Fertilizer Nitrogen Uptake and Utilization Efficiency in Vegetables

Fertilizer nitrogen uptake and its efficiency of utilization were studied in six vegetables using¹⁵N enriched ammonium sulphate. Total uptake of N was the highest in brinjal (egg plant) and the least in onion. Tomato and onion relied more on fertilizer N, whereas the other four vegetables, namely, brinjal, okra, French bean and chilli pepper absorbed more soil N. Brinjal had the highest average rate of N uptake (3.53 kg ha⁻¹d⁻¹). and chilli pepper the lowest (0.6 kg ha⁻¹ d⁻¹). Recovery of fertilizer N ranged from 13.9 per cent in chilli pepper to 44.7 per cent in brinjal. Onion had the highest nitrogen use efficiency ratio as well as physiological efficiency, whereas brinjal had the highest Agronomic efficiency.