But in addition to its over $1 billion value to the state of California, alfalfa provides a host of environmental benefits that are frequently overlooked. What are these benefits?
Benefits to the soil. In addition to being an important cash crop for growers, alfalfa is good for our soil. Alfalfa is a perennial flowering plant in the pea family that is planted in the fall and remains in a field for four to six years. The crop requires few inputs, as the plants fix their own nitrogen from Rhizobia bacteria colonizing the roots, with 90 percent coming from atmospheric nitrogen. Free fertilizer from nature! The long alfalfa stand life also gives the soil a chance to rest from frequent field crop rotations, helps provide nitrogen for subsequent crops and improves soil tilth.
Alfalfa is an insectary. Alfalfa also hosts a diversity of insects, many of which are beneficial, such as lady beetles and parasitoid wasps. These in turn help control other types of insect and mite pests in alfalfa and other crops, potentially saving growers money for pest control. One option to further manage crop pests is by strip cutting the alfalfa, a process that leaves some uncut areas during harvest so that alfalfa serves as a trap crop, holding pests that could infest neighboring crops.
Many of these wildlife benefits have been documented by bird-lovers (For more information, see Farming for birds: Alfalfa and forages as valuable wildlife habitat).
Alfalfa-ice cream in the making! Markets for alfalfa primarily include the dairy industry, with alfalfa being an important part of a cow’s feed ration, as it provides high protein and energy for high milk production. This is economically important (the dairy industry is worth $7 billion per year) but also important for human nutrition. A California alfalfa field can produce 2,400 gallons of milk per acre. So the next time you have pizza (with cheese), milk on your cereal, or ice cream, thank alfalfa.
When you smell the fragrance of newly mown hay, thank the alfalfa grower and the “Queen of Forages” which helps produce milk right here in California. Watch the fields for bird activity and see if you can spot some Swainson’s hawks feeding on rodents and helping alfalfa growers with pest control, or curlews and egrets foraging for prey. But also be grateful for a host of important wildlife and environmental benefits to the landscape that alfalfa provides.
For more information, see the UC alfalfa workgroup website.