Abstract

Bacteria play determining roles in forest soil environment and contribute to essential functions in the cycling of nitrogen (N) and phosphorus (P). Understanding the effects of different fertilizer applications, especially successive fertilization, on soil properties and bacterial community could reveal the impacts of fertilization on forest soil ecology and shed light on the nutrient cycling in forest system. This study aimed to evaluate the impacts of successive mineral N (NH₄NO₃) and P (NaH₂PO₄) fertilization at different rates, alone or together, on soil bacterial biomass and communities at 0–5, 5–10, and 10–20 cm. Compared with the control, N fertilization decreased soil pH, but P alone or with N fertilization had negligibly negative impacts on soil pH. Different mineral fertilizer applications, alone or together, showed no significant effects on soil organic matter contents, relative to the control treatment. Bacterial biomass remained stable to different fertilizations but decreased with sampling depths. Sole N or P fertilization, rather than combined fertilizations, significantly changed soil bacterial community structures. Our results demonstrated that mineral N or P fertilization alone significantly affected bacterial community structures rather than biomass in the plantation soils.

Key points

• Impacts of successive mineral fertilization on soil bacteria were determined.

• Mineral fertilization showed negligible impacts on bacterial biomass.

• N additions stimulated Chloroflexi relative abundances.

• Mineral N or P fertilization significantly altered bacterial community structure.

中文翻译：

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单独的连续氮或磷施肥会显着改变人工林土壤中的细菌群落，而不是细菌生物量。

摘要

细菌在森林土壤环境中起决定性作用，并在氮（N）和磷（P）循环中发挥重要作用。了解不同肥料的施用方式（特别是连续施肥）对土壤特性和细菌群落的影响，可以揭示施肥对森林土壤生态的影响，并阐明森林系统中养分循环的情况。本研究旨在评估连续矿物N（NH ₄ NO ₃）和P（NaH ₂ PO _{4）的影响。}）分别对0-5、5-10和10-20 cm的土壤细菌生物量和群落施以不同速率的肥料。与对照相比，氮肥的施用降低了土壤的pH值，但是单独施用磷肥或施用氮肥对土壤pH值的负面影响微不足道。相对于对照处理，单独或一起施用不同的矿物肥料对土壤有机质含量均无明显影响。细菌生物量对不同的施肥量保持稳定，但随着采样深度的增加而降低。单独施氮或磷，而不是联合施肥，显着改变了土壤细菌群落结构。我们的结果表明，单独施用矿物氮或磷会显着影响细菌群落结构，而不是影响种植土壤中的生物量。

关键点

•确定了连续矿物施肥对土壤细菌的影响。

•矿物肥料对细菌生物量的影响可忽略不计。

•N的添加刺激了Chloroflexi的相对丰度。

•矿质氮或磷肥显着改变了细菌群落结构。