Elucidating the effects of forage grass exudates upon soil N cycling and microbiota

• Grant number: 18/09622-8
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• Start date: September 09, 2018
• End date: December 31, 2018
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Ciro Antonio Rosolem
• Grantee: Camila da Silva Grassmann
• Supervisor: Karl Ritz
• Host Institution: Faculdade de Ciências Agronômicas (FCA). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Institution abroad: University of Nottingham, Sutton Bonington, England
• Associated to the scholarship: 16/25253-7 - Nitrogen dynamics in a cropping system with forages as cover crops and corn, BP.DD

Abstract

Forage grass species can affect the functioning of the N cycle in the soil, mainly nitrification, and can decrease N availability for the next crop grown in the same area. It has been shown that ruzigrass (Urochloa ruziziensis) can impair the N nutrition of maize plants grown concurrently or subsequently, thought to be via modification of soil N dynamics and the microbiological processes involved. It has been shown that substances exuded by some species of Urochloa inhibit soil biological nitrification under certain circumstances. To elucidate such effects further, root exudates of ruzigrass, palisade grass (Urochloa brizantha) and Guinea grass (Panicum maximum) will be collected and applied to soils in an experimentally controlled manner. Phenotypic and genotypic responses of associated microbial communities will be assessed through PLFA, as well as the impacts of exudates on N mineralization. To determine if such effects are intrinsically affected by the presence of another species, maize and ruzigrass will be grown in novel systems that control the nature and extent of inter-species root-to-root interactions. (AU)