15N-fertilizer rates in energy cane under irrigated and rainfed conditions: N recovery and crop yield

• Grant number: 25/00935-7
• Support Opportunities: Scholarships in Brazil - Master
• Start date: October 01, 2025
• End date: July 31, 2026
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Cassio Hamilton Abreu Junior
• Grantee: Bubacar Baldé
• Host Institution: Centro de Energia Nuclear na Agricultura (CENA). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

ABSTRACT: In Brazil, energy cane (Saccharum spontaneum) is a variety of sugarcane with high potential for biofuel and bioenergy production. With rapid growth and high biomass production, it has attracted attention for second-generation ethanol production. While there are studies on nitrogen (N) rate and use efficiency in conventional sugarcane related to water availability, such information for energy cane is scarce. This project aims to evaluate the effect of 15N-fertilizer rates on stalk and sugar yield and the utilization of N by energy cane cultivated under irrigated and rainfed conditions, aiming to optimize fertilizer use. Two field experiments will be conducted to evaluate levels of 15N-fertilization in two energy cane varieties: Vertix 2 (high fiber production) and Vertix 3 (medium sucrose and fiber production). The experiments will be set up under full irrigation and rainfed conditions, using a randomized block design with three replications in a 4 × 2 factorial arrangement, comprising four levels of 15N-fertilizer (0, 60, 180, and 300 kg ha¹ of N-urea) and two energy cane varieties: Vertix 2 and Vertix 3. The allocation of 15N in different plant fractions will be assessed to estimate N-fertilizer uptake and its efficiency in increasing stalk and sugar yield. Data will be subjected to variance analysis and regression analysis. The results are expected to contribute valuably to optimizing nitrogen fertilization management in energy cane.