In order to obtain significant data about the plant nutrient utilization from mineral fertilizers and maximum allowed dosages of fertilizers, a project, financed by the Ministry of Agriculture of the Republic of Latvia, was started in the year 2008. The aim of the project was to determine the utilization indicators of mineral fertilization, mainly nitrogen fertilization, on different nitrogen fertilization application dosages, also the maximum limit of and economically substantiated nitrogen fertilization dosages in different regions of Latvia depending on the year under the variable meteorological conditions. Different important field crops were used within the project: winter rye, winter and spring wheat, winter and spring oilseed rape, spring barley and potatoes. Field trials were established in research stations in different regions of Latvia: at the Research and Study Farm 'Vecauce" of the Latvia University of Agriculture; at the Research and Study Farm 'Peterlauki' of the Latvia University of Agriculture; at State Stende Cereals Breeding Institute and State Priekuli Field Crops Breeding Institute. Plant nutrition nitrogen agronomic efficiency from mineral fertilizers changed depending on the nitrogen fertilizing norm and yield. The specific results were observed concerning the nitrogen and potassium utilization, also the result differed between crops.
