for Containerized Nursery Production

Abstract

Mongolian pine holds immense ecological and economic values as a vital biobased material. Its wood fiber, rosin and turpentine are important raw materials suitable for multiple industrial applications, it also exhibited soil and water conservation capabilities. To improve its seeding efficiency, this study designed a precision seeding machine for Mongolian pine (Pinus sylvestris var. mongolica L.) bud-seeds, and optimized the technical seeding parameters, which utilized a combined vibration-air blowing fluidization device to overcome seed flowability limitations and facilitate accurate seed selection. A particle model was established based on the seeds’ physical characteristics, and EDEM software was utilized to simulate the spatial distribution of seed particles under various seeding parameters through seeding experiments. The optimal air pressure for the combined seed supply was approximately 0.24 kPa, with a frequency of 20 Hz and an amplitude of 5 mm, to obtain an optimal spatial distribution of the seed particles. The most effective seeding area for seed adhesion was determined to be 5–15 mm from the bottom of the seeding plate. When the seed suction negative pressure is set to 6.7 kPa, with an upper hole diameter of 0.9 mm, a lower hole diameter of 3 mm, and a hole depth of 1.5 mm, the seedling emergence rate reached 89.06%, and the fastest emergence time was 2 days. One month after sowing, the seedlings exhibited a height growth rate of 16.1%, and a ground diameter growth rate of 20.9%. This study demonstrates the effectiveness of the precision seeding machine and optimized parameters in achieving efficient and accurate sowing of Mongolian pine bud-seeds. This work provides basic technical and data support for advancing the development and sustainable utilization of Mongolian pine as a vital biobased material resource.