Nutrient (N, P, K) input and offtake were studied for 4 years with crops grown on sandy soil containing peat in The Netherlands. The crop rotations were S (potato/sugar beet/potato/spring wheat) and C (continuous cropping with potato). Two levels of nitrogen supply were: (1) the standard rate for the region minus 15% (N1); and (2) the standard rate plus 15% (N2). Soil analyses were used as a guide for input of P and K. Organic matter treatments were a control versus extra addition of organic matter. Nutrient inputs considered included nitrogen deposition from the atmosphere (44 kg ha −1 year −1). Offtake was nutrients in harvested products. Nitrogen balances (input minus offtake) ranged from 31 to 100 kg ha −1 year −1 and were significantly higher for N2 than for N1. The P and K balances were close to zero. Averaging data per crop species yielded characteristic values for nutrient concentrations in harvested products, nutrient offtake and nitrogen balances. Spring wheat showed the smallest nitrogen balance, followed by potato; sugar beet showed large nitrogen surpluses. The differences in nitrogen balances between the extremes of the potato plots were 134 kg ha −1 for N1 and 154 kg ha −1 for N2 treatments, caused by a factor 2 in difference in yield and a factor 1.6 in nitrogen concentration.