Agronomic performance of sugarcane as affected by sources and nitrogen rates in the brazilian Savannah region

Abstract

In the different agricultural environments, the productivity of Brazilian sugarcane plantations has been limited, mainly, by the availability of nutrients in the soil, especially nitrogen. The cerrado (savanah) region covers the main Brazilian agricultural frontier, and sugarcane cultivation has advanced to these areas. Based on the hypothesis that the availability of N in soil influences the agronomic performance of sugarcane, the objective of this study was to evaluate the effects of N sources and rates on the growth, development and productivity of sugarcane- (CTC-4 variety), cultivated in a dystroferric Red Latosol. The experiment was carried out under field conditions at Fazenda Rio Paraiso II, belonging to the Raízen Usina, in the municipality of Jataí, GO, southwest region of Goiás, Brazil. The experimental design used was a randomized block design, with three replicates, analysed in factorial scheme of 4 × 2 × 4. The treatments were four doses of N (0, 60, 120 and 180 kg ha -1 ), two N fertilizers (urea and ammonium nitrate) and four evaluation periods (210, 250, 290 and 330 days after planting - DAP). The increase of the nitrogen fertilizer rate provided an increase in plant height, stalk diameter and stalk yield. Ammonium nitrate at doses of 60 and 120 kg ha -1 of N provided higher yield of stalks than did urea.