A population boom across the world will undermine food security and urgent counter-measures are needed, the Land Bank said on Wednesday.

CEO Phakamani Hadebe said a new approach was needed to sustain food security as the world moved towards the 22nd century.

"We really have to review the way we do business. Food security will demand new thinking and a new approach."

Hadebe was briefing reporters in Centurion at the signing of a multi-billion rand agricultural loan deal between the bank and agricultural services and food group Afgri.

"For the world to be able to produce sufficient food, we will need to improve our technology. We need new systems to enhance our productivity. We also have to work smarter."

Without sufficient food, cross-border migration would swell rapidly, he said.

"The boundaries that we have will diminish over time, which means we will see a lot of migration. Countries that appear to be doing better [economically] will attract more people."

United Nations forecasts indicated the global population was likely to reach nine billion by 2050, with the major growth taking place in developing countries. Factors such as water shortages, climate change, and rising growth rates in developing countries would also jeopardise food security.

"South Africa is beginning to feel the impact of water shortage. The country's population by 2050 could be at around 55- to 60-million. How are we going to achieve this objective [of food security]?"

Hadebe said the Landbank/Afgri deal was beneficial not only to South Africa, but the whole African continent.

"The combination of the two entities' efforts, not only benefits our institutions, but the whole country. The impact will not only reside in South Africa, but we have efforts of looking beyond South Africa."

Afgri CEO Chris Venter said Africa's thriving population would soon put pressure on the continent's food reserves.

"We want to continue to expand our footprint into Africa. We need this partnership to ensure the sustainability of food security and we can't do that on our own."

Venter said his company was actively supporting farming in countries, including Zambia and Zimbabwe.

"Through our involvement in Zimbabwe, we have realised an improvement in the agricultural activities there. On the sugar [production] and tobacco side there are increases, but the country is still a long way from where it was.

"There is a general positivity in terms of agriculture across the African continent. More African governments realise that they need to secure food security," he said.

Last week, the Land Bank announced it had raised R1-billion from the African Development Bank, and a further R830-million from the South African capital markets.