- Urea is the predominant nitrogen fertiliser used in New Zealand; around 90% of all synthetic nitrogen applied on farms.
- About 700,000 tonnes of urea is used in NZ every year. Approximately 40% is manufactured at Kapunui, while the remaining urea is imported from places such as Saudi Arabia and Qatar.
- The price of urea has increased just over 50% in the last ten years, from $395/tonne in 2002 to $610/tonne at the end of 2013.
- Similarly the demand for urea has increased by 45% in the last ten years. This increase is well correlated with the growth in dairy farming over the same time period.
While there are certainly benefits to using nitrogen fertiliser, there are drawbacks as well. These include:
- nitrogen being converted to nitrate in the soil. In this form it is very mobile and prone to leaching.
- when soil is wet and cold the nitrogen is unable to be fully utilised by the pasture and can leach into groundwater, detrimentally affecting water quality as nitrate eventually finds its way into streams and lakes.
A contributor to nitrogen leaching is the over application of nitrogen fertiliser where there is more nitrogen in the soil than plants can take up. Excess nitrogen that leaches into groundwater is therefore an environmental issue, as well as a waste of resources. With the rise in demand and price of N fertiliser, as well as the implementation of limits on N loss from farms, it is now more important than ever to be as efficient as possible with our nitrogen use.
In the coming weeks we’ll be producing more posts based off our One Click Surveys and our own research. Keep a look out for our post in a fortnight where we discuss the factors that can affect your nitrogen efficiency in more detail.