小麦蚕豆间作施氮对小麦氮素吸收、累积的影响

Effect of N supply and wheat/faba bean intercropping on N uptake and accumulation of wheat

田间试验研究了小麦蚕豆间作及4种施氮水平(0、90kg·hm-2、180kg·hm-2和270kg·hm-2)对小麦植株体内氮含量、小麦地上部氮素累积及氮素养分吸收速率的影响。结果表明:间作显著增加了小麦地上部植株的氮含量,与单作相比,分蘖期、拔节期、抽穗期和成熟期不同施氮处理间作小麦植株的氮含量平均比单作提高20.0%、21.9%、21.4%和17.1%;抽穗期和成熟期间作小麦叶、茎和穗中的氮含量均高于单作;间作显著提高了小麦植株的氮素累积量和氮素吸收速率,与单作相比整个生育期间作小麦氮素累积量增幅为15.5%～30.4%。无论单作还是间作,小麦植株氮含量和氮素累积量随氮肥用量的增加而增加,施氮对单作小麦植株氮含量、氮素累积量和氮素吸收速率的影响大于间作,随着氮肥用量的增加,间作优势逐渐减弱;单作小麦植株的氮素吸收速率随氮肥用量的增加而增加,间作小麦植株的氮素吸收速率随氮肥用量的增加呈先增后降的趋势。本研究表明,间作和施氮促进了小麦对氮素的吸收利用,间作优势与施氮水平密切相关,间作体系中氮素养分的合理投入是发挥间作优势的关键。

Field experiment was conducted to investigate the effects of 4 nitrogen application rates （0, 90 kg·hm^-2, 180 kg·hm^-2 and 270 kg·hm^-2） and intercropping on N content, N accumulation and N uptake rate of wheat plant in wheat/faba bean intercropping system. The results show that intercropping can significantly increase the contents of N in wheat plants during growth stages. In comparison with monocropping, N contents of wheat plant in intercropping are increased by 20.0%, 21.9%, 21.4% and 17.1% in tillering, elongating, heading and maturing stages, respectively. The contents of N in leaves, stems, and panicles of wheat in intercropping are significantly higher than those of monocropping in heading and maturing stages. Intercropping can significantly increase N accumulation and N uptake rate of wheat plant compared with monocropping. N accumulation in plants of wheat increases by 15.5%～30.4% in intercropping during growth stages. N accumulation and N content of wheat plant are increased with increasing of nitrogen supply in both monocropping and intercropping, but impacts of N supply on N content, N accumulation and N uptake rate of wheat plant are stronger in monocropping comparison with intercropping. Intercropping advantages reduce with increasing of N application rate. N uptake rate of monocropped wheat plant increases, and that of intercropped wheat plant increases and then decreases with increasing of nitrogen application rates. The findings indicate that both N supply and intercropping can promote N uptake and accumulation of wheat. N supply influences intercropping advantages in wheat/faba bean intercropping, and a rational N supply is important for crop intercropping.