What Characteristics of Grass Keeps the Soil From Eroding?

Grasses

• Grass is in the family Poaceae, a group of 9,000 different species. Grasses are grown around the world in every climate. They are characterized by flat or rolled blade-like foliage. The root systems are fibrous and they form clumps or wide spread mats. Many grasses spread from rhizomes or stolens which create a tangled system under the soil or at the soil surface. Grasses grow and spread easily from seed or vegetatively and require little intervention once they are established. All these characteristics make member of the Poaceae family ideal for erosion control.

Ornamental Grass

• Large ornamental tufting grasses are useful to deflect runoff and provide wind barriers. Even shorter grasses can be planted closely together and help prevent erosion loss because the tight foliage prevents high winds or excess runoff from removing the soil. The grasses essentially become barriers or dams to wind and water. Grasses such as pampas grass which produce tussocks can get 6 or more feet high and offer superior wind control. They seed prolifically and can produce many more plants which add to the soil support. Ornamental grasses may be planted as waterways which funnel rain runoff into appropriate directions and away from erosion prone fields or hills.

Native Grasses

• Native grasses of many varieties once covered the slopes and prairies of North America. They provided forage, cover, building materials, fuel and anchored the soil on windy plains. Human activities have caused the loss of much of this natural erosion control which has opened flat lands up to wind erosion and caused the loss of vertical land. Native grasses offer the best erosion control choice because they produce deep roots that hold the plant to the ground. Native grasses also will not need special care and are not a threat to other native species in a well managed ecosystem.

Turf Grass Suitability

• As mentioned, turf grasses are not the ideal selection for erosion control due to their high cultivation demands. Grasses are almost all green and comprised of leafy growth which is fueled by nitrogen. Nitrogen can be acquired from the air but it is difficult to fix in soil. Grasses use much of the available nitrogen that is in the earth and may create a nutrient deprived soil. Many of the grasses spread so prolifically from seed that they become pest plants that compete with native plants for resources. Turf grasses are prone to many pests and disease problems and require management to ensure their health. Turf grass must also have plenty of water to stay alive which makes it impractical as an erosion control.