Soil testing and correct pH levels are the basic starting points for soil efficiency
FERTILISER prices are likely to increase by approximately 10% in Ireland this spring due to a continued disruption of supply channels as well as the introduction of a range of taxes and tariffs.
That’s the prediction of Teagasc Training and Development Specialist, Mark Plunkett in the latest edition of the advisory body’s advice magazine, ‘Today’s Farm’.
He also advises farmers to put a number of steps in place to maximise the response they get from the application of nitrogen [N], phosphorous [P] and potassium [K].
The first piece of advice Mark Plunkett gives is to have your soils at the optimum pH levels, of 6.3 to 6.5, for productive grasslands and to prepare a farm fertiliser plan, based on up-to-date soil analyses.
He also advises farmers to only apply nutrients to fields when the soil temperature is at least 6°C and when there is a favourable weather forecast.
“Low pH, indicating high levels of soil acidity, will impede the release of soil mineral N from organic matter. This naturally released nitrogen costs you nothing.
“Encourage it by increasing soil pH which can potentially increase the supply [N] by 70kg/N/ha/year. A pH of greater than 6.3 also increases soil P availability and improves the efficiency of applied P in organic manures or bag fertilisers,” states Mark Plunkett.
He also advises that nitrogen should only be applied when plant growth starts [mid to late February] starting with low amounts [15 to 25kg/ha] and that urea based N, such as protected urea, is the most stable and efficient form of nitrogen to apply early in the season as well as helping to reduce Greenhous Gas emissions.
Mark Plunkett said that mid/late March to early April is the best time to apply P with 10.10.20, 18.6.12+S and 13.6.20+S tending to be the best value for money.
He also outlined the benefits of sulphur [S] including a reduction in N leaching and a consequent reduction in nitrate losses across grassland farms.
Mark Plunkett makes five observations which can help farmers to reap the best dividend from the spreading of slurry:
■ Weather conditions permitting, early springtime is the best period to spread slurry.
■ All cattle slurry should be returned to the silage fields to replenish P and K levels.
■ Slurry should be applied at the rate of 2,500 to 3,000 gallons per acre.
■ Typical cattle slurry contains 9 units of nitrogen, 5 units of P and 32 units of K per 1,000 gallons. [One 50kgs bag of 9:5:32].
■ Cattle slurry tends to be quite low in S due to sulphur ‘being bound up in the organic matter and unavailable at the time of spreading.
As regards lime requirements, Mark Plunkett points out that the soil test report will indicate the recommended lime rate to correct the soil pH to the optimum level.
He says that a soil with a pH of 5.7 would have a lime requirement of 12.5 tonnes per hectare [5 tonnes per acre].
“It is recommended to apply 50% of lime now and 50% in two-years’ time to correct soil pH to optimum level 6.3,” states Mark Plunket.
■ The article – ‘Get more from your fertiliser spend in 2026’ can be read in full in the January-February-March edition of the Teagasc Today’s Farm magazine.
Pictured: Ensure that your soil pH is at an optimum level by applying lime where needed: otherwise, the returns from N, P and K application will be reduced.