Phosphorus bioavailability through the rhizosphere effect of urochloa brizantha plants

• Grant number: 22/13165-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2022
• End date: November 30, 2023
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Marcelo Raphael Volf
• Grantee: Gabriel Almeida de Farias
• Host Institution: Faculdade de Ciências Agrárias. Universidade do Oeste Paulista (UNOESTE). Campus de Presidente Prudente. Presidente Prudente , SP, Brazil

Abstract

Tropical soil is several weathered therefore is poor in P and has a high capacity to fix this element. This work aims to evaluate the efficiency of Brachiaria brizanta (Uruchloa brizantha) plants in the solubilization and availability of phosphorus sources. An experiment will be care out in a greenhouse (bioassay). The seeds of the plants will be, or not, inoculated with bacteria that solubilize P, and the soil will be applied with five sources of P. A soil cultivated will be used, which will be sampled at a depth of 0.0-0.1 m. For the study, the planar rhizosphere technique will be used, obtained by growing the plants in pots specially built for this purpose. In order to verify the effect of the rhizosphere on P solubilization, soil samples will be sampled from the root mat formed by the grass from 0-0.5, 0.5-1, 1-2, 2 when harvesting the plants. -3, 3-4, 4-5, and 5-10 mm. Soil P will be fractionated in order to identify the forms of soluble P, P-Al, P-Fe, P-Ca, and P-occluded in the form of Fe and Al phosphate. The labile conditions of inorganic (Pi) and organic (Po), moderately labile P, strongly adsorbed P, residual P, total inorganic P, and total organic P, the activity of acid phosphatases, and soil pH will be determined. The P content of the aerial part of the plants will also be evaluated.