Design and experiment of precision rice hill-drop drilling machine for dry land with synchronous fertilizing

According to the agronomic requirements of rice direct seeding technique with synchronous fertilizing, a precision rice hill-drop drilling machine for dry land with opening furrows, forming ridges, applying fertilizer, covering and seeding synchronously was developed. A fertilizing device was added to the 2BDH-8 type rice hill-drop drilling machine developed in South China Agricultural University. The power transmission system, fertilizing system and furrow opener were designed. The seeding and fertilizing system was both powered by the tractor engine to ensure the synchronization of seeding and fertilizing. An acute angle furrow opener was designed to open furrows with 50 mm wide, 50-70 mm deep and 100-120 mm away from seeding furrows. Fertilizers were applied into the bottom of the furrows through an external slot wheeled feeder and then covered with soil. Experimental results showed that the synchronous deep fertilizing could increase the production efficiency significantly than the manual fertilizing. With the same fertilizing level, compared with artificial fertilization seeding, synchronous fertilizing improved the rice tillering by an average of 6.9 spikes per individual plant with an increase of 25.2%, increased the average SPAD value by 8.9 with 29.8%, improved nitrogen use efficiency by 13.78% with 22.3%, improved partial productivity of nitrogen by 20.54 kg/kg·N with an increase of 46.3%, and increased rice yield by 1411.5 kg/hm2 with an improvement of 29.5%.The results showed that this machine can complete opening furrows, forming ridges, applying fertilizer, covering and seeding synchronously, and the yield increased significantly than the manual fertilizing. The experimental results can provide a theoretical basis of nitrogen saving cultivation for guiding the rice hill-drop drilling machine in dry land with deep fertilization.