JOHANNESBURG -- Early in 1991, President Frederik W. de Klerk is expected to announce the scrapping of one of the oldest and most fundamental of South Africa's apartheid laws -- the Land Act, first passed in 1913, which prohibits blacks from owning land outside the 13 percent of the country demarcated as tribal reserve or "homeland" territory.

The promised scrapping of the Land Act and the Group Areas Act, which apportions separate living areas for the different races in towns and cities, will mark the turning point between the country's segregationist past and its integrationist future. Thereafter, race will no longer be the determining factor in where a South African may live.

But if the scrapping of the Land Act will be huge in symbolism, it also will be fraught with more difficulties than any reform that de Klerk has attempted so far. To both black Africans and white Afrikaners, land is charged with emotion. The history of both people is writ large in the struggle over it, and both invest it with a significance out of all proportion to its intrinsic worth. It is a matter of blood and soil, of faith and roots, of sacred ancestors.

To blacks, it is axiomatic that a scrapping of the act must be followed by a redistribution of land. To them, the Land Act entrenched in law the dispossession of their land by the white pioneer settlers nearly two centuries ago, and scrapping the law will enable them to reestablish themselves as farmers. As they see it, their stolen birthright must be given back. Little attention is paid to how this redistribution is to be brought about, or to its possible impact on the agricultural industry and the ability of the country to feed itself.

The Freedom Charter of the African National Congress, the movement's basic policy document, states that "the land shall be shared among those who work it." In almost biblical terms, it goes on to declare that the "restriction of land ownership on a racial basis shall be ended, and all the land redivided among those who work it, to banish famine and land hunger."

The more radical Pan-Africanist Congress says it will nationalize all land and resettle "the people," meaning blacks, on it. There is no talk of compensation.

White farmers say they will resist. Some talk of fighting another Boer War -- in which the Afrikaners, or Boers, descendants of the Dutch colonists, fought and lost to the British in South Africa in 1899-1902 -- if there is an attempt to force them off their land. Andries P. Treurnicht's far-rightist Conservative Party, which has the bulk of support among white farmers, says it has extensive plans to oppose the scrapping of the act. While not disclosing any details on what it plans, Dries Bruwer, the party's spokesman on agriculture, says de Klerk is in for a shock. "The future of any country is built on land. Wars have started over land," he said darkly.

The government, seeking a middle way, is relying on the free market to resolve the land problem, and its tight spot. The official line for this and other problems brought on by reform is: Remove the legal restrictions, then leave it to market forces to sort out who owns what.

The government is anxious to keep out of the treacherous political waters of redressing past injustices. Asked whether people who have been dispossessed of their land should not get first option on it once the act is gone, Constitutional Affairs Minister Gerrit N. Viljoen replied recently that the acceptance of such a principle around the world would cause chaos, beginning with the United States and Australia.

There are many whites, including some close to the government, who regard the free-market approach as a cop-out. A modest farm in South Africa costs around $160,000, and hardly any blacks could afford that, even if credit were extended to them. The change in the law would not automatically alter the lopsided state of land ownership.

Aninka Claassens, a land specialist at Witwatersrand University's Center for Applied Legal Studies, worries that it might even make things worse. She points out that the present imbalance is not just a matter of the ruling minority, 5 million whites, holding 87 percent of the land while the majority, 28 million blacks, hold 13 percent. The blacks do not even own the 13 percent allocated to them, she notes.

It is nearly all held in trust for them by the white government and its tribal homeland administrations. Although this land is occupied by millions of black families and communities who have rights to particular parcels of it by grants, certificates of occupation, purchase or inheritance, these rights are not registered on the title deeds, Claassens notes.

"That means if it is simply opened up to the free market, many blacks who have owned and occupied land for generations may find it sold from under them by the nominal owners," Claassens warned.

But whatever the government's present intentions, South Africa is in political transition, which sooner or later will bring in a black government that almost certainly will set about redistributing at least some land. Both sides of the political divide are studying how this can be done without wrecking the agricultural production of one of the few countries in Africa able to feed itself.

