Flooding and prolonged drought have differential legacy impacts on soil nitrogen cycling, microbial communities and plant productivity
Flooding and prolonged drought have differential legacy impacts on soil nitrogen cycling, microbial communities and plant productivity
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DOI：
10.1007/s11104-018-3774-7
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发表时间：
2018-08
期刊：
影响因子：
4.9
通讯作者：
L. Nguyen;Y. Osanai;I. Anderson;M. Bange;D. Tissue;B. Singh
中科院分区：
文献类型：
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作者：
L. Nguyen;Y. Osanai;I. Anderson;M. Bange;D. Tissue;B. Singh
背景和目标极端气候事件，包括洪水和长期干旱，可能对土壤非生物和生物特性产生长期（遗留）影响，可能影响土壤氮循环、微生物群落和植物生产力。氮肥通常会刺激植物生长，但添加氮肥是否可以减轻遗留干旱或涝害事件对作物的影响仍不清楚。我们的目的是评估遗留极端气候事件和氮添加对这些过程的交互影响。方法使用棉花作为模型系统，利用先前遭受涝渍和长期干旱的土壤来研究极端气候对土壤氮处理速率、相关微生物群落的丰度和结构以及不同施氮水平（0、100、200和 300 kg N/ha)。结果长期干旱对植物生产力的有害遗留影响是由于对微生物丰度、群落结构以及土壤养分可用性的负面影响，从而对硝化速率以及植物有效氮产生负面影响。尽管施肥量高达 300 kg N/ha，但长期干旱的遗留影响在整个实验过程中持续存在。唯一观察到的涝渍遗留影响是未添加氮的土壤中 NO3− 水平较低，以及 N2O 还原群落丰度和结构的变化。结论 长期干旱对土壤和作物产量有强烈的遗留影响，但渍水对土壤和作物产量的遗留影响较小，无法通过高施氮量完全抵消。这项研究提供了关键知识，有助于制定适应和土壤氮管理策略，以在极端天气事件频率和强度增加的背景下最大限度地减少农业生产力的损失。
Background and aimsExtreme climate events, including flooding and prolonged drought, may establish long-lasting (legacy) effects on soil abiotic and biotic properties, potentially influencing soil N-cycling, microbial communities, and plant productivity. Nitrogen (N) fertilizer often stimulates plant growth, but it remains unknown whether N addition can alleviate the impact of legacy drought or waterlogging events on crops. Our aim was to assess the interactive effects of legacy extreme climate events and N-addition on these processes.MethodsUsing cotton as a model system, soils previously exposed to waterlogging and prolonged drought were used to examine potential legacy impacts of extreme climate on soil N process rates, abundance and structure of associated microbial communities, and cotton growth and productivity under different levels of N fertilizer application (0, 100, 200 and 300 kg N/ha).ResultsThe deleterious legacy effects of prolonged drought on plant productivity were due to negative impacts on microbial abundance and community structure, and soil nutrient availability, thereby negatively influencing the rate of nitrification, and consequently plant available N. The legacy impacts of prolonged drought persisted throughout the experiment despite fertiliser applications of up to 300 kg of N/ha. The only observed legacy impacts of waterlogging were low NO3−levels in soils without N-addition and shifts in the abundance and structure of the N2O-reducing community.ConclusionsThere were strong legacy impacts of prolonged drought, but minor legacy impacts of waterlogging, on soils and crop yields which could not be fully counteracted by the high rates of N fertilizer application. This study provides critical knowledge contributing to the development of adaptation and soil N management strategies to minimize the loss of farm productivity, within the context of increased frequencies and intensities of extreme weather events.