施氮制度对燕麦‖豌豆间作体系产量及种间竞争力的影响

Effect of nitrogen application on interspecific compe⁃ tition and yield of oat-pea intercropping system

摘要:

于 2019 年在甘肃省通渭县以燕麦‖豌豆间作和燕麦单作为研究对象，在总施氮量相同且基肥占总施氮量 20% 的条件下，设不施氮(N0)、氮肥后移(N1：基肥 20%+分蘖期追肥 20%+开花期追肥 60%)、拔节期前、后均匀配施(N2：基肥 20%+分蘖期追肥 30%+开花期追肥 50%)和氮肥前移 (N3：基肥 20%+分蘖期追肥 40%+开花期追肥 40%)4 个施氮制度，探讨不同氮处理对燕麦//豌豆间作体系产量及其种间关系的影响。结果表明：燕麦//豌豆间作系统的地上生物量和籽粒产量均高于相应单作，基于地上生物量的 LER 在施氮处理下均大于 1；籽粒产量计算所得的 LER 在所有处理下均大于 1，间作优势明显。间作燕麦籽粒产量和地上生物量在 N2 处理下最大，分别为 3 705. 3 kg/hm² 和 8. 53 t/hm² ，较 N1 和 N3 分别增产 5. 11% 和 22. 48%，18. 47% 和 22. 03%。间作豌豆在 N1 处理(分枝期追肥 20 kg N/hm² )下籽粒产量最高(2 073. 7 kg/hm² )。间作系统中燕麦相对豌豆的种间竞争力随生育期和施氮处理呈先增后减的变化趋势，拔节期时燕麦处于竞争劣势，随生育期的延长，燕麦逐渐恢复竞争优势，相对豌豆的全生育期平均竞争力均＞0，为竞争优势植物。间作群体籽粒产量与燕麦相对豌豆的平均竞争力呈二次曲线关系，当竞争力为 0. 14 时，利于间作群体高产。燕麦灌浆期是调控种间竞争力、提高产量的关键时期。

Abstract:

This research was undertaken in 2019 in Tongwei County，Gansu Province. Under the same total ni- trogen application，four different N application regimes were set，including N0：without N；N1：20% basal N + 20% top dressing N at tillering stage + 60% top dressing N at flowering；N2：20% basal N+30% top dressing N at tillering+50% top dressing N at flowering and N3：20% basal N+40% top dressing N at tillering+40% top dress- ing N at flowering. The effect of different nitrogen treatment regime on the yield advantage and interspecific relation- ship of the oat/pea intercropping system were investigated. The results showed that both above ground biomass and grain yield of oat//pea intercropping system were higher than those of corresponding monoculture，and the LER based on above ground biomass was greater than 1 under N treatment. The LER calculated by grain yield was greater than 1 for all treatment，the intercropping advantage was obvious. The grain yield and above ground biomass of intercropped oat were the highest under N2 treatment，which were 3 705. 3 kg/hm² and 8. 53 t/hm² ，respectively. When compared with those under N1 and N3 treatments，the grain yield and above ground biomass increased by 5. 11% and 22. 48%， 18. 47% and 22. 03%，respectively. . Intercropping pea had the highest grain yield(2073. 7 kg/hm² )under N1 treat- ment with top dressing 20 kg N/hm² at branching stage. In the intercropping system，the interspecific competitiveness of oat to pea increased first and then decreased with the growth period and nitrogen application. Oat was at a competi- tive disadvantage at the jointing stage，but restored its competitive advantage with the extension of the growth period. Its average competitiveness of the whole growth period relative to pea was greater than 0，and became a competitive advantage plant. There was a quadratic correlation between the grain yield of intercropped population and the average competitiveness of oat to pea. The high yield of intercropped population could be achieved at 0. 14 competitiveness. Grain filling period of oat was a critical period for regulating interspecific competitiveness and yield improvement.