对于土壤，你该了解到以下15点！

导  读

将一欧元的硬币铺出一公顷（10000平方米），换成表土，则为10吨重。

编译：陈能场（广东省生态环境技术研究所研究员）

来源：《soil protection — a new policy for the EU》

对于土壤，你该了解到以下15点：

1. 土壤构成我们星球的最外层，由岩石和腐烂的植物和动物组成。

2.土壤中含有有机物质（由生物体分解产生），矿物质和营养物质。

3. 土壤帮助净化我们喝的水和我们呼吸的空气 –而且是免费的！

4. (理想的)土壤样品平均含45％矿物质，25％水，25％空气和5％有机物。矿物颗粒大小不一，有砂砾，粉粒，黏粒，构成不同的质地的土壤。

5. 表土是生产力最强的土壤层次。

6. 将一欧元的硬币铺出一公顷（10000平方米），换成表土，则为10吨重。

7. 在自然的成土过程中，形成两厘米的表层土需要500多年。

8. 在某些情况下，在一公顷土壤中可有五吨的动物生命。

9. 在土壤中真菌和细菌帮助分解土壤中的有机物质。

10. 蚯蚓消化土壤有机物，回收营养物质，使土壤表面更加肥沃。

11. 根系让土壤变松，让氧气渗透其中。这有益于生活在土壤中的动物。根系还将土壤保持在一起，有助于防止侵蚀。

12.功能完备的土壤通过中和或过滤掉潜在的污染物，每公顷储存3 750吨水，从而降低洪水的风险并保证地下水供应。

13. 在树上没有两片相同的树叶，地上没有两块相同的土壤，土壤科学家已经在欧洲确定了超过10 000种不同类型的土壤。

14. 全球土壤含有15500亿吨有机碳（大气碳为7600亿吨，活着的生物和植物(iving organisms and plants)）碳为5600亿吨）。

15. 世界上人为排放的二氧化碳量的20％左右被土壤捕捉。

附英文原文：

Key facts you should know about soil

1. Soil makes up the outermost layer of our planet and is formed from rocks and decaying plants and animals.

2. Soil has varying amounts of organic matter (resulting from the decomposition of living organisms), minerals and nutrients.

3. It helps clean the water we drink and the air that we breathe — for free!

4. An average soil sample is 45 % minerals, 25 % water, 25 % air and 5 % organic matter. Different-sized mineral particles, such as sand, silt and clay, give soil its texture.

5. Topsoil is the most productive soil layer.

6. Ten tonnes of topsoil spread evenly over a hectare is only as thick as a one Euro coin.

7. Natural processes can take more than 500 years to form two centimetres of topsoil.

8. In some cases, five tonnes of animal life can live in one hectare of soil.

9. Fungi and bacteria help break down organic matter in the soil.

10. Earthworms digest organic matter, recycle nutrients and make the surface soil richer.

11. Roots loosen the soil, allowing oxygen to penetrate. This benefits animals living in the soil.

They also hold soil together and help prevent erosion.

12. A fully functioning soil reduces the risk of floods and protects underground water supplies by neutralising or filtering out potential pollutants and storing as much as 3 750 tonnes of water per hectare.

13. Soil scientists have identified over 10 000 different types of soil in Europe.

14. Soils worldwide contain 1 550 billion tonnes of organic carbon (to be compared with an atmospheric carbon pool of 760 billion tonnes and 560 billion tonnes of carbon in living organisms and plants).

15. Soil captures about 20 % of the world’s manmade carbon dioxide emissions.