美国田纳西农业机械公司研制出一种水陆两用拖拉机，这种拖拉机的发动机和底盘采用铝合金和工程塑料制造，以尽量减轻车体重量，四个车轮采用聚酯纤维填充泡沫塑料制成。在旱地上工作时，这四个车轮对地面的压力很小，在农田中耕、除草、喷药时不会压坏农作物，如要在水田中工 Tennessee Agricultural Machinery Company has developed an amphibious tractor with an engine and chassis made of aluminum alloy and engineered plastic to minimize body weight and four wheels made of polyester filled foam. When working in the dry land, the four wheels exert little pressure on the ground, cultivating and weeding in the farmland, and do not crush crops when they are sprayed. For example,