中文摘要：

通过盆栽试验研究了施氮水平对大麦间作豌豆种间竞争优势的影响，并对间作作物竞争力与产量问的关系进行了量化分析，以期为禾豆间作高效施氮技术提供理论依据。结果表明，大麦分蘖期和灌浆期，土地当量比（LER）均大于1，表现间作优势，但大麦拔节期和抽穗期LER小于1表现间作劣势；高氮素水平（N2）在大麦分蘖期、拔节期和灌浆期的LER分别为1．17、1．03和1．34，均大于低、中氮素水平，表明高氮素水平更利于形成间作优势。共生期内，大麦分蘖期不施氮、中施氮和高施氮处理大麦的相对竞争力（AbD）分别是-0．1066、-0．2133和-0．1407，收获期分别为0．0664、-0．0144和0．0276，全生育期平均竞争力分别为0．1328、0．0425和0．0187，说明施氮水平可调节大麦的相对竞争力。间作系统总产量与大麦灌浆期的相对竞争力呈极显著性正相关关系，与大麦相对于豌豆的平均竞争力呈二次曲线关系。大麦平均相对竞争力在不施氮时比高施氮高7．6％，中施氮时则小于零。因此，适当提高大麦灌浆期的竞争优势有利于提高复合群体的产量，施氮水平强烈影响大麦一豌豆种间的竞争关系和综合生产力。

英文摘要：

A pot experiment was carried out to investigate the effects of nitrogen fertilization rates on the inter-competitiveness of a barley-pea intercropping system, and to quantify the relationship between the relative competitiveness and the production of crops for optimizing management of pastoral legume intercropping techniques in terms of nitrogen fertilization. Our results showed that the land equivalent ratio （LER） of barley was greater than one during crop tillering and grain-filling stages, indicating the intercropping advantage; whereas it was less than one during crop jointing and heading stages, indicating the inferior performance. With high levels of nitrogen （N2）, the LER of barley during the tillering, jointing and grain-filling stages were 1.17, 1.03 and 1.34, respectively and were significantly higher than those with low levels of nitrogen（N1）, indicating that a high nitrogen level may result in the certain intercropping advantage of barley. During the symbiotic period, the relative competitiveness（Abp） of barley under no nitrogen（N0）, N1 and N2 were -0.1066, -0.2133, and - 0.1407 during the tillering stage, 0.0664, -0.0144 and 0.0276 at harvest, and 0.1328, 0.0425 and 0.0187 during the whole growing period, respectively, suggesting that nitrogen fertilization may adjust the Abp in the barley-pea intercropping system. Production of intercropping system was positively correlated with the Abp during the grain-filling stage, and correlated with the mean relative competitiveness in a form of quadratic curve. The average relative competitiveness of barley was 7.6% higher in No than that in N2, while it was less than zero in the N1 treatment. These results might suggest that an appropriate increase of the competitiveness advantage of barley during the grain-filling stage is helpful to improve the total production of a intercropping system. Therefore, nitrogen fertilization played an important role in impacting the relative competitiveness and the production of the barley-pea intercropping