Supplementary Nitrogen Fertilization in Sugarcane

In Brazil, sugarcane (Saccharum spp.) is considered one of the most economically important crops. Nitrogen (N) is one of the most required elements in sugarcane cultivation. Nevertheless, the information about the soil and foliar applications of this nutrient in crops are discrepant. Therefore, the importance of this study is evident. Given the above, this study aimed to evaluate the soil-applied and foliar N fertilization of sugarcane. The experiment was conducted at the Araporã Bioenergia S.A. power plant, located at Fazenda Santa Rita, in the municipality of Itumbiara-GO. The 5 × 5 factorial design was adopted, with four repetitions, including five doses of soil-applied ammonium nitrate and five doses of foliar Amidic N polymer. The nutrient extraction, the experiment’s initial and final total chlorophyll content, the biometric indexes and the industrial quality indexes were analyzed for sugarcane. The ammonium nitrate doses caused differences in fiber, sacarose content, total recoverable sugar, sugar cane Brix, magnesium, and zinc, which was statistically different for the foliar polymer doses. There was no increment of the production variables with the increase of the nitrogen supply in the soil. On the other hand, the levels of zinc and magnesium in the leaves increased 12% and 27%, respectively, reflecting the importance of this fertilization in sugarcane cultivation.