New guidance on applying inorganic nitrogen to autumn-sown barley and oilseed rape in Scotland’s Nitrate Vulnerable Zones during their respective closed periods has been welcomed by NFU Scotland.

The interim advice comes as SAC research gets under way to see whether winter barley sown at the lowest rotational fertility point could experience “agronomic benefit” from the technique.

SAC trials show there is no such benefit in winter wheat, notes SAC technical director Keith Dawson.

Soil sampling can be costly and the accuracy of the results depends on how well samples are taken and handled, the SEERAD guidance notes acknowledge.

So to simplify procedures for 2006 the department says it will accept (but does not recommend) inorganic autumn N application provided the main soil type in the field is sand, loamy sand, or sandy loam topsoil, the crop is winter barley, no organic manure has already been applied, the previous crop is in N residue group 1, and the dressing does not exceed 25kg/ha of nitrogen.

On all other soils autumn inorganic N will also be accepted on winter barley established by minimum tillage or direct drilling, provided no organic matter has been applied for that crop and applications do not exceed 25kg/ha.

Treatments under both circumstances must be recorded, but there is no need to notify SEERAD’s area offices.

Growers in any doubt should check first, state the guidelines.

Growers planning to use liquid PK fertilisers, which mostly contain N, should tell their area office before going ahead, explaining why there is no alternative available.

Applications of inorganic N to winter oilseed rape need not be notified to SEERAD, but must be recorded and should not exceed the seed-bed recommendation in Table 9, Booklet 3 of Guidelines for farmers in nitrate vulnerable zones.

“The new guidance note is a significant improvement over what has been published previously,” says NFUS policy director Scott Walker.

“Not only is it clearer, but it reduces some of the bureaucracy involved.”

“It’s a welcome step forward,” adds Dr Dawson.

The NFUS also welcomes the impending formation of a SEERAD NVZ technical stakeholder group to address remaining outstanding issues, says Mr Walker.

andrew.blake@rbi.co.uk