February is barely past but already Spanish farmers are on drought alert as reservoirs shrink, crops wilt and brush fires crackle after the country's driest winter in 70 years.

Spain is used to fires in the summer, but this year they have come early, ravaging woodland, while the general dryness stunts crops and leaves farm animals without grass for grazing.

Brush fires have already swept across 400 hectares in the wooded northwestern region of Galicia.

Near the Galician village of Brocos, the Portodemouros reservoir has visibly shrunk and egg-shell cracks have appeared in the mud.

"We have a very hard drought, spectacularly intense in some territories," said agriculture minister Miguel Aras Canete.

"The water reserves are not at alarming levels, but we are beginning to have a lot of forest fires."

Spaniards emerged from their usual choking summer last year gasping for rain, but over the past three winter months Spain has had average precipitation of just 55 litres per square metre, far below the average of 200 litres.

"We have experienced three winter months with minimal levels of rain in all of Spain -- December, January and February have been the driest since at least the 1940s," state weather service spokesman Angel Rivera told AFP.

"Previously the driest winter had been in 1980-81," Rivera said. "Then it rained 30 litres more per square metre than it is now."

The latest official drought report on February 22 said Spain's reservoirs were only two-thirds full, meaning less water for the fields where crops grow and animals graze.

"Leafy plants, vegetables and cereals are suffering the most," said Gregorio Juarez, a spokesman for the young farmer's association ASAJA, warning that olives, vines and almonds may be next.

"There is a large part of southern Andalucia and Aragon where there is land that has already been lost, where there is now no solution whether it rains or not," he added.

"The fields in Granada could lose 35 percent of olive production and are counting on the loss of 50 percent of plant crops."

In the southern province of Malaga farmers are calculating their losses at 14 million euros, he added.

The little water that has fallen "has not soaked through to the earth," said Alejandro Garcia of the farmers' association COAG.

"In the coming month this lack of moisture is going to make plants sprout less strongly and affect the fruit they bear," he added.

He and other officials warn the drought is also threatening livestock, which cannot graze and must eat expensive feed instead.

In Galicia and other northern regions such as Asturias and Castilla y Leon "livestock farmers are seeing production costs rise by at least 20 percent", the Union of Small Farmers and Stockbreeders warned.

"There is the hope that if it rains soon, in the next week or two, things could get a bit better," said Garcia.

Rivera the weatherman forecast four days of rain from Sunday, followed by another high pressure system, likely to bring with it more dry weather.

"We need water, not just because of the fire risk but for grazing," said Galicia's regional rural affairs councillor Rosa Quintana.

"We'll see if the weather helps us."