Dorothy had to abandon the Kansas wheat fields for Oz in order to find a tin man. Soon, though, the tin man will be right there on the farm -- plowing the north 40.

A new wave of mechanization could reach the farm in the next decade, with robots sowing the seeds and reaping the crops, while computers in the field monitor soil moisture and nutrients. But small farmers are less likely to harvest the benefits than to feel increased financial pressure that will speed consolidation in the nation's largest industry. "The farmers who are devoting full-time to farming and earning from $10,000 to $100,000 a year in gross sales are going to be squeezed -- and squeezed badly," says Ben Blankenship, director of economic information at the U.S. Department of Agriculture.

The increased use of technology is already powering a drive to bigger, more productive farms. The biggest 50,000 farms -- just 2% of the total -- will produce 63% of all U.S. agricultural sales in 1990, up from 31% in 1974, according to government projections. The size of the average farm has increased from 200 acres in 1950 to 456 acres in 1985.

The new wave of more sophisticated equipment will bring a new leap in productivity. Robotic fruit harvesters could slash labor costs by 75%, according to Philip Martin, an agricultural economics professor at the University of California at Davis.

Smaller farmers -- squeezed by high debt and by the declining value of their land, which serves as collateral on loans -- may not be able to afford the new technology, which will only worsen their competitive position. In an era of overproduction and stiff global competition, the large farms will continue to widen their cost advantage over small operators. "Fewer, larger, more efficient farmers is what it's going to come down to," Martin says.