High prices over the past 18 months have meant some farmers have scaled back on secondary and micro-nutrients in favour of maintaining nitrogen inputs, but according to Origin Fertiliser technical director Peter Scott, it is possible in some circumstances for growers to use less nitrogen and have a greater influence on nutrient availability.
“Not applying other nutrients can quickly see soil reserves drop, which can then take years to build back up to sufficient levels,” explained Peter.
“Plants require access to up to 14 key nutrients for growth and quality and this will be limited by the most deficient nutrient within the soil, so understanding where these are can help supply the plant with what it requires to increase both yield and nutritional value.
“Grassland systems will always need a certain amount of nitrogen as it is the building blocks of life. However, we must increase its use efficiency and prevent environmental losses, which means we could apply less and use a greater percentage of it. Without a balanced soil profile, more nitrogen applied will be left unused,” says Peter.
Goulding Soil Nutrition’s Richland, a 22.7:2.5:5 + 3% S plus magnesium, copper, manganese and zinc, is formulated to give extra growth of sweet palatable grass that helps livestock thrive.
Independent trials at Waterford and Cork have shown that 15% less nitrogen applied, as Richland gave the same yield as standard practice 27:2.5:5.
Every farm should be considering if its fertiliser strategies are making the most of late grass growth and the individual requirements, such as production systems, sward management, cutting and grazing frequency, all contribute to how fertiliser is used by the crop.
Similarly, sodium added in fertiliser will help maintain sward quality throughout the growing season and improving palatability leads to increased dry matter intake.
National University of Ireland trials at Athy, Co Kildare, showed that applying fertiliser with sodium increased the sugar content by 21% in cuts from June and September.
Goulding offers three grades containing sodium - SWEET 18s, an NPK containing protected urea; SWEET SUSTAIN, containing protected urea and sulphur; and SWEETGRASS, with CAN and sulphur.
Peter concludes: “Making sure the fertiliser is applied at the right rate, is the right type and is correctly placed for the crop and at the right time will help improve fertiliser use efficiency.
"Following a nutrient management plan and getting advice and recommendations from an adviser throughout the growing season is key to understanding where savings can be made.”