ARCHIVE: Nitrate Vulnerable Zones (NVZs) - Guidance for Farmers. The N max limit (Leaflet 7 - PB12736g)

1. The N Max Limit

YOU MUST ensure that the average nitrogen application rate (from manufactured nitrogen fertiliser and crop available nitrogen from livestock manure) to the following crops does not exceed the N max limit for that crop type:

  • winter wheat, spring wheat, winter barley, spring barley, winter oilseed rape, sugar beet, potatoes, forage maize, field beans, peas and grass.

Note – the N max limits for these crops are provided in Table 5, Leaflet 3.

The N max limit applies to the average nitrogen application rate for that crop type across your farm. This means that it may be possible, in one or more individual fields with the same crop type, to apply nitrogen at a rate that is higher than the N max limit, provided that the average application rate across the whole area of the crop type on your farm does not exceed the N max limit.

In the majority of cases you should be applying considerably less than the N max limits and in line with your plan of nitrogen applications (as developed in accordance with the rules described in Leaflet 6).

There are only N max limits for the crop types listed in the above box. Although nitrogen application rates to other crops are not limited, you will need to plan the applications of nitrogen to these crops and are encouraged to balance nitrogen inputs from all sources with the foreseeable nitrogen requirements of the crop (see Leaflet 6).

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