Formiguer Soils The Mediterranean analogue to terra preta de Indio in the humid tropics?

由于全球变暖、土壤退化、世界人口增长和相关的粮食安全等全球性问题尚未解决，受人类活动严重影响的土壤越来越重要。正如潮湿热带地区的土壤例子所表明的那样，几百年后，人为土壤可以含有大量的养分和土壤有机质。然而，只有很少的人为土壤被深入研究，比terra preta。 一个有趣的例子是地中海加泰罗尼亚（西班牙）旨在提高土壤肥力的Formiguer施肥技术。该方法是基于在厚厚的土壤覆盖层下的生物质堆的碳化。燃烧后，被加热的土壤覆盖物、灰烬、木炭和极有可能还有粪便被散布并融入土壤。所得土壤仍含有大量肉眼可见的木炭颗粒，土壤颜色较深，具有良好的土壤水分和活跃的土壤动物，这与周围未处理的土壤形成对比。该项目的一个关键问题是，在多大程度上，formiguer土壤的投入材料和性质与terra preta de cubndio以及地中海地区可持续土地利用的地中海类似物和模式具有可比性。该项目使用最先进的方法重点关注三个主要问题。首先，将利用放射性碳测年（14 C）、磷和氮同位素（d15 N）分析，结合分子标记，对木炭（黑碳）和粪便物质（甾烷醇和胆汁酸）进行鉴定和定量，重建土地使用历史。将通过与未处理的邻近土壤相比，确定形成剂施肥对土壤性质的影响。长期集约化耕作条件下土壤木炭性质的变化仍然知之甚少。因此，第二个主题解决了新鲜和老化的木炭在formiguer土壤中的化学性质和可能的稳定机制，这可能会导致，除了化学稳定性，它在土壤中的长期稳定。木炭的元素组成（C、N、O、H和O）以及黑碳的质量和数量将为木炭的形成过程（火强度）和木炭的燃烧提供更深入的见解。结合SEM-EDS、FTIM、XPS和薄片等显微镜和光谱技术，研究了暴露于土壤中的木炭化学性质的变化。本项目的第三个课题是研究配方施肥技术对微生物生物量和微生物群落结构的影响。氨基糖、胞壁酸和PLFA将被用作真菌和细菌的标记物。

Soils heavily influenced by human action are increasingly gaining in importance because of unsolved global issues such as global warming, soil degradation, increasing world population and related food security. As shown by the example of terra preta de Índio in the humid tropics, Anthrosols can contain tremendous nutrient and soil organic matter stocks after several hundred years. However, only few Anthrosols are comparably intensive investigated than terra preta. An interesting example is the formiguer fertilization technique in the Mediterranean Catalonia (Spain) aiming an increasing soil fertility. The method is based on carbonization of piles of biomass under a thick soil cover. After burning, the heated soil cover, ash, charcoal and highly probable also dung were distributed and incorporated into the soil. The resulted soils still contain high amounts macroscopically visible charcoal particles, are dark in soil colour, having a good soil moisture and active soil fauna, which is in contrast to surrounding non-treated soils. In how far the input materials and properties of the formiguer soils are comparable to terra preta de Índio and thus its Mediterranean analogue and model for sustainable land use in Mediterranean regions, is a key question of the project. The project focuses three main issues using state-of-the-art methods. First, land use history will be reconstructed using radiocarbon dating (14C), phosphorous and nitrogen isotope (d15N) analysis combined with molecular markers for identification and quantification of charcoal (black carbon) and faecal matter (stanols and bile acids). The impact of formiguer fertilization on soil properties will be determined by soil basic characterisation of formiguer soils compared with non-treated adjacent soils. Changes of charcoal properties in the long-term under intensive soil cultivation are still poorly understood. Thus, the second subject addresses the chemical properties of fresh and aged charcoals in formiguer soils and possible stabilization mechanisms, which may lead, beside chemical recalcitrance, to its long-term stabilization in soils. Elemental composition of charcoal (C, N, O, H and O) as well as the quality and quantity of black carbon will provide deeper insights in charcoal formations process (fire intensity) and recalcitrance of charcoals. Changes of chemical properties of charcoals exposed in soil will be determined by combining microscope and spectroscope techniques such as SEM-EDS, FTIM, XPS and thin sections. The third subject of the project focusses on the impact of the formiguer fertilization technique on microbial biomass and microbial community structure. Amino sugars, muramic acid and PLFA will be used as marker for fungi and bacteria.