大田冬小麦根系吸收活力的空间分布及其变化动态的研究

Study on Space Distribution and Dynamic Changes of Root Absorption Activities of Field Winter Wheat

应用放射性同位素示踪技术研究了大田冬小麦根系吸收活力的空间分布及其变化动态,结果表明,大田冬小麦根系吸收活力的增加与降低,在水平方向上是按由近及远,垂直方向上是从上到下,在整个土体空间内是从里到外的顺序进行的,到黄熟时表现为整个根系群体全面衰亡。根系吸收活力的空间扩展与根系的形态建成范围相一致。从起身到黄熟前平均有85％的根系吸收活力分布在水平幅度0～20cm垂直深度20cm左右的土体中,它对整个大田根系吸收活力影响最大,这不仅表现在其根系吸收活力数值的高低变化上,且其分布比例在开花后也显著降低,其外围根系吸收体活力数值和分布比例的降低幅度则相对较小。

The space distribution and dynamic changes of root absorption activities were studied by using radiotracer technique of field winter wheat. The results showed that the increase and decrease of root absorption activities was from proximal to anticous parts for lateral directions, from upper layer to lower layer of soil for vertical direction, and from internal to ex ternal parts in whole soil mass. The spread range of root absorption activities was consistent with that of root system in field soil. At yellow ripe stage the root absorption activity senseced as a whole. From erecting to yellow ripe stage, about 85 percentage of root system activity distribut ed from 0 cm to 20 cm on lateral direction and about 20 cm in depth, it had an important effect on the change of whole field root absorption activities, and it was not only the change of root sys tem activity, but significantly decreased in the percentage of distribution after anthesis. And the range of decrease in the absorption activity and the proportion of distribution of peripheral roots was relatively narrow.