Production of field vegetables is known for its high nitrogen input and consequently high nitrogen losses towards the environment. All over the world research tries to find opportunities to reduce these losses. In 2000 the Dutch government initiated and funded a research project (Telen met toekomst) to explore the possibilities to reduce the adverse effects of nitrogen and phosphate inputs on the quality of soil and surface water by farm management. A participatory research approach was chosen, so the farmer, the consultant and scientist work closely together in making annual plans to reach a number of set goals for fertilization on the farm level. By registration of all activities concerning fertilization on the farm, the nitrogen input and output could be monitored. The gap between the reference point at the start of the project and the environmental goals is big for nitrogen: the nitrogen balance surplus on the whole farm level should be reduced from 300 kg N/ha to 90 kg N/ha. First results show that this gap is unlikely to be bridged on all farms within the set period of time, without affecting the farmer's income. However, distinct differences could be observed in the farmers' attitude towards the challenge, the rate of progress varied significantly among farmers.