The Benefits of Alfalfa to the Southwest Ecosystem

Ayman Mostafa

The possibility of “mega drought” in the southwest U.S. was the subject of a debate on NPR’s Diane Rehm Show on April 15, 2015. The guests went through the record, probable causes and possible solutions for the shortage in water in the region. The panel discussed how to harmonize environmental goals, urban expansion and agriculture needs. The share of water going toward alfalfa hay production that supports the dairy and livestock industry, and changing crop selections were among the topics of discussion.

This is a good opportunity to emphasize some facts. Alfalfa in the southwest ecosystem provides many environmental benefits: it is a rich habitat for wildlife; provides an insectary for diverse beneficial insects; improves soil characteristics; fixes atmospheric nitrogen; traps sediments and takes up nitrate pollutants; mitigates water and air pollution; and provides aesthetically pleasing open spaces.

  • Areas depleted of row crop or specialty crop production, like many agricultural areas in the western US would benefit environmentally by stabilizing soils when incorporating a perennial legume such as alfalfa.
  • Alfalfa fields are important contributors to the biodiversity of agricultural systems by functioning as insectaries for beneficial insects, many of which are pollinators or natural enemies that play important roles in the low desert agroecosystem. Beneficial insects move from alfalfa fields into other crops, where they play crucial roles in pollination and biological control.
  • Alfalfa also plays an important role in insecticide resistance management by acting as a refuge, especially for aphids and whiteflies. Low desert alfalfa production is quite different from production in other areas where non-dormant, irrigated varieties provide a year-round habitat for insects.
  • Non-dormant alfalfa hay varieties are uniquely adapted to the low desert climates of central and southern Arizona and the adjacent region of California along the Colorado River. Unlike many other production regions in the nation, low desert alfalfa is irrigated and produces an average of eight cuttings every year. Alfalfa acreage in the region is likely to increase given the importance of the dairy industry and other livestock enterprises and a reduction in cotton acreage due to low cotton prices.

You can access the show audio by Clicking Here.

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