Most white farmers say it is impossible, citing as testament the impoverished communal grazing lands in the homelands, scrub cattle, the few patches of corn and sorghum growing among the thorn trees.

But a handful of agricultural economists working for the Development Bank, a semi-governmental agency, disagree. Five years ago, the bank began financing a number of agricultural support programs in the homelands that involve giving a package of aid -- seed, fertilizer, a few implements, basic advice -- to black subsistence farmers at a cost of $150 each.

According to the bank's general manager, Johan Kruger, these have been "quite remarkably successful." They have significantly upgraded the production of about 25,000 of these smallholders, greatly improving their ability to feed their families.

"The perception that blacks can't farm and that people can't make a living on small pieces of land in South Africa is a fallacy," Kruger said. "Provided they have the necessary support services and infrastructure, black farmers have shown that they can farm as well as whites."

Boy Mukwana, who farms 10 acres in the Lebowa homeland of northern Transvaal province, is one who has demonstrated this. His production increased fivefold after taking the aid package last year. After paying for the package and using 20 bags of corn to feed his family, Mukwana still had enough corn left over to sell for $600, the first cash profit of his life.

Johannes Mavimbela is another example. He used to be a foreman on a white-owned farm earning $32 a month until he moved to the Kwandebele homeland in northern Transvaal, opened a shop and began farming a small plot in 1977.

Four years ago, Mavimbela was allocated a sizable piece of land when the government bought a number of white farms to add to Kwandebele as part of its homeland consolidation program. With 1,630 acres, he is one of very few blacks in South Africa who can be classified as a commercial farmer.

With the help of loans and a training program financed by the Development Bank, Mavimbela is proving a conspicuous success. Last year, he made a net profit of $10,000 and hopes to improve on that this year. He owns three tractors and a pick-up truck, in addition to his Mercedes-Benz.

Nico van Hulst, credit manager of the homeland corporation that runs the assistance program, said a number of farmers on it are doing as well as Mavimbela. "In the second year of our program, the black farmers produced 32,000 tons of maize, which was the biggest crop ever produced in this area," van Hulst said.

But the question remains of how to get black farmers on the land.

An official at the Development Bank, Nicholas T. Christodoulou, proposed one answer at a conference two months ago that caused an uproar in white farming circles and brought bomb threats against him and the bank's chief executive, Simon Brand.

Christodoulou's plan is for the banks and agricultural assistance agencies to foreclose on the 3,000 white farmers so heavily in debt as to be beyond salvation. That, he estimates, would make about 10.75 million acres immediately available for transfer to black farmers "at affordable cost" to the treasury.

Add to that another 5 million acres of trust land that has not yet been shifted to the black homelands, 4.2 million acres zoned for small holdings close to cities, an unknown amount of mission land belonging to the churches, plus the return of "black spots" from which 1.3 million black people were forcibly removed under apartheid, and Christodoulou reckons that a quarter of the country's arable land could be made available to blacks.

Pieter le Roux, an economist at the University of the Western Cape, near Cape Town, has a more radical proposal based on changing the tax system. At present, farmers are taxed according to profit. Le Roux, a white member of the ANC, has called for a tax system based on the land's productive capacity as reflected in its market value. That, he says, would force inefficient white farmers to increase their productivity or sell out, making more land available for transfer to blacks.

If a farmer were to put an artificially low price on his land to reduce the tax, le Roux says, the state could buy it at that price and add it to the transfer pool.

Le Roux's plan also would close a popular tax loophole used by rich white city-dwellers. Since capital development on farms is tax deductible, top-bracket professional and business people often buy farms for this purpose but do little else with them. "Under my scheme, they would either have to farm them properly or suffer the tax consequences. Since they bought the farms for tax purposes to begin with, most would quit and sell," le Roux said.

Officials at the Development Bank have expressed cautious interest in Le Roux's idea. Without referring to it directly, Christodoulou noted in his conference paper that land tax was "an instrument of great potential in ensuring that land gets used productively, and that it becomes available to the most productive users."