Studies On The Printing-Sowing Technology Of Mechanical Transplanting Rice

The seedling nurse of the mechanical transplanting rice is the key link of the high-yield cultivation technique of the mechanical transplanting rice. The cultivation of Suitable seedlings, big and strong seedling, for mechanical transplanting is the key to mechanical transplant successfully. Low, appropriate density and well-distributed sowing were the premise of improving the quality of big, strong seedling and ensuring the quality of mechanical transplanting in field. The individual seedling indicators are optimized at the condition of low sowing quantity. However, the population indicators could not meet the requirements of machine transplanting rice. Bad-distributed sowing at the low density resulted in the high vacancy hill rate of mechanical transplanting rice. To reduce the miss-seeding in seedbed and the miss-transplanting in field, increasing the seed quantity had to be done in rice production. On the other hand, the high seed quantity would cause thin seedling and short seedling age suitable for mechanical transplanting, which reduced the rice production and effected the application of mechanical transplanting rice negatively. Aimed at some problems in the product of mechanical transplanting rice, such as high seed quantity (causing seed waste), poor seedling quality and ineffective transplant, this study explored the feasibility of the appropriate low-density sowing and uniform seeding in the link of seedling nurse combined with the seedling nurse in mechanical transplanting rice. In this study, the technique, called Printing-Sowing, was development. In the Printing-Sowing technique, rice seeds could be adhered to the sheets accurately and orderly. The sheets stuck seeds were treated by printed plastic points.The Printing-Sowing technique could achieve precise, quantitative and uniform seeding in the seedling nurse. Also, this technique could reduce the seeds quantity moderately and effectively control the miss-transplanting rate of mechanical transplanting rice, which could cultivate strong, well-distribution seedling, reduce the missed, vacancy pill rate of mechanical transplanting rice and benefit high yield for mechanical transplanting rice product. The main results of this absorption were as follows:1. The technique of Printing-Sowing could realize the precise, quantitative and uniform seeding in mechanical transplanting rice.In this study, adhered-seed sheets suitable for mechanical transplanting rice was screened and the special plastic was developed to meet the requirement of the technique of Printing-Sowing. And printing pastern planks were designed for the different sowing density, the proper pore suited with the Printing-Sowing were made sure. Through the experiment prove that Different aperture of printing pastern planks influenced the rate of seed-stick greatly. The plastic-points area on the sheets were decided by the aperture of printing pastern planks. If the plastic-points area on the sheets was too small, it was difficult to adhere seeds, which resulted in empty holes. By contrast, when the plastic-points area on the sheets was too big, each plastic-point would stick more than one seed, which could result in the uneven seeding. When the aperture of printing pastern planks was 2mm, the rate of missing seeds and the multi-seeds could meet the requirement of mechanical transplanting rice product. Analyzed the seed weight, total grain number, the rate of missing seeding and the multi-seeds, the result showed that the plastic-points printed on the sheet were clear, independent and well-distributed, which could adhere seeds according to the spacing preinstall. Furthermore, on the seeds-stick sheets, the missing seeds rate was less than 1%, double seeds rate was about 15%, and the seed distribution was even. The precision, quantitation, position seeding was realized preliminarily.2. The study on the application effect of the Printing-Sowing technique on the conventional japonica rice productionThe results showed that, based on ensuring the basic planting density in field, low seeding rate and even seeding would benefit for the seedling nurse of the conventional japonica rice production using the Printing-Sowing technique. The seed amount per tray (28cm×58cm) using the Printing-Sowing technique was controlled about 100g, and the recommended specifications of stick-seeds sheet was 0.7cm×0.7cm. For the nursed seedlings using the Printing-Sowing technique, the age of seedling suitable for mechanical transplanting was 18d - 25d, the height of seedling was less than 20cm, and the age of leaves was 4.0-4.5. Also, using the Printing-Sowing technique, the nursed seedlings were strong, having stout stalk, well growing and could meet the requirement of mechanical transplanting rice. Infield, the seedling density was moderate, the seedling grew uniformly. The transplanted seedlings in field were well distributed. And the vacancy hill rate was low, about 2.5%, reducing the workload of complement seedling.3. The study on the application effect of the Printing-Sowing technique on the hybrid rice productionThe results showed that, the recommended specifications of stick-seeds sheet was 1.0cm×1.1cm, and the weight of seeds per tray was only 40g. The amount of nursed seedling per mu (666 m2) was 23 trays, saving seeds quantity about 0.5 kg per mu. Using the Printing-Sowing technique for the mechanical transplanting hybrid rice, the vacancy hill rate was only 4%, the rate of 2-3 seedlings per hill was above 65%, and the seedlings were strong and well distributed. In field, the increasing yield of the mechanical transplanting using the Printing-Sowing technique, compared with the manual sowing, was more than 15%.In this study, the printing technology was used in agricultural seeding at the first time, which realizing the ultra-low seeding rate and uniformity seeding for the rice production, especially applied on the mechanical transplanting hybrid rice and having more broad application prospects.