Tools for Refining Soil

Cultivation

• To initially grow crops in a soil, the surface must be broken. The depth of cultivation needs to be approximately 1 foot deep, the depth of most of the roots of annual plants. To break the surface of the soil, a heavy tool is required to cut into the soil, lift it and turn it over. Plows have been used for thousands of years to refine the surface of the soil for growing crops. There are many different kinds of plows for various soil types and conditions. The power used to pull plows can also be considered tools for refining the soil. Animals and tractors are the tools that provide the tremendous energy needed to refine the surface of the soil.

Seedbed Preparation

• Once a soil has been brought into cultivation, it needs to be refined further. Crop seeds require good contact with the soil in order to germinate. If the soil is rough and full of clods, planted seeds will only come in contact with the rough edges of clods. Seeds with inadequate soil contact cannot absorb enough water to grow. There are various kinds of tools used to refine the soil for planting seeds, and all of them are used to break up clods and level the surface of the ground. Harrows, cultivators and rakes are tools pulled over the ground after plowing to refine the soil for planting.

Sample Preparation

• Soil that needs to be processed for analysis must first be refined. The refining process for soil samples requires crushing all clods until they are 2 mm (0.079 inch) or smaller. The mineral constituents of soil that chemical and other analyses are performed on are defined as particles of these sizes. A screen is used to separate out any stones larger than this size, as well as sticks and leaves. Samples can be ground with a mortar and pestle or with machine grinders.

Sterilization Considerations

• The soil is full of microscopic organism, some which can be harmful to plants. You should take care to clean all tools used to refine the soil, especially when moving from one soil to another. If there is a known problem in one field, such as a damaging nematode infestation, certain equipment should be designated to be used only on that soil. If tools have been exposed to diseased plants, they should be cleaned before coming in contact with the soil again. In laboratory work, all tools used for refining the soil must be completely cleaned to avoid contaminating other samples.