We are fast approaching the closing date of 15th September for the application of chemical Nitrogen (N) and Phosphorus (P). It is important to note there is no closing date for either Potassium (K) or Lime, while the closing date for slurry is 15th October.
Early cut silage was behind in yield this year, however due to exceptional grass growth over the summer months this improved for 2nd cut, 3rd cut and surplus grass as bales. With winter feed well provided for at this stage on most farms, our advice is to concentrate on the supply of autumn grass for extended grazing towards the end of the year.
Grass growth remains at 60-65 Kg DM/ha/day on average. This is driven by good ground temperatures, plenty of moisture and optimum fertiliser application. Nevertheless, this will drop due to an expected lowering in temperature and shorter daylight hours. For this reason, it is wise to apply your last Nitrogen (N) application earlier rather than later during the month of September.
Recent high levels of rainfall were a problem in some parts of the country and in some cases, it was necessary to take animals indoors to avoid poaching. Others used strip grazing and available roadways to utilise drier paddocks. It is best to avoid taking out surplus grass as bales as you may need it for the grazing platform as growth rates will drop. Taking out any bales as silage will have to be well managed but best avoided.
Many progressive farmers will aim for a cover of 1200 kg/ha by the 15th September and this will provide a grazing platform up to the end of November. Note an extended grazing season will reduce costs and increase margins. It will also reduce the quantity of slurry to manage over the winter months.
For late Nitrogen (N) application, Target Fertilisers recommends 30/35 units per acre. This can be achieved as a straight N product or as a compound NPK, in conjunction with your soil test results. The winter months are an ideal time to build up Phosphorus (P) and Potassium (K) where you have deficiencies. Consider purchasing your fertiliser towards the end of the season, as it is often more competitively priced. It is advisable to check your nutrient allowance as you will need to comply with the SI No 605 2017.
At Target Fertilisers we recommended the following products for late application:
- Straight N or N+S in the form of CAN (27N) or SUPERCAN CCF (27N 4S)
- Protected Urea options: UREAMAX (46 N); UREAMAX +S (38N 7S) or 29-0-14+S
- For farms on restricted Phosphorus (P) application consider using an NK product such as 19-0-15+S
- For P & K replenishment use products such as 10-10-20 or 18-6-12.
Potassium (K) fertiliser advice
Potassium can be applied once ground and weather conditions are favourable. Given that there is no closed period for Potassium, the winter months are an ideal time to apply. It is recommended to maintained Potassium at Index 3 on mineral soils (101 – 150 mg/l) or peat type soils at (176 – 250mg/l).
Why do low Potassium (K) levels need to be addressed?
Potassium (K) is one of the three major plant nutrients along with Nitrogen (N) and Phosphorus (P). It facilitates important processes within the plant cells such as photosynthesis, respiration, and protein synthesis. It also plays a key role for adequate stomata function for optimal water transpiration and regulation within the plant. This has proven to be more significant in our recent weather trends where there are long periods of rain, followed by long periods of drought, high Potassium (K) soil levels have shown increased plant growth and improved drought tolerance.
In cereals adequate levels of Potassium (K) in soils (Index 3) increases the strength of plant cell walls and reduces lodging and brackling within the crop.
What are the reasons for low Potassium (K) in soils?
- Under application in the Spring due to risk of grass tetany
- Over estimating K nutrient value of slurry
- Not replenishing K levels in silage fields
- Silage bales taken from grazing platform and K not replenished
- K locked up in areas with high Magnesium (Mg) soils
- K not replenished after high yields of cereal crops such as Maize and Winter Oats
Straight Potash can be applied as Muriate of Potash (MOP) (50% K) or Sulphate of Potash (SOP) (42% K; 18% S).
Using MOP is much more cost effective and suitable product to build up soils to Index 3.
Many farmers apply one bag per acre at the end of the season.
Fertiliser closing dates:
Note the Nitrate Directive closing dates apply only to Nitrogen (N) and Potassium (K).
The closing dates for all Zones A, B and C are as follows:
- 15/09/20 – chemical fertiliser
- 15/10/20 – organic fertiliser
- 1/11/20 – farmyard manure
If you would like to find more about our protected urea products, contact our office on 053 9255389.
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