Effect of root depth penetration on soil nitrogen competitive interactions and dry matter production in pea-barley intercrops given different soil nitrogen supplies
Effect of root depth penetration on soil nitrogen competitive interactions and dry matter production in pea-barley intercrops given different soil nitrogen supplies
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DOI：
10.1016/j.fcr.2007.04.008
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发表时间：
2007-07-25
影响因子：
5.8
通讯作者：
Crozat, Yves
中科院分区：
文献类型：
--
作者：
Corre-Hellou, Guenaelle;Brisson, Nadine;Crozat, Yves
对土壤资源的竞争对间作系统的结果起着关键作用。在粮豆间作中，营养生长阶段对土壤氮素的竞争极大地影响了间作物种的最终表现。然而，有一个缺乏知识的主要因素参与种间土壤氮竞争的相互作用。谷类作物之所以比豆类作物占优势，往往是因为它们的根系生长更快。然而，由于过程与环境之间的强烈相互作用，仅使用现场实验方法很难隔离一个因素的影响。考虑到间作系统的复杂性，动态模拟模型可以特别有助于检验有关驱动物种之间竞争的关键因素的假设。本工作的目的是调查，在非限制性的水分条件下，通过实验和建模的方法，无论是在根深渗透豌豆和大麦一起生长的差异确定竞争土壤氮和干物质积累（DM）的每个物种在营养生长阶段。通过使用STICS作物模型生成的几种模拟情景对这一假设进行了检验。该模型首先被用来比较竞争土壤氮根据不同物种之间的根深渗透率。这种生根深度渗透效应，然后研究在三个水平的土壤氮供应导致不同程度的N需求和N应力。2003年进行的一项田间试验包括种植130 kg N ha（-1）或不施肥的豌豆-大麦间作，用于测试模型。在作物生长周期中定期监测地上生物量、氮素积累量、固氮量和生根深度，并与模拟结果进行比较。模拟结果与实验数据吻合较好。使用该模型，很明显，在营养生长阶段，大麦根系生长更快，使其获得比豌豆更多的土壤氮。然而，这种优势，这是有限的营养阶段，只影响结果的间作时，土壤氮供应低。随着土壤氮供应量的增加，土壤氮分配不受物种间生根深度差异的影响。看来，较高的氮供应，物种之间的氮需求的差异有更大的影响，物种优势比生根深度的差异。(c)2007 Elsevier B. V.保留所有权利。
Competition for soil resources plays a key role in the outcome of intercropping systems. In cereal-legume intercrops, competition for soil nitrogen during the vegetative phase greatly influences the final performance of the intercropped species. However, there is a lack of knowledge on the main factors involved in interspecific soil N competitive interactions between species. The dominance of cereals over legumes is often attributed to their faster growing rooting system. Nevertheless, using only field experimental approaches makes it difficult to isolate the effect of one factor because of the strong interactions between processes and the environment. Given the complexity of intercropping systems, dynamic simulation models can be especially helpful for testing hypotheses about the key factors driving competition between species. The present work was designed to investigate, under non-limiting water conditions, through an experimental and modelling approach, whether differences in root depth penetration among pea and barley grown together determined competition for soil N and dry matter accumulation (DM) by each species during the vegetative phase. This hypothesis was tested through several simulated scenarios generated using the STICS crop model. The model was first used to compare competition for soil N according to differences in root depth penetration rates between species. This rooting depth penetration effect was then studied at three levels of soil N supply leading to different degrees of N demand and N stress. A field experiment carried out in 2003 including pea-barley intercrops grown either with 130 kg N ha(-1) or without any fertilizer was used to test the model. Experimental results of aboveground biomass, nitrogen accumulation, N-2 fixation and rooting depth monitored regularly during the crop cycle were compared to simulated results. The simulated responses of the intercrops were in agreement with the observations from the experimental dataset. Using the model, it is clear that faster root growth in barley gives it access to more soil nitrogen than pea during the vegetative phase. However, this advantage, which is limited to the vegetative phase, only affects the outcome of the intercrop when soil N supply is low. With higher soil N supplies, soil N sharing is not affected by the differences in rooting depth penetration between species. It appears that with higher N supplies, the differences in N demand between species have more influence on species dominance than differences in rooting depth. (c) 2007 Elsevier B.V. All rights reserved.