土壤压实是指家畜或碾压机器的重量压在土壤上，导致土壤失去其内部的空隙。土壤压实，也可能会导致土壤中缺水。因为土壤变得不那么能够吸收雨水，从而增加了地表溢流和土壤侵蚀的可能性。矿物颗粒同时加压使得植物难以生存，压实的土壤使土壤几乎不留有储存空气和水的空间，而水与空气对植物的根的生长来说是必要的。经过压实的土壤对掘穴动物来说也是一个不好的环境，因为土壤密度的增加使其更难以穿透。

恢复土壤压实的能力取决于气候、矿物和动物。高收缩膨胀能力的土壤，如变性土，能在雨雪量发生改变的时候迅速从压缩后的状态恢复过来（干旱慢慢收紧土壤，造成裂纹）。但粘土不崩裂，因为它们干不能自己从压实的状态恢复，除非他们所在的地方有蚯蚓等动物居住-塞西尔土壤系列就是一个例子。

In geotechnical engineering, soil compaction is the process in which a stress applied to a soil causes densification as air is displaced from the pores between the soil grains. When stress is applied that causes densification due to water (or other liquid) being displaced from between the soil grains, then consolidation, not compaction, has occurred. Normally, compaction is the result of heavy machinery compressing the soil, but it can also occur due to the passage of (e.g.) animal feet.