Results of Hungarian field test trials set up for establishing new maximum permitted N dose values

The advancement of crop production has not yet been followed by the increase in maximum permitted nitrogen doses set out in the Hungarian Action Programme of the Nitrate Directive. According to the farmers’ observations, crops grown in nitrate vulnerable zones with good agricultural conditions already have much higher nitrogen uptake than the maximum permitted values, so the genetic potential of the plants cannot be exploited at the current level. In order to prove this, in the autumn of 2017, a small-plot long-term experiment was set up in three different regions of Hungary. The results were evaluated in a complex way, based on an agronomic approach, Nitrogen Use Efficiency (NUE) and an economic approach. In terms of the agronomic evaluation, no clear differences were found between treatments: the highest yields were obtained in respect of different treatments at the three experimental sites, but the differences were not significant. From the point of view of NUE, the Nmax experiment on the Nagyhörcsök calcareous chernozem soil showed the highest values, which, according to the EU N Expert Panel (EUNEP), are already in the unfavourable soil depletion range. From the economic point of view, there was no significant difference in net profits between the Present and New planned Nmax values. The EUNEP approach also confirms the need to increase Nmax values in order to decrease the potential for soil depletion. However, with a view to establishing the final optimum range for the EUNEP, it seems necessary to take into account economic considerations as well, especially regarding the financial conditions of Central and Eastern European countries.