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Water issues and others face alfalfa

California alfalfa growers must ride out a tide of perennial water issues while managing waves from market shifts and public perception of their industry, says Dan Putnam, forage specialist at the University of California, Davis.

Speaking at the recent 31st California Alfalfa and Forage Symposium in Modesto, Putnam said water quality, availability, and price make up “the Achilles heel” of agriculture, particularly for alfalfa, which occupies one million acres in the state at a value exceeding $1 billion.

Attention is on alfalfa because its water needs average about five acre-feet per year (per acre) across the various growing regions in California. It claims about 15 percent of the state's agricultural water and lacks flexibility because it is a perennial crop.

And alfalfa returns are only moderate when compared with those of the many specialty crops, so it is challenged when water is expensive.

But the nature of alfalfa's water use should to be discussed and appreciated, Putnam said. “The high water use of alfalfa is mainly due to its high acreage, its length of season, and its high yield. If you look at the water use on a per-month basis, it's probably comparable to most other herbaceous crops.”

In addition, the crop's high water use efficiency and deep roots ensure recovery of residual water. That efficiency calculates to 303 pounds, vs. 109 pounds for rice and 31 pounds for almonds, per inch of applied water.

Water implications

Even when supplies appear relatively adequate, the value of water is subject to interpretation from many interests: agricultural, urban, and environmental.

A long list of water transfers from one end of California to the other has implications for the future of the crop.

One example is the transfer of 200,000 acre-feet per year from the Imperial Water District to the city of San Diego; another is continued uncertainty of water availability in the Klamath Basin where Endangered Species Act rulings regulate lake levels and stream flows.

The complete list, he said, “is probably enough to make most alfalfa growers curl up in a fetal position.”

Putnam stopped short of making narrow predictions but asserted that “water will be a key factor in our future and we need to keep track of the various issues.”

Aside from water quantity, water quality poses questions. Chief among them is concern with offsite movement of pesticides, mostly organophosphates and certain winter dormant herbicides in watersheds where most of the crop is produced.

Allowing that these technical questions are linked closely with water management, Putnam said they do require response and raised interest among the industry.


As the rest of agriculture, alfalfa faces its share of issues relating to biotechnology. Alfalfa will be affected from the standpoint of pest management and is at the threshold of the so-called “Biomaterials Age.”

An important development is Roundup-resistant alfalfa, expected to enter the market in 2004 and following in the wake of herbicide resistance in corn, soybeans, and other crops. Resistant genes are being transferred from other plants into alfalfa.

“But remember that traditional plant breeding is still the primary engine for improvement of alfalfa. Advances in biotechnology will have a big impact, but we still need traditional plant breeding to make sure they are relevant.”

Putnam said the alfalfa industry must respond to public fears with gene-splicing and content of milk and meat of animals fed the forage.

Alfalfa is going through a shift in its market share. It and other field crops have been pressured for the last 25 years by shortages of water and conversion of land to other crops or housing tracts.

Corn silage acreage in California, Putnam said, is now at about three times its acreage of 1970. At that time alfalfa production per dairy cow in the state was 45 to 50 pounds per day, but now it is about 20 to 25 pounds per day.

The big question for alfalfa is whether it has unique forage traits that the dairy industry cannot afford to do without. “This has much to do with quality and how we define it, and some things must change.”

Forage quality assessment too has been transformed during the past 30 years. Under recent Nutritional Requirements of Dairy Cows, nutrition rating is moving to combinations of actual measurements of quality along with measurements to estimate energy.

Although nutritionists differ in how to calculate total digestible nutrients, fiber-value methods to predict TDN are expected to give way to neutral detergent fiber and digestibility estimates. Putnam urged the California industry, whose marketing system is based on the older fiber value methods, to take note of the new approach.

Price has a huge effect on quality, and Putnam cited an estimate of $300 million per year in value of quality factors. “This will likely continue or even intensify as we look at the different ways of measuring forage quality.”

The public, including decision makers, he said, knows very little about alfalfa.

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