Long term trials have been established in favour of exploring and observing plant and soil interrelations on site. We may determine long term trials as live instruments providing ceteris paribus conditions in temporal sequences. This review is dealing with the introduction to major long term trials in the World and in Hungary. Giving a brief summary on plant nutritional research roots beginning with some data from Homer, and the fabulous initial willow tree experiment of van Helmont, as well as the basic inventions of physiological processes by von Liebig, Lawes and Boussingault. The most profound long term trials like Padova's Orto Botanico, the Linné Garden of Uppsala and the Broadbalk of Rothamsted are presented in the lecture.Agronomic, educational and scientific benefits of the major Hungarian long term trials are also discussed from Westsik 1929 via Maronvásár and the National Plant Nutrition Trials (OMTK) founded in 1963. There is a list of experimental sites giving information on the most important recent long term trial locations and the activities.

Winter wheat (Triticum aestivum L.) yield samples taken from a consecutive series of crop years representing drought, normal and moist conditions at the Nagygombos experimental site of the Szent István University have been evaluated. The impact of N topdressing and crop year conditions on the performance of protein and wet gluten content were studied.The results suggest that ascending levels of N topdressing, and increased number of applications had a beneficial effect on the protein content, as well as on wet gluten values. Crop year had a significant effect on quality manifestation. The drier the crop year, the better the recorded quality performance. The magnitude of changes was bigger in case of gluten than in that of protein values. There were minor differences between the two varieties examined, especially in their response patterns to nitrogen supply. Dough formation depends mainly on the gliadin/ glutenin ratio, but there is less information on the agronomic and climatic impacts that may cause alterations in that.

Long-term trials are established in order to explore and observe plant and soil interrelationships in situ. Long-term trials can be described as live instruments providing ceteris paribus conditions in temporal sequences. This review provides an introduction to major long-term trials in Hungary and in other parts of the world. It gives a brief summary of the origins of plant nutritional research, beginning with some data from Homer and the willow tree experiment of van Helmont, as well as the discovery of physiological processes by von Liebig, Lawes and Boussingault. The most profound long-term trials, like the Orto Botanico in Padova, the Linné Garden in Uppsala and the Broadbalk in Rothamsted are presented in the paper. The agronomic, educational and scientific benefits of the major Hungarian long-term trials are also discussed, from Westsik (1929) to Martonvásár and the National Plant Nutrition Trials (OMTK) set up in 1963. There is a list of experimental sites giving information on the most important recent long-term trial locations and their activities.