Does the form of nitrogen affect the phosphorus use efficiency by corn?

• Grant number: 15/03976-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2015
• End date: May 31, 2016
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Ciro Antonio Rosolem
• Grantee: Camila da Silva Grassmann
• Host Institution: Faculdade de Ciências Agronômicas (FCA). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

The form of nitrogen may increase the use efficiency of phosphorus and improve the productivity in tropical soils whose acidity affects the phosphorus availability. The aim of this project is to evaluate the effect of forms of nitrogen (ammonium and nitrate) on the use efficiency of phosphorus, production and root development of maize under field conditions. The experiment will be conducted with eight treatments and four replications. Nitrogen will be applied at 120 mg/kg as calcium nitrate and ammonium sulfate (plus dicianodiamide-DCD), combined with 0, 40, 80 and 120 mg/kg of P doses. The root information will taken through Trench Method (JORGE, 1999) and the digital images will be analyzed on the SAPPHIRE-2010 software to determination of length, area and volume. Plants will be randomly selected and separated into leaves, stems and reproductive components in tasseling stage and physiological maturity of culture to determination of levels of N and P. Then, will be made the nutritional assessments and will be calculated the efficiency indices and absorption according Roberts (2008). At the harvest, corn grain yields will be calculated from the total grain mass.