摘要
针对禾豆间作密植机理研究薄弱问题,以大麦间作豌豆为研究对象,设施氮[不施氮:0 mg(N)·kg?1(土);施氮:100 mg(N)·kg?1(土)]、隔根(不隔根、隔根)和密度[低密度:15株(大麦)·盆?1;高密度:25株(大麦)·盆?1]3个参试因子,通过盆栽试验探讨了施氮和根系分隔对密植间作群体氮素竞争互补关系和利用效率的影响,以期为禾豆间作密植和氮素高效利用提供调控依据。结果表明:1)施氮、根间互作和增加大麦密度均可提高大麦||豌豆间作群体的吸氮量,其中施氮较不施氮处理提高33.8%,不隔根处理较隔根处理提高81.1%,高密度较低密度处理提高4.2%;根间互作在低氮条件下对间作吸氮量的贡献相对较高,不施氮和施氮条件下,根间互作提高间作吸氮量的比例分别为92.4%和11.0%;根间互作条件下增大大麦种植密度可显著提高间作群体吸氮量。2)大麦为氮素竞争优势种,密植使大麦氮素竞争比率显著提高,施氮能弱化大麦氮素竞争比率,抽穗期大麦相对于豌豆的氮素竞争优势达到最大值。3)根间互作使大麦、豌豆籽粒氮含量在施氮条件下分别提高126.7%、26.9%,不施氮时分别提高188.5%、46.5%,且施氮水平和根间作用方式对间作籽粒氮含量有显著的交互作用。4)高密度大麦和根间互作可显著提高间作群体的氮肥利用率,根间互作条件下增加大麦密度使间作群体氮肥利用率提高59.8%;大麦相对于豌豆的氮素竞争比率与间作群体氮肥利用率呈显著正相关关系。本研究表明,施氮、根间作用与大麦密度对大麦||豌豆间作氮素利用呈显著的交互作用,适宜的施氮量和充分的根间作用是支撑间作密植、优化种间对氮素的竞争关系,最终提高群体吸氮量和氮肥利用率的重要途径。
To investigate the mechanism of high planting density in cereal-legume intercropping system, a pot experiment of barley-pea intercropping system was carried out and the effects of nitrogen (N) application and root barrier on nitrogen and fertilizer use efficiency under high planting density of barley were determined. In the experiment, three factors, each with two treatment levels -- N fertilizer application [no N application and N application with 100 mg(N)·kg^-1], root barrier [no barrier with root interaction and root barrier without root interaction) and planting density (low density with 15 barley plants per pot and high density with 25 barley plants per pot) were set up. The results showed that: 1) N application, plant root interaction and high barley planting density improved N uptake of barley-pea intercropping system. Compared with no N application treatment, N uptake increased by 33.8% in N application treatment. There was also 81.1% increase in N uptake under no root barrier treatment over root barrier treatment. N uptake under high planting density treatment increased by 4.2% compared with low planting density treatment. Plant root interaction improved N uptake by 92.4% and 11.0%, respectively, under no N application and N application treatments. Increasing planting density with root interaction significantly increased N uptake of the intercropping system. 2) Barely plant performed better for N competition, and its' N competition ratio significantly increased under high planting density. However, N application reduced barley N competition ratio. Compared with pea, barley was highest in competitive advantage at heading stage. 3) Root interaction improved grain N content of barley and pea, respectively, by 126.7% and 26.9% under N application treatment. Also barley and pea kernel N content increased, respectively, by 188.5% and 46.5% under no N treatment. There was a significant interaction between N application and root interaction for kernel N content. 4) High barley planting density significantly improved N use efficiency by 59.8% under root interaction treatment of the intercropping system. N competition between barley and pea was positively correlated with N use efficiency in the intercropping plant population. In conclusion, interactions of N application, root barrier and barley planting density enhanced crop productivity of barley-pea intercropping system. Proper N application and sufficient root interaction made feasible high planting density intercropping system, optimized competition between barley and pea, and improved N uptake and use efficiency.
出处
《中国生态农业学报》
CAS
CSCD
北大核心
2017年第2期200-210,共11页
Chinese Journal of Eco-Agriculture
基金
国家自然科学基金项目(31160265
31360323)
甘肃农业大学"伏羲杰出人才培育计划"资助~~
关键词
大麦间作豌豆系统
根间互作
施氮量
吸氮量
氮肥利用率
氮素竞争比率
Barley-pea intercropping
Root interaction
Nitrogen application amount
Nitrogen uptake
Nitrogen use efficiency
Nitrogen competition ratio