Huang Yong-Zhen, Wang Sheng-Qiang, Ye Shao-Ming
College of Forestry, Guangxi University, Nanning 530004, China.
Ying Yong Sheng Tai Xue Bao. 2020 Sep 15;31(9):2857-2865. doi: 10.13287/j.1001-9332.202009.003.
Exploring the microscopic characterization of organic carbon and nutrients in surface soil of different Chinese fir stands at aggregate scale can lay a theoretical foundation for promoting the sustainable use of soil resources with implications for improving soil health and fertility. We mea-sured the concentrations of soil organic C (OC), total nitrogen (TN), alkali-hydrolyzed nitrogen (AN), Olsen-P (AP), and available K (AK) in aggregate fractions collected from 0-10 cm and 10-20 cm soil layers in three different stands, mixed plantation of and (Ⅰ), and (Ⅱ) and pure plantation of (Ⅲ) respectively. Soil aggregates were classified into >2, 0.25-2, and <0.25 mm fractions by a dry-sieving procedure. The organic carbon and nutrient contents of soil aggregates in different stands increased with the decreases of particle size while the contribution rate of aggregates with different particle sizes to soil organic carbon and nutrient storage in 0-10 cm soil layer mainly was (>2 mm)>(0.25-2 mm)>(<0.25 mm), which was (>2 mm)>(<0.25 mm)>(0.25-2 mm) in 10-20 cm soil layer. The average weight diameter (MWD), the contents and stocks of OC, TN, AN and AP in surface soil aggregates of different stands ranked as Ⅰ>Ⅱ>Ⅲ (except the AP in 10-20 cm soil layer), while the contents and stocks of AK ranked as Ⅲ>Ⅰ>Ⅱ. Compared with pure plantation, aggregate structure of surface soil of mixed plantations was more stable, and Ⅰ was better than Ⅱ, because Ⅰ was artificially disturbed but Ⅱwas not. Therefore, the mixed plantation of and could effectively promote the formation and stability of soil aggregates, and alleviate decomposition of soil organic matter and nutrient loss in plantations.
从团聚体尺度探究不同杉木林分表层土壤有机碳和养分的微观特征，可为促进土壤资源可持续利用、改善土壤健康和肥力提供理论依据。我们分别测定了来自三种不同林分（Ⅰ为 与 的混交林、Ⅱ为 与 的混交林、Ⅲ为 纯林）0 - 10 cm 和 10 - 20 cm 土层采集的团聚体组分中土壤有机碳（OC）、全氮（TN）、碱解氮（AN）、有效磷（AP）和速效钾（AK）的浓度。通过干筛法将土壤团聚体分为 >2、0.25 - 2 和 <0.25 mm 组分。不同林分土壤团聚体的有机碳和养分含量随粒径减小而增加，0 - 10 cm 土层不同粒径团聚体对土壤有机碳和养分储量的贡献率主要为（>2 mm）>（0.25 - 2 mm）>（<0.25 mm），10 - 20 cm 土层则为（>2 mm）>（<0.25 mm）>（0.25 - 2 mm）。不同林分表层土壤团聚体的平均重量直径（MWD）、OC、TN、AN 和 AP 的含量及储量排序为Ⅰ>Ⅱ>Ⅲ（10 - 20 cm 土层的 AP 除外），而 AK 的含量及储量排序为Ⅲ>Ⅰ>Ⅱ。与纯林相比，混交林表层土壤团聚体结构更稳定，且Ⅰ优于Ⅱ，因为Ⅰ受到人为干扰而Ⅱ未受干扰。因此， 与 的混交林能有效促进土壤团聚体的形成与稳定，减轻人工林土壤有机质分解和养分流失。
