Dissertation Research: Nitrogen Dynamics in a Legume- Nonlegume Intercrop System

论文研究：豆类-非豆类间作系统中的氮动态

• 批准号: 8715448
• 负责人: Deborah Goldberg
• 金额: $ 0.97万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-03-15 至 1990-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8715448&HistoricalAwards=false
• 关键词: Dissertation; Research; Nitrogen; Dynamics; Legume

The overall goals of the proposed research are to quantify the contributions of different mechanisms by which nonlegumes yield more in intercrops with legumes than in monocultures and to quantify how the contribution of each mechanism varies with interplant distance. The ultimate goal is to use this information to design optimal intercrop systems. Biomass and nitrogen yield of a corn plant surrounded by legumes may be higher than that of a corn plant surrounded by an equal density of corn plants either because of reduced competition for soil nitrogen (greater availability of soil nitrogen to the corn) and/or the transfer of atmospheric nitrogen fixed by the neighboring legume plants, i.e facilitation. These two sources can be distinquished by adding isotopic nitrogen to the soil. Reduced competition would result in an increase in the absolute quantity of labeled soil nitrogen in the intercropped relative to monoculture corn. Facilitation would result in a decrease in the proportion of labeled soil nitrogen in the intercropped corn (increase in proportion of atmospheric-derived N).

本研究的总体目标是量化 非豆科植物的不同作用机制 与豆类间作比单作产量高， 量化每个机制的贡献如何随 株间距离最终目的是利用这些信息 来设计最佳的间作系统。 生物量和氮产量 被豆科植物包围的玉米植株的生长速率可能高于 一株玉米植株被等密度的玉米植株包围， 由于减少了对土壤氮的竞争（ 土壤氮对玉米的有效性）和/或 邻近豆类植物（即豆科植物）固定大气氮 便利化 这两个来源可以通过添加 同位素氮进入土壤。 减少竞争将导致 标记土壤氮的绝对量增加 与单作玉米相比，间作玉米的产量增加了。 便利化 会导致标记土壤的比例下降 间作玉米中氮素（ 大气来源的N）。