Vibrant rows of neatly lined plants grow on a patch once trampled by the cattle of a large commercial farm run by a family of German descent in Namibia.

From that 2,400 square-metre rectangle of sand in the northern Otjozondjupa region, Kornelius Hamasab, 69, now produces spinach, onions and tomatoes.

Hamasab is among the 16 percent of black Namibians owning arable land in the semi-desertic southwest African nation.

White Namibians, who are descended from former colonisers Germany and South Africa and make up six percent of the population, own 70 percent of the land.

"It doesn't seem right to me," said Hamasab, who acquired his land as compensation five years after the farm downsized into a guesthouse in 2000 and laid off its staff.

"The government should do something about it," he added, while his family picked and rinsed collared greens to be sold in the capital Windhoek, 150 kilometres (90 miles) away.

Namibia adopted a "willing-buyer, willing-seller" approach to land reform after independence from South Africa in 1990.

Farmers wishing to sell their business must first offer it to the state, which parcels it into smaller plots and redistributes to "previously disadvantaged Namibians".

That strategy has done little to redress the imbalance, however, prompting President Hage Geingob to call for a more muscular approach.

"The willing-buyer, willing-seller principle has not delivered results," Geingob told a land conference last year, adding that the "status-quo should not be allowed to continue".

Geingob has since demanded constitutional amendments to allow for the forceful expropriation of white-owned commercial farms with "fair compensation".

His proposal echoed controversial plans in neighbouring South Africa to expropriate land without compensation.

It also brought back memories of land seizures in Zimbabwe in 2003, when thousands of white farmers were chased off their properties.