Thousands of tons of sandy soil has been blown off the fields, blocking roads and damaging valuable crops.
Farmers face losses of tens of thousands of pounds and say the dust and sand could take weeks or even months to clear.
Barley farmer Cameron MacIver, of Forres, said: "The problem is that the sand has blown in and stripped the soil off the top of the seeds. So it's exposed some and in other cases it's buried them.
"So the ones that are buried are so deep that they won't grow and the ones that are exposed are just getting battered by sand and being worn down like how sandpaper wears things down.
"I'm scared that the seed won't be able to recover and they will be killed."
There have been claims that up to 50% of the crop yield may have been lost.
A National Farmers' Union official said: We might have lost 10% of the harvest and then again we might have lost 50%. It's too early to say at the moment.
"The situation will only become apparent over the coming weeks when crops either grow or don't."
Saharan-style conditions have become almost an annual occurrence in Moray, due to the nature of the soil.
But the recent sandstorms are the worst in living memory.
Drivers have been warned to take extra care, particularly on narrow country roads. Some motorists have even compared the visibility to the conditions caused by the Los Angeles smog.
The strong winds have coincided with farmers cultivating their fields and the sandstorm conditions will continue while the weather is dry and until recently sown crops take root.
Last week a number of roads were blocked by sand drifts as much as 4ft high while others were only barely passable.
Moray Council mobilised snowploughs and other equipment to clear the roads but the winds are still blowing sand across the carriageways.
A council spokesman said: "Keeping roads open is an obvious priority and for the most part we succeeded in doing that following last week's winds.
"To achieve that, the sand was either ploughed to the sides of the roads and on to verges or, where it was very deep, dug out by excavator.
"However, the return of the strong winds means it is being blown back on to the roadway and in some cases it is filling back in as soon as it is cleared."
The spokesman added: "There is already be a sizeable cost implication in terms of mobilising resources over the past few days to deal with the blown sand, although we are fortunate that some farmers have put in their own resources to help with the clear-up."
The spokesman warned there was a continuing risk of sandstorms.
He said it depended on where the sand was deposited, which way the wind was blowing and how quickly vegetation stabilised the situation.