The nitrate directive does not affect best practices for fertiliser nitrogen application on most farms, with stocking rates up to two livestock units per hectare (170 kg organic nitrogen per hectare).
Up to a stocking rate of 2.5 livestock units per hectare (210 kg organic nitrogen), the permitted levels of nitrogen fertiliser are only slightly restricted, but at higher stocking rates, levels are very restricted.
The biggest changes in updated nitrogen advice are: the equivalent of half a bag of urea for the first application, which shouldn’t be until late January at the earliest.
The science behind this is that there is sufficient soil reserve nitrogen for early growth. High levels of nitrogen are advised in March, April and May — the period of highest grass growth potential, when the grass requirement for nitrogen is greater than that available from soil reserves.
Teagasc advises that where 20 units per acre were applied early, followed by 40 units a month later and again in April, then 40 units should be applied in May, 25 in June, 20 in July, 20 in August and 12 mid-September.
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