1、3700 英文单词，英文单词，18500 英文字符英文字符，中文中文 5900 字字 文献出处：文献出处：Karayel D. Performance of a modified precision vacuum seeder for no-till sowing of maize and soybeanJ. Soil and Tillage Research, 2009, 104(1): 121-125. Performance of a modifi ed precision vacuum seeder for no-till sowing of maize and soybean D.K
2、arayel Abstract The purpose of this research was to examine the performance of a modifi ed precision vacuum seeder for no-till sowing of maize (Zea mays L.) and soybean (Glycine max L.) following wheat (Triticum aestivum). A wavy-edged disc and side gauge wheels were fabricated and mounted to each u
3、nit of a common precision vacuum seeder (with a hoe opener on one row unit and a double disc-type opener on another row unit) and used to sow at three forward speeds (1.0, 1.5 and 2.0 m/s). Multiple index, miss index, quality of feed index and precision of the distribution of the seeds along the len
4、gth of the row, sowing depth uniformity, mean emergence time and percent emergence were determined. Sowing depth uniformity, mean emergence time and percent emergence of both maize and soybean seeds were decreased and precision of the distribution of the seeds along the length of the row was increas
5、ed as a result of increasing forward speed. The distribution of the seeds along the length of the row, sowing depth uniformity and percent emergence of the seeder equipped with the double disc-type opener was better than the seeder equipped with the hoe-type opener. The precision of the distribution
6、 of the seeds along the length of the row for forward speeds of 1.0 and 1.5 m/s experienced in this study was well below 29%, and therefore is acceptable for both maize and soybean seeds. The modifi ed precision vacuum seeder generally performed best using the double disc-type furrow opener at the forward speed of 1.0 m/s, based on the distribution of the seeds along the length of the row, sowing depth uniformity, and percent emergence. Keywords: Seeder；No-till sowing；Furrow opener；Seed place
