Alfalfa Overview

Production

Alfalfa is a perennial crop, which means it will grow for several years after planting. Alfalfa is planted in the spring or fall. Since the seeds are so small (1-2 millimeters), slightly wider than the tip of a pencil lead, they must be planted close to the surface of the soil. Between 15-25 pounds of seeds are planted per acre, which is about the size of a football field. There are about 200,000 alfalfa seeds per pound. Alfalfa is harvested with a swather, which cuts off the crop a few inches above the ground and places it in strips three to five feet wide where it dries in the sun. When the cut alfalfa is dry enough, the hay is raked and a baler is used to gather it up and compress it into a bale. Alfalfa can also be made into silage by harvesting the forage and storing it in a silo while it is still moist, where it is preserved in a process called fermentation.__

Varieties

Many alfalfa varieties are available to growers. Those that tolerate freezing are grown in the northern United States and Canada. Other varieties continue to grow during the winter months in areas such as Southern California and Arizona where growers may harvest all 12 months of the year. Alfalfa breeders have developed many varieties of alfalfa that are highly resistant to diseases and insect pests, thereby reducing the need for pesticides.

Commodity & Nutritional Value

Alfalfa is an important rotation crop as it adds nitrogen to soil and improves soil structure for future crops. Unlike other crops, alfalfa does not need nitrogen fertilizer. Nodules on alfalfa roots contain bacteria that take nitrogen gas from the air and convert it to nitrogen plants can use. This process is called nitrogen fixation. The exact financial value of this soil improvement is not calculated, but is significant. Wildlife, including over 130 bird species, use alfalfa fields for food and shelter. For many animals, including endangered species, alfalfa fields are their preferred habitat.

Alfalfa is considered the premier forage of dairy cows. Thus, much of the milk, yogurt, cheese, cream, dried milk and ice cream we eat are connected to alfalfa.

• __Information from the California Foundation for Agriculture in the Classroom (http://www.cfaitc.org)