施氮对胡麻/大豆间作体系作物间作优势及种间关系的影响

Effect of nitrogen application on intercropping advantages and crop interactions under an oil flax and soybean intercrop system

农业生产中氮是最大的土壤养分资源,影响间作体系的生产力优势,然而,氮对作为北方旱作农业的新型间作模式的胡麻/大豆间作体系的影响机理并不清楚。本研究通过田间试验,探讨了不同施氮水平(0,75,150kg/hm2)对胡麻/大豆间作体系的间作优势特征、种间关系和间作产量的影响。结果表明,胡麻/大豆间作体系表现出明显的种间优势,胡麻/大豆间作的生物量和产量的土地当量比(LER)值均大于1,且随施氮量的增加呈先增大后减小的趋势,在N1(75kg/hm2)下均达到最大,分别为1.25和1.30。胡麻的种间竞争能力在N0(0kg/hm2)和N1(75kg/hm2)下强于大豆(Ao>0,CRo>1),在N2(150kg/hm2)下弱于大豆(Ao<0,CRo<1)。胡麻/大豆间作体系的籽粒产量和生物学产量在N1下均达到最大,分别为2440.5kg/hm2和7594.3kg/hm2。说明胡麻/大豆间作体系在N1(75kg/hm2)下最利于胡麻大豆协调增产。

Nitrogen is one of the greatest nutritional resources in agriculture,affecting the yield advantage of many intercrop systems.However,it is unclear how nitrogen application affects oil flax and soybean intercrop systems in northern dry farming land.A field experiment was conducted to explore productivity,interaction and yield under intercropping supplemented with different nitrogen rates (0,75 and 150 kg N/ha).Oil flax/soybean intercropping systems exhibited interspecific advantages.The land equivalent ratio (LER)based on bi-omass and yield were greater than 1.With increased nitrogen application,the LER initially increased before peaking at 75 kg N/ha,1.25 and 1.30 respectively for biomass and yield,and subsequently declining.The in-terspecific competition ability of oil flax was better than soybean under 0 and 75 kg N/ha,and weaker under 150 kg N/ha.The yield and biomass of oil flax/soybean intercrop systems were maximized at 75 kg N/ha,a-chieving 2440.5 and 7594.3 kg/ha respectively.