Carbon input and turnover in subsoil biopores

碳(C)输入到底土，特别是生物孔的重要性尚不清楚。本项目的目的是评估不同根系作物生物孔对碳转运和碳转化到地下土壤的贡献。将详细研究不同来源（蚯蚓来源、根来源和混合来源）的生物孔的生化特性。不同来源的生物孔中的碳周转将通过培养和二氧化碳分析进行研究。在作物序列试验（CeFiT）中，通过13C标记来估计根系和生物孔密度对底土碳输入的影响。利用13C-PLFA分析生物孔内外微生物群对根沉积物的利用。生物孔周围的酶活性分布将通过最近开发的土壤酶谱法来测量。在控制条件下，通过14C脉冲标记和成像分析前代作物形成的生物孔及其被主要作物利用的情况。根在生物孔内外的菌根化将在CeFiT实验中进行分析，并与土壤深度有关，具体取决于表层土壤的水分和养分含量。基于这些研究，我们将量化生物孔对碳运输和碳周转的重要性，以及对土壤微生物活动的重要性，这取决于以前的作物。

The carbon (C) input into the subsoil and especially the importance of biopores remains unclear. The aim of this project is to evaluate the contribution of biopores to the C transport and C turnover into the subsoil depending on crops with contrasting root systems. Biochemical properties of biopores of various origins (earthworm-derived, root-derived and mixed) will be studied in detail. C turnover in biopores of various origins will be studied by incubation and CO2 analysis. C input into the subsoil depending on the root system and on biopore density will be estimated by 13C labeling in the crop sequence experiment (CeFiT). The utilization of rhizodeposits by microbial groups in and out of biopores will be analyzed by 13C-PLFA. The distribution of enzyme activities around the biopores will be measured by recently developed soil zymography. The biopore formation by preceding crops and their use by main crops will be analyzed by 14C pulse labeling and imaging under controlled conditions. Mycorrhization of roots in and out of biopores will be analyzed in the CeFiT experiment and related to soil depths, depending on moisture and nutrient contents of the topsoil.Based on these studies, we will quantify the importance of biopores for C transport and C turnover and for microbial activity in the subsoil depending on preceding crops.