根系分隔方式对燕麦/豌豆间作产量及氮素固定和积累的影响

Effects of root separation on yield, nitrogen fixation and accumulation in oat/pea intercropping

摘要:

【目的】 了解分析燕麦和豌豆间作系统中地下部互作对产量、氮素积累与固定的影响。【方法】 设燕麦单作、豌豆单作、燕麦豌豆间作不隔根、尼龙网隔根和塑料膜隔根共5个处理，探究了间作系统的产量及构成，分析了各器官氮素积累以及氮素固定、结瘤固氮特性对根系分隔的响应。【结果】 燕麦/豌豆间作不隔根和尼龙网隔根处理的土地当量比分别为1.16和1.08，产量较单作分别提高了 16. 93%和9.05%；塑料膜隔根处理的土地当量比为0.94，不具产量优势。根系互作促进了燕麦株高及穗部的生长发育，降低了豌豆单株荚数和单株粒重。在燕麦灌浆期，不隔根的燕麦叶片和根部氮含量显著高于其他处理（P＜0.05）；尼龙网隔根的豌豆豆荚和叶片氮含量最高，而塑料膜隔根处理的根部氮含量较单作、不隔根和尼龙网隔根分别高21.54%、22.08%和120.51%；尼龙网隔根的根瘤数、根瘤重及固氮酶活性较塑料膜隔根分别提高了84.62%、66.67%和81.16%，较单作分别提高了54.84%、 11. 11%和122.22%。在燕麦成熟期，不隔根的燕麦穗部、茎秆、叶片和根系的氮含量较塑料膜隔根处理分别高16.99%、68.01%、3.47%和14.18%；尼龙网隔根处理的豌豆豆荚、茎秆和根部以及不隔根处理的叶片氮含量最高；根瘤数及重量在各处理间由大到小依次为：根系不分隔＞尼龙网隔根＞单作 ＞塑料膜隔根，而固氮酶活性的大小顺序正好相反。【结论】 燕麦和豌豆间作的产量优势主要来自于地下部贡献。不隔根时间作产量最高，尼龙网隔根时的豌豆在结荚期能够固定更多的氮素，增加自身器官及燕麦对氮的吸收和积累。燕麦旺盛的氮需求通过根系互作刺激并增加了豌豆对氮素的固定，地下部根系互作是燕麦/豌豆间作增产的主要原因。

Abstract:

【Objective】 In order to analyze the effects of subsoil interaction on yield，nitrogen fixation and distri bution in oat and pea intercropping system.【Method】 five treatments were set up：oat single cropping，pea single crop ping，oat and pea intercropping without root separation，nylon net root separation and plastic film root separation，and the yield and composition of the intercropping system were investigated. The responses of nitrogen accumulation，ni trogen fixation，nodulation and nitrogen fixation to root separation were analyzed.【Result】 The results showed that the soil equivalent ratio of oat/pea intercropping without root separation and nylon net separation were 1. 16 and 1. 08，and the yield was increased by 16. 93% and 9. 05% compared with single cropping. The soil equivalent ratio of plastic film root separation treatment was 0. 94，which did not have yield advantage. Root interaction promoted the plant height and ear growth of oat，and decreased pod number per plant and grain weight per plant of pea. At the fill ing stage，the nitrogen content in the leaves and roots of oat without separate roots was significantly higher than that of other treatments （P＜0. 05）；The nitrogen content of pea pods and leaves with nylon mesh was the highest，while the nitrogen content of the root treated with plastic membrane was 21. 54%，22. 08% and 120. 51% higher than that of the single cropping，non-isolating and nylon mesh，respectively. The number of nodules，the weight of nodules and the activity of nitrogen-fixing enzyme in nylon mesh were increased by 84. 62%，66. 67% and 81. 16%，respec tively，compared with plastic membrane，and 54. 84%，11. 11% and 122. 22% compared with monoculture. In the mature stage of oat，the nitrogen content of panicle，stem，leaf and root of oat without root separation was 16. 99%， 68. 01%，3. 47% and 14.18% higher than that of plastic film separation，respectively. The nitrogen content of pea pod，stem and root treated with nylon mesh and leaf treated without root separation were the highest. The number and weight of root nodules in descending order were： root system was not separated ＞ nylon mesh partition root ＞ single production ＞ the plastic membrane separated the roots，and the order of nitrogenase activity was reversed. 【Conclusion】 It can be seen that the yield advantage of oat and pea intercropping is mainly due to underground contri bution. The highest yield was obtained when no root time was separated. The pea with nylon mesh could fix more ni trogen at pod stage and increase the nitrogen absorption and accumulation of its own organs and oat. The high nitro gen demand of oat was stimulated by root interaction and increased nitrogen fixation in peas. Root interaction in under ground part was the main reason for the yield increase of oat/pea intercropping.