A Single and Robust Critical Nitrogen Dilution Curve for Miscanthus × giganteus and Miscanthus sinensis

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• 作者：M. Zapater ; M. Catterou ; B. Mary ; M. Ollier ; L. Fingar ; E. Mignot…
• 关键词：Miscanthus x giganteus ; Miscanthus sinensis ; Critical nitrogen dilution curve ; Nitrogen requirements
• 刊名：BioEnergy Research
• 出版年：2017
• 出版时间：March 2017
• 年：2017
• 卷：10
• 期：1
• 页码：115-128
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Plant Sciences; Plant Genetics & Genomics; Plant Breeding/Biotechnology; Plant Ecology; Wood Science & Technology;
• 出版者：Springer US
• ISSN：1939-1242
• 卷排序：10

文摘

The sustainable development of miscanthus as a bioenergy feedstock requires optimizing its fertilizer inputs and, therefore, determining its nitrogen (N) requirements. The ‘critical nitrogen dilution curve’ is a powerful tool to characterize such N requirements; it relates the N concentration ([N]) in aboveground organs to their biomass, defining two domains depending on whether the N factor limits biomass growth or not. We aimed to develop such a tool in miscanthus. Using a rhizome N depletion strategy with green cutting pre-treatment over several years before the start of the experiment, we grew, in 2014, two cultivated species, Miscanthus × giganteus (M×g) and Miscanthus sinensis (Msin), at four fertilizer levels (0, 80, 160 and 240 kg N ha−1). We found a strong nitrogen fertilization effect. The shoot [N] decreased as the aboveground biomass increased in both species and in all of the treatments. [N] was strongly correlated with leaf/stem biomass ratio. The N treatments enabled the identification of the observed critical points, i.e. points with the maximum biomass (W) and the lowest [N], on each measurement date. These points could be fitted to the following critical dilution curve that was common between M×g and Msin: N concentration (Nc) (critical [N], g N kg−1) = 27.0 W−0.48 when W > 1 t ha−1 and Nc = 27.0 when W ≤ 1. This curve was validated by literature data, separated into N-limited or not-limited conditions. The similarity of the curves between the two species was due to compensation between leaf/stem biomass ratio and [N] in the stems. This curve is helpful to diagnose the crop N status and define the optimal fertilizer requirements of miscanthus crops.