The brothers William and Joseph Misoi and Kipsoimo arap Busienei are three men who are ensnared in a poverty cycle of peasant subsistence farming while their Kilibwoni neighbors, with equal amounts of land, each season gain ground in income. The gap between the two groups may soon be unbridgeable.

The three men's lean frames and calloused palms attest to the hard work they do most days of their lives, but that sweat has yet to produce the growing cash margin they need to invest in their land so as to get its maximum worth in cash.

The rural poor -- people in circumstances identical to those of the Misois and Busienei, together with their children -- are a constant source of worry to most African governments. None of the three have considered leaving their small farms, but it is from their ranks that the largest percentage of peasant migrants emerge in the generally overburdened cities to look for a better life. Marginally educated and lacking employable skills in good economic times as well, many of these migrants end up in the shanty slums in Africa's capital cities.

African governments have not been able to keep up with the social services these new city arrivals require nor effectively halt the crime that inevitably spreads with the slums.

The three-year-old civilian government in Nigeria, an oil-rich nation with an estimated one-quarter of Africa's 400 million people, has belatedly been pouring millions of dollars into rural development to stem the flow of peasants into the already grossly overcrowded capital of Lagos. The success of that effort is still far from clear.

Kenya has been more successful than many other African countries in providing taken-for-granted urban amenities for its rural population, such as clean, piped drinking water, free rural health care and expanding rural educational opportunities, programs that have been overlooked or unaffordable in many other parts of the continent.

The potential dimensions of the problem for Kenya, however, are reflected in the limits of fertile lands which are only 20 percent of the country's 224,900-square-mile area and already overbrimming with an estimated 13 million people on 1.7 million small farms. It would cost billions of dollars, which Kenya does not have, to bring the remaining 80 percent, both marginal and semiarid lands, into agricultural use.

Its capital, Nairobi, a city of almost a million people, has not entirely escaped the rural-urban migration problem. Nairobi's growing shanty slum spreads through the Mathare Valley on the city's outskirts. While Nairobi has a low yearly 2 percent population increase from recorded births, rural arrivals account for a high 8 percent annual growth rate.

Mounting land density pressures are a major contributor to the migration into Nairobi, population experts said, but of immediate concern for the government is this migrant underclass' evident alienation. The depth of their estrangement was recently demonstrated when an easily suppressed Air Force coup attempt unleashed a long orgy of looting, vandalism and violence by the Mathare Valley dwellers in the richer parts of the city.

Out in the countryside, however, during a return visit to Kilibwoni, which is where I worked as a Peace Corps volunteer teacher in 1969 and 1970 and is 184 miles northwest of Nairobi, I was impressed by the amount of progress accomplished in 13 years and by the daily swirl of development-connected activity. Almost every day, my host, Subchief Cleophas arap Moro, was running off to an area chiefs' planning meeting, receiving delegations from other parts of Kenya that had come to see crop management improvements in his Sigilai district or putting on his khaki chief's uniform, topped by a rakishly slanted black beret, to go to a public rally.

The overwhelming impression was one of movement -- upward. All of the evident drive among many of the Nandi farmers, every conversation I had with friends, eventually came around to maendeleo, "progress" in Swahili, which made the plights of William Misoi, 42, his brother Joseph, 39, and Kipsoimo arap Busienei, 39, that much starker. They are also old friends, and my conversations with them were depressing.

A decade and a half ago, when they were younger and land here was one-tenth today's $700 per acre price, the initial start-up costs to get into cash farming were very low. Now, if they could qualify for a small farmer's loan, the decade-long rise in petroleum-based fertilizers has substantially increased the initial investment required and the rental of a diesel-fueled tractor to plow the land.

The Misoi brothers have evenly subdivided between them their late father's 20-acre farm where they live with their families. William and his wife, Clementina, have seven children. Joseph and his wife, Susanna, have three children.

Their father had been too poor to send either of them to school, but today all of their children attend. William's two oldest have luckily made it up to high school with the financial assistance of relatives. Kenya secondary school fees range from $200 to $400 a year per pupil. Even the lower amount is well above each brother's yearly income.

"We still struggle each year for the $10 for each child's primary school uniform," said William while we all sat in his traditional Nandi mud-walled, thatch-roofed home eating boiled cornmeal dough with stewed chicken and tea.

It takes $170 per acre to properly prepare the land with a tractor and then plant, fertilize, weed, harvest and shuck hybrid corn for an average 15 bags an acre yield. The profit per acre at this year's prices is just $24. Agronomists contend that the yield and profits per acre can be more than doubled by using improved planting techniques, but that means little to the Misois. The investment required remains the same.

Walking through their adjacent farms, I noticed that the corn was not as far advanced as it should be with the harvest expected to begin in mid-December this year. "We were late planting because we didn't have the money for the [$5 per bag per acre] seed," Joseph explained. In addition, they used an ox-drawn plow to furrow the seven acres they planted, meaning the most fertile soil could not be brought to the top. They could not afford any fertilizer. They will be lucky to get seven bags an acre for home consumption.

The other man, Busienei, taught me how to hunt using traditional Nandi knob-headed throwing sticks. On Sundays, we would leave Kilibwoni in a large hunting party with a dog pack before dawn and walk north for several hours to the Uasin Gischu plateau to hunt impalas, guinea fowl and rabbits on the untilled plains. That area is all farmland today.

Those reminiscences provided the only light moments in our recent conversations. Busienei and Jepkirong had only recently married then. It was nothing for us to go to my house for goatmeat sandwiches or to his for Jepkirong to stew a chicken if we came back empty-handed, which was often.

Today, they have four children, Busienei's elderly mother to look after, 4 1/2 acres of land and no money. When we finished laughing about our many luckless hunting forays and came up to the present, a cloud dropped over his face.

Over cups of tea and bowls of corn mixed with beans we talked about the reasons. "I was chased from school in the beginning of the fifth grade because my father did not have" $8 for school fees and 90 cents for a school uniform, he remembered.

When his father died, Busienei and a younger brother were left with six acres of land. The younger brother lives on one, the government took half an acre to build a country dirt road past Busienei's traditional thatch-roofed house and he has been left with 4 1/2 acres.

One and a half acres are planted with corn for the home and six mixed-breed cows graze on the remaining three acres. "They produce very little milk, almost nothing for sale," he shrugged. "There is not enough grass on three acres.

"There is not much else I can do but try to earn some money from odd jobs here and there and provide for my family the best I can," he said. "My children are lucky that they at least can go to primary school. Like my father, I cannot afford to pay."