中文摘要：

为实现杂交水稻（3～4）粒/穴精量直播要求，设计了一种用于水稻气力式精量穴播排种器的具有群布吸孔的吸种盘。以培杂泰丰种子为对象，采用4×24正交试验设计的方法，对吸室真空度、吸孔直径与清种对吸种盘吸附精度的影响进行了试验研究。结果表明，真空度、孔径、清种对吸种精度有影响。3因素对平均穴播种量的影响顺序为孔径＞清种＞真空度；对≤2粒/穴率的影响顺序为真空度＞孔径＞清种；对（3～4）粒/穴率的影响顺序为孔径＞清种＞真空度，对≥5粒/穴率的影响顺序为孔径＞清种＞真空度。在真空度3.2kPa、孔径1.5mm和采用清种装置的最佳参数条件下，≤2粒/穴率为8.27%，（3～4）粒/穴率为81.87%，≥5粒/穴率为9.86%。试验结果显示群布吸孔吸种盘吸附精确性较高，可应用于水稻精量穴播。

英文摘要：

Rice is the most important grain crop in China with a growing plant area year after year in recent decades. Direct seeding and transplant are the two main plant modes. Direct seeding by planter is getting popular in China, India, and other countries, with high efficacy and economy, as well as easy operation. Due to high capacity of tilling, generally three to four seeds are required for each hole in order to avoid a planter-like high empty hole rate. Meanwhile, the different variety and irregular shape of the seeds results in either excessive seeds in each hole, or empty holes when planters plant hybrid rice seeds that makes it quite difficult to meet requirements for current needs in the field. In order to realize precise farming, a unique precise pneumatic metering device was designed with a group sucking plate in seed metering device, by which three to four seeds can be sucked and dropped at the same time. The plate was divided into five parts, a seed sucking place, seed clearing place, seed carrying place, seed dropping place, and a blank place. The seeds were sucked by the vacuum and rotated to the dropping place by the plate. Different influences from the diameter of the hole, vacuum degree, and clear-up equipment on precision of metering devices have been discussed. In the experiment, the sucking plate rotating speed was 8 rpm and its diameter was 165mm. Rice varieties were Indic hybrid Peizataifeng whose moisture content （wet basis） was 11.6%~11.9%, and its 1000-grain was 22 g. Its overall dimension （length×width×thickness） was 8.94mm×2.30mm×1.94mm,and the 4×24 orthogonal experiments were conducted to investigate the suck characteristic of the group holes on the sucking plate under vacuum, diameter of the holes, and the seed-clearing device. The experimental equipment consisted of a pneumatic metering device with group holes, a U-shaped manometer, a positive and negative pressure air pipeline, a cut-off valve, and a vortex pump. The sucking probability of the group holes was the conditional p