Commercial farmers ensure greater food security in the country by producing more food than emerging or subsistence farmers, a study has found.

The study found commercial farms accounted for 95% of the country's locally-produced food, the South African Institute of Race Relations (SAIRR) said on Tuesday.

The remaining five percent was produced by the country's 220 000 emerging farmers and 1.3-million subsistence farmers.

SAIRR researcher Kerwin Lebone said South Africa's food security was heavily dependent on commercial farming.

"While emerging and subsistence farmers may feed their own families and some others, the above information demonstrates that national food security depends on commercial farming."

The study, which was based on information from Statistics South Africa, the Bureau for Food and Agricultural Policy, and a statement by Economic Development Minister Ebrahim Patel, found there were 94.5-million hectares of agricultural land in South Africa.

Only 13.1-million hectares, or 14% of this land, was cultivated to grow crops. The remaining 81.3-million hectares, or 86% was used for grazing or other activities, such as mining.

A commercial agriculture census, published by Stats SA, showed the country's 47 500 commercial farmers planted all their crops on 4.6-million hectares.

This meant they used only 36% of cultivated agricultural land, and five percent of the total agricultural land available.