There are a number of different options including disc, chain, tine, spring, and power. The tine option is helpful for improving the land before planting and it can help to remove weeds and unwanted items from the soil. The chain harrows are helpful for covering up seeds, and the disc option is generally better for harder and heavier work. Many will actually use this to break up the soil initially. You can also find a number of different power harrows that are very popular today.
How harrows work
The harrows today are generally mounted onto tractors. They can be attached to the tractor using something such as a drawbar, or by mounting them on a hitch. The tractor can then drive over the land that needs breaking up and tilling and the harrow will go to work. These are extremely helpful to farmers who need to till their land so they can plant, and you will see these on many farms of all sizes.
Keep in mind that not all of the devices serve the same function. As you will learn below, some are better for breaking up the land, while some are better for removing weeds or covering seeds.
In the past, these types of machines were man or horse powered. Fortunately, technology has helped to make the process of breaking up soil and tilling it much easier for people, and the modern harrows can help make the work far faster and more efficient. You will commonly see these in use today for certain landscaping projects, and they are very prominent in agriculture.