Nitrogen Utilization from Ammonium Nitrate and Urea Fertilizer by Irrigated Sugarcane in Brazilian Cerrado Oxisol

• Main Authors: Nelmício Furtado da Silva, Edson Cabral da Silva, Takashi Muraoka, Marconi Batista Teixeira, Frederico Antonio Loureiro Soares, Fernando Nobre Cunha, Joseph Adu-Gyamfi, Wendson Soares da Silva Cavalcante
• Format: Article
• Language: English
• Published: MDPI AG 2020-08-01
• Series: Agriculture
• Subjects: <i>Saccharum</i> spp.; stalk yield; N recovery; nitrogen-15; Oxisol; cerrado
• Online Access: https://www.mdpi.com/2077-0472/10/8/323

Sugarcane is the most promising among renewable biofuel-producing crops. An adequate availability of water and nutrients, especially nitrogen (N), is of utmost importance. From the hypothesis that the source and the rate of N fertilization influence the N use efficiency of an irrigated soil–sugarcane system, this study aimed to evaluate the stalk and crop residues (pointer and leaves) yield, as well as the N utilization, from different rates of ammonium nitrate and urea by irrigated sugarcane in the cane plant cycle, using an ¹⁵N isotopic dilution technique. The soil used for the experiment was an Oxisol (Rhodic Haplustox) Cerrado (savannah) phase. The experiment was carried out at a farm of the Raízen Mill, which was located in the municipality of Jataí, Goias State, Brazil. The sugarcane variety IACSP95–5000 was used in a randomized block design, with three replicates, four N rates (30, 60, 120, and 180 kg ha⁻¹), and two fertilizer sources labeled with ¹⁵N isotopes (urea and ammonium nitrate). The average value for N utilization was 60.17% for the ammonium nitrate source and 44.95% for urea. The responses in the percentage and quantity of N in the sugarcane from the fertilizer increase with the increasing N rate. The soil was the main N source for sugarcane. The higher stalk and pointer yield was recorded at the average rate of 143.61 kg N ha⁻¹. Further studies are needed to evaluate the residual effect of N in the next cycles.