Root distribution and properties of a young alley-cropping system: effects on soil carbon storage and microbial activity
Root distribution and properties of a young alley-cropping system: effects on soil carbon storage and microbial activity
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DOI：
10.1007/s11104-022-05714-9
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发表时间：
2022-10
期刊：
影响因子：
4.9
通讯作者：
Lorène Siegwart;C. Jourdan;G. Piton;S. Sugihara;Karel Van den Meersche;I. Bertrand
中科院分区：
文献类型：
--
作者：
Lorène Siegwart;C. Jourdan;G. Piton;S. Sugihara;Karel Van den Meersche;I. Bertrand
在农林复合系统中，一年生和多年生植被的根系分布和特性知之甚少，尽管人们认识到它们通过年度根系来源的碳输入和改变微生物活动来促进土壤碳(C)储量。本研究旨在评价林下植被带（UVS）根系和作物根系对0 ~ 100 cm表层和底土C储量的潜在贡献。方法在垂直于林木线的不同深度和位置，评估根系生物量、化学成分、功能性状和解剖结构，同时评估土壤理化和微生物特性（包括酶活性）。结果由于不同植物群落的存在和垂直于林木线位置土壤矿质氮含量的异质性，幼龄旱作系统根系生物量和性状存在异质性。土壤微生物特性和有机碳储量在农林业的这一阶段没有水平变化，但应该通过多次采样进行监测，以确认根系化学计量与微生物胞外酶活性之间的紧密联系所表明的后续年份的分化。综上所述，农林复合系统表层土壤根系生物量的增加对土壤有机碳储量的增加有积极的促进作用，但在深层土壤中，高C:N比凋落物的增加可能会加剧微生物氮的限制，限制土壤碳储量。
PurposeIn agroforestry systems, the root distributions and properties of the annual and perennial vegetation are poorly known, although they are recognized for fostering soil carbon (C) stocks through annual root-derived C inputs and by altering microbial activity. This study aimed to evaluate the potential contribution of roots from the understory vegetation strip (UVS) and the crop to top- and subsoil C stocks (0–100 cm) to a 3-year-old agroforestry system of the alley-cropping type.MethodsRoot biomass, chemical composition, functional traits and anatomical structure were assessed in parallel to a characterization of soil physicochemical and microbiological properties, including enzymatic activity, at different depths and locations perpendicular to the tree line.ResultsThe root biomass and properties were heterogeneous in the young alley-cropping system due to the presence of different plant communities and the heterogeneity of the soil mineral N content according to the location perpendicular to the tree line. The soil microbiological properties and organic C stocks did not vary horizontally at this stage of agroforestry but should be monitored through multiple-time samples to confirm a differentiation in subsequent years suggested by the tight link between root stoichiometry and microbial extracellular enzymatic activities that we found.ConclusionsAltogether, our results suggested that increasing the root biomass in topsoil in agroforestry systems positively contributes to increasing soil organic C stocks, but in deeper soil layers, an increase in litter inputs with a high C:N ratio might accentuate microbial N limitations and limit soil C storage.