William Chancellor, professor emeritus of biological and agricultural engineering at UC Davis, is a rather modest man.

Reflecting on his career, he invokes a proverb from Thailand, usually used to describe a person who has stumbled into good luck: "He is like the mouse that fell into the rice bin."

Chancellor recalled, "I came to UC Davis straight from school, I was supplied with help and guidance and got free rein to do anything I felt useful. I've just been having fun going in different directions."

In fact, for more than 50 years, Chancellor has studied technology, labor and energy use in farming, and has worked to improve the efficiency of agriculture — the world's biggest employer and arguably the most fundamental industry — in the U.S. and abroad.

Earlier this year, Chancellor's lifetime achievements were recognized with his election to the National Academy of Engineering, one of the four prestigious National Academies. Dateline recently talked to him about his career and about developments in agriculture.

How did you become interested in agriculture, energy and international development?

I came from a small Wisconsin dairy farm. In the 1940s, farms ran on the muscle power of farmers and their horses, and during the war there were shortages of machines and fuel. The human effort seemed to be an unreasonable burden on farmers, and I felt that reducing this burden might be an interesting field for me to get into. I took joint degrees in agriculture and engineering at the University of Wisconsin-Madison, then a master's and a doctorate at Cornell University, where I studied problems in handling forage on dairy farms.

In 1957, Roy Bainer invited me to come to UC Davis to join a statewide project on soil compaction, a problem caused by use of heavy machinery on agricultural soils. I was lucky enough to be able to study with one of the leaders of the field, Walter Soehne, then visiting UC Davis from Germany.

One time I was taking the train from Wisconsin back to Cornell, and the train broke down. There was a Thai student in the seat behind mine, and I helped her with her luggage in the transfer to a replacement train. Four years later, Nongkarn and I were married in Thailand. To get to Thailand in 1960, I took a sabbatical from UC Davis to study the country's agricultural tools — some of them representing technology that had been in use for more than 500 years.

On the same trip, I visited classmates from Cornell who had returned home to the Philippines to work. Then in 1962-63, I received a Fulbright award to start instruction in agricultural engineering at the University of Malaya. Since then, I have made many trips overseas, especially to Southeast Asia, mostly carrying out surveys of farming practices. I've also been lucky to participate in the programs of so many constructively minded graduate students from around the world.

Why study energy in farming?

Energy is one of the key elements in farming. That includes muscle power, fuel to run machines, make fertilizer and run irrigation pumps, transport produce and so on. With basic food crops such as cereals and potatoes, you generally get a net energy gain, more calories in the food than you had to put in to grow it. In this country, many of those grain crops are fed to cattle, pigs and poultry, causing the animal products to be very energy intensive. In developing countries, diets contain more starches and little meat.

In the U.S., seven calories of fossil fuels are spent to put one calorie of food energy on your plate.

For developing countries, the Green Revolution of the 1960s promoted new crop varieties, fertilizers and advanced farming methods, leading to rapid increases in harvests. Those changes were based on using fossil fuels to make fertilizer, pump water and drive machinery — effectively substituting cheap oil for land and water. But farmers took a hit when oil prices rose sharply in the early 1970s.

Now the current surge in oil prices is also hurting Asian farmers who cannot easily go back to using buffalo to plow their fields and windmills to pump water.

What about farming as a source of fuel?

Plant oils are more valuable as foods than as fuel, though that changes as the price of crude oil goes up. Oil palm and sugarcane can produce more energy as a crop than you have to put in to grow and process it, but we found about 20 years ago that if you had to pump water from any significant depth to irrigate your crop, then you had a net loss of fossil-fuel energy.

Producing ethanol from corn is close to breaking even in terms of energy. Sugar cane is a more efficient crop for producing ethanol as fuel because the crop residue is burned to get the processing energy. In fact at one time, the Big Island of Hawaii got about 50 percent of its electricity needs from the surplus energy from sugar cane processing.

What impact has mechanization had on agricultural workers?

In the 1970s, we did a series of studies on the impact of mechanization on California's farmworkers. We collaborated with agricultural economists here at UC Davis.

Overall, jobs for hired workers didn't decline, but the work was in different places at different times. For example, mechanization reduced the need for labor in such formerly high-labor-intensity crops as grapes and almonds, which encouraged farmers to switch land use from low-labor-intensity crops such as cereals to the now intermediate-labor-intensity crops such as grapes and almonds, netting higher per-acre returns.

What about in the developing world?

In many developing countries, 70 to 95 percent of the population works in food production. Here it is about 15 percent (2 to 3 percent on the farm). If you have fewer people working to provide food, that releases a lot of human capacity to do other things.

In places like Malaysia and Thailand now, there are a lot of manufacturing industry, electronics, automobiles and auto components, disk drives and so on. These industries take the young people from rural areas, so those remaining on the farm bring in technology to help them work the fields.

If the economy is prepared to move forward, they can create new jobs in other areas. For example in Thailand, they have moved into food processing and export. Much of the machinery they are using on farms is locally designed and built, such as two-wheeled tractors that are easy to repair and maintain.

There's a movement in the U.S. and Europe in favor of organic or sustainable agriculture. Is it possible to go from mechanized agriculture back to a more traditional approach?

I think so many people now have made the transition to modernized agriculture that it would be hard to quickly go back to the near-organic, near-sustainable agriculture of 150 years ago. There would not be enough food to feed today's population, and the people with the skills to do this are almost gone. What we do need to do is to find ways to maintain, and even increase, food production while bringing the adverse environmental impacts of materials and methods used as close to zero as possible — all while conserving, and finding renewable substitutes for, non-renewable resources like fossil fuels.

What was your reaction to being elected to the National Academy of Engineering?

The first I heard of it was when I got a FedEx package from the academy in February. I couldn't understand what I had done to be elected, causing me to realize and especially appreciate the heroics that must have been performed by those who put my name forward. I have been lucky to have worked and have had help from so many remarkable individuals and institutions. They gave me a free rein in many ways. Finally, I have tried to pass on that atmosphere to my students.