This is a subscriber-only article
The year is moving through the seasons faster than one might think. In just six weeks’ time, farmers will no longer be permitted to spread chemical nitrogen or phosphorus as the closed period for winter will begin.
Before any fertiliser is spread, farmers should ask themselves why am I spreading it? The first thing to remember is that fertiliser is a cost and if it can be avoided it should be.
The second thing to remember is that if excess fertiliser is spread there is a risk that some will be lost to the environment.
The third thing to remember is that fertiliser grows grass and there can be a very good economic response to fertiliser, particularly at the shoulders of the year when grass growth is less than herd demand.
Grass growth
At present, grass growth rates are really strong, outstripping demand, so farmers are having to regularly remove excess grass in the form of bale silage.
In this context, applying fertiliser and/or feeding meal will increase the amount of grass available, thereby necessitating the making of more silage. In many cases this silage is surplus to herd requirements. Effectively you are spending money in order to incur extra costs. It’s not very sensible.
However, we need to look past the present situation and ask what is likely to happen over the next three or four weeks, because fertiliser spread today will have an effect for weeks to come.
Certainly, as we move into August, grass growth rates are likely to decline and this will happen at the same time as average farm cover should start to increase in advance of growth rates going below herd demand in late-September and early-October.
How much?
In my view, farms that are stocked at around three cows per hectare on the milking block should continue to spread nitrogen after grazing at a rate of about 20 units/acre.
Fields that have a high clover content should receive half of this rate, as the clover will be fixing free nitrogen.
Those with fields that are stocked at higher and lower levels than this should adjust their rates accordingly. A decision can then be made in late-August or early-September about a blanket application, which would be the last application of the year.
SHARING OPTIONS: