The most important change in agriculture in the past 50 years, say members of North American Agricultural Journalists, was the hybridization and improvement of many crops.

A list of 40 important events and changes in agriculture was prepared for NAAJ by three leading agricultural historians: R. Douglas Hurt of Iowa State University, C. Fred Williams of the University of Arkansas at Little Rock, and David Vaught of Texas A&M University. NAAJ members then voted on the top 10 developments in agriculture during the past 50 years.

The results were released recently at the 50th anniversary meeting of NAAJ in Washington.

Hybrid corn was developed long before NAAJ was formed in 1953. Plant scientists were experimenting with it at the turn of the 20th century, and hybrid corn began to be sold commercially in the 1920s.

When NAAJ was founded 50 years ago, the average corn yield in the United States was 40.7 bushels per acre. Last year, even after a severe drought in many states, hybrid corn helped U.S. farmers harvest an average of 130 bushels an acre.

Here are the events and developments of the past 50 years that agricultural journalists picked, in order of importance:

  1. Hybridization and other improvements of crops.

  2. Genetically modified crops engineered to kill insect pests and tolerate herbicides. Most U.S. farmers adopted this technology in less than a decade, starting in the 1990s.

  3. The discovery of DNA (deoxyribonucleic acid), the chemical building block of heredity, by James Watson and Francis Crick in 1953. These researchers discovered the ladder-like double helix structure of DNA, helping to start the biotechnology revolution now underway.

  4. Norman Borlaug's “Green Revolution.” Plant breeder Borlaug, who won the Nobel Peace Prize in 1970 and now teaches at Texas A&M, developed high-yielding dwarf wheat varieties that helped turn Third World countries such as India into food exporters.

    The wheat varieties were introduced into India and Pakistan in 1965. Borlaug's work helped prevent starvation and malnutrition across the globe.

  5. The agricultural debt crisis of the 1980s, which started when the Federal Reserve Bank encouraged higher interest rates to slow inflation. This forced many full-time family farms out of business, created rural bank failures and crippled small towns.

  6. The 1962 publication of Rachel Carson's book, “Silent Spring.” Carson, a nature writer and former marine biologist, documented how the insecticide DDT accumulates in the environment and harms mammals and birds.

    Her book helped start the environmental movement.

  7. The use of antibiotics for livestock and poultry, approved by the Food and Drug Administration nearly 50 years ago. Adding antibiotics to feed for hogs and chickens not only prevents diseases, but also makes the animals grow faster.

    It also makes it easier to confine them in large buildings with fewer disease outbreaks. Medical research has identified overuse of antibiotics in livestock production as one reason antibiotics are becoming less effective medicines for humans.

  8. Tie. NAAJ members gave equal votes to two developments: the adoption of no-till farming and the farm population dropping below 2 percent of U.S. population for the first time during the 1990s.

  9. The adoption of anhydrous ammonia fertilizer, a cheap source of nitrogen fertilizer made by using natural gas. Until anhydrous ammonia was adopted in the 1950s, farmers relied on animal manure and leguminous plants such as clover to provide this key plant food.

    Without cheap nitrogen, the high yields of hybrid corn and dwarf wheat would not have been possible.

  10. Integration of the poultry industry. Most farmers once raised a few chickens for meat and eggs. In the 1960s, once chickens could be confined in large buildings thanks to antibiotics and abundant cheap corn, ownership of chickens gradually concentrated with a few companies.

A similar process of vertical integration is taking place today in the hog industry.

NAAJ members identified several other key trends that weren't on the historians' lists. They include the increasing mechanization of agriculture in general. For example, mechanical tomato pickers (which were on the list but didn't make the top 10) became popular in the 1960s.

The U.S. grain export boom of the 1970s that followed sales to the former Soviet Union in 1972, was another key event. So was elimination of rail freight subsidies for grain in Canada, which led to more exports of Canadian crops and livestock into the United States.

NAAJ was formed as Newspaper Farm Editors of America. Today the group represents about 100 newspaper, magazine and news service writers who cover agriculture in the United States and Canada.