Many farmers are focused on liming and getting their second-cut silage in as a result of favourable weather conditions this week.
With the Minister for Agriculture, Food and Marine Charlie McConalogue’s recent decision to leave fertiliser allowances at 2023 levels for 2024, there seems to be an urgency in finding out how much more nitrogen (N) can be spread before the chemical fertiliser season closes.
There is no doubt that it has been a poor growing year, which has left a lot of farmers fearing of a fodder deficit come the winter time.
Being able to apply the same level of fertiliser might allow a lot of farmers to build up more fodder stocks and potentially extend the grazing season, which, in turn, can help with fodder supplies.
While it’s important to find out how much extra N, phosphorus (P), and potassium (K) you can spread before September 15, the cheapest fertiliser of all, in the form of lime should not be overlooked.
It needs to be realised that your soil fertility is the most important aspect of growing grass, as your soil fertility status dictates the response to fertiliser.
The pH of your soil is the single most important chemical property in soil. If it is not at an optimum level of above 6.3, you are not giving your soil the best possible chance to grow as much grass as possible.
Liming
Research shows that liming acidic soils increases grass production by 1.0t DM/ha. This is valued at €180/t DM on a dairy farm.
An application of 5t/ha of ground limestone to correct soil pH represents a cost of €25/ha/year over five years.
The return on investment from lime gives €4 to €7 worth extra grass for every €1 invested in lime.
Applying lime as soon as possible after a cut of silage is essential to reduce the risk of lime residues. The aim should be to avoid high grass covers of over 800kg DM/ha.
A decision has to be made after the second cut, whether you will need a third cut off the same block of land. Ideally, silage fields should be left sufficient time of up to three months in dry weather between applying and cutting for silage.
However, it’s not just silage fields that may require lime at this time of the year – any field with a low pH should be targeted after a tight grazing.
Identify blocks of land that require lime; this could require ordering a load of lime (20t) after each grazing rotation to correct soil pH (covers approx. 10ac at 2t/ac lime application rate).
There has to be a focus on improving the response to fertiliser as it will increase the amount of grass grown which will help you utilise more grass and reduce the amount of concentrates fed.
Therefore, by improving the amount of nutrients your soil can uptake through liming could potentially reduce your costs and minimise the amount of extra supplement being fed which will also help build fodder supplies.
Now, and over the next couple of months is the the time to start focusing on improving your fertiliser response by applying lime where needed, to correct the pH status.
The pH of your soil is the easiest part of soil fertility to rectify while being the cheapest way of improving your soil status and yet, it is still the one part of fertiliser plans and applications that gets overlooked.
It is important over the next week or so, when harvesting of second cuts is all finished to remember that now is the time to act on your soil pH.