NIBIO has developed three nitrogen calculators that can be used for support and guidance when fertilizing with nitrogen. The calculators are based on Norwegian data. They do not provide definitive answers, but contribute to knowledge and information that can be used for fertilization scheduling and for adjusting nitrogen fertilization during the growing season.
Calculator: Manure N calculator
The manure N calculator calculates the uptake of nitrogen in various crops with different manure spreading methods and spreading conditions. Nitrogen loss to the surrounding environment is also displayed.
The calculations are based on the amount of nitrogen and dry matter in the manure, manure spreading method, weather conditions after spreading and risk of leaching.
Calculator: Optimal N fertilization for grain
This calculator is used to calculate the optimal N fertilization for grain from a financial and environmental perspective, based on the results of 300 fertilization trials carried out in the period of 1991–2014.
The calculator determines the optimal amount of N for different types of grain based on estimates for the expected crop yield and current grain and fertilizer prices. It also calculates the N uptake and the protein content of the grain.
Calculator: N status during growing season
The service provides a quick and easy overview of nitrogen status in the soil for grain, potato and forage crops during growing season.
The calculations are based on information about growth and sowing dates, fertilization and expected harvests. Weather data is automatically retrieved from the selected weather station, and the calculator provides indicative information about the nitrogen status in the soil throughout the growing season.