The Nmin‐method – an aid to integrating various objectives of nitrogen fertilization

There is increasing interest in the rate and timing of N‐fertilization from both an economical and an ecological point of view. Fertilizer recommendations for a variety of aims can be made using the Nmin‐method, as shown by experiments on deep rootable loess loam soils. Yields of cereal crops and sugar were increased by 2–3 dt/ha by application of the Nmin‐method. The Nmin‐method led to a reduction in the rate of fertilizer application by 30 kg N/ha with sugar beet. Any stipulated NO3 level in leaf vegetables can be met, if N is fertilized according to Nmin‐method. The necessary data for many vegetable crops are given. In particular low nitrate content in spinach and lettuce at high yield was achieved without loss of yield by adjusting both their NO3 and Cl nutrition. Leaching of nitrate out of soils often follows the application of too much fertilizer, but fertilization errors can be avoided and leaching reduced if the Nmin‐method is used. Applications and limitations of the Nmin‐method are discussed.