| 【Objective】The traditional double cropping of rice was replaced by the new planting mode of direct seeding in early season and regeneration in late season. Through the application of one-time fertilization technology for early season direct seeding rice and spraying liquid fertilizer for promoting root and tillering for ratoon rice, it is intended to solve the problems of low yield caused by less grains per panicle and small panicle shape of ratooning rice, and realize the increase of output and production benefit.【Method】Pot experiment was used to explore the effects of onetime fertilization on rice root system, yield and its components. Field experiment was used to study the effects of onetime fertilization of early season direct seeding rice and spraying root promoting and tillering promoting liquid fertilizer for ratooning rice on double cropping rice yield, ratooning rice development and overall benefit.【Result】The early tillering and the number of tillers of rice with one-time fertilization were slightly higher than those with two-time fertilization, which increased the panicle number of rice and was conducive to the cultivation of large root system of rice. The rice yield of one-time fertilization was 3.7%, 8.7% and 31.3% higher than that of the other treatments, which indicated that the onetime fertilization increased rice yield significantly. Under the condition of one-time application of 600 kg/hm2 and 750 kg/hm2 controlled release fertilizer combined with spraying of two kinds of liquid fertilizer to promote the root and tillering, the panicle number and grain number were higher than those of the control, indicating that it could promote panicle and increase the number of grains, and the effect of promoting root and tillering by fertilizer Ⅰ was better. The results showed that the annual benefit of the treatment of three fertilizer rates combined with root promoting and tillering promoting fertilizer was significantly higher than that of conventional cultivation of double cropping rice, among them, the annual benefits of 750 kg/hm2 and 900 kg/hm2 treatments combined with root promoting and tillering promoting fertilizer were increased by 6 859 yuan/hm2 and 8 291 yuan/hm2, respectively.【Conclusion】The technique of one-time fertilization has the effect of increasing rice yield. Liquid fertilizer Ⅰ for promoting root and tillering could increase tillering of rice effectively. Compared with the conventional planting, the benefit of early season direct seeding rice（double cropping rice）can be improved obviously by using one-time fertilization technology and spraying root promoting and tillering promoting fertilizer on ratooning rice. |
