Microorganisms associated with alternative sources of phosphates for greater phosphorus use efficiency by crops

Abstract

The low efficiency of phosphate fertilization in tropical soils demands more research for sustainable and economically viable strategies that increase the availability of phosphorus (P) for crops and better use efficiency of phosphate fertilizers. In this view, the general objective is to understand the mechanisms and effects of the interaction between microorganisms associated with different sources on the bioavailability of P in the soil, through their performance in altering the P fractions and increasing the dissolution of fertilizers, and also through of crop response to plant utilization of this nutrient. For this purpose, a pre-selection will be carried out, through a bioassay, of the strains that will be used as treatments for carrying out experiments with microorganisms, with the objective of understanding their effect and their interaction with phosphate sources of different solubility in root development and on the bioavailability of P to plants in the short term, as well as understanding the response in production and quality of the accumulation of sugars in sugarcane over 300 days. Tests will also be conducted with organomineral fertilizers (FOMs) developed from sewage sludge compost, to better understand and prove the efficiency of these organic compounds' efficiency in P use for crops, associated or not with microorganisms. In general, the analyzes to be carried out involve the production of crop biomass, root evaluation of the length, area and average diameter, P accumulated in plant tissue, recovery of P from fertilizers, sequential chemical fractionation of P in the soil and soil microbiological analyzes (acid phosphatases, alkaline phosphatases, phytases and ²-glucosidase). With this research, it is expected to indicate the best mixtures for agricultural use of FOMs, as well as the best microorganisms (isolated and/or in consortium) capable of making P bioavailable from the understanding of its mechanisms and contributing to the increase of the efficiency of the phosphate fertilization in Brazilian soils. (AU)