Every year, there is a little confusion surrounding closed periods for fertiliser and slurry application, regarding whether listed dates are inclusive or exclusive of the period.

A simple answer is that all dates are inclusive, meaning the upcoming closed period for chemical fertiliser application begins at midnight Saturday, with no chemical fertiliser to be spread after this time until spring of next year (dates vary between different land zones).

The only exception to this rule is muriate of potash (MOP), which can be spread at any time of the year with no closed period.

Farmers with lactating animals tend not to spread this in spring time due to the associated risks with grass tetany, so autumn application is usually advised.

While there is no closed period, be mindful that trafficability is likely to deteriorate as days get shorter and rainfall increases, so apply sooner rather than later where required.

MOP is a good fertiliser to correct K levels where P allowance has already been used up through compounds.

Organic fertilisers

The closed period for slurry is also fast approaching. While a derogation for spreading was given last year owing to the horrendous weather, no such talk of an extended period has been mentioned so far.

As such, all slurry must be applied by midnight of 30 September or be held over until the following spring. This rule exists for all farmers, irrespective of whether they are in derogation or not.

Farmyard manure can be applied up until midnight 31 October, with the next opportunity to spread this being in January.

Soiled water is the final restricted fertiliser, with a 31-day closed period now in place. Farmers are prohibited from spreading soiled water between 1 December and 31 December inclusive.