Trees, deep-rooted grasses and perennials are excellent plants to prevent soil erosion. Used individually or in conjunction they all address the two main sources of erosion: wind and rain.
Plants with deep roots are capable of anchoring soil, preventing it from being washed or blown away. Grasses grow particularly quickly and many species have very deep root systems. However, they may not be a long-term solution as they are vulnerable to grazing and other disturbances, leaving the field vulnerable to weeds.
Deep-rooted perennials can be used instead of or as a supplement to grasses. They do not grow as quickly, but are robust and last for many years. Their roots help hold the soil and persist throughout the winter. They are not as susceptible to disturbances, keeping weeds from invading the field.
Trees are perhaps the most effective method of preventing erosion, but the slowest to grow. Tree roots are very sturdy, and their size makes them very effective at blocking wind. This in turn protects both the soil and shallow-rooted plants. The most effective strategy utilizes all three types of plants, each supporting the others. The best species to use differs by climate and soil condition, but plants native to the area tend to be lower maintenance.