ABSTRACT For effective management of sandy grasslands, it is important to determine whether adding P fertiliser is conducive to plant growth under global N deposition. We therefore carried out a field experiment in which N and P fertiliser was added to sandy grasslands. The results showed that, with increasing N addition (or N + P addition), the C, N and P concentrations in the leaves and roots and the above- and belowground biomass of plants increased significantly. The maximum per cent increases in the N and P concentrations in the leaves and roots and the total biomass under N + P addition were greater than those under N addition. When N deposition exceeded 15 g N m−2 a−1, the N + P treatments were greater than the N treatments in terms of their effects on N concentrations in the leaves and roots, on the above- and belowground biomass and on the RSR, with the exception of the leaf N concentrations under the addition of 15 g N m−2 a−1. Our results suggest that P fertiliser under N deposition may increase the self-regulatory adaptation of plants via the C:N, C:P and N:P stoichiometry of both the leaves and roots, increase plant biomass, and promote grassland restoration.

中文翻译：

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施氮磷肥对沙质草地黑麦草生物量及生态化学计量特征的影响

摘要 为了有效管理沙质草地，确定在全球氮沉降下添加磷肥是否有利于植物生长非常重要。因此，我们进行了田间试验，在沙质草地上添加氮磷肥。结果表明，随着N添加量（或N+P添加量）的增加，植物叶片和根部的C、N、P浓度及地上、地下生物量显着增加。在N+P添加下，叶子和根中N和P浓度以及总生物量的最大增加百分比大于N添加下的那些。当氮沉积超过 15 g N m−2 a−1 时，N + P 处理对叶和根中 N 浓度的影响大于 N 处理，在地上和地下生物量以及 RSR 上，除了在添加 15 g N m-2 a-1 下叶片 N 浓度。我们的研究结果表明，氮沉降下的磷肥可能通过叶和根的 C:N、C:P 和 N:P 化学计量增加植物的自我调节适应，增加植物生物量，促进草地恢复。