Workshops set to clear confusion
EXTENSION of nitrogen vulnerable zones in the UK will have less impact on maize growers than many are led to believe, according to one agronomist.
To help clear this confusion, NVZ workshops will be held alongside the maize demonstration meetings, says MGA agronomist Simon Draper. "Its widely believed that most growers will be affected by rules such as restricted timing for slurry application, which is not true.
"The crucial factor when assessing the impact of NVZ rules on your unit is to check that stock numbers and land area is within permissible levels. Initially, this will be about 0.8 cows/acre, falling by 30% within four years on arable land.
"When stocking rates fall outside the limit, extra land is required for muck."
But Mr Draper stresses that this calculation is not simpleas grassland and maize areas have different nitrogen limits. The size and type of animal must also be taken into account to determine the number of animals a unit can carry before exceeding nitrogen limits.
Another concern is whether closed periods apply to your unit. Non-spreading periods only apply to sandy and shallow soils, therefore, most units will not be affected. In addition, dirty water and farmyard manure applications can be made at any time.
The workshop will also address how to estimate nitrogen inputs from slurry and manure. This is crucial as it determines how much artificial nitrogen can be applied, he adds. *