Although current weather conditions wouldn’t suggest it, the harvesting of first-cut silage is just over two months away for most farmers.
Most farmers will be aiming to close silage ground in late-March or early April, with an aim to harvest it in May.
The aim should be to harvest the highest quality of silage as possible, and the best way to achieve this is to harvest in mid-May.
The target should be to harvest silage with a dry matter digestibility (DMD) of 72%. In order to achieve this, it needs to be harvested before May 26.
Silage
Ahead of the harvesting of silage, the first thing that should be completed is determining how much forage is left on the farm.
Once you have determined how much forage is left on the farm you should then be able to work out how much silage is required for 2023/24.
According to Teagasc, for a 100-cow herd with 20 bulling heifers and three bulls, a total of 220t of dry matter (DM) is required – which includes a 10% loss or waste.
The aim should be that 50% of this silage is high-quality milking-cow feed or 110t of DM.
To determine how many acres will be required to achieved this, based on a yield of 4.5t of DM, around 44ac or 17.8ha will need to set aside for silage.
A further 45ac or 18ha with a yield of 6t of DM will be required to achieve 110t of DM.
This will meet the fodder requirements for this farm.
However, where possible, more silage should be made to ensure fodder security in the event that it is required.
Fertiliser
Using a 6% DM slurry at a rate of 3,000 gallon/ac will make up nearly all of the phosphorus (P) and potassium (K) requirements and a third, or 30kg of the N requirements.
This means urea, or protected urea and sulphur (S) can then be used for the remaining N requirements of 70kg/ha.
Farmers should spread the slurry when the fields are closed for silage and that the urea or protected urea and S is spread about a week later.
Where slurry is not available, farmers can use a chemical fertiliser such as 10-5-25 at a rate of 3-3.5 bags/ac.
This will supply all the P and K for the crop at closing, but if this is being used the crop needs to be topped up with N. This can be the same form of urea or protected urea and S.
Fertiliser requirements for a first-cut silage crop:
- 100kg N/ha or 80 units/ac;
- 20kg P/ha or 16 units/ac;
- 125kg/ha or 100 units/ac of K, to total 90kg prior to cutting and 35kg after silage has been cut;
- 20kg of S/ha or 16 units/ac.