Agriculture Minister Hendrik Schoeman recently clambered onto a tractor and told South African farmers that flower power was the answer to their problems.

Sunflower power, that is. The South African government is seriously investigating the possibilities of using oil from the sunflower seed as a substitute in the nation's diesel-fueled tractors. This program is just one of many alternative fuel possibilities Pretoria is studying.

Long before Americans were aware of the necessity to find substitutes for their imported oil by the recent OPEC price hikes and the annoying lines at the pumps, South Africans had their consciousness raised on that score.

Without a drop of domestic crude oil of its own, and facing repeated calls for economic sanctions to protest its racial policies, South Africa has long given its attention to ways of decreasing its dependence on imported oil.

This determination was sharpened by the recent price rises and by the abrupt dissolution of the supply contract South Africa had with Iran while the shah was in power. Iran formerly supplied South Africa with 90 percent of its crude.

All these factors have put the South Africans way ahead of the United States in terms of a government commitment to replacing imported oil and to promoting research on viable "synfuels." This research efforts is complemented by an offshore search for oil deposits, which up to now has been unlawful, and by construction of two nuclear power stations at Koeberg, set to start operation in 1982.

A Cabinet=level committee of economic and transport ministers makes the political decisions on the country's energy program. It is advised by an energy policy committee, including scientists and top civil servants.

Research into synfuels is coordinated by a special committee at the 34-year-old Council for Scientific and Industrial Research, located on a sprawling site just east of Pretoria. The council, which operates primarily from an annual government grant, employs more than 4,000 people working on a wide variety of programs.

The primary thrust of the council's research focuses on the resource South Africa has in abundance -- coal.

In a recent speech, the council's chairman, Chris Brink, said: "Coal research hs not been adequately promoted in South Africa in the past three decades, and we shall have to make up much lost ground."

Brink made the criticism despite the fact that a gigantic $6.6 billion oil-from-coal project called Sasol makes South Africa the only country in the world with a large-scale oil-from-coal operation. The government claims that when the third state of the complex is completed in the mid-1980s it will provide 47 percent of South Africa's domestic oil needs at present consumption levels. It already has given the country unique expertise in the production of oil-from-coal.

Robert Scott, head of the council's Energy Research Committee, said other studies are being conducted on the use of "biofuels" converting "biomasses" of plants and plant products into usable energy forms. For example, their scientists are looking for enzymes that will convert crushed sugar cane stalks into alcohol or ethanol, which can be blended with diesel.

The government is encouraging research and testing on diesel blends as well as alternate fuels such as sunflower oil.

Testing of an ethanol-diesel blend "is in an advanced stage," according to the council's publication, Scientiae. This program aims to find a usable blend "in case of an oil boycott," the magazine said.

In order to get ethanol, the government recently announced two argicultural programs, one promoting production of cassava, a tropical plant which can be fermented into ethanol, and another promising a guaranteed water supply to farmers who will grow sugar cane for ethanol production.

Schoeman's optimistic predictions about the use of sunflower oil, either alone or as a blend, are tempered by problems researchers have encountered. The principal one is a side-effect called "gumming" in which the engine pistons become coated with a slick of the sunflower oil. It also causes problems with the fuel injection in some tractor engines. While sunflower oil is a potential replacement for diesel in tractors, is far from satisfactory in high compression engines like those in automobiles.

While the council experiments to see if these problems can be excised, the Agricultural Department is looking at the other main problem -- an economic one. Costs of pressing the oil from the seed currently make the price of the sunflower oil almost 77 cents a gallon more than diesel fuel from crude oil.

Officials are investigating whether the economics of pressing plants -- now geared to producing oil for table use and operating below capacity -- could be altered by the bulk production of oil for fuel.

According to Burri Boshoff, head engineer at the Argiculture Department's mechanical engineering research station, much more testing must be done before the government could make a commitment to the widespread and regular use of sunflower oil in tractors. Still, the government hopes to have all these answers in six to 12 months, he said.

Using sunflower oil is attractive not only because its efficiency is about the same as diesel but also because it causes less pollution, although as one Rhodesian engineer put it, "Your fields smell like a fish and chips shop."