Background and aims

Leaf litter constitutes a major fraction in litter production in Masson pine forests. However, productivity declines due to infertile soil. In these plantations, fertilization is a key management practice to sustain productivity. Our study aimed to: (1) evaluate the effect of mineral fertilizer on the decomposition dynamic of leaf litter; (2) evaluate its effect on amino acid concentration; and (3) explore the relationship between soil properties and amino acid.

Methods

Leaf litters of Masson pine were placed into litter bags in the following treatments: Control (CK), N fertilization (+ N), N and P fertilization (+ NP), and N, P, K fertilization (+ NPK) and collected every three months during 12 months of decomposition. Litterbags and chromatography techniques were employed to assess litter mass and amino acid concentration.

Results

Our study found that Masson pine leaf litter significantly affected by fertilizers, and the decomposition process accelerated with + NPK, and + NP. Out of the 16 amino acids, only GAALAGL showed significant increase under fertilizer treatments. The total amino acid concentrations were 229.33 ± 4.46, 205.37 ± 4.49, 206.28 ± 4.17, 186.74 ± 4.32 mg/g, respectively, in + NPK, + NP, + N, and CK. Soil chemical properties had a negative effect on amino acid concentration except for GVITMAS. N and P concentrations in leaf litter significantly increased while K concentration decreased; similarly, soil N and P exhibited significant increases, while K decreased.

Conclusions

NPK fertilizer might be the preferred management option as it can positively impact leaf litter decomposition and increase amino acid concentration. The findings serve as a valuable reference for implementing fertilization strategies in subtropical forests.

中文翻译：

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亚热带森林矿物肥添加对马尾松羊羔落叶分解及氨基酸浓度的影响

 背景和目标

落叶构成了马森松树林凋落物生产的主要部分。然而，由于土壤贫瘠，生产力下降。在这些种植园中，施肥是维持生产力的关键管理实践。本研究旨在：（1） 评价矿物肥料对凋落叶分解动态的影响;（2） 评价其对氨基酸浓度的影响;（3） 探索土壤特性与氨基酸之间的关系。

 方法

将马尾松的凋落叶放入垃圾袋中，进行以下处理：对照 （CK）、氮肥 （+ N）、氮和磷肥 （+ NP） 和氮、磷、钾肥 （+ NPK），并在 12 个月的分解过程中每三个月收集一次。采用垃圾袋和色谱技术评估垃圾质量和氨基酸浓度。

 结果

我们的研究发现，马尾松落叶受肥料的显著影响，并且 + NPK 和 + NP 加速了分解过程。在 16 个氨基酸中，只有 GAALAGL 在肥料处理下表现出显著增加。总氨基酸浓度分别为 229.33 ± 4.46、205.37 ± 4.49、206.28 ± 4.17、186.74 ± 4.32 mg/g，除 GVITMAS 外，土壤化学性质对氨基酸浓度有负面影响。凋落叶中 N 和 P 浓度显著增加，而 K 浓度降低;同样，土壤 N 和 P 表现出显著增加，而 K 表现出显着减少。

 结论

NPK 肥料可能是首选的管理选择，因为它可以对落叶分解产生积极影响并增加氨基酸浓度。研究结果为在亚热带森林中实施施肥策略提供了有价值的参考。