Dataset on the long-term effects of nitrogen and phosphorus fertilization on soil phosphorus availability.

We examined the responses of bulk soil chemical properties, enzyme activities, microbial biomass, P fractions, and cycling indices to N and P fertilization in Metasequoia glyptostroboides plantations under a subtropical monsoon climate. The experiment spanned 10 years and included five levels of N (0, 56, 168, 280, 336 kg ha⁻¹) and P (0, 7.8, 31, 93, 155 kg ha⁻¹) fertilization. P fertilization resulted in stronger response of available P and inorganic P fractions, such as Resin-Pi, NaHCO₃-Pi, and NaOH-Pi, compared to N fertilization. Under N fertilization, available P was mainly influenced by microbial biomass P and carbon, with NaOH-Pi being its dominant sources of supply, while both the direct and indirect effects of N fertilization on available P were minimal. In contrast, , available P under P fertilization was regulated by total P, nitrate (NO₃⁻), and organic carbon contents, with NaOH-Pi, NaOH-Po, NaHCO₃-Pi, and NaHCO₃-Po as the dominant forms. The direct effects of P addition on available P, reflected by a pathway coefficient of 0.37, slightly exceeded its indirect effects.

本研究针对亚热带季风气候下水杉（Metasequoia glyptostroboides）人工林，探究了原状土壤化学性质（bulk soil chemical properties）、土壤酶活性、微生物生物量（microbial biomass）、磷组分（P fractions）及循环指数（cycling indices）对施氮（N fertilization）与施磷（P fertilization）的响应。本实验为期10年，设置了5个施氮梯度（0、56、168、280、336 kg·ha⁻¹）与5个施磷梯度（0、7.8、31、93、155 kg·ha⁻¹）。相较于施氮处理，施磷处理对有效磷（available P）及树脂结合态无机磷（Resin-Pi）、碳酸氢钠提取态无机磷（NaHCO₃-Pi）、氢氧化钠提取态无机磷（NaOH-Pi）等无机磷组分（inorganic P fractions）的响应更为显著。施氮处理下，有效磷主要受微生物生物量磷（microbial biomass P）与微生物生物量碳（microbial biomass C）调控，氢氧化钠提取态无机磷为其主要供应源，而施氮对有效磷的直接与间接影响均较弱。与之相反，施磷处理下的有效磷受总磷（total P）、硝酸根（NO₃⁻）与有机碳（organic carbon）含量调控，氢氧化钠提取态无机磷、氢氧化钠提取态有机磷（NaOH-Po）、碳酸氢钠提取态无机磷与碳酸氢钠提取态有机磷（NaHCO₃-Po）为其主要赋存形态。施磷对有效磷的直接影响以通径系数0.37表征，略高于其间接影响。