The option that correctly identifies a result of agricultural practices is Soil erosion.
Soil erosion is often a consequence of various agricultural practices, especially those that involve tillage and the clearing of land for farming. While water diversion and slash-and-burn agriculture are specific methods or practices used in agriculture, they are not necessarily direct results of agricultural practices in a general sense. Biodiversity can be affected by agricultural practices, but it can be both negatively and positively influenced depending on how agriculture is conducted.