Growth-promoting bacteria on a commercial Emerald grass production area, aiming the reduction of nitrogen fertilization

• Grant number: 19/05814-2
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): July 01, 2019
• Effective date (End): August 31, 2021
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal researcher: Marcelo Carvalho Minhoto Teixeira Filho
• Grantee: Graziela Franceschini Ferraz
• Home Institution: Faculdade de Engenharia (FEIS). Universidade Estadual Paulista (UNESP). Campus de Ilha Solteira. Ilha Solteira , SP, Brazil

Abstract

The relevance of the use of turfgrasses in their various purposes (ornamental, sports, highways, protection of degraded areas) has increased the demand for grasses in Brazil and, consequently, their production. The Emerald grass (Zoysia japonica Steud.) is the most commercialized, being relevant in residential gardens and highways. For your production, the most required nutrient is nitrogen (N). However, the application of plant growth-promoting bacteria (PGPB) can promote relevant results in the N2 fixation, generating greater root development due to phytohormonal action, increasing, therefore, the absorption of water and nutrients by the grass, being more sustainable to the environment. However, the effects of PGPB inoculation on lawns are not known. In this sense, this research aims to study the application of PGPB (Bacillus subtilis, Pseudomonas fluorescens and Azospirillum brasilense) in commercial Emerald grass production area, in Pereira Barreto/SP, aiming to reduction of nitrogen fertilization and, consequently, reduce costs for the producer. The experiment will be conducted from October 2018 to September 2019. Will be used the randomized block design with 16 treatments arranged in a factorial scheme 4 x 4, with four replications, in 12 m2 per plot. The treatment will be: three PGPB s (A. brasilense, B. subtilis and P. fluorescens) plus without them combined with three rates of N (100, 75 and 50% of the applied rates in the production area, 280 kg ha-1)) plus the control (without N). The N rates, using urea as the source, will be applied manually after sod cutting and replicate every 2 months until total soil cover by the grass. The application of the PGPBs will be done after the cutting of the previous sod at the beginning of the grass bud, with the inoculant containing 200 mL of the PGPBs diluted in 400 L ha-1 sprayed on the soil. Will be evaluated: the rate of soil covers by turfgrass (RSC) and the intensity of grass green coloration by the digital image analysis of the shoot; the normalized difference vegetation index (NDVI); the dry matter and the concentrations of macronutrients in the leaves as well as the grass root system (dry matter and macronutrient concentration in roots + rhizomes). The agronomic efficiency of the treatments will also be evaluated.