Aims The effect of cropping regime on nitrogen (N) uptake in two coexisting plant grass species ( Avena sativa and Agropyron cristatum ) was investigated. Methods The two grass species were cultivated by monocropping or intercropping. 15 N-labeling was used to examine N uptake of NH 4 + versus NO 3 − at 0–5 cm and 5–15 cm soil depths. Results The aboveground and total biomass of intercropped A. sativa was 1.3 times greater than monocropped A. sativa . The biomass of A. cristatum did not change between cropping systems. In the 0–5 cm soil layer, uptake of NO 3 − by A. sativa was 0.5 times less in the intercropped system than in the monocropped system, whereas uptake of NO 3 − by A. cristatum was 2.0 times more in the intercropped system. In the 5–15 cm depth, intercropping did not change N uptake by A. sativa but decreased NO 3 − uptake to 0.6 times by A. cristatum . Conclusions Complementarity in N uptake between A. sativa and A. cristatum in the upper 0–5 cm soil layer is conducive to biomass accumulation. Intercropped A. sativa and A. cristatum does not compete strongly for soil resources and can alter their N uptake patterns to optimize biomass production.

中文翻译：

---

间作Avena sativa和Agropyron cristatum之间对氮吸收的相互作用

目的 研究了种植方式对两种共存植物禾本科植物（Avena sativa 和 Agropyron cristatum）中氮 (N) 吸收的影响。方法 两种草种采用单作或间作栽培。15 N 标记用于检查 NH 4 + 与 NO 3 - 在 0–5 cm 和 5–15 cm 土壤深度处的 N 吸收。结果间作水稻的地上生物量和总生物量是单作水稻的1.3倍。A. cristatum 的生物量在种植系统之间没有变化。在0-5 cm土层，间作系统中苜蓿吸收NO 3 - 比单作系统少0.5倍，而间作系统中A. cristatum吸收NO 3 - 多2.0倍. 在 5-15 cm 深度，间作没有改变 A. sativa 对 N 的吸收，但将 NO 3 - 吸收降低到 0。A. cristatum 6 次。结论 A. sativa 和 A. cristatum 在上部 0-5 cm 土层中氮吸收的互补有利于生物量的积累。间作 A. sativa 和 A. cristatum 对土壤资源的竞争不激烈，可以改变它们的 N 吸收模式以优化生物量生产。