Due to the very low levels of water and soil nutrients desert ecosystems are difficult habitats to survive for plants. Under such conditions, survival strategies of desert plants essentially involve sensing the resources available in the surrounding, and modifying their development plans accordingly. Our study of the root system architecture of Crotalaria medicaginea, a plant of Indian desert, indicate the presence of some features which are modified according to the amount of nitrogen in surrounding. We have investigated the growth of Crotalaria at seedling stage with variable levels of N in the growth medium (0, 5, 10, 25, 50, 75 and 100%), of the total complement in the media (Murashige and Skoog media). The number and lengths of first order lateral roots were higher in the middle range of N supply and lower in the other treatments. Basal Zone and Apical Zone Lengths were also significantly influenced by the amount of N available. The Basal Zone Length was very low in treatments with more N, indicating the origin of first order laterals near the base of the main root, and this growth strategy was responsible for the increased length of the Apical Zone Length in the similar treatments, indicating a longer tip of the main root without lateral roots when roots experienced excess supply of nitrogen. Basal and Apical Zone Length had significant negative relationship (r2=0.05, p<0.001).