AgriSA has called for the drought to be declared a national disaster, as commercial and emerging farmers watch the devastation unfold around them.
Omri van Zyl, executive director of AgriSA, said towns such as Senekal in the Free State were running out of drinking water.
"People are leaving bottles of water for them on the N1," he said.
A drought has already been declared in the North West, KwaZulu-Natal, Mpumalanga, Limpopo and the Free State.
He said he had just come from a farmers' meeting where alarm bells were sounded over a possible white maize and wheat shortage.
If the country ran out of maize it would have to import, and the currency's volatility would play havoc with food inflation.
Importing maize would lead to job losses on South African farms and cause a movement of people to areas where there was food.
In the red meat livestock industry, farmers were selling off their animals and thousands of animals were dying, he said. "The next planting season is going to be a credit crunch," he warned. Van Zyl explained that farmers took a line of credit to buy their inputs and then paid the money back after the harvest.
But this time they would not be able to repay the money.
The Land Bank announced last year that it would extend some of the farmers' loans on its books because of the drought.
In the meantime, the country's grain stores have enough to last until April.
"Hopefully it will rain sufficiently between now and June, because we won't have enough."
Landbou Weekblad reported that only 25% of the usual mielie crops have been planted in the North West and 20% in the north western and central Free State.
Meanwhile, Democratic Alliance Free State leader Patricia Kopane said the party had warned the Free State government repeatedly about the looming water crisis.
It had even laid a complaint with the South African Human Rights Commission. She said the lack of water was because of poor infrastructure maintenance and the hiring of incompetent technical staff.