he sugarcane root system is a major sink accounting for up to half of the total crop nitrogen (N). Such N 'stored' in roots raises questions regarding the role of the belowground component in sugarcane nutrition, especially during the crucial period of regrowth. Nutrient storage in the belowground component during sugarcane growth and nutrient remobilization at the early growth stage, both via internal translocation, could directly affect the N requirements of the crop during its growth and justifies further studies. In this greenhouse study, two experiments based on 15N isotope tracing were conducted to quantify: 1) storage of N in the belowground components of sugarcane biomass throughout a year of growth; 2) remobilisation of the N stored in the belowground components during subsequent regrowth. Only 26% of the fertilizer-N taken up 2 months after fertilization was recovered after 18 months of growth, and was contained mainly in the root, stem and straw components. Two months after harvesting, 52% of the N of the belowground components were recovered with more than half in the new shoots of the sugarcane plants. This study showed that the root component was not a storage organ per se but still contained some of the fertiliser N after 12 months of growth. An important finding was the remobilisation of a significant part of the N from the roots during ratooning.