交替灌溉下作物水分运移过程的稳定氢同位素示踪研究

Stable Hydrogen Isotope Tracing of Crop Water Transport under Alternate Partial Root-zone Irrigation

利用稳定氢同位素示踪,研究了交替灌溉下水在番茄植株体内的运移过程。结果表明,质量分数为1‰与2‰的氘水灌溉后,水分在植株体内的运移过程相似,氢同位素比率(δD)随氘水质量分数倍增,灌水侧根系、木质部茎、叶片的δD分别在灌水后2、5、8h达到峰值,非灌水侧根系的δD在8h内仅为灌水侧根系的5.2%,灌水后12h才有微弱增加。交替灌溉下作物水分以纵向运移为主,横向运输的主要动力是渗透势作用下的组织液再分配。

In order to further clarify the water-saving mechanism of alternate partial root-zone irrigation （APRI）, stable hydrogen isotope was used to trace the water transport process in plant after irrigation. The results showed that under APRI with 1‰ and 2‰ concentration deuterium water, water transport processes within the plant were similar, and the hydrogen isotope ratio values （δD） multiplied with deute- rium water concentration; the 3D of the irrigation root, xylem stem and leaf reached the peak values within 2 h, 5 h, 8 h respectively after irrigation, and 3D of non-irrigation root was only 5.2% of the peak value of the irrigation root within 8 h, maintaining in a lower value and having a weak increase for 12 h. Under APRI, mostly there was a vertical transport process of the crop water, and the main driving force of the hori- zontal transport was the reallocation of the inter-organizational water under osmotic potential.