Changeable weather across Britain has been forcing farmers to adjust their plans for crops and livestock.

After the warmest March on record, April looks set to be one of the wettest.

Weather experts at the Met Office are warning that the unsettled weather is likely to be here to stay for at least another month.

The heavy April rain has been welcome for crops and livestock, especially in the parched central, south and east of England, where many regions officially remain in drought.

But after 18 months of dry weather, the Environment Agency is warning that prolonged periods of above-average rainfall are still needed to replenish reservoirs, rivers and underground aquifers and improve soil-moisture deficits.

Trevor Bishop, head of water resources at the Environment Agency, said more rain was needed to ease restrictions.

“It’s going to take more than a week of two of rain to undo the effects of nearly two years of below-average rainfall,” he said.

“The recent rain is good for farmers and gardeners, and the cool temperatures ease the pressure on fish and wildlife in rivers.

“But with dry soils, most of the rain will be soaked up – or, worse still, run off quickly if the surface is compacted, causing flash floods.”

Months of dry weather in drought-hit regions has compacted surfaces leading to fears the rain will not penetrate the ground far enough to top up groundwater.

Livestock farmer Roger Webster, who rears beef cattle at the family farm in Lathom, Lancashire, said: “It’s been cold here. We had a bit of rain yesterday, 9mm, and it’s raining again today (Thursday).

“We have had a bit of grass, but it’s not growing that much. The cows and calves have been turned out, but have come in every night. The grass is just not growing because of the cold.”

Cambridgeshire grower Edd Banks said recent wet and windy weather was affecting spraying plans at Manor Farm, in Harlton, Cambridge.

“We have been trying to finish off our T1s in cereals. We’re 95% there, but the last last few fields are waiting to be done,” he said.

“It’s been wet and windy and we have been chomping at the bit to get things done. It’s mainly been a problem of getting the sprays on at the right time.

“Due to the rain, the risk of sclerotinia for oilseed rape is also increased.”

But Mr Banks said the rain has improved the prospects for his spring beans and spring barley crops, which he planted earlier than usual this year, fearing the effects of yet another drought.

“The rain has really perked everything up and we’re really happy with the spring crops,” he said.

According to the Met Office, April 2012 is on course to be one of the wettest Aprils since records began.

The wettest April on record was in 2000, with an average UK rainfall of 120.3mm. Last year, the UK saw an average of 36.7mm of rainfall – only slightly above half the long-term average for April of 69.6mm.

April 2010, however, was only slighter wetter, with 48mm of average rainfall. The driest April on record is 1938, when 14.1mm of rainfall was recorded.

Met Office forecaster Dan Williams said heavy downpours have been affecting many regions over the past few days.

Notably, Exeter Airport had 35mm of rainfall on Wednesday (25 April) – about half its monthly average for April.

“Over the past couple of years, most months have featured below-average rainfall in the dry parts of England,” said Mr Williams.

“April is on course to be one of the wettest on record, which is welcome news for farmers in drought-hit regions in terms of restoring some of the water deficit.

“But we are going to need more than one month of wet weather to make a real difference.”

The unsettled weather was expected to continue over the next 30 days, he added, “The changeable weather is likely to continue, although more stable conditions are forecast towards the end of May, with average temperatures, rainfall and sunshine hours.”

More on the drought

See more on the drought on our dedicated drought page.