养分化学计量比对稻田土壤葡萄糖矿化及其激发效应的影响

发布时间：2018-11-03 15:56

【摘要】：选择13C-葡萄糖作为稻田土壤典型易利用态外源有机碳,通过室内培养试验,研究不同C/N/P/S计量比条件下,葡萄糖分解矿化的动态规律及其激发效应。结果表明,稻田土壤中葡萄糖-碳(C)快速矿化,60 d培养实验后,有65.5%~74.6%的葡萄糖-C矿化。养分元素的添加使土壤中葡萄糖-C快速转化碳库的比例逐渐由58%增加至65%,从而使葡萄糖-C矿化率提高了3.9%~12.5%,养分元素的添加量与葡萄糖-C快速转化碳库的比例和矿化率均表现出显著的正相关关系(R2=0.63,p0.05;R2=0.83,p0.05)。葡萄糖-C矿化过程中,导致稻田土壤碳的累积负激发效应为-370~-570 mg kg-1,养分元素添加比例越大,其负激发效应越强,二者呈显著的负相关性(R2=0.66,p0.05)。研究表明,稻田土壤中易利用态碳的矿化受C/N/P/S元素计量比的影响,高比例养分元素的添加,促进土壤中易利用态碳的矿化,抑制土壤原有有机质的分解,增强负激发效应。本研究可为深入了解稻田生态系统碳循环、实现农田土壤肥力提升和温室气体减排提供理论依据。
[Abstract]:13C- glucose was selected as the typical readily available organic carbon in paddy soil. The dynamic law of glucose decomposition and mineralization and its excitation effect under different C/N/P/S stoichiometric ratios were studied in laboratory culture. The results showed that Glucose-carbon (C) mineralization was rapid in paddy soil, and 65.5% of Glucose-C mineralization occurred after 60 days culture. With the addition of nutrient elements, the proportion of glucose C rapidly transforming carbon pool in soil gradually increased from 58% to 65%, and the mineralization rate of glucose C increased by 3.9% to 12.5%. There was a significant positive correlation between the addition of nutrient elements and the ratio of glucose to C rapidly transformed carbon pool and mineralization rate (R2O0.63, p0.05). R2 + 0.83% (p0.05). In the course of glucose-C mineralization, the cumulative negative excitation effect of carbon in paddy soil was -370 ~ 570 mg kg-1, and the negative excitation effect was stronger. The results showed that the mineralization of readily available carbon in paddy soil was affected by the C/N/P/S ratio, and the addition of high proportion of nutrient elements promoted the mineralization of the easily available carbon in the soil, and inhibited the decomposition of the original organic matter in the soil. Enhance the negative excitation effect. This study can provide a theoretical basis for understanding the carbon cycle of paddy ecosystem, improving soil fertility and reducing greenhouse gas emissions.
【作者单位】：湖北大学资源环境学院;中国科学院亚热带农业生态研究所农业生态系统过程重点实验室;中南林业科技大学环境科学与工程学院;
【基金】：国家自然科学基金项目(41430860,41371304) 湖南省自然科学基金项目(2016JJ3132) 中国科学院战略性先导科技专项(XDB15020401)资助~~
【分类号】：S153

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