Abstract: In order to clarify the water management mode of substitute soil cultivation strong seedling of mechanically transplanted rice, the effects of three kinds of water management （per 1 d, 3 d, 5 d irrigation to the saturated state matrix）on the growth of rice seedlings were discussed in this study, using Zhongjiazao 17 as material. The results showed that different water managements have obvious effects on the quality of rice seedling. The appropriate water deficit would inhibit the height of seedling, promote the growth of root, improve the activity of root and the seedling rate. The seedlings during the 2~3 leaf stage were sensitive to water deficit. Water deficit made seedlings leaf emergence slow, leaf length and leaf sheath length shorten, light leaf color lighten, exert an inhibitory effect on seedlings growth. However, suitable water deficit would enhance the carbon and nitrogen metabolism, increase the dry weight of seedlings, and improve the strong seedlings index of rice. It was the best for straw substrates cultivation rice seedling in 3 days （W2） irrigation, which was beneficial to improve the comprehensive quality of seedling, and was suitable water management mode for mechanical transplanted rice seedling.

Key words: straw substrates, water management, early rice, seedling quality

摘要： 为了明确代土基质培育水稻机插壮秧的水分管理模式，以中嘉早17为试验材料，采取早稻稻草基质育秧，探讨3种水分管理方式（每隔1 d、3 d、5 d灌水1次致基质呈饱和状态）对水稻秧苗生长的影响。结果表明，不同水分管理方式对秧苗素质有明显的影响。适宜的水分亏缺能抑制苗高，促进秧苗根系生长及提高根系的活力，提高成秧率。秧苗2~3叶期对水分亏缺敏感；水分亏缺使秧苗出叶缓慢，叶片长度及鞘长度变短，叶色变淡，对秧苗生长有抑制作用。适宜的水分增强C、N代谢，增加秧苗的干物质量，提高壮苗指数。稻草基质育秧以3 d（W2处理）左右灌水1次的处理有利提高秧苗综合素质，是适于培育水稻机插壮秧的水分管理方式。

关键词: 稻草基质, 水分管理, 早稻, 秧苗素质