When determining a slurry and fertiliser regime for second cut remember you must know your offtakes or silage crop requirement. It is best to get your advice from your local advisor if you are not sure of this.
Benefits of Adding Sulphur
To meet the silage crop NPK requirement deficit, Target Fertilisers have blended adequately balanced NPK + S fertiliser products for second cut silage.
We recommend using an NPK or Nitrogen product with added Sulphur to increase Nitrogen use efficiency as Sulphur is used to convert Nitrogen to plant dry matter which is critical in the production of good quality silage.
Sulphur is also essential in the formation of some amino acids which are the building blocks of proteins which are needed in the growth and development of the silage crop and animals.
Where soil pH levels are below the optimum level of between 6.3 – 6.5, it is recommended to use granulated lime at a rate of between 2–3 (50kg) bags per acre.
Allow a time frame of between 4-5 days between slurry application and chemical fertiliser application
Where P & K levels are adequate, and Nitrogen alone is being applied, we recommend using a product from our new protected Urea range:
UREAMAX + S which contains 40 units of Nitrogen and 6 units of Sulphur, coated with a NBPT inhibitor at a rate of 1.5 – 2 bags per acre
UREAMAX (46N + NBPT inhibitor)
This product has proven to perform on par with CAN-based products in research conducted by Teagasc at Johnstown Castle.
Where additional P & K is required alternative products from the Target Fertilisers range are:
- 27-2.5-5 +S CCF
- 24-2.5-10 + S
- 21-2.2-10 + S
This table below shows typical offtake/requirement on a typical 3T DM /Ha yield:
|Soil Index||N kg /ha (units/ acre)||P Kg / Ha (units/acre)|
|1||100 (80)||30 (24)|
|2||100 (80)||20 (16)|
|3||100 (80)||10 (8)|
*Where P build up has been already applied to the previous crop of grass silage therefore apply P offtake based on yields for 2nd cut silage crops as shown for Index 3 advice. (Source: Teagasc)
Table below shows rates of K for 1st, 2nd 3rd cut grass silage (source Teagasc, 2018)
|Soil Index||1st Cut
|1||185 (148)||75 (60)||50 (40)||310 (248)|
|2||155 (124)||75 (60)||50 (40)||280 (224)|
|3||125 (100)||75 (60)||50 (40)||250 (200)|
Note: On Index 4 soils omit K for one year and revert back to index 3 advice until next soil test. Adjust your K advice by +/- 25kg K/Ha per tonne of grass DM
Target Fertilisers’ Tips:
- The secret to good silage is achieving good fermentation and by pretesting a grass sample before cutting will help manage and spot some of the risks associated accomplishing a good fermentation. A grass leaf analysis will indicate water soluble carbohydrate (WSC) level and Nitrate Nitrogen levels. The WSC value should be in the region of 3% for the lactic acid bacteria to rapidly multiply and drop the pH, ensuring unwanted microorganisms multiplying.
- Farmers must keep in mind that a typical grass crop will uptake 2 units / day of Nitrogen in good growing conditions, so the amount of Nitrogen applied whether organic or chemical, will determine the cutting date e.g. 80 units applied equals minimum of 40 days to harvest.
- Luxury uptake of Nitrogen can occur after prolonged dry spells followed by rain.
- We would advise all farmers to test a sample of their grass and get a Nitrate leaf analysis test to ensure Nitrogen levels are adequate before cutting. Ideally Nitrate, Nitrogen levels should be below 0.1%.
- Mow silage fields if possible, at midday when sugar content is at its highest.
- Do not wilt the grass for more than 24 hours as this will increase DM losses due to the shatter of the grass leaf
To learn more about compiling a slurry and fertiliser programme for second cut silage, contact us here
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