Solubilização de fósforo por Bacillus velezensis na cultura do milho em diferentes ambientes de produção

Abstract

Corn (Zea mays L.) is the most consumed grain in the world, primarily used in animal feed. In the last harvest, consumption was equivalent to 98.5% of global production, with Brazil ranking as the third-largest producer and consumer. However, its cultivation faces the challenge of low phosphorus availability in many soils, particularly tropical ones, requiring fertilization. Phosphate exploitation encounters challenges related to sustainability, economic feasibility, and environmental impact. As an alternative, biotechnologies such as phosphorus solubilizing microorganisms offer a promising solution to increase the availability of this nutrient, promoting more sustainable agriculture and enabling cost reduction. This study aimed to evaluate the impact of B. velezensis on corn crops across different locations and application methodologies during the 2023/2024 growing season, justified by the need to reduce phosphate fertilization in corn fields. The experiment was conducted in Dourados, MS; Londrina, PR; and Guarapuava, PR, using a randomized block design with four replications. Eight treatments were evaluated, including new B. velezensis dose proposals for corn cultivation. The evaluated variables included 1,000-grain weight, yield, phosphorus acquisition efficiency (PAE), phosphorus utilization efficiency (PUE), and phosphorus use efficiency (PUsE). In Dourados and Guarapuava, the variables that showed significance in the F-test were PAE and PUsE. In Londrina, the only variable that was not significant was yield. Across all three environments, there was a positive and significant correlation between PAE and PUsE. Multivariate analysis using the Principal Component Analysis (PCA) method showed different dispersion graphs for each environment, suggesting significant differences between locations. This was confirmed by the joint ANOVA across the three environments, where the interaction partition was complex for all pairs of locations. The new B. velezensis dose were not effective in the environments of Dourados and Londrina. However, in Guarapuava, seed treatment with a concentration of 50 mL.50Kg⁻¹ of B. velezensis resulted in higher phosphorus use efficiency. The PCA was able to demonstrate the differences among the studied locations, explained by the environmental variations of each region, highlighting the importance of conducting experiments in multiple areas.