Medicago sativa

Alfalfa, Lucerne

Temperate

Introduction

Alfalfa or lucerne is a perennial forage plant belonging to the pea family Leguminosae. It was first cultivated in hot, dry regions of Mesopotamia before the advent of recorded history. From there it was taken to Greece in the 5th century BC and to Spain in the 8th century AD. Spaniards introduced alfalfa to North and South America in the 16 ^th century. Alfalfa now is grown throughout the world under extremely varied climatic and soil conditions. It has been an animal feed longer than any other forage crop and today is considered to be the most important fodder crop in the world.

Alfalfa sprouts are widely eaten and very young shoots have been eaten as potherbs in various cultures. However, the plant's potential as a direct human food has barely been touched. Of all the crops whose leaves can be eaten by humans, alfalfa is currently by far the most prolific. Alfalfa production in the United States averages about 70 million metric tons harvested annually for hay. This is about 570 lb. per person per year or over 1 1/2 lb. per day per person. The problem is that most alfalfa is too tough and stringy and some is too bitter to eat the way we eat spinach or lettuce. The solution is that alfalfa needs to be processed before humans can eat much of it.

There are two relatively simple techniques that can convert alfalfa into a useful ingredient for small-scale commercial food processing. An exceedingly nutritious leaf concentrate can be made by heating juice pressed from pulped alfalfa. A stable powder can also be made by the even simpler technique of drying alfalfa in inexpensive solar dryers and grinding the dried leaves in a manual grain grinder. Information on these two basic leaf processing techniques can be found elsewhere in this web site.

Alfalfa leaf concentrate and dehydrated alfalfa meal can be used in food products ranging from pasta and drinks to cookies and candies. Some of these products are already being produced and marketed on a micro-enterprise basis. In communities where both new sources of nutrition and new businesses are badly needed, alfalfa may lead dark green leafy vegetables to a more central role in the human diet.

Pros

- Probably the best overall crop in the temperate zones and high altitude tropics for the production of leaf concentrate

- Excellent source of iron, calcium, and beta-carotene

- Alfalfa's extremely deep roots (up to 9 m [30']) enable it to reach otherwise inaccessible nutrients from the subsoil, and to reach water during droughts.

- The deep roots also create channels for air and water to penetrate the subsoil and create improved drainage for crops to follow.

- Yields up to an amazing 100 tons of green leaf crop/ha with irrigation. In trials in Aurangabad, India alfalfa yielded 150 t/ha fresh crop.

- One of the best plants for converting atmospheric nitrogen to forms that can be used by plants.

- Does well in high elevations (up to 4000 m [13,000 ']) where few other crops thrive

- Withstands repeated cutting (8 to 15 cuts per year in Mexico)

- Needs replanting only every 6-8 years

- Has a dense and erect growth ideal for easy harvest with scythe or sicklebar cutter

- Dehydrated alfalfa leaf has been successfully marketed in the form of capsules, tablets, powders, and tea through health food stores for many years. Its health giving properties are well accepted in many areas where it is grown.

- One of the best of all commercial crops at preventing erosion

- An excellent honey plant for bees

Cons

- Too tough and fibrous for humans to eat without processing of some kind

- Thought of exclusively as an animal feed in many regions

- Won't thrive in high heat or humidity

- Requires more water than maize or sorghum to make comparable yield of dry matter; this makes it less appropriate for low rainfall areas.

- Can have a biting aftertaste due to saponins (bitter glycosides that foam in water)

- Susceptible to viral diseases, especially in hot humid areas

Notes

- Generally alfalfa yields increase with additional rain or irrigation water with a minimum of 50 mm and a maximum of 250 mm.

- Tropical varieties have been developed at the University of Florida and in Brazil. These do better in heat and humidity, but still have problems compared to tropical natives.

- Best suited to soils with a pH of 6.2 – 7.8. Grows very poorly below 6.0.

- Alfalfa is a potential source of a variety of medicinal and industrial compounds. Research has begun at the University of Wisconsin and elsewhere to commercially extract compounds from genetically altered alfalfa.

- Nitro is an annual type of alfalfa that fixes more nitrogen than the normal perennial alfalfa because it continues fixing nitrogen until it is killed by frost.

- Seeds are very hard and should be scarified or soaked in water before planting.

- Fresh seed does not germinate as well as seed that is 2-3 years old.

- Suggested seeding rate is 12-20 kg/ha when broadcast; 10-12 kg/ha seed when planted in rows or ridges.

- Planting in ridges or rows 1 1/2 to 2 feet (50 – 75 cm) apart makes weeding much easier until cover is established.

- Optimum nutritional value of leaves is just before flowering begins.

- Leaf growth is greatly stimulated by adding phosphorus to the soil.

Seeds

Normally available commercially in afalfa growing regions. Small packets of tropical varieties available from ECHO. Non-hardy, heat resistant variety CUF 101 (grown in California's Central Valley) is available from - Cal/West Seeds, Ramsey Seed Co, and Gunson Seed. Nitro seed is available from Pleasant Valley Farm Supply and other good mail order houses.

Related Plants with Edible Leaves

Medicago lupulina (black medic, hop clover); M. polymorpha (toothed bur-clover) About 185 species of related leguminous plants produce leaves that are eaten to some extent by humans.