Efficient Lime and Nitrogen Fertiliser Use
Soil test results show that the pH on many farms is below optimum and farmers would see an immediate benefit from spreading lime.
Good soil fertility management for efficient grass production helps to stabilise feed costs and protect profitability especially during periods of low dairy and beef prices. Two key areas to increase the production efficiency of soils are through lime and nitrogen (N) fertiliser use. Teagasc launched factsheets on Lime and Urea fertiliser management at the Teagasc BEEF 2016 open day in Grange earlier this month. These factsheets, which are available on www.teagasc.ie , provide tips to support cost effective soil fertility management on farms.
Teagasc Director, Professor Gerry Boyle said: “Soil test results show that the pH on many farms is below optimum and farmers would see an immediate benefit from spreading lime. Correcting the soil pH is a worthwhile investment and our studies show that it delivers extra grass growth which obviously delivers a financial return. For those farmers who still don’t soil test I would urge them to do so, as the first step towards more efficient milk and meat production. ”
According to Dr David Wall, leader of the Teagasc Soil Fertility Research Programme; “The management of soil fertility levels should be a priority for every drystock and dairy farmer. Lime applications for soil pH correction and efficient N fertiliser use are two ways that all farmers can boost grass production and lower feed costs, thus increasing the resilience of their farms when prices are low. These factsheets support the Teagasc led national soil fertility campaign and are aimed at helping farmers and advisors to maximise the benefits of lime and to use N fertilisers more sustainably.”
Soil sample results for soils analysed at Teagasc show that 90% of samples have sub optimal levels of the principle soil nutrients Lime, Phosphorus (P) and Potassium (K). Mark Plunkett, Teagasc Soil and Plant Nutrition Specialist said: “The first principle in fertiliser planning is controlling soil acidity through liming soils on a regular basis. Soil test results indicated that up to 65% of our soils require lime on a regular basis to maintain a soil pH 6.3 for grassland. Lime is a cost effective soil conditioner and in effect is a fertiliser as it is required to unlock major soil nutrients. Best practice guidelines for effective lime use on farms are provided in the Lime factsheet.”
Speaking about N fertiliser selection, Dr Patrick Forrestal, Teagasc Soil Fertility Researcher at Johnstown Castle said: “Urea based fertiliser is an excellent source of plant available nitrogen. Variable response to urea early in the year is to be expected but this is because grass growth rates are variable. Teagasc trials show that when applied under the same growing conditions urea and CAN frequently give the same yields, however, when urea is treated with the urease inhibitor NBPT ammonia gas loss is dramatically reduced, yields are consistently equal to CAN and greenhouse gas loss is lower than CAN. Up to date Information on N fertiliser types is available in the Urea factsheet.”