Know your new Nitrates rules
Published 15/02/2011 | 05:00
The revised Nitrates Action Plan includes several changes that will affect tillage growers and their fertiliser choices this year.
Speaking at the National Tillage Conference recently, Teagasc Oak Park's Dr Richie Hackett outlined the main changes, which include higher phosphorus (P) rates for cereals, higher nitrogen (N) rates for winter barley and spring barley, additional nitrogen for malting barley and changes to the rules on successive organic manure applications.
Until now, where organic manure was applied to an arable field for two years in a row, the field was deemed to move from index 1 to index 2 in the third season. This meant that less nitrogen could be applied in year three, a nitrogen penalty that most growers considered too severe. Their reaction was to restrict their use of organic manures to every second year.
Under the revised Nitrates Action Plan, organic manures can now be applied to the same field for two or more years in succession without having any effect on the soil N index.
While farmers will still have to reduce the amount of fertiliser N applied to crops to take account of the N in the organic manure, spreading manure in one season will not affect the chemical N allowances in the next season.
Simply put, tillage growers can now spread organic manure on a field every year, without moving up into the higher soil index.
Under the old Nitrates rules, the limits for P applications were 45kg/ha at soil index 1, 35kg/ha at soil index 2, 25kg/ha at soil index 3 and 0kg/ha at soil index 4. These rates were the same for all cereal crops, regardless of yield expectations.
However, research has shown that because most P is contained in the grain, higher-yielding crops can accumulate and remove more P than the farmer is allowed to apply. Over time, this would result in a reduction in soil P reserves.