Effects of different sowing cylinders on seeding amount and seeding uniformity of rice in pot-seedling

To investigate the effects of different seeding rollers on the seeding quantity and uniformity of rice seedlings in pots, and to provide a basis for selecting suitable rollers for rice seedling seeding. Four types of sowing drums with different sowing hole diameters（a circular sowing drum with a sowing hole diameter of 9 mm and a depth of 4 mm, an elliptical sowing drum with a major axis of 12 mm, a minor axis of 9 mm and a depth of 4 mm, a small square sowing drum with a side length of 12 mm and a depth of 3 mm, and a large square sowing drum with a side length of 14 mm and a depth of 3 mm）were used to conduct sowing experiments on 15 rice varieties. The grain shape structure of each rice variety and the sowing amount, leakage rate and uniformity under different sowing drums were analyzed. The results show that the variations in grain length, grain width, and aspect ratio of the 15 rice varieties range from 7.97 to 12.23 mm, 2.13 to 3.04 mm, and 2.62 to 5.40 respectively. The hole rate of rice sowing decreases as the grain length increases. Except for Yongyou 7850, the hole rates of the other rice varieties sown using circular sowing drums and small square sowing drums range from 6.55% to 85.12%, which is significantly higher than the hole rates of other sowing drums. The hole rate of Yuzhixin in all four sowing drums is higher than 7.89%. The seeding rate and seeding uniformity decrease as the grain length increases, when the grain length variation range is 7.97-9.82 mm, the seeding rates for different rice varieties using elliptical seeding drums and large square seeding drums are 5.76-8.82 seeds per hole and 4.03-5.25 seeds per hole, and the seeding uniformities are 73.90% -87.31% and 61.40%-75.80%, respectively. When the grain length variation range was 9.97-10.93 mm, the sowing rates of rice using elliptical seeding drums and large square seeding drums were 3.99-4.74 grains per hole and 2.05-3.25 grains per hole respectively, and the sowing uniformity was 63.79%-75.60% and 28.78% - 68.28%. Taking into account the hole leakage rate, sowing quantity and uniformity, when the length of rice seeds is 7.97-9.82 mm, a large square sowing roller is suitable; when the length is 9.97-10.93 mm, an elliptical sowing roller is suitable; when the single sowing quantity per hole of rice seeds is 3-5 and the hole leakage rate is less than 5% and the uniformity is greater than 61.40%, it is suitable for rice pot seedling sowing; while for the longer Yuzhenxiang rice seeds, none of the four sowing rollers can meet the suitable sowing effect for pot seedlings, and it is not suitable for rice pot seedling sowing.