| At these times, there are a lot of problems pertaining | | | | topsoil part to the extent that much of the soil flora |
| to the maintenance of soil as it is needed to preserve | | | | dies out. |
| the plant and animal populations. First one is the | | | | The next problem is soil erosion. Erosion is a |
| depletion of soil minerals. Mineral exhaustion can be | | | | destructive way by which soil is lost through the action |
| brought about by overproduction. The most important | | | | of water and wind. This occurs when the land is |
| minerals lost from the soil are nitrates, phosphates and | | | | stripped of its natural vegetation and also when poor |
| potassium compounds. Soil that is badly depleted of | | | | farming methods are applied. Much of the land that is |
| minerals becomes acidic or sour, and lime and fertilizer | | | | badly eroded today had been abandoned by the |
| are added to correct this kind of condition. | | | | farmers who used to till it. |
| The next problem is loss of organic matter. Normally | | | | These farmers made use of every square meter of |
| the organic matter present in topsoil decays slowly as | | | | land to the extent that they cultivated hillsides, river |
| it is acted on by bacteria and other soil organisms. | | | | bottoms, and other areas, only to leave the area |
| However, humans may disturb this natural balance by | | | | empty and denuded, and thus suited for erosion. |
| planting and harvesting agricultural crops too frequently. | | | | Wind erosion results from natural strong winds or dust |
| This will just deprive the soil of much organic matter. | | | | storms made possible by man's carelessness and |
| Sometimes, woods and native grasses are even | | | | short sightedness. Water erosion may be of three |
| burned off in the fields before plowing. This process, | | | | kinds. They are namely sheet erosion, rill erosion and |
| together with seasonal clearing fields, diminishes the | | | | gully erosion. |