不同施氮水平及根系分隔方式对间作小麦蚕豆氮吸收的影响

Effects of Nitrogen Levels and Root Barriers on Nitrogen Absorption of Intercropping Triticum aestivum and Vicia faba

通过盆栽试验设置了3种根系分隔方式(无分隔、尼龙分隔、塑料分隔)和3个氮(N/2、N、3N/2)水平,分析了间作小麦蚕豆的干物质量、氮素累积吸收量和养分竞争比率,研究不同种植模式及不同施氮水平对小麦蚕豆氮素营养累积吸收特征和养分竞争规律的影响。结果表明:不同氮水平和根系分隔方式改变了间作小麦和蚕豆的干物质量,小麦拔节期,低氮、常规施氮和高氮水平下,尼龙分隔方式下小麦干物质累积量分别高于不分隔和塑料分隔60.8%、61.46%,71.19%、73.42%,63.02%、61.54%。低氮水平下,无分隔方式蚕豆干物质平均累积量分别低于尼龙和塑料分隔15.46%和20.68%;推荐施氮水平下,抽穗期和成熟期,尼龙分隔蚕豆干物质累积分别低于无分隔和塑料分隔24.53%、23.11%和26.66%、26.96%;高氮条件下,3种根系分隔方式间差异不明显。不同氮水平和根系分隔方式也改变了间作小麦和蚕豆的氮素累积吸收量。其中低氮条件下,无分隔小麦氮素累积吸收量明显高于尼龙和塑料分隔,随施氮量增加,这种优势逐渐不明显;低氮和高氮条件下,3种根系分隔(PB、MB、NB)蚕豆氮素累积吸收量差异不显著,推荐施氮条件下,塑料分隔方式下蚕豆氮素吸收量急剧增加,尤其籽粒膨大期,与尼龙分隔和不分隔相比分别增加29.03%、26.48%。低氮和常规施氮条件下,拔节期、孕穗期和灌浆期,尼龙和无分隔体系小麦相对于塑料分隔体系养分竞争比率(NCRcs)高于蚕豆。

Pot trials of Triticum aestivum and Vicia faba intercrop with 3 root barriers （no barrier, mesh barri- er, polythene barrier） and 3 nitrogen levels （N/2, N, 3N/2） were carried out in the greenhouse. Dry matter and the nitrogen absorption and nutrient competition ratio （NCRcs） were analyzed to study the effects of different plant-ing patterns and nitrogen application levels on nitrogen nutrition accumulation and nutrient competition in Triticum aestivum and Viciafaba. The results showed that different nitrogen levels and root barrier altered dry matter of Tritic- um aestivum and Vicia faba, the mesh barrier increased dry matter than no barrier and polythene barrier 60. 8%, 61.46% ; 71.19%, 73.42% ; 63.02%, 61.54% under deficiency, adequate and high nitrogen level （N/2, N, 3N/2） at wheat jointing stage. Under deficiency nitrogen level, dry matter of no barrier Vicia faba decreased by 15.46% and 20.68% than that of mesh and polythene barrier. Under recommended nitrogen application rate, dry matter of mesh barrier decreased by 24. 53%, 23.11% and 26.66%, 26.96% than that no barrier and polythene barrier at heading stage and maturity stage of Vicia faba. However, there were no significantly differences among all 3 root barriers under high nitrogen level. Different nitrogen levels and root barriers also altered nitrogen absorption of Triticum aestivum and Vicia faba. Under deficiency nitrogen condition, the nitrogen absorption of no barrier wheat were significantly higher than those of mesh and polythene barrier, but this advantage was not obvious with the in- creasing of nitrogen application rate. Under the conditions of deficiency and high nitrogen, there were not signifi- cantly differences of Vicia faba in the nitrogen absorption among 3 root systems （PB, MB, NB）, however, under the recommendation of nitrogen application, nitrogen absorption of polythene barrier Vicia faba increased sharply, especially in the grain expansion stage, which increased by 29.03% and 26. 48% respectively compared with the no barrier and mesh barrier. Under deficiency and adequate nitrogen application rates, the nutrient competition ratio （NCRcs） of wheat was dominant relative to Viciafaba between mesh barrier and polythene barrier system and be- tween no barrier and polythene barrier system at jointing, booting and filling stages of Triticum aestivum.