Smart-N technology uses optical sensors to detect nitrogen-rich zones in order to avoid application of liquid nitrogen to these areas, thereby reducing fertiliser use. In dairy systems, urine and dung patches on pasture can reach a nitrogen loading of 1000 kg N ha-1. Researchers examined the application of Smart-N technology to reduce nitrogen application and greenhouse gas emissions on four Tasmanian dairy farms.
Fertiliser application was reduced by 30-40% with no impact on pasture production. A 30% reduction in fertiliser use would save a typical Tasmanian dairy farm $10,000 / annum in fertiliser costs. If the technology was adopted as a CFI / ERF method, the emissions mitigation income would be $1,150 (at a carbon price of $23 / t CO2-e).