19 April 1996

Rainfall needed urgently as dry soils affect crops

By Robert Harris

SOILS are drying out fast in many eastern areas of the country. Although dustbowl conditions are a way off, plentiful rain is needed to maintain rapid crop growth and prevent water shortages later in the season.

Some crops are already struggling. "Sugar beet is a major worry. The top 1.5in of soil is dry," says Morley Research Centres Doug Stevens.

Recent forecasted rain has petered out. "We have had 83.6mm in the first three months of this year compared with a 27 year mean of 147.4mm. And we have had just 3mm more in April. Its not doing any more than lay the dust. We need an inch of rain in the next week."

Winter cereals have enough moisture for the next few weeks, he adds. Most spring crops are growing well, although those drilled into cloddy seedbeds are struggling. Crop rolling has been widespread.

Although potato fields are coming into deficit, there is plenty of moisture to see crops through until irrigators are switched on to control scab in May, says Potato Marketing Board agronomist David Hudson.

But substantial rainfall is needed in the next few weeks or many growers will face irrigation curbs even earlier than last year.

"There is not a wealth of water available for agricultural use – we are watching things very closely," says Mark Sitton, the Environment Agencys water resource co-ordinator.

77% of normal

In the Anglian region, just 77% of normal rainfall in the last 12 months coupled with last years exceptionally dry summer means prospects for the regions 4500 licensed abstractors are described as "generally moderate to poor, locally poor" (see box).

The second biggest abstraction area, Severn-Trent, with 2500 licence holders, is in a similar position. "We have written to all growers with restriction clauses in their licences explaining restrictions could come in earlier than normal," says senior hydrologist Gordon Davies.

That could mean two to four weeks ahead of last year unless prolonged wet weather over the next six weeks keeps river flows up, he explains.

A similar picture exists in Yorkshire, where river flows are very low for the time of year, and in Kent, where ground water levels remain near the lowest ever recorded.

Roger Bailey, irrigation consultant at ADAS Gleadthorpe, stresses that normal rainfall soon would stave off trouble.

"It is difficult to predict the need for irrigation and current soil moisture deficits. Much depends on how much rain falls in the next few weeks. Water status is not dependent on the total soil moisture deficit, only that in the rooting profile."

Inch of water a week

On average, arable crops in the east of the country use one inch of water a week at full crop cover. "If we had that much, we wouldnt need to irrigate. And some years we get plenty of rain in June."

The Environment Agency is taking a prudent course with its advice, says Mr Hudson. "Its really too early to worry. Some reservoirs, especially new ones, have not filled, and some boreholes are below the April average. If we dont get rain for some time, then we will be struggling. But there is no need to panic yet." &#42


What restrictions?

&#8226 Moderate – most of eastern England – abstraction controls possible in sensitive ground water areas. Most boreholes secure. Limited controls on surface water possible by mid-summer.

&#8226 Poor – North and east Lincs, Norfolk, Suffolk and parts of Cambs, Kent and East Sussex – soil moisture deficit developing early. Significant restrictions on surface and ground water probable from early summer.