During the past century different strategies have been used to determine optimal N-fertilizer rates and to develop appropriate crop N-fertilizer recommendations. However, most of these approaches do not address potential environmental issues associated with agricultural production. Therefore, a more holistic approach is required to enhance N-fertilizer uptake efficiency (NUE) for vegetable crops production on vulnerable soils that are prone to N-leaching. A physiological basis for improving NUE in these systems is developed thereby linking physiological crop N uptake dynamics with NUE. Based on a compilation of experimental studies complemented with research finding reported in the literature, it is shown that N uptake for peppers, tomato, potato, and sweet corn followed logistic N accumulation patterns. Up to 80-85% of N uptake occurred between 4-7 weeks (s-corn) vs 6-12 weeks (other crops) while N uptake during initial growth and crop maturation was low. Maximum daily N accumulation rates occurred at 5 weeks (S-Corn) and 8-10 weeks (other crops) and maximum daily N uptake rates were on the order of 4-8 kg N/ha. Overall NUE for most vegetables may range between 23 and 71%, depending on production practices, soil type and environmental conditions. Maximum root interception capacity was typically attained 3-5 weeks prior to crop maturity. It is concluded that during initial growth root interception may the most limiting factor for efficient N use. Although, recent uptake studies have shown that NUE may be highest towards the end of the growing season, this may not coincide with the greatest crop demand for N, which occurs during the onset of the linear growth phase. As a result, yield responses to N applied later in the season may be limited. Integration of these results in production practices and expert systems for vegetable production can minimize the externalities associated with commercial vegetable production on vulnerable soils.