Microbial community interaction and its effect on the phosphorus cycling in native soils from Brazil and United Kingdom

• Grant number: 18/14373-7
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: September 24, 2018
• End date: September 14, 2019
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Fernando Dini Andreote
• Grantee: Bruna Arruda
• Supervisor: David Leonard Jones
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Institution abroad: Bangor University, Wales
• Associated to the scholarship: 16/21596-7 - Interaction between phosphate fertilizer and soil microbial diversity in the plant colonization by arbuscular mycorrhizal fungi, BP.DR

Abstract

In highly weathered tropical soils, phosphorus (P) is not widely available, and the supplementation of P by fertilizer is necessary to satisfy plant demand. In contrast, in temperate soils, P adsorption is reduced, and P is more available to plants. In general, the soil microbial community can interact in many ways (both negatively and positively) with plants to alter P cycling and its availability in the rhizosphere. Thus, optimising P input via fertilizers alongside with the selection of microbial activity in the rhizosphere will substantially affect soil P lability. The aim of this project is to understand the dynamics of different soil microbial communities and P input through plant uptake in contrasting tropical and temperate soils. The experiment will be run in a controlled climate facility with three Oxisol soils from Brazil and three Cambisol soils from UK considering native vegetation conditions. Three contrasting microbial diversity treatments will be used: i) natural microbial community; ii) natural microbial community submitted to a diversity extinction method using heating of the soil by 80ºC for an hour; and iii) natural microbial community inoculated with fungal endophytes. After 20 days of re-establishment of the microbial community in these soils, 33P-labelled fertilizer (Triple superphosphate; TSP) will be applied, and pre-germinated plants of Brachiaria humidicola will be transplanted into the soil. The experiment will be harvested 30 days after, with soil, shoot and root sampling and fractionation of 33P in the plant-soil system. As results we expect: i) part of 33 P applied as TSP will be immobilized by the microbial biomass and become a temporary reservoir, mainly in tropical soils under higher microbial diversity compared to low diversity; ii) tropical soils may have a strong dependency on the microbial community to an adequate plant uptake comparing to temperate soils, even under P application; and iii) addition of novel fungal endophytes will increase plant P uptake. (AU)