The United States of America is the 3rd largest country in the world. The contiguous states span from 25°N to 49°N and from 67°W to 125°W allowing for a huge amount of soil diversity throughout the country. When you choosing the correct ground engaging implements, like tiller tines, it is important to keep your soil type in mind.
To help you, Agristore USA has gathered some soil survey maps of the United States from the National Soil Survey Center of the USDA.
Soil moisture is a crucial component of growing crops. It is also important when working the land. If you are working with soil that is very low in moisture, you will need different equipment than if you are working with moisture-heavy soil.
Here is a map showing average soil moisture throughout the United States.
Click any of the maps to expand them. The original files and more information can be found at the NRCS website.
This map shows the regions of the United States which are more vulnerable to drought. This does not mean the red areas are more likely to have drought but rather that they experience droughts more severely.
The next map shows soil density. It was created by attempting to penetrate the ground throughout the United States with radar and measuring how deep the waves traveled. I think this is the most useful map for determining the kinds of implements you'll need, specifically tiller blades.
If you live in a region with low soil density (green, light green, light tan, and some tan areas), you will want to use L shaped tiller tines. The L shape is more aggressive and works well with looser soil. However, if you live in a region with high soil density (purple, brown, and some tan areas), you should use C shaped tiller tines. The C shape is less aggressive and will work better than the L shape tines in dense or rocky soil. You can browse Agristore USA's tiller tines by clicking here.
This is a map showing average soil temperature in different regions of the United States.
Finally, this map shows the different soil types or "textures" which naturally occur throughout the country. It is useful for determining what kinds of crops will thrive in each region.