Regional water Authority “Limburg”, foundations “Boerenbond Zuid” and “Boerenbond Swentibold”, Pilot smart fertilization, DSG-Sustainable Clean Groundwater (WML), Foundation Experimental farm “Wijnandsrade” and DSV seeds the Netherlands financed comparative research of five sorghum varieties and one maize variety on loess soil at experimental farm “Wijnandsrade” in Wijnandsrade (Province Limburg). The average yield of the six varieties for the two N-levels - 70 and 110 kg N/ha - was about 16 tonnes DM/ha. Despite the dry and warm growing season, maize produced at 70 and 110 kg N/ha, 16 and 20 tons DM/ha, with a digestibility coefficient of organic matter (DCOM) of 78% and 79%, crude protein content of 58 and 59 g/kg DM and starch content of 267 and 230 g/kg DM, respectively. When fertilizing 70 kg N/ha compared to 110 kg N/ha, the average yield of all sorghum varieties was higher (15 vs 13 tonnes DM/ha), the crude protein level equal (91 g/kg DM), the starch content higher (238 vs 173 g/kg DM), the DCOM almost equal (67 vs 66%), the crude fibre level lower (206 vs 232 g/kg DM) and the lignin (ADL) level lower (25 vs 27). At 70 kg N/ha, the five sorghum varieties had an average of 37% less residual-N/ha than maize. At 110 kg N/ha, the opposite appeared: the five sorghum varieties had on average 33% more residual-N/ha than maize.