Those strange circular fields in American agriculture are known as center pivot irrigation systems. They are used to efficiently water crops by rotating around a central pivot point, delivering water to the crops in a circular pattern. This method of irrigation is popular in arid regions where water is scarce, as it allows for precise and efficient watering of crops. The circular shape of the fields is a result of the pivot point and the rotation of the irrigation system. **

No, there are no American settlements that are still active in Germany. After World War II, the United States had military bases and installations in Germany as part of the Allied occupation, but these have since been scaled back and most have been closed. The remaining U.S. military presence in Germany is primarily focused on supporting NATO operations and does not constitute permanent settlements. **

The structural change in American agriculture brings several problems, including the consolidation of farmland into larger, corporate-owned operations, which can lead to the displacement of small family farms. This consolidation can also result in decreased biodiversity, as large-scale monoculture farming practices become more common. Additionally, the shift towards industrialized agriculture can have negative environmental impacts, such as soil degradation, water pollution, and increased greenhouse gas emissions. Finally, the focus on maximizing profits in this new agricultural model can lead to exploitation of farm workers and contribute to income inequality in rural communities. **