Effects of increased seeding density on seedling characteristics, mechanical transplantation quality, and yields of rice with crop straw boards for seedling cultivation

Abstract

The high demand for labor during rice seedling cultivation and transplantation poses a major challenge in advancing machine-transplanted rice cultivation. This problem may be solved by increasing the seeding rate during seedling production while reducing the number of seedling trays. In this study, the commonly used combination of 150 g/tray with a 20-day seedling age in rice production was used as CK. Besides, some field experiments were conducted under seedling age conditions of 10 and 15 days from 2021 to 2022 to explore the effects of 250, 300, and 350 g/tray on the seedling quality, mechanical transplantation quality, yields, and economic benefits of rice. The cultivation of seedlings under a high seeding rate and short seedling age significantly affected seedling characteristics, but there was no significant difference in seedling vitality compared to CK. The minimum number of rice trays used in the experiment was observed in the treatment of 350-10, only 152-155 trays per hectare, resulting in a 62% reduction in the number of trays needed. By increasing the seeding rate of rice, missed holes during mechanical transplantation decreased by 2.8 to 4%. The highest yields and economic gains were achieved by the treatment of 300-15. These results indicated that using crop straw boards can reduce the application of seedling trays. On that basis, the yield of rice can be increased by increasing the seeding rate and shortening the seedling age of rice under the premise of ensuring seedling quality.