| I was wondering how soil holds water? What are the benefits and disadvantages of soil holding water? |
| Think about the components of soil--rock particles, organic matter, water and air. If you pour water over a bed of gravel, it runs right through. Pour water over a bed of clay, and it will take a long time to filter through. Generally, the smaller the rock particle, the more tightly packed the soil. Clay particles are very small, and they are also flat so they pack very hard. This subject can get quite complicated, when you take into account water's surface tension, etc. Organic matter, too, can absorb water, especially if it is the form of humus, the end product of decomposition. Now think about why it's important for soil to hold water--but not too much water. Plant, as I'm sure you know, take up water through their roots. Butroots also need a certain amount of air around them, or they'll rot. So a good soil holds enough, but not too much, water. |
