Nitrogen use efficiency of winter wheat on farms in Poland: Nitrogen use efficiency of winter wheat on farms in Poland

Abstrakt

Improving Nitrogen Use Efficiency (NUE) in cereal cultivation is of high importance for providing nutrition for the growing population in the world while at the same time reducing the overburdening of the environment with the non-productive excess of reactive nitrogen. Wheat is one of the most vital cereals in human and animal nutrition worldwide. In this study, NUE, N yields (Yn) and N surplus (Nb) of wheat were estimated on the basis of a random survey of 1182 winter wheat growing farms in Poland. The purpose was to characterize the practices of N ferti- lization on the tested farms, and to identify potential possibilities for improving NUE in winter wheat production in Poland. The assessment of NUE, Yn and Nb was based on the methodology tentatively proposed by the EU Nitrogen Expert Panel (EU NEP). In the entire population of farms, the median and median absolute deviation of the tested characteristics were as follows: N dose 114 ± 30 kg N/ha, NUE 89 ± 18%, Yn 100 ± 15 kg N/ha, and Nb 12 ± 23 kg N/ha. The estimated range of NUE (71–107%) indicated that in a part of the farms, NUE was larger than 100%, which means the risk of N soil mining. Such high values were recorded in approximately 50% of the farms, and may undermine the long-term sustainability of wheat production. If NUE in these farms was to achieve the desirable values of 70–90%, the N doses applied would have to increase from 104±19 to 134±20 kg N/ha. It would result in an increase of grain yield from 4.80 ± 0.8 to 6.00 ± 0.8 t/ha and of N yield from 91 ± 15 to 113 ± 16 kg N/ha.