三熟制模式下冬季作物对早稻返青缓苗期植株生长的抑制作用

Inhibitory Effect of Winter Crops on Growth of Early Rice at Returning Green Stage and Slow Seedling Stage under Triple Cropping System

设置3种稻田三熟制模式与“冬闲+早稻+晚稻”模式对比,研究了冬季作物对早稻返青缓苗期植株生长的影响。结果表明:三熟制模式下水稻返青期推迟2~3 d、缓苗期推迟1~3 d,期间水稻株高、叶龄、叶绿素含量(SPAD)、根茎叶干物质下降;在移栽至缓苗期内,三熟制模式下水稻植株根冠比比对照的小;移栽至返青期,三熟制模式下水稻生长速率均比对照处理低,在返青至缓苗期表现则相反。本研究结果表明,三熟制模式下冬季作物明显抑制了早稻返青缓苗期植株生长,其抑制作用在水稻返青后变小。

A field experiment was conducted to study the effects of winter crops on the growth of early rice at returning green stage and slow seedling stage by comparing three-cropping systems in rice field with the “winter fallow+Early rice+Late rice” system control. The returning green period and slow seedling stage of rice were prolonged about two to three days and one to three days, respectively. And the plant height, leaf age, chlorophyll content and dry matter of rhizome and leaves decreased during the two periods under the triple cropping system. The root-shoot ratio of rice under the triple cropping system was smaller than that of the control during the period from transplanting to slow seedling stage. The growth rate of rice under the triple cropping system was lower than that of the control during transplanting to returning green stage, while it was opposite during returning green stage to slow seedling stage. The conclusion is that winter crops significantly inhibits the plant growth of early rice under the triple cropping system at returning green stage and slow seedling stage, and the inhibiting effect becomes smaller after rice plants return to green.