Integrated root system age in relation to plant nutrient uptake activity
Integrated root system age in relation to plant nutrient uptake activity
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DOI：
10.2134/agronj1998.00021962009000040011x
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发表时间：
1998-07-01
期刊：
影响因子：
2.1
通讯作者：
Koenig, RT
中科院分区：
文献类型：
--
作者：
Gao, SY;Pan, WL;Koenig, RT
根段的年龄与其养分吸收活性（单位根长吸收速率）成反比。由于我们无法描述整个根系的年龄，因此不确定如何将这些信息纳入营养吸收模型。定义了综合根系年龄（IRSA）的计算方法，并进行了两个溶液试验，研究了春小麦（Triticum aestivum L.）氮素吸收活性与根系年龄的关系。综合根系年龄定义为各生育期产生的根段平均年龄与各生育期产生的根长与总根长之比加权后的总和。随着IRSA的增加，春小麦对NH4和NO3的吸收活性随植株年龄的增加而降低，而IRSA相同的植株在14和21 d的氮素吸收活性相似。IRSA与玉米（Zea mays L,）对N、P、K、Ca和Mg的吸收活性之间的关系也通过对已发表数据的分析得到了揭示。在幼嫩根系中，养分吸收活性随着IRSA的增加而迅速下降，而较老根系（IRSA bbb10 ~ 15 d）的养分吸收活性随着IRSA的增加而保持相对较低且逐渐下降。IRSA是表征整个根系养分吸收活性的有用参数，为养分吸收建模提供了潜在的工具。
The age of a root segment is inversely related to its nutrient uptake activity (uptake rate per unit root length). It is uncertain how this information should be incorporated into nutrient uptake models, due to our inability to characterize the age of a whole root system. A method of calculating an integrated root system age (IRSA) was defined, and two solution experiments were conducted to relate the N uptake activity of spring wheat (Triticum aestivum L.) to root age. Literature data also were analyzed to characterize the relationship between IRSA and nutrient uptake activity of whole plant root systems, Integrated root system age was defined as the summation of the mean ages of root segments produced during each growth period weighted by the ratio of the root length generated during each growth period to total root length. The NH4 and NO3 uptake activity of spring wheat decreased with plant age as IRSA increased, while plants with similar IRSA at 14 and 21 d had similar N uptake activity. These relationships between IRSA and the uptake activity of N, P, K, Ca, and Mg of corn (Zea mays L,) were also revealed from an analysis of published data. In young root systems, nutrient uptake activity declined rapidly as IRSA increased, while older root systems (IRSA >10 to 15 d) maintained a relatively low and gradually declining nutrient uptake activity with increasing IRSA, The IRSA is a useful parameter for characterizing nutrient uptake activity of an entire root system, providing a potential tool for modeling nutrient uptake.