Alfalfa Improves and Protects Valuable Soil
The importance of alfalfa for hay production is well known. But, alfalfa also plays an essential role in soil sustainability. Not only does alfalfa help prevent soil erosion, but it also protects and improves the soil with its protective canopy, deep root system, and ability to fix atmospheric nitrogen.
Soil erosion is a major problem in agriculture. Valuable soil is permanently lost each year due to wind and water erosion, overgrazing, and poor agricultural practices. Many crops require cultivation one or more times during the growing season to remove weeds. Alfalfa is one of the few crops that requires little to no cultivation once it is established, and as a result, soil loss from wind and water erosion is dramatically reduced.
As alfalfa grows, it quickly forms a dense canopy that covers the soil and protects it from wind and water erosion and reduces runoff. The dense canopy also suppresses the growth of weeds that are common in annual crops. Moreover, frequent cutting prevents weed seed production, which may reduce herbicide use in subsequent crops.
Unlike most other crops, the root system of alfalfa descends deeply into the soil - 9 to 16 feet. This deep and extensive rooting system is very beneficial to the soil. The deep and far-reaching roots hold the soil together. In addition, the root system creates spaces and channels in the soil that aid water movement, which is beneficial to the current crop but may also enhance efficiency of water use in subsequent crops.