Many farmers took the opportunity to cut silage over the past fortnight and even though the weather has broken a bit, many farmers will hope to have silage wrapped up by the end of next week.

Thoughts will then turn to fertilising ground for second cuts. Before even getting into fertiliser requirements, it’s important to assess whether or not you need to make second-cut silage.

Answering this will depend on the fodder budget and the ability of the farm to close up ground for second-cut silage.

If silage ground is being closed up, it probably makes sense to aim for high yields, which will lower the cost per kilo of silage dry matter.

Guidelines

The Teagasc guidelines was always 80 units/acre of nitrogen for second cut, but given price and availability issues with nitrogen, there is scope to reduce this back to 60 or 70 units/acre on most farms.

The amount of phosphorus (P) and potash (K) needed depends on soil fertility. Index three soils need 13 units/acre of P and 80 units of K.

Remember to deduct what nutrients are provided in slurry. Every 1,000 gallons/acre of cattle slurry will provide five units/acre of P and 30 units/acre of K.

Requirements

Effectively, all the P and K requirements can be provided in 2,500 gallons per acre of good cattle slurry.

The nitrogen value of slurry is very hit and miss, especially when spread with a splash plate, so using low emission slurry spreading equipment will utilise nitrogen much better, especially when being spread at this time of year.

Sulphur is also an important nutrient that is often overlooked when it comes to silage making. Around 12 units/acre of sulphur is required for silage making.