Rice transplanting with a transplanter is a cost-effective process. Due to labor shortages during the peak time of rice transplanting, it is a promising technology in Bangladesh. However, the high-quality mat-type see...Rice transplanting with a transplanter is a cost-effective process. Due to labor shortages during the peak time of rice transplanting, it is a promising technology in Bangladesh. However, the high-quality mat-type seedling is a prerequisite factor for mechanical transplanting. The experiments were conducted at three different locations (Gazipur, Tangail, and Rangpur) during the dry season (Boro)/2019-20 to determine the best seeding density for high-quality mat-type seedlings to be prepared for mechanical rice transplanters. The effects of seeding rate on seedling quality such as survival rate, seedling strength, stem thickness of newly released boro rice varieties BRRI dhan86, BRRI dhan89, and BRRI dhan92 were studied using four seeding rates (130, 140, 150, 160 g/tray). Results revealed that BRRI dhan92 showed quick seedling emergence compared to BRRI dhan89 and BRRI dhan86. Seedling mortality was found the lowest BRRI dhan92 while the highest in BRRI dhan86. 25 - 30 days old seedling was found suitable for mechanical transplanting in terms of seedling mortality. Seedling height increased with the increase in seed density. BRRI dhan92 showed the highest stem thickness followed by BRRI dhan89 and BRRI dhan86 with seed rate 150 - 160 g per tray. The suitable seeding rate (150 - 160 g/tray) for the studied varieties was found better for raising mat-type seedlings suitable for mechanical transplanting, which could coordinate the production of larger population growth and higher harvest index to achieve high grain yield.展开更多
The plant-made seedling-growing tray cultivation technique is an effective way to improve maize yield and quality in China’s cold northern area.However,the corn seedling nursery carrier and tray cultivation technique...The plant-made seedling-growing tray cultivation technique is an effective way to improve maize yield and quality in China’s cold northern area.However,the corn seedling nursery carrier and tray cultivation technique has been proved poor in adaptability.After comparing several nursery carriers,a design for a plant-made seedling-growing tray that is suitable for maize transplantation was proposed in which rice straw was used as the primary raw material.The preparation method,processing and structural dimensions of the tray were investigated and designed,five types of plant-made seedling-growing trays with different formulations were proposed.The shear mechanical properties and the shear strength of the plant-made seedling-growing trays were tested to determine the shear force needed for cutting through trays prepared with increasing mass ratios of rice straw and the effect of the shearing rate on the shear strength.The results showed that at a shearing rate of 100 mm/min,the maximum shear force decreased gradually as the mass ratio of straw was increased and that the hardness of the tray decreased as its shear strength decreased.Under three shearing rates(100 mm/min,200 mm/min and 500 mm/min)and a blade displacement of 10 mm,the shear force was the highest at the point at which the tray was cut through;the required shear force to cut through the tray then gradually decreased.Trays with the same straw composition showed no significant influence of shearing rate on the tray’s shear strength at shearing rates of 100 mm/min,200 mm/min or 500 mm/min.This study describes a multi-tray,single-strip nursery carrier for use in plant-made seedling-growing tray cultivation and proposes a theoretical basis for the design of a rotary transplanting device,the key part of a maize plant-made seedling-growing tray transplanter.展开更多
文摘Rice transplanting with a transplanter is a cost-effective process. Due to labor shortages during the peak time of rice transplanting, it is a promising technology in Bangladesh. However, the high-quality mat-type seedling is a prerequisite factor for mechanical transplanting. The experiments were conducted at three different locations (Gazipur, Tangail, and Rangpur) during the dry season (Boro)/2019-20 to determine the best seeding density for high-quality mat-type seedlings to be prepared for mechanical rice transplanters. The effects of seeding rate on seedling quality such as survival rate, seedling strength, stem thickness of newly released boro rice varieties BRRI dhan86, BRRI dhan89, and BRRI dhan92 were studied using four seeding rates (130, 140, 150, 160 g/tray). Results revealed that BRRI dhan92 showed quick seedling emergence compared to BRRI dhan89 and BRRI dhan86. Seedling mortality was found the lowest BRRI dhan92 while the highest in BRRI dhan86. 25 - 30 days old seedling was found suitable for mechanical transplanting in terms of seedling mortality. Seedling height increased with the increase in seed density. BRRI dhan92 showed the highest stem thickness followed by BRRI dhan89 and BRRI dhan86 with seed rate 150 - 160 g per tray. The suitable seeding rate (150 - 160 g/tray) for the studied varieties was found better for raising mat-type seedlings suitable for mechanical transplanting, which could coordinate the production of larger population growth and higher harvest index to achieve high grain yield.
基金the financially support from the Education Department Heilongjiang Province(No.2014TD010)project of the Heilongjiang Provincial Land Reclamation Bureau(No.HNK125B-07-17)Project of the Education Department Heilongjiang Province(No.12531450)。
文摘The plant-made seedling-growing tray cultivation technique is an effective way to improve maize yield and quality in China’s cold northern area.However,the corn seedling nursery carrier and tray cultivation technique has been proved poor in adaptability.After comparing several nursery carriers,a design for a plant-made seedling-growing tray that is suitable for maize transplantation was proposed in which rice straw was used as the primary raw material.The preparation method,processing and structural dimensions of the tray were investigated and designed,five types of plant-made seedling-growing trays with different formulations were proposed.The shear mechanical properties and the shear strength of the plant-made seedling-growing trays were tested to determine the shear force needed for cutting through trays prepared with increasing mass ratios of rice straw and the effect of the shearing rate on the shear strength.The results showed that at a shearing rate of 100 mm/min,the maximum shear force decreased gradually as the mass ratio of straw was increased and that the hardness of the tray decreased as its shear strength decreased.Under three shearing rates(100 mm/min,200 mm/min and 500 mm/min)and a blade displacement of 10 mm,the shear force was the highest at the point at which the tray was cut through;the required shear force to cut through the tray then gradually decreased.Trays with the same straw composition showed no significant influence of shearing rate on the tray’s shear strength at shearing rates of 100 mm/min,200 mm/min or 500 mm/min.This study describes a multi-tray,single-strip nursery carrier for use in plant-made seedling-growing tray cultivation and proposes a theoretical basis for the design of a rotary transplanting device,the key part of a maize plant-made seedling-growing tray transplanter.
