Biological progress and the use of nitrogen by cereal varieties

. Nowadays, the need for sustainable development of agriculture is emphasized. The sector must not only supply enough food world population and provide income for farmers, but also reduce its impact on the environment. The possibility of achieving these two objectives together may result from the introduction of biological innovations in the form of new crop varieties, which use nutrients more efficiently or are better adapted to the production conditions. The aim of the work is to determine the changes in the level of nitrogen utilization from mineral fertilizers by winter wheat and rye varieties introduced for cultivation in Poland in 1998–2014. The results of varietal experiments carried out by RCCT were used in the research. The changes in the productivity level of nitrogen fertilization were determined for the tested varieties. It was found that newer varieties of winter wheat and rye were characterized by higher grain production per 1 kg of nitrogen in mineral fertilizers. Varieties from 2012–2014, compared to those from 1998–2000, were characterized by higher productivity by 4 kg of grain / 1 kg of N and 10 kg of grain / 1 kg of N, respectively for winter wheat and rye. This could significantly contribute to the reduction of emissions from agricultural production, since the estimated reduction in the use of nitrogen fertilizers in cereal production was over 5 % for the volume of production from 2017. It was found that introducing new varieties that use nitrogen fertilization more efficiently can be an important factor leading to reducing emissions from agriculture and to increasing agricultural production without increasing pressure on the natural environment.