Urease inhibitor levels on ammonia volatilization in sugarcane harvested without burning

• Grant number: 15/04188-0
• Support Opportunities: Scholarships in Brazil - Master
• Start date: May 01, 2015
• End date: July 31, 2016
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Rafael Otto
• Grantee: Acácio Bezerra de Mira
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

The losses of nitrogen (N) as ammonia (NH3) are a major problem associated to the use of urea in top dressing. The treatment of urea with NBPT, the main urease inhibitor used in the world, decreases the activity of this enzyme and the volatilization losses in many crops. However, for the culture of sugarcane harvested without burning the commercially available concentrations of NBPT (530 ppm) have not presented satisfactory results, since the high urease activity in the straw which promotes a rapid degradation of the inhibitor and decreases its efficiency. Thus, this work aims to evaluate under field conditions, NH3 losses of urea treated with doses of NBPT, applied in top dressing, over straw on ratoon of sugarcane harvested without burning. Six field experiments will be conducted in the State of São Paulo between May and November, sugarcane harvest season in the South-Central region. There will be used the randomized block design with four replications to test dosages of 0, 530, 850, 1500 and 2000 mg NBPT/kg of urea, besides a treatment with ammonium nitrate and another one without of nitrogen fertilization (control plot). The NH3 volatilization will be measured through the method of semi-open static ammonia containing two polyethylene foam discs soaked with a phosphoric acid and glycerol solution. The foam discs will be collected and replaced on days 2, 4, 6, 8, 10, 12, 16, 20, 25 and 30 after the treatments application. The ammonia trapped in foams will be extracted using deionized water and the N concentration will be determined by Flow Injection Analysis (FIA). The data will be submitted to analysis of variance and, if necessary, to the Tukey test (Pd0,1) or regression analysis (Pd0,1). (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

MIRA, A. B.; CANTARELLA, H.; SOUZA-NETTO, G. J. M.; MOREIRA, L. A.; KAMOGAWA, M. Y.; OTTO, R.. Optimizing urease inhibitor usage to reduce ammonia emission following urea application over crop residues. AGRICULTURE ECOSYSTEMS & ENVIRONMENT, v. 248, p. 105-112, OCT 1 2017. (15/04188-0)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

MIRA, Acácio Bezerra de. Increasing NBPT rates to reduce ammonia volatilization losses from urea applied over sugarcane straw. 2016. Master's Dissertation - Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC) Piracicaba.