人类受精
营养物
草原
生物量(生态学)
农学
开枪
干旱
背景(考古学)
肥料
氮气
生物
环境科学
生态学
化学
古生物学
有机化学
作者
Lu-Jun Li,De‐Hui Zeng,Zehao Yu,Zhiping Fan,Ruifeng Mao,P. L. Peri
标识
DOI:10.1111/j.1365-2494.2011.00781.x
摘要
Abstract To examine whether the critical leaf N/P ratios (of 14, 16) are valid to test nutrient limitation in the context of semi‐arid sandy grasslands, an experiment was conducted on a Keerqin sandy grassland in North‐east China to investigate the responses of plant biomass and nutrient concentrations to fertilization. Plant biomass production and leaf nutrient concentrations were measured after five consecutive years of fertilization with N (20 g N m −2 year −1 ) and/or P (10 g P 2 O 5 m −2 year −1 ). Nitrogen fertilization increased the shoot biomass by twofold and consequently the shoot/root ratio, whereas P fertilization had little effect on either shoot biomass or shoot/root ratio. Leaf N/P ratio varied among species with an average of 5·6 in the control, while the mean leaf N/P ratio (7·5) under the N fertilization treatment remained below the threshold of 14. Our results suggest that the critical N/P ratio (14, 16) is not applicable as a test for nutrient limitations in the context of semi‐arid, sandy grassland.
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