LONDON — It was designed to increase production and exports of vegetable oil, a commodity in short supply after World War Two, and foster growth in post-war Britain and Tanganyika.

Instead, Britain’s scheme to carve out million-acre plantations for growing groundnuts in what is now Tanzania ended in disaster – scuppered by the thick bush that rendered machines to clear land for cultivation useless, and a lack of suitable soil and rainfall for the crop to grow.

Sixty years on, similarly controversial projects are back in fashion in Africa and other parts of the developing world as investors – from foreign governments to wealthy individuals – hunt for land to grow food.

Champions of the deals say they are good for agriculture and ultimately global food security. They say they provide a welcome injection of cash, new seeds, technology and knowledge into a sector that is often the neglected pillar of poor countries’ economies.

But critics describe them as secretive ‘land grabs’ snatched at knockdown prices, which threaten to push smallholder farmers off their land and deprive countries struggling with chronic hunger of fertile, arable land they need for themselves.

‘There’s a huge variety to these (deals). It’s not all bad,’ Rajiv Shah, head of […]