Abstract:

The evolution and modification of 60 years’ double cropping rice (DCR) production along the Changjiang River valley were studied in order to provide references to developing DCR production. According to the rice production achievements of four stages of cultivar modifications from single season rice to DCR, from tall rice to dwarf rice, from inbred rice to hybrid rice and from common rice to super rice, the development of cultivation technology for DCR is summarized. With the cultivar improvement, DCR cultivation has undergone three stages of cultivation technique development: panicle number model, panicle number and size model and panicle weight model. The principle, key technology and adaptation regions of some representative techniques for DCR cultivation is introduced in brief, of which the techniques are: the seed broadcasting and reduced tillage in early season,; the “Shuang-Liang-Da” (two times of raising nursery) cultivation in late season; the ridging-bed cultivation in double seasons; the no-irrigation nursery and thinner planting in early season; the “Vigor roots-Sturdy stems-Weighty panicles” cultivation in double seasons; the seedling broadcasting in double seasons; and the “San-Ding” (to determine target yield, seedlings number and nitrogen rate) cultivation in double seasons. The development tendency of DCR production will be appearred as the chemical fertilizer characteristics, the simplifying and labor saving and mechanization. The suggestion to develop DCR production is also proposed.

Key words: double cropping rice, cultivation technology, yield, Changjiang River Valley