Sugarcane phytomass labeling with application of 15N-urea solution

The objective of this research was to compare three methods of N-15-urea solutions application: spray on leaf, injection in the plant base stem and root immersion, in order to define the most efficient labeling Sugarcane phytomass with N-15 method. The experiment was carried out at APTA - Polo Regional Centro Sul, in Piracicaba, SP, Brazil, and the sugarcane variety SP80 3280 was planted in pots filled out with approximately 120 dm(3) of a Typic Quartzipsamment soil. The experiment was conducted in a completely randomized design with four replicates. There were no difference between the methods in the plant parts dry mass, in 11(o) development month, and their N-15 abundances were superior to the natural one, being verified the following decreasing labeling order: aerial part > rhizome > rhizome + roots in the layer 0.0-0.2 m > roots in the layer 0.2-0.4 m > roots in the layer deeper than 0.4 m. Among the N-15-urea solution application methods, the injection in the base stem is the easiest to apply, the most effective in dry mass labeling and the one wich presented the largest N-15 tracer recovery (96%). The spray on leaf method is comparable to the injection in the base stem only for the labeling with N-15 and tracer recovery for root system.